1999 FINAL REPORT

OREGON

GAP ANALYSIS PROJECT

A GEOGRAPHIC APPROACH TO PLANNING FOR BIOLOGICAL DIVERSITY

Oregon Natural Heritage Program

United States Geological Survey Biological Resources Division

Oregon Department of Fish and Wildlife

Biodiversity Research Consortium

Oregon Biodiversity Project
Oregon Gap Analysis Final State Report

1999

Oregon Natural Heritage Program 

821 SE 14th Ave.

Portland, OR 97214

ph: 503-731-3070 fax: 503-230-9639

http://www.heritage.tnc.org/nhp/or/us

http://sscgis.state.or.us

http://dfw.state.or.us
THE OREGON GAP ANALYSIS PROJECT

FINAL REPORT

OCTOBER 1999

James S. Kagan, PI

Director / Ecologist, Oregon Natural Heritage Program

John C. Hak, Co-PI

GIS Program Manager, Oregon Natural Heritage Program

Blair Csuti

Conservation Program Coordinator, Oregon Zoo

Chris W. Kiilsgaard

Land Cover Analyst, NW Habitat Institute

Eleanor P. Gaines

Zoologist / Data Manager, Oregon Natural Heritage Program

Contract Administration Through:

Oregon Natural Heritage Program and the Oregon Field Office of The Nature Conservancy

821 SE 14th Ave., Portland, OR 97214

Submitted by:

James S. Kagan

Research Performed Under:

Cooperative Agreement No. HQ97AG01882

Research Work Order No.

Bibliographic reference to this publication should read:

Kagan, J.S., J.C. Hak, B. Csuti, C.W. Kiilsgaard, and E.P. Gaines. 1999. Oregon Gap Analysis

Project Final Report: A geographic approach to planning for biological diversity. Oregon Natural

Heritage Program, Portland, Oregon. 72 pp. + appendices.
TABLE OF CONTENTS

LIST OF TABLES ............................................................ ii

LIST OF FIGURES AND MAPS ................................................ iii

EXECUTIVE SUMMARY ..................................................... iv

ACKNOWLEDGMENTS ..................................................... vii

CHAPTER 1. INTRODUCTION ................................................ 1

How This Report is Organized ............................................... 1

The Gap Analysis Program Mission .......................................... 1

The Gap Analysis Concept .................................................. 2

The Gap Analysis Project in Oregon .......................................... 3

General Limitations ....................................................... 4

The Study Area .......................................................... 5

CHAPTER 2: EXISTING LAND COVER CLASSIFICATION AND MAPPING ........... 8

Introduction ............................................................. 8

Land Cover Classification .................................................. 8

Methods ............................................................... 12

Mapping Standards ...................................................... 14

Results ................................................................ 14

Accuracy Assessment ..................................................... 14

Limitations and Discussion ................................................ 15

CHAPTER 3: HISTORIC VEGETATION MAPPING ............................... 17

Introduction ............................................................ 17

The Land Cover Classification Scheme ....................................... 17

Methods, Mapping Standards and Map Development ............................ 17

Results ................................................................ 20

Accuracy Assessment ..................................................... 22

Limitations and Discussion ................................................ 23

CHAPTER 4: PREDICTED ANIMAL DISTRIBUTIONS AND SPECIES RICHNESS ..... 24

Introduction ............................................................ 24

Mapping Standards ...................................................... 24

Methods ............................................................... 25

Version 1 Maps ......................................................... 25

Version 2 Vertebrate Maps ................................................ 28

Historic Distribution Maps ................................................. 33

Existing and Historic Vertebrate Map Creation by Group ......................... 33

Existing and Historic Maps for Other Groups of Species ......................... 34

Results ................................................................ 34

Accuracy Assessment ..................................................... 37

Limitations and Discussion ................................................ 40

Species Richness ........................................................ 40
CHAPTER 5: LAND STEWARDSHIP .......................................... 41

Introduction ............................................................ 41

Mapping Standards and Methods ............................................ 42

Results ................................................................ 47

Discussion ............................................................. 50

Limitations ............................................................. 51

CHAPTER 6: ANALYSIS BASED ON STEWARDSHIP AND MANAGEMENT ........ 52

Introduction ............................................................ 52

Land Cover Analysis ..................................................... 53

Vertebrate Species Analysis ................................................ 55

Summary of Vertebrates in Protected Areas ................................... 59

Priority Species for Conservation ........................................... 62

CHAPTER 7: CONCLUSIONS AND MANAGEMENT IMPLICATIONS ............... 65

PRODUCT USE AND AVAILABILITY ......................................... 67

LITERATURE CITED ....................................................... 72

GLOSSARY OF TERMS ..................................................... 77

GLOSSARY OF ACRONYMS ................................................. 82

APPENDICES .............................................................. 84

Appendix 1.1. List of Example GAP Applications .............................. 84

Appendix 1.2. Descriptions of Oregon’s Ecoregions ............................. 87

Appendix 1.3. GAP Project Standards ........................................ 95

Appendix 2.1. Land Cover Type Descriptions, OR-GAP Version 2 ................. 103

 Forest and Woodland Type Descriptions .......................... 103

 Shrubland and Grassland Type Descriptions ....................... 127

 Other Type Descriptions ...................................... 139

 References ................................................. 144

Appendix 2.2. Report on Aerial Videography by Chris Kiilsgaard .................. 147

APPENDICES Volume 2 ...................................................... 1

Appendix 3.1. Ecoregional Comparison of Current and Historical Coverages .......... 1

Appendix 4.1. Land Cover Types by Management Status .......................... 5

Appendix 4.2. Land Cover in Ownership Types ................................. 7

Appendix 4.3. Wildlife Habitats by Land Cover Crosswalk ........................ 9

Appendix 5.1. Managed Areas in Oregon with GAP Categories .................... 13

Appendix 5.2. Habitat Losses and Priorities ................................... 30

Appendix 6.1. Bird Habitat by Ownership (in hectares) .......................... 32

Appendix 6.2. Bird Losses and Priorities ...................................... 70

Appendix 6.3. Mammal Habitat by Ownership (in hectares) ....................... 79

Appendix 6.4. Mammal Losses and Priorities .................................. 97

Appendix 6.5. Amphibian and Reptile Habitat by Ownership (in hectares) ........... 101

Appendix 6.6. Amphibian and Reptile Losses and Priorities ...................... 110

Appendix 6.7. Land Cover types by ecoregion, ha of management types by owner ..... 112
ii

LIST OF TABLES

Table 2.1. Landscape-level vegetation types and proportional area of land cover for Oregon . . 10

Table 2.2. Landsat TM Imagery and dates used for mapping project. .................... 12

Table 3.1. Historic vegetation types and proportional area of land cover for Oregon ......... 18

Table 3.2. Changes in habitats since European Settlement ............................. 21

Table 4.1. Categories used to qualify species occurrence in hexagons .................... 27

Table 4.2. Published range maps used to create initial hexagon distributions ............... 27

Table 4.3. Existing vertebrate databases used to improve hexagon distributions ............ 27

Table 4.4. Experts reviewing hexagon distributions .................................. 28

Table 4.5. Rank of habitat type by proportional land area .............................. 30

Table 4.6. Riparian species mapped in potential riparian habitats ........................ 32

Table 4.7. Areas with species lists and available groups used in the accuracy assessment ..... 37

Table 4.8. Accuracy assessment for overall species distributions ........................ 38

Table 4.9.A. Accuracy assessment for birds ........................................ 39

 4.9.B. Accuracy assessment for mammals ..................................... 39

 4.9.C. Accuracy assessment for reptiles ....................................... 39

 4.9.D. Accuracy assessment for amphibians ................................... 39

Table 5.1. Management status assigned to land stewardship categories in Oregon. .......... 46

Table 5.2. Ownership and Gap Status in Oregon (hectares) ............................ 47

Table 5.3. Ownership by ecoregion and percentages in Oregon ......................... 48

Table 6.1. Native species with less than 1% of habitat protected ........................ 60

Table 6.2. Native species with more than 50% of habitat protected ...................... 60

Table 6.3. Native species with between 1 and 10% of habitat protected ................... 61

Table 6.4. Top 20 priority (based on habitat loss and lack of protection) bird species ........ 63

Table 6.5. Top 20 priority reptile and amphibian species .............................. 63

Table 6.6. Top 20 priority mammal species ......................................... 64
iii

LIST OF FIGURES AND MAPS

Included Figures

Figure 1.1. Map showing the 10 Ecoregions of Oregon ................................. 7

Figure 4.1. A hexagon distribution map of the snowy plover in Oregon ................... 26

Figure 4.2. Riparian distribution for the water shrew ................................. 31

Figure 4.5. Current and Historic distributions of the pronghorn antelope in Oregon ......... 35

Figure 6.1. Distribution of land cover classes in protection categories .................... 53

Figure 6.2. Distribution of bird species in protection categories ......................... 55

Figure 6.3. Distribution of mammal species in protection categories ..................... 57

Figure 6.4. Distribution of amphibian and reptile species in protection categories ........... 59

Figure 6.5. Formula 1 developed to prioritize species ................................. 62

Figure 6.6. Formula 2 developed to prioritize species ................................. 62

Figure 6.7. Formula 3 developed to prioritize species ................................. 63

Enclosed Color Maps (numbers are the order in which they appear in the document)

Figure 2.1. OR-GAP Version 2 Land Cover ......................................... 1

Figure 3.1. Historic Land Cover Map of Oregon ...................................... 2

Figure 4.3. Map of the Existing Wildlife Habitats of Oregon ............................ 3

Figure 4.4. Map of the Historic Wildlife Habitats of Oregon ............................ 4

Figure 4.6. Maps of Current Species Richness for all species, herps, birds and mammals ...... 5

Figure 4.7. Maps of Historic Species Richness for all species, herps, birds and mammals ...... 6

Figure 5.1. Map of Land Ownership in Oregon ....................................... 7

Figure 5.2. Map of OR-GAP Management Lands in Oregon ............................. 8

Figure 5.3. Map of the distribution of listed plants and sensitive species ................... 9

Figure 6.8. Species Richness Map of all species and of priority species in Oregon .......... 10
iv

EXECUTIVE SUMMARY

The Oregon Gap Analysis project (OR-GAP) began work in 1988, as the second GAP program

started, following only the original pilot project initiated in Idaho by Mike Scott of the Idaho

Cooperative Fish and Wildlife Research Unit of the University of Idaho. OR-GAP was managed by

Blair Csuti of the Idaho Cooperative Fish and Wildlife Research Unit until 1997 and was completed

by the Oregon Natural Heritage Program (ORNHP). It has been a cooperative venture, with the

initial vegetation map completed by contract staff and the ORNHP, and the initial wildlife

distributions developed cooperatively by Oregon State University, the Biodiversity Research

Consortium, ORNHP and the Oregon Department of Fish and Wildlife (ODFW). Oregon was also

fortunate enough to have a separate statewide biodiversity assessment managed by the Northwest

Office of the Defenders of Wildlife. This was the Oregon Biodiversity Project, which started as an

effort to implement the results of the first Oregon Gap Analysis work, but wound up as an

independent analysis. A second generation land cover map was developed by ODFW, and ORNHP

developed updated species distribution maps based on the second generation land cover. Because

we had access to an historical vegetation cover, we were able to model vertebrate species

distributions prior to European settlement. This report outlines all of the work completed to-date.

The major objectives of the project were to (1) produce GIS-databases describing actual land cover

type, historical land cover type, terrestrial vertebrate species distributions, land stewardship, and

land management status at a scale of 1:100,000, (2) identify land cover types and terrestrial

vertebrate species that currently are not represented or are under-represented in areas managed for

long-term maintenance of biodiversity, i.e., “gaps,” and (3) facilitate cooperative development and

use of information so that institutions, agencies, and private land owners may be more effective

stewards of Oregon’s natural resources. The OR-GAP project is a step toward the more detailed

efforts and studies needed for long-term planning for biodiversity conservation in Oregon. The final

(Version 2) map of actual land cover used in this analysis included the distribution of 65 land cover

types, mapped as polygons with a minimum mapping unit (MMU) of 100 hectares.

Individual distributions of 457 vertebrate species were predicted using habitat associations. Range

limits of each species were delineated within a grid of 441 hexagons (635 km2 ) based on published

range maps, locality records and review by local experts. This hexagon database has been in

existence at the Oregon Natural Heritage Program for the last 10 years, and has been updated based

on continual reviews and inclusion of new data, and includes information both on species

distributions, the source of information for each hexagon, and the confidence in the record. Within

hexagons, species distributions were modeled based on species-land cover associations and the

presence of riparian areas. Comparisons of predicted species to species lists maintained for eight

wildlife refuges produced variable results since the tested areas often had incomplete lists.

The Gap Analysis Program (GAP) uses a scale of 1 through 4 to denote how well each tract of land

is managed for biodiversity maintenance, with “1” being the highest, most permanent and best

managed, and “4” being the lowest, or unknown status. Status codes were assigned by ORNHP

staff following GAP guidelines with review by The Nature Conservancy’s Public Lands

Coordinator. A total of 17.2% of the state of Oregon is classified as status 1 and 2 lands, 95% of

these found on federal ownership. Oregon has large portions of its public lands in the western

portion of the state as Late Successional Reserves (LSR), and large portions of the eastern part in
v

Bureau of Land Management Wilderness Study Areas (BLM WSA). The designation of these LSRs

and BLM WSAs as status 2 lands results in high proportion of Oregon found in protected areas

(status 1 and status 2 lands), although these designations do not provide as much protection as do

most other status 2 designations. This is a limitation of using only four land management classes to

represent a complex array of management designations when examining protection patterns for

individual species as well as species richness. Land management status was overlain with land

cover and vertebrate species distributions to conduct a gap analysis of Oregon. We considered land

cover types and vertebrate species as under-represented (i.e., “gaps”) in management areas if < 1%

of the land they occupied or their habitat in Oregon fell within status 1 and 2 lands.

Nine (14%) of 63 natural (non-anthropogenic) land cover types have < 1% of the area they occupy

in status 1 and 2 lands. The highest priority for further protection is recommended for coastal strand

and hawthorn-willow shrublands because their current protection is low and they are the most

vulnerable to ongoing land management practices. Palustrine forest and south coast mixed conifer

forest are also high priorities for protection if WSAs and LSRs are excluded from the analysis. 

Wetland and riparian types are not satisfactorily mapped at our current MMU, and further efforts

are needed to provide an adequate spatial description of their location before long-term planning for

their conservation can be accomplished.

Five (< 2%) of the 263 birds modeled had < 1% of their habitat protected in status 1 and 2 lands.

When LSR lands are put in status 3, three additional species are added to this category. When

historic distributions were compared to current status 1 and 2 lands, one fifth (57) of the birds

modeled had substantial habitat loss or low habitat protection. Of these, nine are of current

conservation concern. No native mammals had < 1% of its habitat in status 1 and 2 lands. When

LSR lands are excluded from category 2, two mammals of conservation concern (California and

Townsend’s voles) fall into this category. Thirty one (24 %) mammals (including seven

conservation targets) have had substantial habitat loss or low habitat protection when compared to

historic distribution. There were no amphibians or reptiles with < 1% of their present distribution in

status 1 and 2 lands. When LSR lands are dropped from the analysis, one reptile, the common

kingsnake, is added to this group. Thirteen (22 %) of the amphibians and reptiles have had

substantial habitat losses or low habitat protection compared to historic distributions.

Using some indices developed to look at how much habitat species have lost, and how well their

current and historic distributions are protected, OR-GAP was able to compare species richness

maps for all species, with a subset of those needing conservation action. The major centers of

species richness (areas with very high species richness values) are the Klamath Basin in southcentral Oregon, the Malheur Basin in east-central Oregon, and the Siskiyou Mountains in

southwestern Oregon in both the all species and the priority species richness maps. However, areas

of high to moderately high diversity change dramatically in the subset of needy species coverage,

with priority areas highlighted in the western Columbia River Gorge, the Alvord Basin, and

southeastern Wasco County that were not important in the overall species richness map.

In general, OR-GAP is hesitant to use the results of the analysis to make important statements about

either diversity patterns in Oregon, or sites where best biodiversity most needs to be protected here. 

However, the development of the stewardship coverage and the species distribution databases has

improved the ability for others to do statewide and local assessments. Both versions of the ORGAP land cover are uneven, with detailed mapping and classification in some areas, and coarser
vi

mapping and classification in others, and neither have had accuracy assessments. The wildlife by

habitat relationship models used in OR-GAP are in the process of being improved, but the new

models were not available in time for this analysis. We believe that using higher resolution

vegetation coverages with more detailed classifications, and the improved wildlife-habitat models

would greatly improve the overall accuracy of the analysis. However, the OR-GAP version 2

species distribution maps are clearly the best wildlife distribution maps available and are quite

useful for ecoregional, statewide and multi-state analyses.

OR-GAP has been most valuable as a focus to develop and integrate these important data sets. 

Using the species distribution databases and the managed area coverage with the new wildlifehabitat models and ecoregional or local vegetation maps which are currently being produced

throughout the state, should provide much more accurate species lists and species distribution

maps. OR-GAP intends to continually update the managed area cover, the species distribution

databases, and to provide crosswalks between the new wildlife habitat models and any new

vegetation or land cover maps which become available. We intend to try to aggregate a 1:24,000

vegetation coverage for Oregon, based on local mapping efforts, and to compare these to the coarser

scale maps based on satellite imagery. And, we intend to remain a source of biodiversity

information for anyone interested in studying or protecting biodiversity in Oregon.
vii

ACKNOWLEDGMENTS

Thanks to Amos Eno and the staff of the National Fish and Wildlife Foundation, who funded the

early development of the GAP concept. Thanks to John Mosesso and Doyle Frederick of the

Biological Resource Division (BRD) Office of Inventory and Monitoring, for their support of the

national GAP program, especially during its transition from the U.S. Fish and Wildlife Service to

the National Biological Service and then to the U.S. Geological Survey Biological Resources

Division. Thanks to Reid Goforth and the staff at the BRD Cooperative Research Units for

administering GAP’s research phase from headquarters. Without those mentioned above, there

could not have been a Gap Analysis Program. Thanks also to the National Gap Analysis Program

staff. We especially acknowledge contributions to this report by Chris Cogan, Patrick Crist, Tom

Edwards, Michael Jennings, and J. Michael Scott.

Due to the long history (over 10 years) of this project in Oregon, many people have contributed to

this program and effort here. For the first eight years, Blair Csuti managed the Oregon State

Project, while working with Mike Scott and others to move the program from a local to a national

scale. During this entire time, the project has been a cooperative venture, with participation from

conservation organizations, researchers, and biologists throughout the state. While it is impossible

to mention everyone who participated, a few people and organizations deserve special mention.

Sara Vickerman of the Northwest Office of the Defenders of Wildlife has been a constant supporter

of both OR-GAP and the national program. She has helped with program funding and has been the

primary driver of efforts to use the information developed and accumulated by OR-GAP to make

conservation more efficient in Oregon. Her focus on GAP implementation led to the creation of the

Oregon Biodiversity Project (OBP). OBP was the first statewide assessment of biodiversity in

Oregon, and its final report, Oregon’s Living Landscape provides a benchmark that will be hard to

match. Sara, Bruce Taylor, Keith Hupperts, Lori Kleifgen, Andrew Briggs and other OBP staff

have assisted in the production of many of the materials used in this report.

The Biodiversity Research Consortium has also been intimately involved in OR-GAP. Ross Kiester

of the Pacific Northwest Research Station, Forestry Sciences Laboratory in Corvallis, Denis White

of the Environmental Protection Agency (EPA) Lab in Corvallis, Eric Preston, currently retired but

formerly with EPA, and Manuela Huso of Oregon State University deserve special mention here.

The Oregon Department of Fish and Wildlife has also been committed to and involved in OR-GAP

since its inception in Oregon. The OR-GAP program certainly would not be where it is today

without the persistence and energy of Tom O’Neil and Meg Shaughnessy. The assistance of Greg

Seigletz, Milton Hill, Charlie Bruce and Jim Greer are also notable.

Finally, while only Jimmy Kagan, John Hak, and Eleanor Gaines from the Oregon Natural Heritage

Program are authors of this report, other heritage staff provided significant help. Mary Finnerty

made a number of the maps, Sue Vrilakas help edit the document, and Mark Stern, Ken Popper,

Terry Campos and Eric Scheuering all provided important assistance in developing the vertebrate

species distributions and habitat associations.

ORNHP would also like to thank ESRI for their donation of ARCINFO and ARCVIEW software

which was critical to the production of this report.
viii
1

CHAPTER 1: INTRODUCTION

How This Report is Organized

This report is a summation of a scientific - technical project. While we endeavor to make it

understandable for as general an audience as practicable, it will reflect the complexity of the project

it describes. A glossary of terms is provided to aid the reader in its understanding, and for those

seeking a detailed understanding of the subjects, the cited literature should be helpful. The

organization of this report follows the general chronology of project development, beginning with

the production of the individual data layers and concluding with analysis of the data. It diverges

from standard scientific reporting by embedding results and discussion sections within individual

chapters. This was done to allow the individual data products to stand on their own as testable

hypotheses and provide data users with a concise and complete report for each data and analysis

product.

We begin with an overview of the Gap Analysis mission, concept, and limitations. We then present

a synopsis of how the current biodiversity condition of the project area came to be, followed by

land cover mapping, animal distribution prediction, species richness, and land stewardship mapping

and categorization. Data development leads to the Analysis section which reports on the status of

the elements of biodiversity (natural community alliances and terrestrial vertebrate species) for this

state. Finally, we describe the management implications of the analysis results and provide

information on how to acquire and use the data.

The Gap Analysis Program Mission

The mission of the Gap Analysis Program (GAP) is to prevent conservation crises by providing

conservation assessments of native vertebrate species and their habitats and to facilitate the

application of this information to land management activities.

This is accomplished through the following five objectives:

1. Map actual land cover as closely as possible to the Alliance level (FGDC 1997).

2. Map the predicted distribution of those terrestrial vertebrates that spend any substantial part of

their life history in the project area and for which adequate distributional habitats, associations,

and mapped habitats are available. Map other taxa as cooperative opportunities allow.

3. Document the representation of natural land cover types and animal species in areas managed for

the long-term maintenance of biodiversity.

4. Make all GAP Project information available to the public and those charged with land use

research, policy, planning, and management.

5. Build institutional cooperation in the application of this information to state and regional

management activities.

To meet these objectives, it is necessary that GAP be operated at the state level but maintain

consistency with national standards. Within the state, participation by a wide variety of cooperators

is necessary and desirable to ensure understanding and acceptance of the data and forge

relationships that will lead to cooperative conservation planning.
2

The Gap Analysis Concept

The Gap Analysis Program (GAP) brings together the problem-solving capabilities of federal, state,

and private scientists to tackle the difficult issues of land cover mapping, vertebrate habitat

characterization, assessment, and biodiversity conservation at the state, regional, and national

levels. The program seeks to facilitate cooperative development and use of information. 

Throughout this report we use the terms “GAP” to describe the national program, “GAP Project” to

refer to an individual state or regional project, “OR-GAP” to refer to the Oregon program, and “gap

analysis” to refer to the gap analysis process or methodology.

Much of the following discussion was taken verbatim from Edwards et al. 1995, Scott et al. 1993,

and Davis et al. 1995. The gap analysis process provides an overview of the distribution and

conservation status of several components of biodiversity. It uses the distribution of actual

vegetation and predicted distribution of terrestrial vertebrates and, when available, invertebrate

taxa. Digital map overlays in a GIS are used to identify individual species, species-rich areas, and

vegetation types that are unrepresented or under represented in existing management areas. It

functions as a preliminary step to the more detailed studies needed to establish actual boundaries

for potential biodiversity management areas. These data and results are then made available to the

public so that institutions as well as individual land owners and managers may become more

effective stewards through more complete knowledge of the management status of these elements of

biodiversity. GAP, by focusing on higher levels of biological organization, is likely to be both

cheaper and more likely to succeed than conservation programs focused on single species or

populations (Scott et al. 1993).

Biodiversity inventories can be visualized as "filters" designed to capture elements of biodiversity

at various levels of organization. The filter concept has been applied by The Nature Conservancy,

which has established Natural Heritage Programs in all 50 states, most of which are now operated

by state government agencies. The Nature Conservancy employs a fine filter of rare species

inventory and protection and a coarse filter of community inventory and protection (Jenkins 1985,

Noss 1987). It is postulated that 85-90% of species can be protected by the coarse filter, without

having to inventory or plan reserves for those species individually. A fine filter is then applied to

the remaining 15-10% of species to ensure their protection. Gap analysis is a coarse filter method

because it can be used to quickly and cheaply assess the other 85-90% of species.

The intuitively appealing idea of conserving most biodiversity by maintaining examples of all

natural community types has never been applied, although numerous approaches to the spatial

identification of areas in which most biodiversity is represented have been described (Kirkpatrick

1983, Margules et al. 1988, Pressey and Nicholls 1989, Nicholls and Margules 1993). 

Furthermore, the spatial scale at which organisms use the environment differs tremendously among

species and depends on body size, food habits, mobility, and other factors. Hence, no coarse filter

will be a complete assessment of biodiversity protection status and needs. However, species that

fall through the pores of the coarse filter, such as narrow endemics and wide-ranging mammals, can

be captured by the safety net of the fine filter. Community-level (coarse-filter) protection is a

complement to, not a substitute for, protection of individual rare species. 

Gap analysis is essentially an expanded coarse-filter approach (Noss 1987) to biodiversity

protection. The vegetation types mapped in GAP serve directly as a coarse filter, the goal being to
3

assess representation of all types in biodiversity management areas. Landscapes with great

vegetation diversity often are those with high edaphic variety or topographic relief. When

elevational diversity is very great, a nearly complete spectrum of vegetation types known from a

biological region may occur within a relatively small area. Such areas provide habitat for many

species, including those that depend on multiple habitat types to meet life history needs (Diamond

1986, Noss 1987). By using landscape-sized samples (Forman and Godron 1986) as an expanded

coarse filter, gap analysis searches for and identifies biological regions where unprotected or under

represented vegetation types and vertebrate species occur. 

More detailed analyses were not part of this project but are areas of research that GAP as a national

program is pursuing. For example, a second filter could combine species distribution information

to identify a set of areas in which all, or nearly all, mapped species are represented. There is a

major difference between identifying the richest areas in a region (many of which are likely to be

neighbors and share essentially the same list of species) and identifying areas in which all species

are represented. The latter task is most efficiently accomplished by selecting areas whose species

lists are most different or complementary. Areas with different environments tend to also have the

most different species lists for a variety of taxa. As a result, a set of areas with complementary sets

of species for one higher taxon (e.g. mammals) often will also do a good job representing most

species of other higher taxa (e.g. trees, butterflies). Species with large home ranges, such as large

carnivores, or species with very local distributions may require individual attention. Additional

data layers can be used for a more holistic conservation evaluation. These include indicators of

stress or risk (e.g. human population growth, road density, rate of habitat fragmentation,

distribution of pollutants) and the locations of habitat corridors between wildlands that allow for

natural movements of wide-ranging animals and the migration of species in response to climate

change. 

The Gap Analysis Project in Oregon

Because of the long history of OR-GAP, we have developed information which both follows

national gap standards, and predates many of them. The first GAP land cover map was developed

in 1990 using LANDSAT MSS false-color infrared positive prints. Species distribution maps were

developed using species distribution data in EMAP (EPA’s environmental monitoring and

assessment program) hexagons. This database (species by hexagon) was developed in Oregon by

ORNHP with funding from EPA, the Biodiversity Research Consortium and The Nature

Conservancy. The first stewardship (ownership) map was drafted by ORNHP, digitized by the

Idaho Department of Water Resources and quality controlled by ODFW. Species distributions were

generated using the first land cover map, ORNHP hexagon distributions, and a wildlife habitat

matrix developed by Blair Csuti and ODFW. A result of this work was the publication of the Atlas

of Oregon Wildlife (Csuti et al.) in 1997. 

OR-GAP was able to complete a gap analysis looking at historic distributions of Oregon wildlife

species. We were able to update a statewide, historic vegetation cover developed by the Oregon

Biodiversity Project. This cover allows a comparison of both how well vegetation alliances are

protected in the statewide network of conservation lands, as well as how much they have declined

over the last 150 years. Combined with excellent historic distribution maps of Oregon’s vertebrate 
4

wildlife species, we were able to use standard techniques to assess how much habitat each species

has lost since the advent of European settlement.

This final state report summarizes the project to-date, focusing on efforts by OR-GAP to meet

national standards. It includes a new land cover map which used most of the new gap standards, a

new stewardship cover, and newly created species distribution maps. All of the coverages, data,

and products created by OR-GAP since its inception in 1988 are available and will be included on

CD-ROM and the National GAP and OR-GAP web sites. The existence of first generation land

cover and species cover maps provides the opportunity to compare methods. While we have not

compared the methods in this report, we believe this is an opportunity for future study.

OR-GAP has become a critical part of ORNHP’s overall objective to maintain and update all

information on Oregon’s biodiversity. For this report, final versions of the primary GAP coverages

have been developed and used. All of the coverages used for this report are OR-GAP Version 2. 

ORNHP will continue to update each of these coverages. The ownership and stewardship coverage

is continually updated as new areas are protected or designated, or as land ownership patterns

change. ONRHP will release an updated ownership and stewardship cover each year. The ORGAP Land Coverage developed by the Oregon Department of Fish and Wildlife will not be

updated, but ORNHP is working to compile more detailed regional and statewide land use/land

cover coverages. Version 2 species distribution coverages are included and analyzed in this report

and will not change. But both the wildlife-habitat matrix and species distributions will be

continually updated by ORNHP. As a result, we will have the capacity to generate updated species

distributions coverages on a local, regional or statewide basis as higher resolution land covers

become available.

Unfortunately, OR-GAP has not yet addressed aquatic biodiversity. In Oregon, aquatic habitats,

anadromous fish, rivers and water quality are the primary drivers of environmental policy and

restoration efforts. As a result, OR-GAP is committed to completing an aquatic gap analysis. 

Developing a macrohabitat or stream classification, attributing all of Oregon streams and lakes, and

obtaining high quality distribution information for some of Oregon’s aquatic biota (all fish and

some key aquatic invertebrates) are high priority goals for OR-GAP and ORNHP over the next two

years.

General Limitations

Limitations must be recognized so that additional studies can be implemented to supplement GAP. 

The following are general project limitations; specific limitations for the data are described in the

sections that describe them:

1. GAP data are derived from remote sensing and modeling to make general assessments about

conservation status. Any decisions based on the data must be supported by ground-truthing and

more detailed analyses.

2. GAP is not a substitute for threatened and endangered species listing and recovery efforts. A

primary argument in favor of gap analysis is that it is pro-active: it seeks to recognize and

manage sites of high biodiversity value for the long-term maintenance of populations of native
5

species and natural ecosystems before individual species and plant communities become

critically rare. Thus, it should help to reduce the rate at which species require listing as

threatened or endangered. Those species that are already greatly imperiled still require

individual efforts to assure their recovery. 

3. GAP data products and assessments represent a snapshot in time generally representing the date

of the satellite imagery. Updates are planned on a 5-10 year cycle, but users of the data must be

aware of the static nature of the products.

4. GAP is not a substitute for a thorough national biological inventory. As a response to rapid

habitat loss, gap analysis provides a quick assessment of the distribution of vegetation and

associated species before they are lost, and provides focus and direction for local, regional, and

national efforts to maintain biodiversity. The process of improving knowledge in systematics,

taxonomy, and species distributions is lengthy and expensive. That process must be continued

and expedited in order to provide the detailed information needed for a comprehensive

assessment of our nation's biodiversity. Vegetation and species distribution maps developed for

GAP can be used to make such surveys more cost-effective by stratifying sampling areas

according to expected variation in biological attributes.

The Study Area

Oregon is the tenth largest of the United States, at 97,060 square miles (251,418 square km)

(Keisling 1999, Oregon Blue Book). Ecologically, it is the most diverse state aside from California

(based on the number of plant associations described in the National Vegetation Classification

(NVCS) by the Oregon Natural Heritage Program). Oregon has coastal rainforests dominated by

California and Alaska species (coast redwood and Sitka spruce), barren deserts receiving less than

seven inches of rainfall a year, and mountain ranges associated with the Rocky Mountains, the

Cascades, the Klamath Mountains and the Great Basin Ranges. The state is known for its forests,

which include the world’s tallest (Oregon is home to the champion big leaf maple, black

cottonwood, white fir, Douglas-fir, ponderosa pine, Port Orford cedar and Sitka spruce trees) and

the most productive, as well as extensive fire maintained ponderosa pine and Oregon white oak

savannas and woodlands. The state’s extensive sagebrush steppe, native prairies and grasslands,

and rivers and lakes are less well known, but no less significant to wildlife and biodiversity.

Oregon is a crossroads for plants from many regions, with numerous species at or near the edge of

their range. Many plants typically found in the Arctic dominate the high Cascades. Coastal Alaskan

plants such as Sitka spruce dominate the north Coast Range, while the southern coast has a

redwood belt that spills over from California. The Wallowa Mountains are the western edge of the

Rocky Mountains and are home to many species common to central Colorado. Southeastern

Oregon is the edge of the Great Basin and is characterized by plants found in the cool deserts of

Nevada and Utah. In the Klamath Mountains, the flora of the Sierra Nevada, the Cascades, and the

Great Basin come together to form unique combinations. A two-mile stretch of the Siskiyou Crest

in southwestern Oregon supports plant communities as varied as old growth Douglas-fir forest,

alpine meadows, western juniper steppe, Jeffrey pine savannas, red fir forests, and rigid sagebrush

steppe.
6

Evidence of humans in Oregon goes back beyond 15,000 years, although there is continued debate

as to the actual earliest settlements here. Native Americans were distributed around the state, with

very different cultures in different areas, although most relied on hunting and fishing for

subsistence. In northwest Oregon, native tribes use of fire played a critical role in establishing

many patterns of natural habitats. Around the end of the Pleistocene, the drier climate had created

open grasslands and oak savannas throughout much of the Willamette Valley supporting numerous

prairie wildlife species, as well as a diverse endemic flora adapted to grasslands. As the climate got

cooler and wetter and summer lightning almost disappeared, Native Americans frequently set fires

in the Willamette Valley, maintaining the prairies and oak savannas which would otherwise have

become conifer forests.

Currently, Oregon’s population is relatively small, with just over 3.2 million people in 1998, most

of whom are concentrated in the Willamette River Valley. This valley, between Eugene and

Portland, was the final destination of the Oregon Trail because of its mild climate and very

productive soils. The eastern half of the state supports a sparse population and a natural resource

economy based mostly on dryland and irrigated farms, ranches and timber production. 

Southwestern Oregon is similar to northern California, with a mix of farmers, timber workers,

fishermen and but with small but rapidly growing communities concentrated around Medford.

Many organizations now use ecoregions to organize biodiversity information and to develop

conservation plans. Ecoregions are geographic areas with similar features, such as climate,

vegetation, geology, geomorphology, soils, and ecosystem processes - which together support

characteristic natural communities of plant and animal life. OR-GAP has recognized ten

ecoregions which occur in Oregon. 

Oregon’s ecoregions include the Willamette Valley, Coast Range, Klamath Mountains, West

Cascades, East Cascades, Columbia Basin, High Lava Plains, Northern Basin and Range, Blue

Mountains and Owyhee Uplands (Figure 1.1). These ecoregions correspond to the ten Sections

from Oregon in Bailey’s (McNab and Avers 1994) U.S. Forest Service Ecoregional Framework,

and for western Oregon were based on those developed by James Omernik of EPA (Pater et al.

1998). Descriptions of these ten ecoregions are included in Appendix 1.2. These ecoregions have

been used as the basis for conservation planning by ODFW, ORNHP, the Oregon Biodiversity

Project as well as in modified form by The Nature Conservancy and the U.S. Forest Service in the

Interior Columbia Basin Management Plan.

For this report, OR-GAP completed the analysis primarily on a statewide basis. Ecoregional

assessments are currently underway on the basis of these ecoregions, and some of the data included

here is displayed on an ecoregional basis.
7

 

Figure 1.1. Map showing the 10 Ecoregions of Oregon. CR = Coast Range, WV = Willamette

Valley, KM = Klamath Mountians, WC = West Cascades, EC = East Cascades, BR = Basin and

Range, HP = High Lava Plains, CB = Columbia Basin, BM = Blue Mountains, and OU = Owyhee

Uplands.
8

CHAPTER 2: EXISTING LAND COVER CLASSIFICATION AND MAPPING 

Introduction

Mapping natural land cover requires a higher level of effort than the development of data for animal

species, agency ownership, or land management, yet it is no more important for gap analysis than

any other data layer. Generally, the mapping of land cover is done by adopting or developing a

land cover classification system, delineating areas of relative homogeneity (basic cartographic

“objects”), then labeling these areas using categories defined by the classification system. More

detailed attributes of the individual areas are added as more information becomes available, and a

process of validating both polygon pattern and labels is applied for editing and revising the map. 

This is done in an iterative fashion, with the results from one step causing re-evaluation of results

from another step. Finally, an assessment of the overall accuracy of the data is conducted. The

final assessment of accuracy will show where improvements should be made in the next update

(Stoms et al.1994).

In its “coarse filter” approach to conservation biology (e.g., Jenkins 1985, Noss 1987), gap analysis

relies on maps of dominant natural land cover types as the most fundamental spatial component of

the analysis (Scott et al. 1993) for terrestrial environments. For the purposes of GAP, most of the

land surface of interest (natural) can be characterized by its dominant vegetation.

Vegetation patterns are an integrated reflection of the physical and chemical factors that shape the

environment of a given land area (Whittaker 1965). They also are determinants for overall

biological diversity patterns (Franklin 1993, Levin 1981, Noss 1990), and they can be used as a

currency for habitat types in conservation evaluations (Specht 1975, Austin 1991). As such,

dominant vegetation types need to be recognized over their entire ranges of distribution (Bourgeron

et al. 1994) for beta-scale define analysis (sensu Whittaker 1960, 1977). These patterns cannot be

acceptably mapped from any single source of remotely sensed imagery, therefore, ancillary data,

previous maps, and field surveys are used. The central concept is that the physiognomic and

floristic characteristics of vegetation (and, in the absence of vegetation, other physical structures)

across the land surface can be used to define biologically meaningful biogeographic patterns. There

may be considerable variation in the floristics of subcanopy vegetation layers (community

association) that are not resolved when mapping at the level of dominant canopy vegetation types

(alliance), and there is a need to address this part of the diversity of nature. As information

accumulates from field studies on patterns of variation in understory layers, it can be attributed to

the mapped units of alliances.

Land Cover Classification

Land cover classifications must rely on specified attributes, such as the structural features of plants,

their floristic composition, or environmental conditions, to consistently differentiate categories

(Küchler and Zonneveld 1988). The criteria for a land cover classification system for GAP are: (a)

an ability to distinguish areas of different actual dominant vegetation; (b) a utility for modeling

vertebrate species habitats; (c) a suitability for use within and among biogeographic regions; (d) an

applicability to Landsat Thematic Mapper (TM) imagery for both rendering a base map and from

which to extract basic patterns (GAP relies on a wide array of information sources, TM offers a
9

convenient meso-scale base map in addition to being one source of actual land cover information);

(e) a framework that can interface with classification systems used by other organizations and

nations to the greatest extent possible; and (f) a capability to fit, both categorically and spatially,

with classifications of other themes such as agricultural and built environments.

For GAP, the system that fits best is referred to as the National Vegetation Classification System

(NVCS) (FGDC 1997). The origin of this system was referred to as the UNESCO/TNC system

(Lins and Kleckner in press) because it is based on the structural characteristics of vegetation

derived by Mueller-Dombois and Ellenberg (1974), adopted by the United Nations Educational,

Scientific, and Cultural Organization (UNESCO 1973) and later modified for application to the

United States by Driscoll et al. (1983, 1984). The Nature Conservancy and the Natural Heritage

Network (Grossman et al. 1994) have been improving upon this system in recent years with partial

funding supplied by GAP. The basic assumptions and definitions for this system have been

described by Jennings (1993).

In 1994, the NVCS classification system was not chosen by ODFW to use for the process of

revising its classification scheme and mapping protocol from the Kagan and Caicco (1992) initial

mapping effort. ODFW felt instead that vegetation physiognomy should be the primary criterion

for the classification since the major purpose of the OR-GAP Version 2 was to map vegetation at a

regional scale using remotely sensed data. A second purpose for the classification was to establish

relationships between major environmental controls and the identified vegetation units. For this

reason, floristic composition was chosen as a second criterion in combination with physiognomy. 

While ODFW was creating the classification a panel of Pacific Northwest resource agencies

proposed another vegetation classification scheme (IRICC 1994). Their scheme was similar to the

NVCS in that it utilized both floristic composition and physiognomy as key classification criteria. 

The appeal of the IRICC approach was that various mapping efforts would become generic in their

utility on the basis of the common classification units. A second appeal to the IREC system is that

label criteria is not restricted to species dominance and allows for more descriptive class types such

as the Northeastern Oregon Mixed Conifer Forest. The IRICC approach was used as the basis for

the ODFW, OR-GAP version 2 coverage.

To classify barren, or non-vegetated lands ODFW followed the classification approach described by

the USGS (Anderson et al. 1976). The Anderson classification system is commonly used in remote

sensing applications and uses a hierarchy that partitions regional landscapes into broad major land

use/land cover categories such as agriculture, urban, forest, etc. Second level distinction separates

the broad level I class into specific categories. For example, the Anderson level I class Barren

Land is classified into dunes, exposed rock, salt flats in level II. We classified barren, or nonvegetated lands to Anderson level II in this mapping project. Agricultural lands were kept at

Anderson level I in the interest of time, project finances and the general focus of GAP, which is to

inventory natural ecosystems. Table 2.1 shows the types classified and mapped on the Version 2

landcover. Appendix 2.1 includes descriptions of each of these types.
10

Table 2.1 Landscape-level vegetation types and proportional area of land cover for Oregon.

 

FOREST AND WOODLAND COVER TYPES

Map Code # CLASS NAME Area of Land Cover (acres) % of State

32 Sitka Spruce-W. Hemlock Maritime Forest 397521 0.631%

33 Mountain Hemlock Montane Forest 331700 0.527%

34 True Fir-Hemlock Montane Forest 1510010 2.398%

35 Montane Mixed Conifer Forest 83834 0.133%

37 Shasta Red Fir-Mountain Hemlock Forest 54086 0.086%

39 Whitebark-Lodgepole Pine Montane Forest 1323 0.002%

40 Ponderosa Pine Dominant Mixed Conifer Forest 427295 0.679%

41 Northeast Ore. Mixed Conifer Forest 3144370 4.994%

42 Jeffery Pine Forest and Woodland 53781 0.085%

43 Serpentine Conifer Woodland 51874 0.082%

44 Lodgepole Pine Forest and Woodland 256444 0.407%

45 Subalpine Fir-Lodgepole Pine Montane Conifer 714286 1.134%

46 Coastal Lodgepole Forest 41869 0.066%

49 Douglas-Fir-W. Hemlock-W. Red Cedar Forest 6618660 10.512%

50 Douglas-Fir-Port Orford Cedar Forest 166450 0.264%

51 Douglas-Fir-Mixed Deciduous Forest 10894 0.017%

52 Douglas-Fir-White Fir/Tanoak-Madrone Mixed Forest 1126290 1.789%

53 Douglas-Fir/White Oak Forest 196692 0.312%

54 Ponderosa Pine Forest and Woodland 4680430 7.434%

56 Douglas-Fir Dominant-Mixed Conifer Forest 2553290 4.055%

57 Ponderosa Pine/White Oak Forest and Woodland 163112 0.259%

58 Ponderosa Pine-W. Juniper Woodland 201553 0.320%

59 Ponderosa-Lodgepole Pine on Pumice 1502790 2.387%

61 Western Juniper Woodland 3784130 6.010%

63 Red Alder Forest 124929 0.198%

64 Red Alder-Big Leaf Maple Forest 4268 0.007%

66 Aspen Groves 22287 0.035%

67 Mixed Conifer/Mixed Deciduous Forest 1412120 2.243%

68 Cottonwood Riparian Gallery 2574 0.004%

72 Siskiyou Mtns Mixed Deciduous Forest 200396 0.318%

75 Oregon White Oak Forest 115579 0.184%

77 South Coast Mixed Deciduous Forest 2894 0.005%

110 Subalpine Parkland 76262 0.121%
11

Table 2.1. continued.

SHRUBLAND AND GRASSLAND TYPES

Map Code # CLASS NAME Area of Land Cover (acres) % of State

85 Siskiyou Mtns Serpentine Shrubland 32404 0.051%

87 Hawthorn-Willow Shrubland 8132 0.013%

89 Manzanita Dominant Shrubland 15440 0.025%

90 Mountain Mahogany Shrubland 1378 0.002%

91 Sagebrush Steppe 5244610 8.330%

93 Low-Dwarf Sagebrush 435480 0.692%

95 Salt Desert Scrub Shrubland 571920 0.908%

96 Big Sagebrush Shrubland 12325200 19.576%

97 Bitterbrush-Big Sagebrush Shrubland 152276 0.242%

103 Northeast Ore. Canyon Grassland 404702 0.643%

105 Subalpine Grassland 107232 0.170%

106 Forest-Grassland Mosaic 382767 0.608%

112 Modified Grassland 963640 1.531%

113 Coastal Strand 1941 0.003%

121 Grass-shrub-sapling or Regenerating young forest 1846210 2.932%

NON-NATIVE OR MINIMAL VEGETATIVE COVER 

122 Alkali Playa 128075 0.203%

124 Urban 601668 0.956%

125 Agriculture 6455430 10.253%

126 Exposed Tidal Flat 23039 0.037%

127 Lava Flow 157010 0.249%

128 Coastal Dunes 48728 0.077%

129 Alpine Fell-Snowfields 154748 0.246%

130 Open Water 1709630 2.715%

RIPARIAN AND HERBACEOUS WETLAND TYPES

114 Wet Meadow 2911 0.005%

135 Palustrine Forest 26901 0.043%

136 Palustrine Shrubland 7640 0.012%

137 Estuarine Emergent 965 0.002%

138 Palustrine Emergent 19950 0.032%

200 NWI Palustrine Forest 921 0.001%

201 NWI Palustrine Shrubland 1005180 1.597%

202 NWI Estuarine Emergent 40822 0.065%

203 NWI Palustrine Emergent 50431 0.080%
12

Methods

Landsat TM Imagery

 

Twenty-three Landsat TM scenes formed the basis for interpretation of the OR-GAP version 2

landcover. All imagery had less than 10% cloud cover and was acquired from May to October

between 1991 and 1993. Cloudy and smoke-obscured regions within the imagery were interpreted

using adjacent imagery, where possible, or using aerial photography as the information source. 

Imagery was registered to the Universal Transverse Mercator (UTM) map coordinate system, zones

10 and 11.

Table 2.2 Landsat TM Imagery and dates used for mapping project

Path/Row Month/year Path/Row Month/year Path/Row Month/year

P42/R28 June / 1991 P44/R28 May / 1993 P46/R28 Aug / 1991

P42/R29 July / 1992 P44/R29 June / 1992 P46/R29 June / 1992

P42/R30 July / 1992 P44/R30 Oct / 1991 P46/R30 July / 1992

P42/R31 June / 1993 P44/R31 June / 1991 P46/R31 July / 1992

P43/R28 Sept / 1993 P45/R28 Oct / 1993 P47/R28 Sept / 1991

P43/R29 July / 1991 P45/R29 June / 1992 P47/R29 July / 1991

P43/R30 Aug / 1993 P45/R30 July / 1992

P43/R31 Aug / 1991 P45/R31 Aug / 1991

Map Development 

Each of the 23 Landsat TM scenes that were used in the classification of Oregon’s vegetation

underwent a two phase, multi-step process. The major steps involved with the two phases are

briefly described below.

Phase I—Image Preparation, Radiometric Preview, and Image Analysis 

1) Partitioning imagery into ecoregional similarity. Previous mapping efforts by the Northwest

Habitat Institute (NHI) staff have demonstrated that whenever classification takes place over a

large land area, (such as a TM scene), the problem of signature extension severely compromises

classification effort. Ecoregional partitioning was used to reduce spectral complexity displayed

in a full TM scene, and to group vegetation types into more “probable” associations. 

2) Construct derivative bands. A normalized difference vegetation index (NDVI) and the first

three principal component bands of a Tasseled Cap Transformation algorithm was incorporated

with TM bands 1-5 and 7 to form a 10 band image. This image was the basis of all subsequent

spectral analysis.

3) Conversion of TM imagery to TIFF format files. A three-band (bands 3, 4 and 5) image was

subset from the 10-band image and converted to a TIFF, which was downloaded to a laptop

computer for field reconnaissance purposes.

4) Conversion of vector format ancillary data. Coverages which assisted the analyst during field

verification, especially the road and stream networks, were converted to a DXF format and

brought into the lap top computer to display over the TIFF images.
13

Phase II—Image Classification, Field Verification, and Accuracy Assessment

1) Unsupervised classification of the scene ecoregion. Initial classification procedure started with

a sufficiently large number of spectral clusters (generally between 100-150), to form mutually

exclusive spectral signatures. These signatures were then run through a maximum likelihood

classifier to produce the initial spectral cluster map.

2) Preliminary assignment of spectral class to vegetation class. Linking spectral clusters to

vegetation information classes was first done through an on-screen examination of the clusters

overlaid on the image. In many cases the information class was spectrally distinct enough that

cluster labeling was very straightforward. However, there were always a number of spectral

clusters that were indeterminable at this stage, as well as classes that did not readily lend

themselves to an identification (like palustrine forest). Which is the reason an iterative process

was used to determine spectral/information class relationships.

3) Field verification of spectral-vegetative condition. This process involved recording vegetation

identity at known points within the image. This entailed linking our global positioning system

(GPS) unit to the TIFF version of the TM scene through Field Notes software and recording

field training sites. A database was developed for each ecoregion using the Field Notes

software that includes XY coordinates, the vegetation/land cover class, and environmental

variables that were determined to be useful for future processing iterations. The database was

brought into ARC/INFO as a point location file and displayed over the various thematic

classifications. Other ancillary data, (the National Wetland Inventory (NWI) and stream and

road network data) were utilized extensively with the TIFF data to assist in cover type

identification.

4) Refinement-reclassification of spectral class to vegetative condition. This step began the

process of winnowing the scene into identifiable and unidentifiable, or “problem” spectral

classes. Once the analyst was confident of the relationship between spectral cluster and land

cover class that class was masked out of succeeding classification iterations. Once the problem

spectral classes were identified, separate classifications were performed where each class

partitioned into many spectral classes and, if possible, those classes were related to probable

land cover types and masked out. Further refinement of spectral cluster/land cover type was

accomplished through the use of ancillary data as “logical operators”. For example, deep

shadows in mountainous terrain typically can be confused with water signatures -- and by using

a digital elevation model the analyst was able to overlay that spectral class on all slopes less

than 1 % and quickly ascertain those areas which are too steep to pond water.

5) Field verification of “problem” spectral-vegetation classes. If the analyst was not confidently

able to relate a spectral cluster to land cover class, another field visit was often necessary to

uncover the spectral cluster identity.

6) Editing the refined coverage. As a last step in the classification phase the analyst used on

screen editing of those areas, which were too obscure to classify by conventional image

processing techniques. Typically, these were the cloud, cloud shadow, or smoke obscured

areas. Aerial photo interpretation of recent aerial photography was the interpretation basis for

the classification within these obscured regions.

7) Accuracy assessment Accuracy assessment techniques and procedures are discussed in

Appendix 2.2, although an accuracy assessment has not been done for either of the OR-GAP

existing land coverages.
14

Mapping Standards

Special Feature Mapping 

Several collateral databases (National Wetlands Inventory, riparian vegetation; and the Oregon

State Service Center urban growth boundary) were incorporated into the vegetation database to

assist with distributional mapping of riparian wetland and urban cover types.

Minimum Mapping Unit

The minimum mapping unit used was 100 hectares.

Results

Landsat TM Imagery Mapping 

The statewide current land cover map (Figure 2.1) displays distributional information on the 65

landscape level vegetation types. Despite the large number of landscape level vegetation types the

10 most commonly occurring types constitute 76.7 per cent of the total vegetation (Table 2.3). Big

sagebrush and its variant sagebrush steppe account for nearly a third of the total vegetation

coverage, and this figure is probably conservative since a fair amount of the western juniper, and

the northeastern Oregon canyon grassland and shrubland types could have been put into big

sagebrush or sagebrush steppe. On the other hand, a number of the types have less than one per

cent of the proportional land area. Some of these types are rare by virtue of their unique

relationship to localized environments (e.g. Siskiyou Mountains Serpentine shrublands). Other

types, particularly the riparian gallery forests and riparian types, are more widespread than

indicated in Table 2.1, but generally are smaller than map resolution.

When you aggregate the cover types by vegetative form (i.e. forest, shrub, etc.), forest and

woodland occupy 48% of total land area. Of the entire state, only 14.6% is classified as either nonvegetated, water or human created (urban or agriculture) types. The remainder, 85.4%, is classified

as having predominantly native vegetation (although areas dominated by exotic species were not

mapped). This proportion of vegetated to other surface type is very similar to California’s (79.8%)

(Davis et al. 1998).

Accuracy Assessment

Introduction

GAP land cover maps are primarily compiled to answer the fundamental question in gap analysis:

what is the current distribution and management status of the nation's major natural land cover

types and wildlife habitats? Besides giving a measure of overall reliability of the land cover map

for gap analysis, the assessment also identifies which general classes or which regions of the map
15

do not meet the accuracy objectives for the Gap Analysis Program. Thus an accuracy assessment

can identify where additional effort will be required when the map is updated.

The purpose of accuracy assessment is to allow a potential user to determine the map's "fitness for

use" for their application. It is impossible for the original cartographer to anticipate all future

applications of a land cover map, so the assessment should provide enough information for the user

to evaluate fitness for their unique purpose. This can be described as the degree to which the data

quality characteristics collectively suit an intended application. The information reported include

details on the database's spatial, thematic, and temporal characteristics and their accuracy. 

 

Assessment data are valuable for purposes beyond their immediate application to estimating

accuracy of a land cover map. The reference data is therefore made available to other agencies and

organizations for use in their own land cover characterization and map accuracy assessments (see

Data Availability for access information). The data set will also serve as an important training data

source for later updates.

Even though we have reached an endpoint in the mapping process where products are made

available to others, the gap analysis process should be considered dynamic. We envision that maps

will be refined and updated on a regular schedule. The assessment data will be used to refine GAP

maps identifying where the land cover map is inaccurate and where more effort is required to bring

the maps up to accuracy standards. In addition, the field sampling may identify new classes that

were not identified at all during the initial mapping process.

Airborne Videography 

ODFW had airborne videography recorded between August 25 and September 3, 1993 in an

attempt to improve the land cover, and to assist in the accuracy assessment. Unfortunately, ODFW

was unable to use this video successfully to validate the Version 2 cover (Barrett, 1998). A more

detailed discussion of the ODFW use of video for OR-GAP is included in Appendix 2.2. 

Assessment of the Oregon GAP Map Accuracy

No statewide accuracy assessment was completed. OR-GAP hopes to complete an accuracy

assessment sometime in the near future. These results will be posted under “Oregon Updates” on

the National Gap Home Page (http://www.gap.uidaho.edu/gap/).

Limitations and Discussion

There are no constraints to the use of these data. However, these data were produced with intended

application at the state, or ecoregional level with an accuracy in detail and precision based on

USGS 1:100,000 maps. These data were created to provide a coarse filter approach to

vegetation/wildlife habitat relationships where not every occurrence of animal habitat is mapped;
16

rather, only large, generalized distributions are mapped. Therefore, this data set is most valid when

used in analysis of 1:100,000 applications or greater.

The method we used to map current vegetative conditions is not suited to analysis of canyon-land

vegetation types or other vegetation that is environmentally restricted to localized environments. 

Some of the cover types mapped (i.e. big sagebrush shrubland), created huge polygons that spanned

a number of environmental conditions. Due to this large intra-polygon variability, there can be

quite a range in the appearance of the type. Physiognomic attributes such as stand structure and

floristic information like sub-canopy species could not be mapped within the project constraints.

Area calculations of the various cover types need to be interpreted with some caveats. The coarse

scale (1:100,000) and large minimum mapping unit (MMU) (100 ha) of the vegetation and habitat

maps provide reasonable representations of the actual acreage, but not as accurate as fine-scale

maps because fine-scale maps depict boundaries with greater precision, which in turn affects area

calculations. 
17

CHAPTER 3: HISTORIC VEGETATION MAPPING

Introduction

In 1997, as part of the Oregon Biodiversity Project (Our Living Landscape 1998), a historic

vegetation cover was developed for the state of Oregon. The goal was to allow OBP to look at

historic vegetation patterns and the changes which have occurred over time. A comparison of the

historic and existing vegetation maps allow for analysis of the vegetation types which have declined

the most. More significantly for the gap analysis concept, it also allows for an analysis of how well

the historic extent of the various vegetation types and species distributions are represented in the

statewide network of conservation lands.

The development of the 1997 version (Version 1) of the historic vegetation cover, and the

subsequent update (Version 2) used in this analysis, are described below. Both covers represent a

compilation of data from three primary sources, and as a result, the accuracy varies. However, the

overall patterns and results appear to be at least as accurate as the information from the existing

vegetation map. Figure 3.1 is a fold-out Historic Land Cover map.

Land Cover Classification

In order to facilitate a comparison with the existing vegetation coverages, the National Vegetation

Classification System (NVCS) (FGDC, 1997) was used in the development of the historic

vegetation map. When data was limited, some types were aggregated, but in general, alliances were

used. Table 3.1 outlines the vegetation types from the Version 2.

Methods, Mapping Standards and Map Development

The Oregon Natural Heritage Program has almost completed the development of a 1:24,000,

historic vegetation coverage for the Willamette Valley ecoregion of Oregon. This region, which

includes most of the population, agriculture and development in Oregon, has been a major focus of

vegetation alteration and restoration. The development of detailed, historic vegetation coverages at

the USGS Quad scale was done to assist in assessing wetland losses, and to help in developing

restoration plans. In addition to the Willamette Valley coverage, the U.S. Forest Service

Experiment Station has digitized a detailed forest vegetation coverage developed by H.J. Andrews

based on detailed forest inventories from the 1920's and 1930's. This coverage mapped most forest

habitats at a very fine level (approximately a 1:100,000 scale) and contained most of the forest

types which corresponded very well to the NVCS alliances. The Bureau of Land Management had

also digitized a detailed forest vegetation map from 1901, although this coverage only had stand

structure mapped, rather than the dominant canopy vegetation type. For the non-forested areas, the

Interior Columbia River Basin Assessment had produced a historic vegetation coverage. Since all

of these pieces were available, the Oregon Biodiversity Project and ORNHP decided to produce a

statewide coverage as an aggregation of these coverages.
18

Table 3.1 Historic vegetation types and proportional area of land cover for Oregon.

Vegetation Type Total Area Vegetation Type Total Area

(hectares) (hectares)

 Forests, Woodlands and Savannas Barren and Non-Vegetated Types

Coast Redwood 5,636 Alpine 54,188

Douglas-fir 4,921,046 Inland Dunes 30,378

Grand Fir 475,527 Lava Field 26,482

Jeffrey Pine 80,716 Open Water 209,396

Lodgepole Pine 619,967 Playa 53,499

Mixed Conifer 330,886 Wetland and Riparian Types

Oak-Madrone Woodland 158,754 Marshes and Riparian Types 204,391

Oregon White Oak Savanna 772,569 Quaking Aspen 20,092

Pacific Silver Fir-Mountain 320,599 Riparian 349,347

Ponderosa Pine 3,796,376 Wet Meadows 104,492

Port Orford Cedar 19,700

Shasta Red Fir-White Fir 235,017

Shore Pine 11,004

Sitka Spruce-Western Hemlock 275,018

Subalpine Fir 340,984

Western Juniper 703,862

Western Red Cedar 1,476

Whitebark Pine 4,157

 Shrublands and Grasslands

Antelope Bitterbrush 45,188

Big Sagebrush 3,292,725

Canyon Shrubland 148,260

Low Sagebrush 1,359,407

Mixed Sagebrush 1,432,452

Mountain Big Sagebrush 626,378

Salt-desert Shrub 332,283

Alkali Grassland 808,543

Perennial Bunchgrass 2,903,020

The ORNHP data in the Version 2 coverage is mainly based on General Land Office (GLO)

surveyor records which have been copied onto microfilm and are available through the Oregon

State Office of the Bureau of Land Management. For the entire Willamette Valley ecoregion, these

GLO surveyor’s notes were transcribed and mapped onto 1:24,000 mylar overlays, showing the

locations and species of all trees and shrubs along survey lines. These overlays and the USGS

topographic maps were used to digitize a historic vegetation coverage. A total of 84 types were

mapped, although for the statewide coverage, these were aggregated into 5 major types. The

minimum mapping unit was 4 hectares. The Columbia Basin ecoregion in Oregon was mapped

directly onto 1:100,000 USGS topographic maps, based on the GLO surveyor’s notes. Since this

area has limited trees, the vegetation information in the notes was less detailed. The Columbia
19

Basin work was completed using a grant from the U.S. Environmental Protection Agency’s

Regional Geographic Initiative program. The minimum mapping unit for this coverage was also 4

hectares, although it is closer to a 100-hectare MMU coverage.

The forest vegetation (outside of the Willamette Valley) in Oregon was developed entirely from the

coverage developed by H.J. Andrews from 1936 and digitized by the U.S. Forest Experiment

Station. The coverage was developed for Oregon and Washington, and the data was provided to

ORNHP and OBP by a USFS Forest Science researcher, Janet Ohmann. A total of 19 types were

included in the H.J. Andrews cover. The Oregon portion of the map included 11 natural vegetation

types which were split into 19 forested natural vegetation types as follows:

1) Balsam Fir-Mtn. Hemlock upper slope types ± a) Silver fir-Mountain Hemlock, b) White 

 fir-Shasta fir, and c) Grand fir

2) Cedar-Redwood ± d)Western red cedar, e) Port-Orford cedar, and f) Coast redwood

3) Lodgepole Pine ± g) Lodgepole pine and h) Shorepine

4) Pine mixture ± i) Jeffrey pine and j) Mixed Conifer

5) Hardwoods - Alder, Ash, Maple ± k) Aspen and l) Riparian Hardwoods

6) Hardwoods - Oak, Madrone ± m) Oak-Madrone woodland

7) Subalpine and certain non-commercial ± n) Subalpine fir and o) Whitebark pine

8) Spruce-Hemlock ± p) Sitka spruce-Western hemlock

9) Douglas-fir ± q) Douglas-fir

10) Western Juniper ± r) Western Juniper

11) Pure Ponderosa pine ± s) Ponderosa pine

A combination of geography, geology (for Jeffrey pine forests), elevation and aspect was used to

distinguish these types. For all of the conifer types, the coverage distinguished stands with large

trees or old growth from smaller trees or second growth. These were all combined in the historic

coverage. The Andrews coverage included three classes of disturbed forested habitats: Deforested

burns, recent cutover, and non-restocked cutover. These classes made up a fairly small portion of

the overall forested landscape in Oregon, and these were individually reclassed into an adjacent

type using expert review. This coverage has no established minimum mapping unit or scale. Based

on the detail, it appears to be finer than the 1:100,000 scale Version 2 Gap Land Use cover. The

smallest polygon mapped in Oregon in this coverage was 1.5 hectares, and there are 2,437 polygons

in Oregon which are smaller than 40 hectares.

For Version 2, all the non-forested lands outside the Columbia Basin ecoregion in Eastern Oregon

were attributed using a model developed at ORNHP. The natural vegetation classes in the

1:250,000 Gap Vegetation Map (Version 1) were used as the basis for the non-forested historic

classes. A combination of factors including soils, geology, and elevation were used to classify nonnative types (agriculture, urban, exotic species). For Version 2, some related vegetation alliances

(e.g. low sagebrush, black sagebrush and rigid sagebrush) were combined. Additionally, historic

data was available for certain major eastern Oregon valleys, particularly the Grande Ronde

(LaGrande) and Klamath Basin (Klamath Falls). These were digitized at ORNHP at 1:100,000

from hard copy maps. Future GLO data acquisition will greatly increase the map accuracy for the

other large eastern Oregon valleys, particularly the Silvies-Silver Creek Basin (Burns), the

Malheur-Snake Valley (Ontario), the Wallowa Valley (Enterprise) and the Powder River Valley

(Baker City).
20

Special Feature Mapping

Only in the Willamette Valley, the Columbia Basin and the forested habitats were riparian habitats

adequately mapped, since they were mapped directly from the GLO information. To deal with the

lack of riparian information, all perennial streams in the 1:100,000 Streamnet (an interagency, four

state database developed by the Bonneville Power Administration, the Northwest Power Planning

Council, Oregon, Washington, Idaho and Montana, and managed by the Pacific States Marine

Fisheries Commission) coverage were buffered at 80 meters, intersected with the upland coverage

and defined as potential Riparian for the wildlife species distributions. In future versions, riparian

vegetation maps or buffers will be included for all the non-forested habitats.

Results

A primary objective of developing the historic coverage was to allow an analysis of declines of the

different habitat types. For analysis purposes, OR-GAP crosswalked the historic vegetation

classification and the existing vegetation classifications to the wildlife habitats because the

vegetation types in the existing vegetation map did not correspond very well to alliance types. 

Table 3.2 shows the historic and current distributions of the habitat types used in the gap analysis,

the changes in area since settlement both by area in hectares and by percentage. Details of habitat

changes by ecoregion for each of the habitat types are included as Appendix 3.1.

The results shown in Table 3.2 must be examined with the knowledge that the two coverages were

developed quite differently, and may not represent vegetation change well at some scales. For

example, natural vegetation types mapped in one coverage but not the other (such as chaparral or

alkaline grasslands) could not be compared. Alpine habitats show a 28% increase -- which almost

certainly is a function of differences in how the types were mapped. Changes of less than 20% in

either direction probably do not represent substantial or significant change, given the potential for

error in both the existing and historic coverage. For example, a 9% increase in overall sagebrush

habitat in Oregon may be close to the actual change, but the accuracy of the historic map certainly

is not sufficient for this to be meaningful. However, the results do provide important insights into

the widespread habitats which have changed significantly over the last 150 years.

The major habitat which shows the greatest decreases are the perennial bunchgrasses. The

conversion of much of Oregon’s Columbia Basin, Willamette Valley and eastern Oregon valley

prairies to farmland is responsible for this very dramatic loss of habitat. Bunchgrass losses

occurred in most of Oregon’s ecoregions and have resulted in significant wildlife losses. 

Unfortunately, the remaining bunchgrass habitats are among the mostly poorly represented in

Oregon’s network of protected areas, as will be seen in Chapter 5.

Salt desert shrub is the other widespread habitat which has shown significant declines. The 36%

(110,000 hectare) decline is probably an underestimation, since the losses shown for playas most

likely are really salt desert shrub declines. This type is very poorly studied, since it generally

provides low forage (and therefore economic) value. While individual stands tend to be species

poor, the communities are quite diverse and variable, and represent a critical part of Oregon’s

diversity. A number of rare and endangered species occur in salt desert shrub habitat. Losses of
21

salt desert shrub appear to be a result of the conversion of habitat to irrigated farmland - and

protection of this habitat type is low.

Table 3.2. Changes in habitats since European Settlement.

Habitat Type Current (ha) Historical (ha) Change (ha) % Change

Alpine 136279 59804 76475 128%

Perennial Bunchgrass 389920 2797022 -2407102 -86%

Sagebrush (Mtn, Big, Mixed and Low) 7320349 6726639 593710 9%

Playa 49014 69495 -20481 -29%

Salt-desert Shrub 199703 310488 -110785 -36%

Canyon Shrubland 164087 146580 17508 12%

Coastal Dunes 38382 32644 5737 18%

Inland Dunes 72002 79972 -7969 -10%

 Wet Meadows 1177 106425 -105248 -99%

 Marshes 45330 199445 -154115 -77%

 Quaking Aspen 9041 15551 -6510 -42%

 Riparian 415813 324382 91431 28%

Wetlands and Riparian 471361 645802 -174442 -27%

Western Juniper 1610870 689633 921237 134%

Ponderosa Pine-While Oak 3049766 4583113 -1533346 -33%

 Douglas-fir Mixed Conifer 1429803 694493 735310 106%

 Early Shrub-Tree 742435 10563 731872 6929%

 Mixed Conifer/Deciduous 626537 14100 612437 4344%

 Siskiyou Mixed Conifer 522636 323957 -198679 61%

 Western Douglas-fir Mixed Conifer 3764028 5683743 -1919715 -34%

Low Elevation Conifer Forests 7085440 6726856 358584 5%

 Montane-Lodgepole Pine 391568 865288 -473720 -55%

 Mountain Hemlock 779396 314452 464944 148%

Montane Conifer Forests 1170965 1179740 -8776 -1%

All Conifer Forests 7085440 6726856 76475 5%

The comparison of the individual wetland, marsh and riparian types probably are not meaningful,

since they were mapped so differently in the two coverages. The changes in total wetland and

riparian areas, shown by the sum of the four wetland habitat types, show losses of about 175,000

hectares of wetlands or 27%, which is fairly close to estimates made by Oregon’s Division of State

Lands. The increases in riparian habitat are an artifact of mapping, since riparian was only mapped

in two small ecoregions (the Willamette Valley and the Columbia Basin) in the historic coverage. 

Version 3 of the historic coverage will include riparian and wetlands from all the other ecoregions. 

Similarly, the very large losses in wet meadow and marsh habitats are from differences in mapping

and from the fact that many marshes and wet meadows are too small to map. However, what is

shown by the comparison is the dramatic decrease in the very large marshes and wet meadows. In
22

eastern Oregon, large river basins were home to some of the largest marshes and wetlands in North

America. The Klamath Basin, Warner Basin, Malheur/Silvies Basin and many others each had very

large marsh-wetland complexes. These complexes have been mapped on the historic coverage as

marsh and wetland, but are mostly agriculture on the existing vegetation coverage – resulting in the

large losses shown. The next version of the historical land cover map will do a better job showing

historic riparian habitats, and using this cover will better reflect the real riparian losses.

The only habitat to show a substantial increase in distribution is Western Juniper. Juniper has

increased 57%, representing approximately 920,000 new hectares of juniper in Oregon. This

reflects major changes in habitat distribution resulting from fire suppression and livestock grazing. 

Juniper expansion has been a major concern for grassland and shrub steppe land managers. Recent

studies have shown that juniper distribution has likely been cyclical in Oregon, although the recent

rapid increases are probably not a natural process (Miller and Wigand 1994). While western

juniper is indeed expanding into many sagebrush and grassland habitats in Oregon, old-growth

western juniper is declining rapidly from development in central Oregon. Efforts to increase

livestock forage and reduce juniper expansion has led to the removal of old-growth juniper in areas

where it has dominated for thousands of years. Restoring fire and developing management

strategies should be a major focus for eastern Oregon land mangers in order to broaden the natural

range of variability for Western Juniper and all grassland and shrub steppe habitats. 

The two most widespread habitat types in Oregon, Sagebrush Steppe and Conifer Forests, show

little overall change. The primary reason is that there has not been large scale conversions of these

types to agriculture, urban or other types. The OR-GAP 1998 vegetation update does not show the

very dramatic qualitative changes which have occurred in these habitat types. For the sagebrush

steppe communities, the introduction of cheatgrass (Bromus tectorum) and other exotic species and

the planting of crested wheatgrass (Agropyron cristatum) have dramatically changed the ecological

function of hundreds of thousands of hectares of sagebrush steppe in Oregon. While these altered

habitats cannot be mapped using TM imagery, finer scale mapping efforts have been done in

southeastern Oregon using Ortho-Photo quads by the Burns District of the BLM. These detailed

maps show major declines in habitats dominated by sagebrush/native bunchgrasses due to large

areas dominated by sagebrush/cheatgrass (Bromus tectorum) or sagebrush/crested wheatgrass

(Agropyron cristatum). These native sagebrush habitat losses are found in all of the eastern Oregon

ecoregions in which they occur (OBP 1998). 

Similarly, there have not been significant changes in the overall acreage dominated by coniferous

forests. However there have been significant changes in how these forests look, how they function

ecologically, and the type of wildlife they support. The increases and decreases in the different

conifer habitat types between the historic and existing coverages do not appear to be particularly

meaningful. Using other coverages of existing vegetation which show conifer forest stand age and

structure, the U.S. Forest Service (FEMAT 1993) has analyzed how dramatically forests have

changed in Oregon.

Accuracy Assessment

No accuracy assessment was done for either Version 1 or Version 2 of the historic vegetation cover. 

Given the lack of baseline data, an accuracy assessment was not practical. It is possible to use the
23

GLO survey data to test the accuracy of the H.J. Andrews coverage, and it should also be possible

to test the accuracy of the modeled non-forested eastern Oregon types. These are both objectives

for future work.

Limitations and Discussion

Unlike many other states, much of Oregon’s landscape is intact and dominated by native

vegetation. As mentioned above, fire suppression, exotic species introductions, grazing and

logging have altered many of the native vegetation types. These processes or changes in the

landscape are not represented in either of the coverages, and therefore not in the analysis. 

However, the changes in vegetation patterns, processes and structure which have occurred over the

last 150 years are dramatic, local, and critical to the protection of Oregon’s wildlife and diversity.

The historic and existing vegetation coverages were completed using very different techniques – so

only very dramatic changes can be assumed to be meaningful. While the accuracy is difficult to

assess for the existing coverage and impossible for the historic coverage, both appear to represent

accurate overall estimates of the aggregated habitat abundances and distributions. An examination

of more detailed (higher resolution) vegetation coverages can provide substantially greater

information on changes in local habitat distributions. For example, ORNHP has completed a

comparison of 1:24,000 existing and historic vegetation coverages for the Willamette Valley

ecoregion. This comparison shows not only how much area each of the historic vegetation

community types has lost, but also accurately shows the patterns of changes. Many natural habitats

have been replaced by agriculture, but fire suppression and changes in the fire regime have also led

to conifer forests and mixed oak-conifer forests replacing many of the upland prairies and oak

savannas reported in 1851. It is quite likely that fire suppression has also significantly altered the

distribution of ponderosa pine forests and mixed conifer forests in Eastern Oregon.

The greatest value the historic vegetation information provides to GAP is an assessment of how

widespread habitats and species were before the major changes that have occurred since European

settlement. This is valuable because it allows conservation planners to attempt to include species

and habitats in the network of conservation lands based on how widespread they were, and how

much genetic diversity they might contain or be representing. Since the vegetation information in

GAP represents the coarse filter, vegetation types which were very widespread likely represent a

greater range of variability than local types. How well the current distribution of habitat types is

represented in the network of conservation areas only provides a partial measure of how well the

coarse filter is protected. How well the original (natural or historic) distribution of these types is

represented in the network is a better measure of the success of biodiversity protection efforts.
24

CHAPTER 4: PREDICTED ANIMAL DISTRIBUTIONS AND SPECIES RICHNESS

Introduction

All species range maps are predictions about the occurrence of those species within a particular

area (Csuti 1994). Traditionally, the predicted distribution of most species begins with collections

made at individual point locations. Most species range maps are small-scale (e.g. >1:10,000,000),

derived primarily from point data, and created to construct field guides. The purpose of the GAP

vertebrate species maps is to provide more precise information about the current predicted

distribution of individual native species within their general ranges. With this information, better

estimates can be made about the actual amounts of habitat area and the nature of its configuration.

GAP maps are produced at a nominal scale of 1:100,000 and are intended for applications at the

landscape or “gamma” scale (homogeneous areas generally covering 1,000 to 1,000,000 hectares

and made up of more than one kind of natural community). Applications of these data to site- or

stand-level analyses (site—a microhabitat, generally 10 to 100 square meters; stand—a single

habitat type, generally 0.1 to 1,000 ha; Whittaker 1977, see also Stoms and Estes 1993) are likely to

be compromised by the finer-grained patterns of environmental heterogeneity that occurs at those

patch sizes.

Gap analysis uses the predicted distributions of native vertebrate species to evaluate their

conservation status relative to existing land management (Scott et al. 1993). However, the maps of

vertebrate species distributions may be used to answer a wide variety of management, planning, and

research questions relating to individual species or groups of species. In addition to the maps, great

utility may be found in the consolidated specimen collection records and literature that have been

assembled into databases used to produce the maps.

Previous to this effort, no maps were available, digital or otherwise, showing the likely present-day

distribution of species by habitat type across their ranges. Because of this, ordinary species (i.e.,

those not threatened with extinction or not managed as game animals) are generally not given

sufficient consideration in land-use decisions in the context of large geographic regions or in

relation to their actual habitats. Their decline, because of incremental habitat loss can, and does,

result in one threatened or endangered species “surprise” after another. Frequently, the records that

do exist for an ordinary species are truncated by state boundaries. Simply creating a consistent

spatial framework for storing, retrieving, manipulating, analyzing, and updating the totality of our

knowledge about the status of each vertebrate species is one of the most necessary and basic

elements for preventing further erosion of biological resources.

Mapping Standards

OR-GAP developed maps using two different methods. The first (Version 1) species distribution

maps for amphibians, reptiles, breeding birds and mammals were developed for the Atlas of Oregon

Wildlife (Csuti et al. 1997a). These maps were created using hexagonalized range maps based on a

database created for the U.S. Environmental Protection Agency’s (EPA) Environmental Monitoring

and Assessment Program (EMAP), overlaid with the OR-GAP Version 1 land cover map (Kagan
25

and Caicco 1992). The Version 1 land cover map had 133 major vegetation types that were

grouped into 30 wildlife habitat types. We created a Wildlife by Habitat Relationships matrix to

link the hexagon distributions to the habitat polygons. 

The second version of the distribution maps were prepared using the revised hexagon data set from

ORNHP, a revised version of the Wildlife by Habitat Relationships matrix, and the Version 2 ORGAP land cover vegetation map from ODFW, consisting of 65 vegetation types which we grouped

into 31 wildlife habitat types.

Methods

The modeling approach used to predict vertebrate distributions included five steps. First, we

determined which species would be included in our analyses. Second, the distributional limits of

each species were defined by recording the species’ presence or absence within the EPA’s hexagon

grid system for Oregon (White et al. 1992). Third, we developed a Wildlife-Habitat Relationships

(WHR) matrix which defined the affinities of terrestrial vertebrate species to land cover types. 

Fourth, the hexagon and WHR databases were used in a GIS-modeling process which assigned

species to habitat polygons based on their known or expected occurrence within hexagons and their

association to habitat features. Finally, hardcopy maps of predicted species distributions were

reviewed by acknowledged experts. Unlike other state GAP efforts, Oregon had access to existing

hexagon distribution maps created for the Biodiversity Research Consortium. These hexagon maps

were used for the Atlas of Oregon Wildlife (Csuti et al. 1997a) and the resulting species distribution

maps served as the first version GAP maps. For this GAP final report, all hexagon distributions

were reviewed, and a new vegetative cover map was used, which necessitated a new WildlifeHabitat Relationships matrix. 

We included in our analysis all 441 terrestrial vertebrates that breed in Oregon, as described in the

Atlas of Oregon Wildlife (Csuti et al. 1997a), as well as 10 additional species. We did not include

birds which only winter in the state, birds found in Oregon only during migration, or accidentals. 

We created maps for full species only, combining all subspecies in the state into one map. We

chose to include non-native species in our analysis. There were no problems identifying which

mammals, amphibians, or reptiles to include in the analysis. However, there were occasional

differences of opinion regarding when to exclude certain bird species. When we began this project

there was no recent statewide publication on Oregon birds, so we relied on the opinion of experts

when deciding whether or not to include certain bird species. The taxonomy and nomenclature used

to describe species was adopted from The Nature Conservancy and selected as a standard by GAP

(Wilson and Reeder 1993, AOU 1998, Collins 1990).

Version 1 Maps

Range maps were created for each species documenting expected occurrence in each of 441 equal

area hexagons. Each hexagon covers approximately 647 square kilometers. Each hexagon record

received an occurrence status code (Table 4.1) reflecting the likelihood of finding that particular
26

species in the given hexagon. An example of a hexagon map for the snowy plover is shown as

Figure 4.1. The primary sources of information used to document species occurrence in hexagons 

Figure 4.1. Hexagon Distribution Map of the Snowy Plover in Oregon. P = probable (80-95%

confidence), C = confirmed (>95% confidence). There are no possible (PO) hexagons for the

Snowy Plover in Oregon.

were published range maps, species locality records, and expert opinion. We started by using

published range maps (Table 4.2) and improved them with species locality records. Species

locality records were obtained from existing vertebrate databases (Table 4.3). Occurrence status

was assigned to species locality records based on the date of the record. Species locality records

collected in 1983 and later were coded as Confirmed (C). Records collected between 1982 and

1973 were considered Probable (P). Records dated prior to 1972 were coded as Possible (PO). 

These dates were the source of much disagreement among Heritage Program staff and outside

reviewers. They were settled on through group compromise. Many species locality records were

too general to be used (e.g. county records). To be included in the data set, a species locality record

had to contain a PLSS (public land survey system) description or some other location description

specific enough to allow us to assign the record to a hexagon. 
27

Table 4.1 Categories used to qualify species occurrence in hexagons.

CONFIRMED (C) The species is confidently assumed (> 95% certain) or known to occur in the

hexagon.

PREDICTED (P) The species is predicted to occur in the hexagon based on the “fact-pattern”

(i.e. presence of suitable habitat or conditions and historical record and/or

presence in adjacent hexagons[s]); at least 80% certain that the species

occurs in the hexagon.

POSSIBLE (PO) The species possibly or potentially occurs in the hexagon; its estimated

likelihood of occurrence in the hexagon is thought to be between 80% and

10% (or less for extremely rare species where suitable habitat or conditions

may be present).

Table 4.2 Published range maps used to create initial hexagon distributions.

Hall, E.R. 1981. The mammals of North America. 2nd ed. 2 vols. John Wiley and Sons, New York,

NY. 1,181 pp.

Jones, J.O. 1990. Where the birds are. A guide to all 50 states and Canada. William .Morrow &

Co., New York. 400 pp.

Leonard, W.P. et al. 1993. Amphibians of Washington and Oregon. Seattle Audubon Soc. 168 pp.

Loy, W.G. et al. 1976. Atlas of Oregon. University of Oregon Books. 215 pp.

Marshall, David B. et al. 1996. Species at Risk: Sensitive, Threatened, and Endangered Vertebrates

of Oregon. Second Edition. Oregon Dept. Fish and Wildlife, Portland, OR.

Nussbaum, R. A., and E. D. Brodie, Jr. and R. M. Storm. 1983. Amphibians and Reptiles of the

Pacific Northwest. University Press of Idaho. 332 pp.

Storm, R.M. and W.P. Leonard, eds. 1995. Reptiles of Washington and Oregon. Seattle Audubon

Society, Seattle, WA. 176 pp.

Verts, B. J. and L. N. Carraway. 1984. Keys to the Mammals of OR. Oregon State University Press,

Corvallis, OR. 178 pp.

Table 4.3 Existing vertebrate databases used to improve hexagon distributions

Carnegie Museum of Natural History, Mammals Collection. Pittsburgh, PA.

Carnegie Museum of Natural History, Herpetology Department. Pittsburgh, PA.

Agassiz Museum of Comparative Zoology, Department of Herpetology. Harvard University.

Agassiz Museum of Comparative Zoology, Department of Mammalogy. Harvard University.

University of Michigan, Museum of Zoology, Herpetology Department. Ann Arbor, Michigan.

Oregon Natural Heritage Program Element Occurrence database. 

Oregon State University Museum of Comparative Zoology. Corvallis, Oregon. Amphibian and

reptile collections.

Oregon State University Museum of Comparative Zoology, Mammals Collection. Corvallis, OR.

Smithsonian Institute, National Museum of Natural History. Mammal Collections.

Museum of Vertebrate Zoology, University of California at Berkeley. Herpetology Collection.

Museum of Vertebrate Zoology, University of California at Berkeley. Mammals Collection

Washington State University Charles F. Conner Museum. Pullman, Washington.
28

The resulting draft hexagon maps were then sent out for review to 16 experts (Table 4.4). Expert

reviewers were asked to add, delete, verify or modify existing records. Once the hexagon

distribution maps were completed and reviewed by experts, we assigned species to habitats in a

wildlife-by-habitat relationship matrix (WHR). For the OR-GAP Version 1 hexagon maps, the

WHR matrix contained the 30 habitat types described by O’Neil et al. (1995) (Appendix 4.3). The

OR-GAP Version 1 land cover map had 133 primary vegetation types (Kagan and Caicco 1992).

These were grouped into the 30 wildlife habitats (O’Neil et al. 1995). We intersected the reviewed

hexagon distribution maps and the land cover map using the WHR matrix, to develop the Version 1

vertebrate distribution maps. These maps were reviewed by experts in the biology of different

groups (Table 4.4) and edits were made as recommended. The resulting vertebrate distribution

maps were used for the Atlas of Oregon Wildlife (Csuti et al. 1997a).

Table 4.4 Experts reviewing hexagon distributions

Expert Maps reviewed

Brad Bales, ODFW Birds

Kat Beal, USACE Birds

Joseph Beatty, OSU Amphibians and Reptiles

Andrew Blaustein, OSU Amphibians and Reptiles

Frank Conley, Ornithologist Birds

Alan Contreras, Ornithologist, Oregon Birds Winter Birds

Blair Csuti, Oregon Zoo, formerly University of Idaho All groups

Jeff Gilligan, Oregon Birds editor Birds

Ross Keister, USFS Amphibians and Reptiles

C.D. Littlefield, USFWS Birds

Harry Nehls, Ornithologist Birds

S. Kim Nelson, OSU Birds

Joe Pesek, ODFW Birds

Ken Popper, ORNHP Birds

Mark Stern, ORNHP All Groups

Merritt Stegmeier, USACE Birds

Al St. John, Private consultant, reptile expert Amphibians and Reptiles

Douglas R. Stone, EA Engineering Amphibians

Robert Storm, OSU Amphibians and Reptiles

Cynthia Tait, BLM Amphibians

Version 2 Vertebrate Maps

To develop the OR-GAP Version 2 maps, we began by editing the Version 1 hexagon distribution

maps and incorporating recommended changes from the users of the Atlas of Oregon Wildlife

(Csuti et al. 1997a). These resulted in corrections to the ORNHP vertebrate species hexagon
29

database. All newly revised maps were reviewed by Heritage Program staff, while Blair Csuti

reviewed the new reptile, amphibian and mammal maps.

The Version 2 OR-GAP land cover map was produced by Oregon Department of Fish and Wildlife

(Kiilsgaard 1999) and is described in detail in Chapter 2. It contains 65 vegetation cover types we

combined into 31 wildlife habitat types (Figure 4.2). The WHR used to develop the Atlas of

Oregon Wildlife (Csuti et al. 1997a) was modified to reflect the new habitat types (Appendix 4.3

shows the crosswalk between the Version 1 and Version 2 WHR and Land Coverages). 

Major changes included dropping two types, Idaho Fescue and Alkali Grasslands, because they

were not mapped in the Version 2 coverage. Three types were added to better represent wildlife

habitats. One type was added by splitting Douglas-fir Forests, to differentiate Westside Douglas-fir

from Eastside Douglas-fir Mixed Conifer Forests. A second new type was created by separating

Agriculture from Urban, which had been lumped in the Version 1 Wildlife by Habitat Relationships

matrix. Finally, a Rocky Shore category was added to represent islands and rocky shorelines along

the coast, using a geologic layer to separate rocky coastal areas from coastal beaches and dunes. 

We combined the revised hexagon maps and the new GAP vegetative cover map using the modified

Wildlife by Habitat Relationships matrix to create the final distribution maps. Table 4.5 shows the

habitat types used in Version 2, with the area covered in Oregon by each type. The statewide

wildlife habitat map (Figure 4.3) displays distributional information for the 31 habitats used in this

analysis.

Creating updated habitat designations to representing wildlife has been the focus of a recent project

in the Pacific Northwest. This project included an analysis of all the 286 NVCS alliances for

Oregon and Washington, and a lumping of alliances into alliance groups which appear to be

suitable for mapping wildlife habitats. This lumping is similar to the development of alliance

mosaics or plant community groups, resulting in the creation of species-habitat vegetation types. 

These types were primarily identified based on vegetative characteristics. Criteria for the

aggregation of alliances (Johnson and O’Neil 1997) were based on:

· Floristic similarity of the vegetation between types

· Physiognomic and environmental similarity of alliances

· Mosaic-like alliances in a similar environment were lumped together if they were not regional

in extent and occurred in close proximity to each other.

· Alliances that were largely the result of human modification were lumped based on

physiognomy, and to a lesser degree, major environmental zones.

In this new study, using the aggregation criteria list above, the 286 NVCS alliances were aggregated

to 87 landscape level alliance groups (Chappell et al. 1997). OR-GAP hopes to use these 87

landscape level alliance groups in future, finer scale wildlife modeling efforts.

O’Neil and Johnson further condensed these 87 types into 27 upland terrestrial wildlife habitat

types using a cluster analysis procedure (O’Neil et al. 1995) first produced for the Version 1

Oregon wildlife habitat types. These 27 types have been tied to the Version 2 Land Cover Map. 

These new types, their relationship to native vertebrates, and a complete discussion regarding

species composition and environmental characteristics defined by this project will be available in
30

the near future (Johnson et al. 1999). Since it was not available, this newly defined version of the

habitats was not used in this analysis.

Table 4.5. Rank of habitat type by proportional land area for OR-GAP land cover Version 2.

Rank Number Habitat # of Polygons Area (ha)

1 4 Big Sagebrush 4570 4,971,165

2 30 Western Douglas-fir Mixed Conifer 9843 3,764,028

3 22 Ponderosa Pine-While Oak 8632 3,049,766

4 2 Agriculture 5876 2,610,343

5 17 Mountain Big Sagebrush 4050 2,112,817

6 31 Western Juniper 3571 1,610,870

7 8 Douglas-fir Mixed Conifer 4556 1,429,803

8 18 Mountain Hemlock 1999 779,396

9 9 Early Shrub-Tree 5002 742,435

10 14 Mixed Conifer/Deciduous 5535 626,537

11 28 Siskiyou Mixed Conifer 1740 522,636

12 24 Riparian 2710 415,813

13 16 Montane-Lodgepole Pine 1438 391,568

14 20 Perennial Bunchgrass 489 389,920

15 19 Open Water 1830 297,182

16 29 Urban 943 245,475

17 26 Salt-desert Shrub 274 199,703

18 12 Low Sagebrush 446 174,593

19 5 Canyon Shrubland 367 164,087

20 3 Alpine 843 136,279

21 6 Chaparral 765 99,660

22 10 Inland Dunes 295 72,002

23 11 Lava Field 67 63,617

24 15 Mixed Sagebrush 84 61,774

25 21 Playa 79 49,014

26 13 Marshes 366 45,330

27 7 Coastal Dunes 264 38,382

28 23 Quaking Aspen 36 9,041

29 25 Rocky Coast 285 5,529

30 32 Wet Meadows 4 1,177

31 27 Saltmarsh 8 803

Total 25080745
31

Figure 4.2. Riparian distribution for the water shrew, showing upland vs riparian

habitat. The outlined light gray areas show upland types within an 80 m buffer of an

aquatic feature that have been designated as potential riparian habitat.

Riparian Habitats

Because riparian habitats were under-represented in both versions of OR-GAP land cover maps, we

wanted to add riparian habitats to our analysis. A riparian vegetation cover is not available for

Oregon, although OR-GAP is working to create one. For this analysis, riparian habitats were

approximated by using the 1:100,000 stream cover buffered to a total of 80 meters (40 meters on

each side of the center line of the stream).

Riparian obligate species (Table 4.6) were mapped in polygons created by intersecting hexagon

distributions, vegetative cover, the WHR, and the buffered streams layer. Thus, species like the

water shrew are shown in

a much smaller

distribution based on

their affinity for wet areas

in forested habitats,

rather than the entire

forested habitat polygon

(Figure 4.2). 

ORNHP staff created the

list of riparian obligate

species, relying on staff

expertise and information

in the Heritage databases. 

Species for this list were

chosen if they occurred in

riparian habitats in any

part of their range. This

was to assure that species

were mapped in hexagons

in which they were

known to occur. In some

other studies, such as one

done for the Muddy

Creek Watershed in

Oregon (Freemark et al. 1996), lists of riparian obligates were much smaller. For Muddy Creek,

only 24 species, most of which were entirely aquatic, were included. However, in this study, shrub

and forest riparian vegetation was fairly well mapped, and birds and mammals which are not

aquatic, but concentrate in these forests could be mapped in them. For OR-GAP, the riparian and

shrub riparian forests do not appear, probably because of the large minimum mapping unit of the

vegetation coverages. Therefore, the list was fairly inclusive. However, it is quite possible that this

list was a bit too expansive.
32

Table 4.6. Riparian species mapped in potential riparian habitats outlined using an 80 meter buffer

of the 1:100,000 stream cover intersected with the upland vegetation cover.

Common Name Scientific Name

Birds 

Pied-billed Grebe Podilymbus podiceps

Great Blue Heron Ardea herodias

Green Heron Butorides virescens

Black-crowned Night-heron Nycticorax nycticorax

Wood Duck Aix sponsa

Mallard Anas platyrhynchos

Northern Pintail Anas acuta

Blue-winged Teal Anas discors

Cinnamon Teal Anas cyanoptera

Northern Shoveler Anas clypeata

Gadwall Anas strepera

American Wigeon Anas americana

Ring-necked Duck Aythya collaris

Harlequin Duck Histrionicus histrionicus

Hooded Merganser Lophodytes cucullatus

Common Merganser Mergus merganser

Osprey Pandion haliaetus

Bald Eagle Haliaeetus leucocephalus

American Coot Fulica americana

Spotted Sandpiper Actitis macularia

Calliope Hummingbird Stellula calliope

Belted Kingfisher Ceryle alycon

Willow Flycatcher Empidonax trailli

Black Phoebe Sayornis nigricans

Tree Swallow Tachycineta bicolor

Marsh Wren Cistothorus palustris

American Dipper Cinclus mexicanus

Veery Catharus fuscescens

Gray Catbird Dumetella carolinensis

Red-eyed Vireo Vireo olivaceus

Yellow Warbler Dendroica petechia

American Redstart Setophaga ruticilla

Northern Waterthrush Seiurus noveboracensis

Macgillivray`s Warbler Oporonis tolmiei

Common Yellowthroat Geothlypis trichas

Wilson`s Warbler Wilsonia pusilla

Yellow-breasted Chat Icteria virens

Black-headed Grosbeak Pheucticus melanocepalus

Lincoln`s Sparrow Melospiza lincolnii

Red-winged Blackbird Agelius phoeniceus

Common Name Scientific Name

Amphibians 

Black Salamander Aneides flavipunctatus

Dunn`s Salamander Plethodon dunni

Cope`s Giant Salamander Dicamptodon copei

Southern Seep Salamander Rhyacotriton variegatus

Cascade Seep Salamander Rhyacotriton cascadae

Columbia Seep Salamander Rhyacotriton kezeri

Tailed Frog Ascaphus truei

Woodhouse`s Toad Bufo woodhousii

Red-legged Frog Rana aurora

Foothill Yellow-legged Frog Rana boylii

Cascades Frog Rana cascadae

Bullfrog Rana catesbeiana

Northern Leopard Frog Rana pipiens

Oregon Spotted Frog Rana pretiosa

Columbia Spotted Frog Rana luteiventris

Mammals 

Water Shrew Sorex palustris

Little Brown Myotis Myotis lucifigus

Yuma Bat Myotis yumaensis

Nuttall`s Cottontail Sylvilagus nuttallii

American Beaver Castor canadensis

White-footed Vole Phenacomys albipes

Long-tailed Vole Microtus longicaudus

Water Vole Microtus richardsoni

Muskrat Ondatra zibethicus

Western Jumping Mouse Zapus princeps

Pacific Jumping Mouse Zapus triornatus

Nutria Myocastor coypus

Mink Mustela vison

Northern River Otter Lutra canadensis

Reptiles 

Painted Turtle Chrysemys picta

Western Pond Turtle Clemmys marmorata

California Mtn Kingsnake Lampropeltis zonata

Pacific Aquatic Garter Snake Thamnophis couchii
33

Historic Distribution Maps

With the availability of an historical vegetation map, OR-GAP was able to create historical

vertebrate species distribution maps. The historical vegetation map consisted of 38 cover types

combined into 28 of the 31 habitat types used in our Version 2 species coverages (Figure 4.4). Two

of the three missing cover types (Urban and Agriculture) were not found in the historic landscape. 

The only habitat not mapped in the historic coverage was chaparral. Therefore, losses could not be

assessed for this type. ORNHP will distinguish chapparal in the next updates of the historic

vegetation cover.

The current WHR was modified to reflect the different types and changes in habitat use from

present times. A new set of vertebrate hexagon maps were created to reflect estimated historic

distributions. Distributions were estimated for extirpated species and introduced species were

deleted (Bailey 1936, Csuti pers. com., Gabrielson and Jewett 1940, Nussbaum et al. 1983, Verts

and Carraway 1984, Verts and Carraway 1998). For riparian obligates we used a buffered stream

layer created the same way as for the current species distributions. 

Existing and Historic Map Creation by Group

Mammals: Existing ranges were approximated from range maps in Hall and Kelson (1959) and

Verts and Carraway (1984). Hexagon maps were refined with ORNHP data and museum collection

data (Table 4.3). Mammal hexagon distributions were reviewed by Blair Csuti. These distributions

were intersected with the first GAP vegetation cover map and the WHR, resulting in the Version 1

maps. After the maps were published in the Atlas of Oregon Wildlife (Csuti et al. 1997a),

additional comments were received. These, and new publications that had been unavailable for the

first version maps (Maser 1998, Verts and Carraway 1998) were used to update the hexagon

distribution maps at ORNHP. When the final GAP vegetation cover was available, the WHR was

modified to reflect the vegetation types in the new vegetation cover and the Version 2 GAP

distribution maps were generated. Historic hexagon distributions were developed largely from

Bailey (1936), with some input from Verts and Carraway (1998). These historic hexagon

distributions were combined with the historic vegetation map to create historic mammal

distributions.

Birds: Existing breeding bird draft hexagon distribution maps were created from information in the

Atlas of Oregon (Loy et al. 1976). The original maps used for this book were available, and were

more helpful than the very small maps actually printed in the atlas. Information from the ORNHP

databases, museum collections, and USFWS National Wildlife Refuge species lists were also used. 

The hexagon maps were then reviewed by Harry Nehls, whose changes were so extensive that it

would have been more time-efficient to simply have asked Harry to create the hexagon distributions

from scratch. Heritage Program staff provided additional review. After the initial hexagon maps

were created, the bird distribution maps proceeded with the same methods described for mammals.

Historic bird distributions were estimated from Gabrielson and Jewett (1940). 

Reptiles: Draft hexagon current distribution maps were created from the dot maps in Nussbaum et

al. (1983) and improved with ORNHP and museum collection records. These reptile hexagon

maps were reviewed by Blair Csuti, Ross Keister, Joseph Beatty, Andrew Blaustein, and Robert
34

Storm. There was no source for historic reptile distributions, so most of the information used was

from Nussbaum et al. (1983) and museum records.

Amphibians: Draft current amphibian hexagon distribution maps were created from the dot maps in

Nussbaum et al. (1983) and improved with ORNHP and museum collection records. Amphibian

hexagon maps were reviewed by Blair Csuti, Ross Keister, Joseph Beatty, Andrew Blaustein, and

Robert Storm. As with reptiles, a source for historic amphibian distributions was not available, so

information in Nussbaum et al. (1983) and museum records were used.

Existing and Historic Maps for Other Groups of Species

Trees and Butterflies: ORNHP created hexagon distribution maps for all tree species, butterflies

and floaters (freshwater aquatic clams in the family Unionidae) using the methods outlined above. 

Habitat distribution covers were not created for these, due to complications regarding habitat

relationships. However, butterfly maps will be completed by OR-GAP in the near future.

Fish: ORNHP created hexagon distribution maps for all fish species which reproduce in the wild in

Oregon. We utilized information from Lee et al. (1980), selected ODFW district fish biologists, and

a data base from Carl Bond and Doug Markle of Oregon State University (OSU). Al Smith and Hal

Weeks, both with ODFW, provided information on warm water fish and sensitive species,

respectively. The US Fish and Wildlife Service, Bureau of Reclamation, and the Klamath Tribes

contributed information regarding suckers and other sensitive fish in the Klamath Basin. Hexagon

distributions were reviewed by Hiram Lee, Doug Markle, and Carl Bond at OSU. Fish hexagon

distribution received a second, very thorough review by members of the Oregon Chapter of

American Fisheries Society. An analysis of this fish distribution information was recently 

completed at OSU and published (Rathert et al. 1999). Habitat distribution maps were outside the

scope of this project but will be available from ORNHP in the near future, hopefully as part of a

statewide aquatic gap analysis.

Results

Distributions of 450 terrestrial vertebrate species were predicted including 263 birds, 127

mammals, 29 reptiles, and 31 amphibians. A listing of WHRs and complete statewide distribution

maps for each of these 450 species are included in an atlas and CD which includes this report,

published by National GAP. OR-GAP is also developing an internet application to make these

maps available. Figure 4.5 shows an example of the mapped current and historic distribution of

one species, the pronghorn antelope.

Mammals: Maps of predicted current distribution for 116 native and 7 introduced mammalian

species were developed. One hundred twenty maps of predicted historic distribution for native

 species were also developed. Four extirpated species were included in the historic distributions:

bison, gray wolf, grizzly bear and Wyoming ground squirrel. 
35

Figure 4.5. Current (top) and Historic (bottom) distributions of the pronghorn antelope in Oregon.

The top (existing) map includes 7,685,865 ha, while the bottom has 10,618,212 ha (a 38% loss).
36

Current and historic distributions for species that are restricted to rocky sub-habitats are not as

accurate as we would have liked. Talus slopes and other rocky areas are usually too small to have

been included in the land cover (and therefore habitat) maps used. Thus, distributions for species

like the canyon mouse, pika and yellow-bellied marmot are either grossly over or under represented

actual area of occurrence. It was decided to represent these species as present in the larger habitat

types that contain rocky subhabitats.

The distribution maps for the common porcupine overestimate the range in the sagebrush areas of

Eastern Oregon. In these areas the porcupine is restricted to riparian habitats. Because this species

is not restricted to riparian areas in forested habitats, it could not be accurately included with the

other riparian obligates, and there was no other way to restrict this species in sagebrush habitats. 

Bats also are particularly difficult to model, since they require caves and rocky micro-habitats

which have been impossible to map. Since so many of Oregon’s bats are sensitive species, ORGAP and ORNHP has very good distribution information for many bats. The more widespread

species, such as the spotted bat, have been somewhat problematic, and show a much greater decline

than probably really occurred.

Birds: There were 256 native and 7 introduced avian species’ maps of predicted current distribution

and 253 maps of predicted historic distribution for native species developed. There are two

extirpated bird species, the California condor and the merlin, that were not modeled for historic

distribution because their habitat areas were too small to be mapped. Three native species that

were modeled for current distribution were not modeled for historic distribution because, from

available data cattle egret, solitary sandpiper and the black-chinned sparrow appear to be relatively

new additions to the state’s fauna.

As with the mammals, there were a few species, such as the peregrine falcon, white-throated swift,

rock wren, and many coastal birds, for which predicted distributions were difficult to model

accurately. The distribution for these species is not correlated to any particular vegetative type but

to small micro-habitat features. Rather than underestimate distributions, they were modeled as

present in the larger habitat types that contain the habitat features required by these species. For

coastal birds requiring rocky habitats, a geologic layer was used to separate rocky coastal areas

from coastal beaches and dunes.

Reptiles: Maps of predicted current distribution for 28 native and one introduced reptile were

developed. Twenty eight maps of predicted historic distribution for native species were also

developed. No Oregon reptiles are known to have been extirpated statewide since historic times.

Amphibians: Maps of predicted current distribution for 29 native and two introduced amphibians

were developed. Twenty nine maps of predicted historic distribution for native species were

developed. No Oregon amphibians have been extirpated statewide since historic times.
37

Accuracy Assessment

Assessing the accuracy of the predicted vertebrate distributions is subject to many of the same

problems as assessing land cover maps, as well as a host of more serious challenges related to both

the behavioral aspects of species and the logistics of detecting them. These are described further in

the Background section of the GAP Handbook on the national GAP home page. It is, however,

necessary to provide some measure of confidence in the results of the gap analysis for each species

(comparison to stewardship and management status), and to allow users to judge the suitability of

the distribution maps for their own uses. We therefore feel it is important to provide users with a

statement about the accuracy of GAP predicted vertebrate distributions within the limitations of

available resources and practicalities of such an endeavor. We acknowledge that distribution maps

are never finished products but are continually updated as new information is gathered. However,

assessing the accuracy of their current iteration provides useful information about their reliability to

potential users. We especially encourage wildlife biologists and amateur naturalists to treat the

predicted distributions as testable hypotheses and engage the process of validation and iterative

modeling. Our goal was to produce maps that predict distribution of terrestrial vertebrates and

from that, total species richness and species content with an accuracy of 80% or higher. Failure to

achieve this accuracy indicates the need to refine the data sets and models used for predicting

distribution. The methods for validating and assessing the accuracy of the vertebrate distribution

maps are presented below along with the results.

Accuracy Assessment Methods

Because Oregon began this project with an existing hexagon data set which utilized all available

data, there was very little data suitable for use in an accuracy assessment that was not already

incorporated into the distribution maps. Checklists from nine National Wildlife Refuges and one

National Antelope Refuge were compared to our distribution maps for these specific areas (Table

4.7).

Table 4.7. Areas with species lists and available groups used in the accuracy assessment.

Refuge Name Amphibians Reptiles Birds Mammals

Ankeny NWR Ž

Baskett Slough NWR Ž

Cold Springs NWR Ž

Finley NWR Ž Ž Ž Ž

Hart Mtn NAR Ž Ž Ž Ž

Klamath Marsh NWR Ž Ž Ž Ž

Malheur NWR Ž Ž Ž Ž

Umatilla NWR Ž

Upper Klamath NWR Ž Ž Ž Ž
38

Accuracy Assessment Results

The results of the accuracy assessment are summarized in the tables below. Table 4.8 lists the sites

sampled, with the errors of commission and omission. Table 4.9, A-D show the results for birds,

mammals, reptiles and amphibians. Overall, errors of omission for all species had a median of

19.4% (range 10.6-57.7%), and when examined across separate classes, was highest for birds

(Table 4.9.A), suggesting that our habitat coverage was not satisfactory for predicting the presence

of bird species. The highest omission errors occurred for birds on three USFWS National Wildlife

Refuges (Table 4.9.A), and all species omitted in these refuges were present in adjacent habitat. 

These refuges are primarily used as wintering/feeding grounds for migratory game birds. The

species checklists obtained from the refuges were for all species observed on the refuge during the

breeding season. Omitted species may feed on refuge lands, but nest outside the refuge in more

suitable habitat. When these refuges were left out of the analysis the median omission rate dropped

to 16.8% (range 10.6-19.9%), suggesting that the intended use of the refuge/protected area must be

taken into account when using supplied list for evaluation purposes.

Table 4.8. Accuracy assessment for overall species distributions. Overall accuracies are 71.8%

Confirmed, 21.4% Commission and 24.7% Omission. * - Birds only; ** - no amphibians/reptiles;

*** - no mammals.

Test Site Confirmed % Confirmed Commission % Commission Omission % Omission Total

Ankeny NWR* 63 42.3% 47 31.5% 65 43.6% 149

Baskett Slough NWR* 98 64.1% 88 57.5% 55 35.9% 153

Cold Spring NWR* 60 65.9% 95 104.4% 31 34.1% 91

Finley NWR 185 81.5% 31 13.7% 42 18.5% 227

Hart Mtn NWR 204 77.9% 41 15.6% 42 16.0% 262

Klamath NWR (basin) 237 89.4% 63 23.8% 28 10.6% 265

Malheur NWR*** 158 81.0% 95 48.7% 37 19.0% 195

Umatilla NWR** 123 71.9% 28 16.4% 34 19.9% 171

Total/Median 1128 74.9% 488 27.6% 334 19.4% 1513

Overall errors of commission were evaluated for all sites, whether or not they had all four

vertebrate classes present. There was a median of 27.6% (range 13.7 - 104.4%) of commission

errors. When the classes were examined separately, these errors were highest for reptiles and

amphibians (Table 4.9.A-B). The greatest number, not percentage, of commission errors were in

mammals (median 24), and were due to incomplete lists from analysis sites. The commission rates

for sites with list for all four taxa was 15.6% (range 13.7 - 23.8%), and was highest for amphibians

(Table 4.9D). 
39

Table 4.9. (A-D) Comparison of OR-GAP predictive species maps with site species lists for the

four vertebrate classes modeled. The median value is the median of the percentages from each site. 

4.9.A. Birds

Test Site Confirmed % Confirmed Commission % Commission Omission % Omission Total

Ankeny NWR* 63 42.3% 2 1.3% 86 57.7% 149

Baskett Slough NWR* 98 64.1% 14 9.2% 55 35.9% 153

Cold Spring NWR* 60 65.9% 39 42.9% 31 34.1% 91

Finley NWR 115 73.7% 14 9.0% 41 26.3% 156

Hart Mtn NWR 145 80.6% 19 10.6% 31 17.2% 180

Klamath NWR (basin) 150 89.8% 47 28.1% 17 10.2% 167

Malheur NWR*** 146 81.6% 20 11.2% 33 18.4% 179

Umatilla NWR** 82 70.7% 28 24.1% 34 29.3% 116

Total/Median 859 72.2% 183 10.9% 328 27.8% 1191

4.9.B. Mammals

Test Site Confirmed % Confirmed Commission % Commission Omission % Omission Total

Ankeny NWR* 28 100%

Baskett Slough NWR* 54 100%

Cold Spring NWR* 42 100%

Finley NWR 48 98.0% 14 28.6% 1 2.0% 49

Hart Mtn NWR 42 64.6% 20 30.8% 10 15.4% 65

Klamath NWR (basin) 68 88.3% 9 11.7% 9 11.7% 77

Malheur NWR*** 67 100.0%

Umatilla NWR** 41 74.5% 5 9.1% 14 25.5% 55

Total/Median 199 81.4% 239 65.4% 34 13.6% 55

4.9.C. Reptiles

Test Site Confirmed % Confirmed Commission % Commission Omission % Omission Total

Ankeny NWR* 12 100%

Baskett Slough NWR* 13 100%

Cold Spring NWR* 9 100%

Finley NWR 12 100.0% 3 25.0% 12

Hart Mtn NWR 14 93.3% 1 6.7% 1 6.7% 15

Klamath NWR (basin) 13 86.7% 3 20.0% 2 13.3% 15

Malheur NWR*** 9 90.0% 7 70.0% 1 10.0% 10

Umatilla NWR** 11 100%

Total/Median 48 91.7% 59 85% 4 10.0% 52

4.9.D. Amphibians

Test Site Confirmed % Confirmed Commission % Commission Omission % Omission Total

Ankeny NWR* 5 100%

Baskett Slough NWR* 7 100%

Cold Spring NWR* 5 100%

Finley NWR 10 100.0% 0 0.0% 0 0.0% 10

Hart Mtn NWR 3 100.0% 1 33.3% 0 0.0% 3

Klamath NWR (basin) 6 100.0% 4 66.7% 0 0.0% 6

Malheur NWR*** 3 50.0% 1 16.7% 3 50.0% 6

Umatilla NWR** 6 100%

Total/Median 22 100% 29 66.7% 3 0% 25
40

Limitations and Discussion 

The lack of complete species lists for analysis sites makes accurate assessment of errors difficult to

evaluate. The data used for the accuracy assessment were heavily skewed towards birds and

limitation in mapping critical habitat, such as wetlands, may skew the analysis. However,

improving both the land cover maps and the wildlife habitat relationships model, particularly for

birds, should increase the accuracy of the predictions.

Species Richness

Species richness patterns for vertebrates have been the focus of extensive research in Oregon. The

Biodiversity Research Consortium (BRC) used OR-GAP Version 1 hexagon data to show species

richness patterns for all vertebrates, and to compare the variations between mammals, herps and

birds (White et al. 1999). This work included a number of prioritization and richness analysis for

the Oregon biodiversity data set, as well as comparisons to similar data sets from Pennsylvania. It

also included some analysis using a supercomputer to establish an exact set of hexagons in Oregon

to include all biodiversity, which they represented by using all vertebrates, trees and shrubs,

butterflies and freshwater clams. An analysis of environmental correlates for species richness

patterns of freshwater fish from Oregon (Rathert et al. 1999) has been recently published. Keister

et al. (1996) report on similar analysis of biodiversity richness patterns for Idaho using hexagon

data.

Figure 4.3 shows the species richness patterns for all the Version 2 coverages; the four maps

displaying richness patterns for all species, birds, herps, and mammals. We were also able to

develop the first species richness maps of the historic distributions for these vertebrate groups,

which are shown as Figure 4.4. The patterns shown are similar to those shown using a similar

analysis of hexagon distributions. However, some of the high richness areas which resulted from a

hexagon containing a large number of habitats (such as the Steens Mountain/Alvord Desert

hexagon) do not appear as important concentrations in these polygon coverages. Bird species

richness is the greatest in the Klamath Basin of south-central Oregon, herps in the Siskiyou

Mountains of southwestern Oregon, and Mammals in the Klamath Basin, the Siskiyou Mountains,

as well as isolated concentrations in the central East Cascades and Coast Range. As a result,

overall richness concentrations are clearly the highest in the Klamath Basin and the Siskiyou

Mountains.

OR-GAP does not feel that species richness patterns are particularly useful in identifying priority

areas in which to try to protect biodiversity. Richness includes no evaluation of how much species

ranges have declined or how well they are protected. Many species may not be represented in

species rich areas (Csuti et al. 1997b). Also, species richness patterns are often driven by

concentrations of more common species, or migratory species and may not indicate concentrations

of species needing conservation. In spite of this, the three areas of greatest species richness, the

Klamath Basin, Siskiyou Mountains, and the Malheur Basin have long been the focus of

conservation activities in Oregon and have been identified in other analyses as critical areas for

conservation work (OBP 1998). OR-GAP has developed species richness maps for a subset of

species which are not well protected or have experienced substantial declines. These are discussed

in Chapter 6.
41

CHAPTER 5: LAND STEWARDSHIP

Introduction

To fulfill the analytical mission of GAP, it is necessary to compare the mapped distribution of

elements of biodiversity with their representation in different categories of land ownership and

management. As will be explained in the Analysis section, these comparisons do not measure

viability, but are a start to assessing the likelihood of future threat to a biotic element through

habitat conversion—the primary cause of biodiversity decline. We use the term “stewardship” in

place of “ownership” in recognition that legal ownership does not necessarily equate to the entity

charged with management of the resource, and that the mix of ownership and managing entities is a

complex and rapidly changing condition not suitably mapped by GAP. At the same time, it is

necessary to distinguish between stewardship and management status in that a single category of

land stewardship such as a national forest may contain several degrees of management for

biodiversity.

The purpose of comparing biotic distribution with stewardship is to provide a method by which

land stewards can assess their relative amount of responsibility for the management of a species or

plant community, and identify other stewards sharing that responsibility. This information can

reveal opportunities for cooperative management, which directly supports the primary mission of

GAP to provide objective, scientific information to decision makers and managers to make

informed decisions regarding biodiversity. It also is likely that a steward that has previously borne

the major responsibility for managing a species may, through such analyses, identify a more

equitable distribution of that responsibility. We emphasize, however, that GAP only identifies

private land as a homogenous category and does not differentiate individual tracts or owners, unless

the information was provided voluntarily in recognition of a long-term commitment to biodiversity

maintenance.

After comparing distribution with stewardship, it is also necessary to compare biotic occurrence to

categories of management status. The purpose of this comparison is to identify the need for change

in management status for the distribution of individual elements or areas containing high degrees of

diversity. Such changes can be accomplished in many ways that do not affect the stewardship

status. While it will eventually be desirable to identify specific management practices for each

tract, and their influence on each element, GAP currently uses a scale of 1 to 4 to denote relative

degree of maintenance of biodiversity for each tract. A status of “1” denotes the highest, most

permanent level of maintenance, and “4” represents the lowest level of biodiversity management, or

unknown status. This is a highly subjective area, and we recognize a variety of limitations in our

approach, although we maintain certain principles in assigning the status level. Our first principle

is that land ownership is not the primary determinant in assigning status. The second principle is

that while data are imperfect, and all land is subject to changes in ownership and management, we

can use the intent of a land steward as evidenced by legal and institutional factors to assign status. 

In other words, if a land steward implements a program backed by legal and institutional

arrangements that are intended for permanent biodiversity maintenance, it is taken into

consideration when assigning status.
42

The characteristics used to determine status are as follows:

 • Permanence of protection from conversion of natural land cover to unnatural (humaninduced barren, exotic-dominated, arrested succession).

 • Relative amount of the tract managed for natural cover.

 • Inclusiveness of the management, i.e. single feature or species versus all biota.

 • Type of management and degree that it is mandated through legal and institutional

arrangements.

The four status categories can generally be defined as follows (after Scott et al. 1993, Edwards et

al. 1995, Crist et al. 1995):

Status 1: An area having permanent protection from conversion of natural land cover and a

mandated management plan in operation to maintain a natural state within which disturbance

events (of natural type, frequency, and intensity) are allowed to proceed without interference or are

mimicked through management.

Status 2: An area having permanent protection from conversion of natural land cover and a

mandated management plan in operation to maintain a primarily natural state, but which may

receive use or management practices that degrade the quality of existing natural communities.

Status 3: An area having permanent protection from conversion of natural land cover for the

majority of the area, but subject to extractive uses of either a broad, low-intensity type or localized

intense type. It also confers protection to federally listed endangered and threatened species

throughout the area.

Status 4: Lack of irrevocable easement or mandate to prevent conversion of natural habitat types to

anthropogenic habitat types. Allows for intensive use throughout the tract. Also includes those

tracts for which the existence of such restrictions or sufficient information to establish a higher

status is unknown.

Mapping Standards and Methods

Stewardship Mapping

The land stewardship and management status layer is a key component developed by OR-GAP. 

Like many of the other covers, this has been an iterative process. The cover used in this analysis is

Version 2 (Figure 5.1), which was based on, but developed slightly differently from OR-GAP

Version 1. In spite of the fact that Oregon is more than 50% publicly owned, there has never been a

comprehensive land ownership coverage available for the state. 

The OR-GAP Version 1 coverage was developed by Blair Csuti and the Oregon Natural Heritage

Program. The 1:100,000 Bureau of Land Management (BLM) land ownership coverage served as

the base cover. Boundaries of The Nature Conservancy (TNC) preserves, Research Natural Areas

(RNAs), Wilderness Areas, National Wildlife Refuges, National Parks and Monuments, and BLM

Areas of Critical Environmental Concern (ACECs) were transcribed from the original documents at
45

the ORNHP managed area files onto BLM 1:100,000 paper base maps. The base data for these

varied from 1:24,000 to 1:100,000. They were labeled consistently, sent to Idaho Department of

Water Resources and hand digitized under contract with National GAP. The Oregon Department of

Fish and Wildlife independently digitized their Wildlife Management Areas to add to the coverage.

Version 2 was developed by OR-GAP using the 1:100,000 land ownership coverage provided by

the Oregon State Service Center for GIS (SSCGIS) as the base coverage. The 1993 version of this

cover used for OR-GAP was developed by the Bureau of Land Management. Protected areas were

obtained from the BLM, the U.S. Forest Service (USFS) and all other agencies, at the finest scale

possible. Most USFS protected areas were obtained in digital format at 1:24,000 (although most

lacked metadata). Most BLM data were incorporated at 1:100,000. Fine scale (1:24,000) data for

Fish and Wildlife Refuges were obtained from the U.S. Fish and Wildlife Service, while similar

scale information on National Parks was provided by the National Park Service.

For the 1998 Oregon Natural Heritage Plan (ORNHP 1998), ORNHP developed a 1:24,000 cover

and cross reference for all formerly proposed natural areas in the state, including all RNAs, ACECs,

state Natural Heritage Conservation Areas (NHCAs), and TNC preserves. This coverage is

continually updated and published each calendar year (with OR-GAP version 2 including the 1999

update).

Additional data layers were obtained from BLM and Forest Service interagency offices. These

included some obtained from the Columbia River Basin Assessment Project in Walla Walla, which

provided digital coverage showing all the BLM Wilderness Study Areas (WSAs) and eastern

Oregon Wild and Scenic Rivers. Others were from their Regional Ecosystem Office in Portland,

particularly the Late Successional Reserves (LSRs) established by Forest Ecosystem Management

Assessment Team (FEMAT 1993).

Management Status Categorization

The Version 1 Management categorization was developed by Blair Csuti using standard GAP

methodology. Version 1 did not include either the LSRs or the WSAs, so was more typical of GAP

categorizations. RNAs, ACECs, TNC Preserves, NHCAs, Wilderness Areas, and the undeveloped

portions of National Parks were assigned Category 1. Wildlife Refuges, State Wildlife

Management Areas, State Parks, and local parks were assigned Category 2. Other public lands

were assigned Category 3, and private lands were assigned Category 4.

The Defenders of Wildlife, OR-GAP, ORNHP and the Oregon Field Office of TNC were also

involved in the update of the Version 1 Management cover for the Oregon Biodiversity Project

(OBP 1998). For the OBP, each of the protected areas in the Version 1 cover was assigned a

category of 1-10, with 10 representing the best protection, and 1 the least. A detailed description of

the process of designating these 1-10 categories, and their definitions are contained in the final

report, Oregon’s Living Landscape (OBP 1998). For their analysis, OBP used categories 8-10 to

represent the network of conservation lands. The primary difference from Version 1 was that each

protected area was individually assessed. 
46

Viability and defensibility of sites were important considerations in management rankings. As a

result, nature reserves managed by The Nature Conservancy ranged from 7-10, as did Research

Natural Areas and Wilderness Areas. Small nature reserves designed to protect a local population

of an endangered plant species might be rated lower than a larger reserve managed for all

biodiversity. State Parks also varied widely, some providing important biodiversity protection and

ranked as an 8 or 9, while others largely developed for recreation, ranked as a 5 or 6. Using size

and quality of the areas make the designations somewhat different from the 1-4 gap designations. 

The OBP designations match the gap designations for public lands pretty closely. Lands

designated as 9 or 10 generally correspond to Gap 1 sites, 7 and 8 usually correspond to Gap 2

sites, and 4-6 mostly match Gap 3 sites. OBP characterized LSRs as 9, so they were part of the

protected area network. BLM WSAs were 5 or 6, similar to general BLM lands, and were not

counted in OBP’s network of protected areas.

In OR-GAP version 2, each site in the network of conservation lands was also individually ranked,

using the 1-4 standard GAP ranking system. Figure 5.2 shows the map of Oregon with the ORGAP classifications displayed. The OBP categorization and information, along with any other data

we had, were used to update the sites’ classification. Sites were designated by ORNHP staff, and

reviewed by the public lands coordinator of The Nature Conservancy. The primary difference

between the OR-GAP Version 2 cover was the inclusion of the BLM WSAs and the USFS and

BLM LSRs. These two categories of public stewardship designations impact large areas of forest

lands in western Oregon, and rangelands in eastern Oregon. Their designations clearly impact

biodiversity, but are more difficult to categorize, especially using a 1-4 scale. OR-GAP finally

chose to include these areas as Category 2, although they do seem intermediate between general

public lands and protected areas. In both the rangelands of eastern Oregon, and the forests of the

Cascades and Coast Range, these designations more than triple the overall size of Oregon’s

network of protected areas. Table 5.1 below shows the major groups of land in Oregon, and the

GAP status they were assigned. Appendix 5.1 has the complete list of managed areas in Oregon,

with their GAP and OBP categorization. 

Table 5.1. Management status assigned to land stewardship categories in Oregon.

Status 1 Status 2 Status 3 Status 4

USFS Wilderness Area BLM Wilderness Study Area (WSA) BLM matrix lands Private

Lands

NPS National Parks Late Successional Old Growth USFS matrix lands 

NPS National Monuments Reserves (LSRs) State Forestry lands

Nature Conservancy Preserves BLM ACEC (Areas of Critical DSL lands

Research Natural Areas Environmental Concern) USFS National Grasslands

State Natural Heritage USFS Special Interest Areas USFS National Recreation Areas

 Conservation Areas USFWS Wildlife Refuges 

State Parks
47

Results 

Public lands account for over 56% of Oregon, of which 52% is federally owned or managed, and

3% managed by the State of Oregon. Table 5.2 provides a summary of the ownership patterns, and

how they vary by GAP Status in Oregon. While including only 52% of the land base in Oregon,

federal lands account for 94.9% of the Status 1 and 2 lands. Private lands (1%), state lands (1.5%),

and water (2.4%) account for the rest of the protected areas. Undoubtedly, federal lands have been

the source of most protection in Oregon and will likely continue to be critical.

Table 5.2 Ownership and Gap Status in Oregon (hectares).

Owner Status 1 Status 2 Status 3 Status 4 Total Percent

City 0 2,227 0 0 2,227 0.01%

County 0 0 1,233 0 1,233 0.00%

Exempt 317 638 29,956 217,093 248,004 0.98%

Federal 1,206,293 2,912,591 8,857,243 7 12,976,135 51.49%

Private 44,366 249 11,218 10,882,251 10,938,084 43.40%

State 2,215 65,233 185,464 396,949 649,862 2.58%

Water 43,836 58,818 235,408 48,655 386,716 1.53%

Total 1,297,027 3,039,756 9,320,522 11,544,955 25,202,260

Percent 5.1% 12.1% 37.0% 45.8%

It is equally important to evaluate land ownership and stewardship on an ecoregional basis, so that

land stewards can see to what degree their lands generally contribute to biodiversity maintenance. 

Public lands are distributed throughout the state, although two ecoregions, the Willamette Valley

and the Columbia Basin, are unique due to their very high proportion of private lands. Table 5.3

shows the ownership distribution by ecoregion, which identifies the varied pattern of ownership by

ecoregion. These differences create major variations in conservation strategies for the different

ecoregions. For example, the Basin and Range ecoregion is over 75% federally owned, with over

70% managed by the Bureau of Land Management, mostly in two districts (Lakeview and Burns). 

Similarly, the West Cascades ecoregion is about 73% federally owned, with 63% managed by the

U.S. Forest Service as part of four national forests (Mount Hood, Willamette, Umpqua and Rogue

River). Conservation or stewardship land patterns in these ecoregions are a result of decisions

made by these agencies. On the other hand, in the Willamette Valley and the Columbia Basin

ecoregions, the majority of the lands (94% and 90% respectively) are in private ownership. In these

ecoregions, there is only limited potential for protected areas on public lands, and therefore

conservation strategies must involve private landowner cooperation and participation. 

Appendix 5.2 is an analysis of the habitat types in Oregon, including a comparison of the current

and historic distribution of each of the types. A detailed discussion of this comparison is included

in Chapter 6 (page 52) related to species losses. Appendix 5.2 includes information on changes in

the distribution and abundance of each habitat type, as well as how much of each type is currently

represented in the network of protected areas.
48

Table 5.3. Ownership by ecoregion and percentages in Oregon

Owner

Basin & Range

hectares percentage

Blue Mountains

hectares percentage

Coast Range

hectares percentage

Bureau of Land Management 2642914 70.30% 350295 8.14% 325225 13.25%

Bureau of Reclamation 0 0.00% 0 0.00% 0 0.00%

Bonneville Power Administration 0 0.00% 0 0.00% 0 0.00%

Army Corps of Engineers 0 0.00% 17 0.00% 24 0.00%

Department of Defense 0 0.00% 17 0.00% 1517 0.06%

National Park Service 0 0.00% 0 0.00% 41 0.00%

US Forest Service 14005 0.37% 2292551 53.26% 355000 14.46%

US Fish and Wildlife Service 172388 4.59% 0 0.00% 90 0.00%

Federal lands 2829307 75.26% 2642881 61.40% 681897 27.77%

State lands 105238 2.80% 24493 0.57% 258136 10.51%

Tribal lands 7714 0.21% 5748 0.13% 1531 0.06%

County lands 0 0.00% 0 0.00% 860 0.04%

City lands 0 0.00% 0 0.00% 1819 0.07%

Private 734957 19.55% 1624429 37.74% 1499212 61.07%

Water 82347 2.19% 7124 0.17% 11651 0.47%

Total 3759563 100.00% 4304674 100.00% 2455105 100.00%

Owner

Columbia Basin

hectares percentage

East Cascades

hectares percentage

Klamath Mountains

hectares percentage

Bureau of Land Management 90989 5.29% 123581 4.65% 366493 23.44%

Bureau of Reclamation 0 0.00% 31 0.00% 0 0.00%

Bonneville Power Administration 0 0.00% 0 0.00% 0 0.00%

Army Corps of Engineers 491 0.03% 0 0.00% 1367 0.09%

Department of Defense 24119 1.40% 0 0.00% 0 0.00%

National Park Service 0 0.00% 1474 0.06% 185 0.01%

US Forest Service 22 0.00% 1315635 49.48% 427214 27.32%

US Fish and Wildlife Service 3567 0.21% 13252 0.50% 0 0.00%

Federal lands 119187 6.92% 1453974 54.68% 795258 50.85%

State lands 46482 2.70% 19796 0.74% 11462 0.73%

Tribal lands 3391 0.20% 95056 3.57% 0 0.00%

County lands 4 0.00% 342 0.01% 0 0.00%

City lands 0 0.00% 0 0.00% 0 0.00%

Private 1549881 90.03% 1035254 38.93% 754233 48.23%

Water 2528 0.15% 54764 2.06% 2886 0.18%

Total 1721473 100.00% 2659186 100.00% 1563839 100.00%
49

Table 5.3 (continued). Ownership by ecoregion and percentages in Oregon.

Owner

Lava Plains

hectares percentage

Owyhee Uplands

hectares percentage

Pacific Ocean

hectares percentage

Bureau of Land Management 564545 29.13% 1709419 70.84% 2 0.04%

Bureau of Reclamation 0 0.00% 10980 0.46% 0 0.00%

Bonneville Power Administration 0 0.00% 0 0.00% 0 0.00%

Army Corps of Engineers 0 0.00% 0 0.00% 0 0.00%

Department of Defense 0 0.00% 0 0.00% 80 1.48%

National Park Service 4237 0.22% 0 0.00% 0 0.00%

US Forest Service 85944 4.43% 0 0.00% 135 2.50%

US Fish and Wildlife Service 107 0.01% 0 0.00% 40 0.73%

Federal lands 654833 33.79% 1720399 71.30% 257 4.75%

State lands 32760 1.69% 129502 5.37% 676 12.49%

Tribal lands 49794 2.57% 0 0.00% 0 0.00%

County lands 0 0.00% 0 0.00% 0 0.00%

City lands 0 0.00% 0 0.00% 0 0.00%

Private 1195042 61.66% 548221 22.72% 2361 43.63%

Water 5627 0.29% 14780 0.61% 2117 39.13%

Total 1938055 100.00% 2412902 100.00% 5411 100.00%

Owner

West Cascades

hectares percentage

Willamette Valley

hectares percentage

Total Statewide

hectares percentage

Bureau of Land Management 205931 7.12% 35605 2.59% 6415000 25.57%

Bureau of Reclamation 0 0.00% 0 0.00% 11011 0.04%

Bonneville Power Administration 0 0.00% 165 0.01% 165 0.00%

Army Corps of Engineers 7597 0.26% 6850 0.50% 16345 0.07%

Department of Defense 0 0.00% 0 0.00% 25734 0.10%

National Park Service 66032 2.28% 0 0.00% 71969 0.29%

US Forest Service 1837739 63.58% 196 0.01% 6328442 25.23%

US Fish and Wildlife Service 138 0.00% 4435 0.32% 194016 0.77%

Federal lands 2117437 73.26% 47251 3.44% 13062682 52.07%

State lands 8374 0.29% 18689 1.36% 655607 2.61%

Tribal lands 53729 1.86% 0 0.00% 216964 0.86%

County lands 409 0.01% 1000 0.07% 2615 0.01%

City lands 21 0.00% 408 0.03% 2249 0.01%

Private 691042 23.91% 1296639 94.35% 10931270 43.58%

Water 19355 0.67% 10277 0.75% 213455 0.85%

Total 2890368 100.00% 1374264 100.00% 25084841 100.00%
50

Discussion

Land ownership and protection patterns are critical to this analysis - and to protection of

biodiversity in Oregon. The state has a long history of endangered species controversy, and the

Endangered Species Act continues to be the major force driving conservation activities of public

agencies. Recent listings of anadromous fish by the National Marine Fisheries Service, and listings

of the lynx and bull trout by the US Fish and Wildlife Service have resulted in endangered species

impacts occurring throughout the state. 

Figure 5.3 contains two maps showing endangered and sensitive species locations in Oregon. The

top map has the distribution of state and federally listed threatened and endangered species in

Oregon, from ORNHP’s element occurrence database. Fish occurrences are shown as lines, while

plant and animal occurrences are shown as points. The distribution of these points has driven the

distribution of protected areas in western Oregon. However, they do not do a good job of

representing overall species patterns, or other species of concern. In western Oregon, the

concentration of endangered species match the pattern of the LSRs, since spotted owls were driving

the creation of these areas. 

However, while the network of protected areas matches the distribution of concentrations of listed

endangered species, it does not adequately represent the distribution of other species of concern. 

The bottom map in Figure 5.3 shows the locations of all the rare, threatened and endangered

species currently tracked by ORNHP. A number of these species, such as the sage grouse and the

Washington ground squirrel may soon be proposed for federal listing in Oregon. Neither of the

maps in Figure 5.3 adequately represents the distribution of listed or sensitive fish in Oregon, since

that information has not yet been centralized. However, a comparison of the two coverages shows

how poorly the distribution of both currently listed endangered species and the current network of

protected areas match the distribution of rare species in Oregon. It also shows that the Endangered

Species Act, in spite of being the most effective tool of conservation in the United States, is not a

reliable way to protect diversity. 

Oregon is fortunate to have a large number of LSRs and BLM WSAs, many of which are very large. 

Unfortunately, they tend to bias the overall protected area network. LSRs in Oregon account for

2,104,501 hectares, although some LSRs include established Wilderness, RNAs or other protected

sites. If these are excluded, non-wilderness LSRs include 1,499,697 hectares of general BLM and

USFS matrix lands. The BLM WSAs add another 1,149,924 hectares. The overall network of

protected areas in Oregon (GAP 1 and 2 lands), including these LSRs and WSAs, adds up to

4,336,782 hectares. This means that together, WSAs (26.5%), and non-wilderness LSRs (34.6% of

the total protected area network) account for over 60% of GAP 1 and 2 lands. While the LSRs and

BLM WSAs do not provide permanent protection, they certainly are more protected than GAP

Category 3, general public lands, and must be placed in Category 2. This is a good case for

considering some new system of GAP stewardship categorization, which includes at least one more

category. In Chapter 7, we examine the impact that LSRs and BLM WSAs have on how well

habitats and vertebrate species groups are protected in Oregon.

In spite of this huge network of protected areas in Oregon, including LSRs, USFS wlderness areas,

BLM WSAs, and a major private and public network of preserves and natural areas, only 17.2% of

Oregon is managed for wildlife or biodiversity. As can be seen in the final chapter, this large
51

protected area network does not do a very good job of including either the current or historic

distribution of Oregon’s habitats and wildlife.

Limitations

This map and coverage is a compilation of ownership maps provided by a variety of sources who

are individually responsible for their accuracy. It was created for the purpose of conducting the

analyses described in this report and may not be suitable for locating boundaries on the ground. It

is certainly not suitable for determining precise area measurements of individual tracts, given the

scale of 1:100,000 for the baseline data. Some of the data for protected areas in the Oregon cover

was mapped at 1:24,000, and can provide good estimates of the locations of these sites, although all

the boundaries are limited by the coarseness of the scale. The baseline data had some significant

problems, particularly in southwestern Oregon, where there is a patchwork mosaic of public and

private ownerships. These patchwork or checkerboard lands, were digitized separately for the

ownership cover and the stewardship coverage, and the linework did not match. OR-GAP spent

considerable time rectifying these errors, but some slivers and mis-matched polygons still remain.

While OR-GAP and ORNHP will continually update the Stewardship and Management Cover, for

this report and analysis, a single edition had to be used. The Version 2 cover (1999 edition) was

completed in March of 1999. A number of land ownership and designation changes have occurred

since that time. An updated coverage will be produced each year and will be available at both the

National GAP and OR-GAP FTP sites. However, it is important to keep in mind that the analysis

contained in this report are based on the Version 2 stewardship cover. The OR-GAP ownership

designations currently reflect surface feature only, and do not consider either mineral or water

rights, which can be critical to wildlife maintenance. In addition, many of the smaller designated

areas have varied land uses in a single designated area. For example, a number of US Fish and

Wildlife Refuges have areas which are farmed to increase waterfowl production. While these areas

do not generally provide the same protection for all biodiversity, they were not segregated out in

this coverage. Similarly, the US Forest Service and BLM have different management prescriptions

for some of the Late Successional Reserves which were not shown in the categorizations. 

Oregon is now involved in a statewide effort to restore watersheds and salmon stocks throughout

the state. In an effort to improve water quality, recover listed and declining salmon, and to restore

Oregon’s rivers, Governor Kitzhaber developed a Watersheds and Salmon Restoration Plan. This

involves the creation of watershed councils throughout the state, and all state agency actions must

support the plan, which now includes significant funding to both restore and acquire lands and

water to benefit fish and wildlife habitat. Many of the ongoing or proposed restoration efforts are

occurring on private lands or on the un-designated public lands. While these sites and projects may

provide important protection for fish and wildlife, they are not available in a digital form and could

not be included in this stewardship coverage. 

However, in spite of all these limitations, the stewardship cover and designations are the only

statewide representation of protected lands in Oregon and do an excellent job of representing areas

currently set aside for biodiversity protection.
52

CHAPTER 6: ANALYSIS BASED ON STEWARDSHIP AND MANAGEMENT STATUS

Introduction

As described in the general introduction to this report (see pg. 1), the primary objective of GAP is

to provide information on the distribution and status of several elements of biological diversity. 

This is accomplished by first producing: maps of land cover (see pg. 16), predicted distributions for

selected animal species (see pg. 46), and land stewardship and management status (see pg. 63). 

Intersecting the land stewardship and management map with the distribution of the elements results

in tables that summarize the area and percent of total mapped distribution of each element in

different land stewardship and management categories. The data are provided in a format that

allows users to carry out inquires about the representation of each element in different land

stewardship and management categories as appropriate to their own management objectives. This

forms the basis of GAP’s mission to provide land owners and managers with the information

necessary to conduct informed policy development, planning, and management for biodiversity

maintenance.

Although GAP "seeks to identify habitat types and species not adequately represented in the current

network of biodiversity management areas" (GAP Handbook, Preface, Version 1, pg. I), it is

unrealistic to create a standard definition of "adequate representation" for either land cover types or

individual species (Noss et al. 1995). A practical solution to this problem is to report both

percentages and absolute area of each element type in biodiversity management areas (as described

above) and allow the user to determine which types are adequately represented in natural areas. 

Opinions will differ among users, but this is an issue of policy, not scientific analysis. We have

however provided a breakdown along three levels of representation (10%, 20%, and 50%) that have

been recommended in the literature (Noss and Cooperider 1994; Noss 1991; Odum and Odum

1972; Specht, Roe, and Boughlon 1974; Ride 1975; Miller 1994). 

The network of Conservation Data Centers (CDCs) and Natural Heritage Programs (NHPs)

established cooperatively by The Nature Conservancy and various state agencies maintains detailed

databases on the locations of rare elements of biodiversity. GAP uses these data to develop

predicted distributions of potentially suitable habitat for these elements (see pg. 16), which may be

valuable for identifying research needs and preliminary considerations for restoration or

reintroduction. Conservation of such elements, however, is best accomplished through the finefilter approach of the above organizations. It is not the role of GAP to duplicate or disseminate

Heritage Program or CDC Element Occurrence Records. Users interested in more specific

information about the location, status, and ecology of populations of such species are directed to

their state Heritage Program or CDC. 

Currently, land cover types and terrestrial vertebrates are the primary focus of GAP's mapping

efforts although other components of biodiversity, such as aquatic organisms or selected groups of

invertebrates, may be incorporated into GAP distributional data sets. Where appropriate, GAP data

may also be analyzed to identify the location of a set of areas in which most or all land cover types

or species are predicted to be represented. The use of “complementarity” analysis, that is, an

approach that additively identifies a selection of locations that may represent biodiversity rather

than “hot spots of species richness” may prove most effective for guiding biodiversity maintenance

efforts. Several quantitative techniques have been developed recently that facilitate this process
53

Protection Category Land Cover

0%

5%

10%

15%

20%

25%

30%

35%

Cat. 1 (<1%) Cat 2 (1-10%) Cat. 3 (10-20%) Cat 4 (20-50%) Cat 5 (>50%)

Protection Class

Percent Protected

11

15

16

17

7

8

10 10

18

12

Figure 6.1. Distribution of land cover classes in protection categories from 1-5. Light

gray lines include all protected areas, while dark, solid lines exclude LSRs.

(see Pressey et al. 1993, Williams et al. 1996, Csuti et al. 1997b, for details). These areas become

candidates for field validation and may be incorporated into a system of areas managed for the

long-term maintenance of biological diversity.

Land Cover Analysis

The table found in Appendix 4.1 provides the area in hectares of each types’ mapped distribution

by management status, and Appendix 4.2 in land stewardship designations. For example Oregon

white oak forest type has 311 ha in US Fish and Wildlife Service (USFWS) lands that are ranked

Status 2, which represents 0.66% of it’s total distribution. Distribution of protected areas (GAP 1

& 2 lands) occur throughout a majority of the state with a mix of 165 BLM ACEC/RNA’s, 76 BLM

WSA, 35 USFS Wilderness

Areas, 3 NPS units, 18 USFWS

Wildlife Refuges, 158 USFS

RNAs and PRNAs, and other

minor special management areas

in various administration units. 

Three ecoregions in Oregon have

limited protection (Appendix 3.1,

Figure 5.2), the Willamette

Valley (WV), the Columbia

Basin (CB) and the East

Cascades (EC). Ownership in

both the WV and the CB is

primarily private (94% and 90%

respectively), with protected

lands are managed by State

Parks, USFWS, the Department

of Defense (DOD) and The

Nature Conservancy (TNC). 

Ownership pattern in the EC is

primarily USFS (49%) and

private (39%) with protected areas managed primarily by BLM (ACEC/RNA) and TNC. 

OR-GAP has identified five categories (or protection classes) of land cover types, based on their

overall conservation concern. These range from Category 1 which has less than 1% of habitats

included in the network of conservation lands to Category 5 with over 50% of their distribution are

in the network on conservation lands. Figure 6.1 shows the distribution of cover types in these

categories.

Nine non-anthropogenic land cover types have < 1% of their total area protected in status 1 and 2

lands, and include five types of conservation concern (Appendix 6.7). None of the nine land cover

types are widespread (> 100,000 ha) in Oregon. There are five types in Category 1 that have high

wildlife value and substantial threats due to habitat loss and habitat conversion: hawthorn-willow

shrubland, palustrine wetlands, wet meadows, modified grassland (which mostly represent native
54

Idaho fescue bunchgrass habitats), and Oregon white oak forest. Historically, Oregon white oak

covered over ten times the area in the Willamette Valley that it now covers and remnants are

limited to patches in private ownership. Immediate threats include expansion of urban growth

boundaries in the Willamette Valley and conversion to agriculture. Both coastal strand and

hawthorn-willow shrubland land cover types are conservation targets identified by state

organizations and currently have limited protection in Oregon. 

When LSR lands are removed from status 2 designation an additional three land cover types are

included in Category 1. Both palustrine forest and south coast mixed conifer forests have limited

distribution (< 12,000 ha) in Oregon, offer high wildlife habitat value, and are a high priority for

conservation. Ponderosa-lodgepole pine on pumice has moderate distribution (> 500,000 ha) and

probably has a lower priority for conservation effort.

Fifteen naturally occurring land cover types are in Category 2, with 1-10% of their total distribution

in protected areas. These occur primarily in the East Cascades and Blue Mountains ecoregions. 

Four ponderosa pine types comprise over 2.5 million ha with the majority described as ponderosa

pine forest and woodland (1.9 million ha). All ponderosa pine types in Oregon require a moderate

conservation effort. The structure of ponderosa types have changed dramatically since the 1800s

due to alterations in natural fire regimes, timber harvest, and cattle grazing (OBP 1998). 

Ponderosa types are predominantly managed by the USFS and because ponderosa occurs at lower

elevations, little is protected by wilderness designation. Sagebrush steppe is widely distributed in

Oregon (2,113,257 ha), and while not currently a conservation priority, the potential federal listing

of the sage grouse may focus future efforts in this land cover type. 

Four additional land cover types are included in protection Category 2 when LSR lands are

excluded (Figure 6.1). Both Douglas-fir dominant-Mixed Conifer Forests (1,032,916 ha) and

Douglas-fir-Western Hemlock-Western Red Cedar Forest (2,678,388 ha) have 86% of their current

protected extent in LSR lands, and are considered critical habitat for the northern spotted owl and

marbled murrelet (coastal areas only). The Siskiyou Mountains Mixed Deciduous Forest has 70%

of its current protected extent in LSR lands and is important habitat for two endemic salamander

species (see Amphibians and Reptiles results).

Seventeen land cover types have more than 10% and less than 50% of their total extent in Status 1

and 2 protection (Categories 3 and 4). All but five (excluding open water) have > 100,000 ha in

total distribution and are considered adequately protected. Open Water was not satisfactorily

described for this analysis and will be covered in more detail by future efforts including Aquatic

Gap Analysis (P. Crist, personal communication) and TNC’s ecoregional planning efforts. Exposed

tidal flats may also be better represented in a conservation planning effort focusing exclusively on

aquatic systems. Coastal Lodgepole Forests are under-mapped in Oregon (225 ha, 30% protected)

and protection for the type is likely higher because the largest contiguous stands occur in federally

protected dune areas. As in previous land status categories, the exclusion of LSR lands has an

effect on the protection of the included land cover types. Without LSRs, six land cover types

moved from the > 50% category to the 10-50% categories (Categories 3 and 4) and five dropped

from one of the 10-50% categories to the 1-10% protection category.

Eighteen land cover types have most (> 50%) of their total distribution protect in status 1 and 2

lands. Fourteen of these occur primarily on USFS lands at higher elevations and include all the
55

Protection Category

(birds)

0%

10%

20%

30%

40%

50%

60%

<1% 1-10% 10-20% 20-50% >50%

Protection Class

Percent Protected

5

44

114

92

7 8

131

89

31

5

Figure 6.2. Distribution of 263 bird species in five categories based on protection class. 

Light gray lines include LSRs and dark, solid lines exclude the LSRs as protected areas.

sub-alpine forest and grassland types. Only the whitebark-lodgepole pine montane forest has 100%

of its distribution protected. Four types are considered conservation targets in Oregon and have <

70,000 ha of total distribution. Coastal dunes (16,644 ha, 57% protected) are likely underestimated

for protection since state laws prohibit development of any dune area (although these are very

threatened by exotic species). The Douglas-fir-Port Orford Cedar Forest (67,434 ha, 81%

protected) is also a coastal type. However, its extent is not covered by state laws but protected

primarily by USFS wilderness areas and LSRs. The final land cover type of conservation concern

is the mountain mahogany shrubland (512 ha, 80% protected) which is mapped exclusively in the

Steens Mountains of southeast Oregon. Six land cover types drop from the > 50% protected

category when LSR lands are excluded from protected status (Figure 6.1). All but one of the

downgraded land covers are forest types and includes Douglas-fir-Port Orford Cedar Forests. 

Appendix 3.1 shows the area in hectares and percentages of all mapped cover types in the different

gap management categories. Appendix 6.7 shows the distribution of land cover types by ecoregion,

with both ownership and protected area designation displayed for each type.

Vertebrate Species Analysis

Birds

Five (<2%) of the 263 birds modeled in Oregon had <1% of their predicted distribution in habitats

occurring in status 1 and 2 lands. Of these five species only the grasshopper sparrow is tracked by

ORNHP and is considered a

state vulnerable species by the

Oregon Department of Fish and

Wildlife (ODFW). The blackchinned sparrow is on the

northern edge of its range in

Oregon, its breeding occurrence

in the state is uncertain, and

possibly should not have been

included. Habitat for three of

the four species is primarily

bunchgrass and riparian habitat

which have been highly

impacted by habitat loss and

fragmentation. The inclusion

of LSR lands as status 2,

described in the stewardship

chapter, had a substantial effect

on protection status of bird

species (Figure 6.2) . When

LSR lands are left as status 3,

as done in Washington GAP,

two species (solitary sandpiper

and least flycatcher) are included as unprotected. Both of these birds have limited, somewhat

peripheral distributions in Oregon and as such are not high conservation priorities.
56

Forty-four (17%) bird species have 1-10% of their predicted distribution protected (Figure 6.2).

Approximately one-third of these species are associated with, or have habitat occurrence in, areas

protected by the BLM Wilderness Study Areas (BLM WSA), or are strongly affected by LSR lands

(Figure 6.2). Species habitat use for this group is not limited to one type of habitat, but twentyseven (10%) of these bird species had historic use of much of the Oregon coast and are now limited

to breeding populations on coastal islands. Six (2%) bird species are considered globally or state

rare (Appendix 6.2), and are tracked by state agencies as conservation targets. A majority of the

species occurring in this category are broad ranging species and likely have adequate protection,

but ten species (Appendix 6.1) have <100,000 ha of total habitat in the state, nine of which are

considered breeding residents and may not be adequately protected. The inclusion of LSR lands as

a status 2 management category may artificially decrease the number of species which might fall

within this category (Figure 6.2). Without LSR’s, the number of species listed is tripled to 131

species, including 10 (4%) of the bird species tracked as conservation targets in the state. 

One-hundred fourteen (43%) bird species have 10-20% and ninety-two (35%) birds have 20-50%

of their predicted habitat in protected areas (Figure 6.2). As observed with the other management

status categories, the designation of LSR lands has a major affect on the distribution of protection

status bird species. Both the federally threatened marbled murrelet (20% protected) and spotted

owl (29% protected) have 77% and 74%, respectively, of their predicted protected distribution in

LSR lands, and drop to the 1-10% protection category when LSR lands are not included. 

Additionally, the northern waterthrush, yellow rail, and harlequin duck lose 18-24% of their

protected habitat and are included in the 1-10% category. Two bird species, the black swift (48%

of protected range in LSR) and Cassin’s auklet (1% of protected range in LSR) drop from the 20-

50% category to the 10-20% category. 

Included in the eight (3%) bird species protected in more than 50% of their distribution only the

black rosy-finch has 100% of its distribution protected in status 1 or 2 lands. This protection is

due exclusively to the network of BLM WSA lands across the alpine habitat of the Steens

Mountains of southeastern Oregon. The trumpeter swan displays a similar trend with 81% of its

distribution protected by US Fish and Wildlife Service (USFWS) refuges. The remaining six

species (Figure 6.2) fall within areas set aside as US Forest Service Wilderness Areas (USFS WA),

or a combination of BLM WSA, USFWS Refuge or other coastal protected areas.

Birds - Historic

One-fifth (57 species) of all (the 253 modeled) birds in Oregon have faced substantial habitat loss

and/or low habitat protection when compared to their historic habitat distribution. Twenty species

have more than 20% of their current distribution in protected areas and would generally be

identified as adequately protected, if habitat loss is not a consideration. For example, upland

sandpiper has 31.65% (6,365 ha) of its current distribution protected. However it lost over 160,000

ha and current protection represents only 1% of its historic range. Thirty species occur in

wetland/shoreline habitats and many are now limited to offshore islands all of which are protected

in reserves by USFWS. Species with the greatest habitat loss and smallest ratio of currently

protected habitat include nine sensitive species (Appendix 6.2).
57

Protection Category

(mammals)

0%

10%

20%

30%

40%

50%

60%

<1% 1-10% 10-20% 20-50% >50%

Protection Class

Percent Protected

1

19

52 50

1

1

4

1

59

50

9

Figure 6.3. Distribution of 123 mammal species in five categories based on protection

class. Light gray lines include LSRs, while the solid, dark lines exclude the LSRs as

protected areas.

Conversely, 58 (23%) bird species have gained in either total habitat, or increased protection

(Appendix 6.2). Seven of these species gains are from non-native upland game bird introductions. 

One species (cattle egret) had no historic distribution, but is considered a naturally occurring

emigrant (Gilligan et al. 1994). The majority of species which have increased range or high

protection status occur in agriculture/urban and open water (reservoir) habitats. While species such

as the orange-crowned warbler, chipping sparrow, mountain bluebird and Lazuli bunting are not

associated with agriculture or urban areas, they are considered early successional species and have

increased their range in managed forests.

Mammals

None of the 116 modeled native mammals have less than 1% of their habitat protected with LSRs

and WSAs included. Mammals exhibit a trend similar to birds when LSRs are removed from

protected status, with two mammal species included in the <1% protection category: the California

vole and Townsend’s vole. Both

vole species lose over 50% of

their protected range (59% and

68% respectively) with the loss

of LSR lands. There are no

mammal species tracked by state

agencies in this category. 

Nineteen (48%) mammal species

have 1-10% of their predicted

distribution in protected areas

(Figure 6.3). 

Three species, the Brazilian freetailed bat, Columbian whitetailed deer (a federally listed

subspecies from western

Oregon) and the Washington

ground squirrel, are tracked by

Oregon as conservation targets. 

The Washington ground squirrel

is limited to the Umatilla Basin

and has specific conservation concern for Oregon since much of its remaining distribution is

limited to state lands which are leased to a private company and threatened by habitat conversion. 

The Columbian white-tailed deer is a federally listed endangered subspecies of the more

widespread species. It is limited to the Puget Trough ecosystem, including the Willamette Valley

and is threatened primarily by habitat conversion. When LSR lands are excluded, no species of

state concern are removed from this category, but 40 (30%) additional species are included in this

protection category. All additional species, excluding the white-footed vole, have > 100,000 ha of

total state distribution. As observed in the birds distribution, the inclusion of LSRs in protected

areas weighs towards species which predominately occur in forested habitats (Appendix 6.3).
58

Fifty-two (42%) mammal species have 10-20% and 51 (41%) mammals have 20-50% of their

predicted distribution in protected areas (Appendix 6.3). Six of these species are considered

conservation targets within the state, but all have > 800,000 ha of total distribution in Oregon. The

predicted distributions for the pygmy rabbit and the spotted bat may be misleading since both

species may be more limited by micro-habitat selection than macro-habitat as modeled by GAP. 

The exclusion of LSRs has the greatest effect on total species in the 20-50% category with a total

loss of 42 species. The kit fox (50.61%) is the only mammal which has >50% of it’s predicted

distribution in protected areas. The high level of protection assigned to the kit fox is due to the

assignment of BLM WSA lands as status 2 protection. The kit fox would decrease substantially

(2% protected) if BLM WSA lands were dropped from status 2 protection to status 3 protection.

Mammals - Historic

Thirty-one (24%) mammal species have experienced substantial habitat loss or low protection (< 0,

Index 2), when compared to historic distributions (Appendix 6.4). Four are extant in Oregon and

are covered by the endangered species act for reintroduction. Fourteen (11%) have more than 20%

of their existing distribution in protected areas and should be re-evaluated for their protection status

in Oregon. When historic distribution is taken into account, median habitat loss for mammals was

65%. Eight mammal species had more than 70% decreases in habitat, although unlike birds,

mammals with historic loss were found in all ecoregions and habitats. Seven of these mammal

species are considered conservation targets in Oregon, including the Washington ground squirrel. 

Ninteen native mammal species have gained habitat or protection status. 

Amphibians and Reptiles

Figure 6.4 shows the distribution of reptile and amphibians in five protection categories. No

amphibians or reptiles had < 1% of their predicted distribution in status 1 and 2 lands. When LSRs

were excluded from status 2, only the common kingsnake, with 85% (4,012 ha) of its protected

habitat in LSR lands, had < 1% of its habitat protected. Three of the nine species with 1-10% of

their predicted distribution are considered species of conservation concern in Oregon. Both the

common kingsnake and the painted turtle are threatened by habitat loss in Willamette Valley and

the Klamath Mountains ecosystems. When LSR lands are excluded from the analysis the total

number of species in the 1-10% protection category increased by over 370% with an additional 25

species. 

The analysis shows that the Northwest Forest Mangement Plan (Femat 1993) and associated LSRs

does an especially good job in protecting amphibians, as shown in Figure 6.4 (below). Looking at

the 19 amphibians taxa with less than 10% of their habitat protected, a median of 18% of their

predicted distributions occur in LSRs. The 14 reptiles in the same group have a median of 6% of

their predicted distribution in the same management category. The discrepancy observed between

the two groups is due primarily to forest lands in the Klamath ecoregion where newt and

salamander diversity is second only to the Great Smoky Mountains.

Eight amphibians and 16 reptiles have between 10-20% of their predicted distribution in protected

areas, and include four amphibians of state conservation concern (Table 6.4). The Siskiyou

Mountain salamander (31,615 ha protected), a state conservation target, is endemic to the Klamath
59

Protection Category

(Herps)

0 %

10%

20%

30%

40%

50%

60%

<1% 1-10% 10-20% 20-50% >50%

Protection Class

Percent Protected9

24

2 6

1

1

3 4

2 0

5

Figure 6.4. Distribution of 60 amphibian and reptile species in five

categories based on protection class. Light gray lines include LSRs, solid

dark lines exclude the LSRs.

Mountains and occurs primarily on BLM, USFS and private land with 81% of its protected lands in

LSR designation. 

Eighteen amphibians and 7

reptiles have between 20-50% of

their predicted distribution in

protected areas, and include four

salamanders of state conservation

concern (Appendix 6.5). The

ensatina has a subspecies (E. e.

picta) endemic to the Klamath

Mountains (1,857,972 ha

protected) found primarily on

BLM, USFS and private lands

with 74% of its protected habitat

in LSRs. The species

distribution for the 20-50%

category of protection has the

greatest reduction of species

richness when LSR lands are

excluded from status 2 protection,

with a loss of all amphibians and

a decrease of three reptiles. Only

the Larch Mountain salamander

has > 50% of its predicted

distribution in protected areas with 57,894 ha (51%) in status 1 and 2 lands. Protection for this

species occurs primarily in USFS Wilderness Areas and LSR lands. When LSR are removed from

protected status the Larch Mountain salamander drops to 17% protected with 66% on LSR lands

(Appendix 6.5).

Amphibians and Reptiles - Historic

Similar to birds and mammals, 22% (13) of amphibians/reptiles have experienced substantial

habitat losses and are poorly protected (Appendix 6.6). No amphibians or reptiles with this level of

loss are proposed for federal or state listing in Oregon, and historical losses may not be as critical

an issue as in other groups. Three of these taxa have < 60,000 ha of total current distribution and

historically none had > 100, 000 ha. Most herps have high mico-habitat requirements and are

likely better evaluated using a finer scale analysis. Fourteen (22%) species have substantial habitat

gains, or high protection, and include three introduced species. 

Summary of Vertebrates in Protected Areas

Vertebrate species protection in Oregon follows the same trend observed in land cover with species

ranges comprising a higher percentage of their range in protected areas. A summary of all species

in Category 1 is found in Table 6.1, Category 5 in Table 6.2, and Category 2 in Table 6.3 below.
60

Table 6.1. Native species with less than 1% of their distribution in status 1 or 2. Taxa are listed by

relative degree of protection, with those at the beginning being least protected.

Amphibians/Reptiles Mammals Birds

Tiger salamander Camas pocket gopher Black-chinned sparrow - Common snipe

Common kingsnake Gray-tailed vole Least flycatcher - Sandhill crane

Columbia seep salamander California vole Bobolink - Bullock’s oriole

Northern leopard frog White-tailed deer Grasshopper sparrow - Blue-gray gnatcatcher

Painted turtle Townsend`s vole White-tailed kite - Ash-throated flycatcher

Northwestern garter snake Western harvest mouse Pinyon jay - Rhinoceros auklet

Western pond turtle Brazilian free-tailed bat Wilson`s phalarope - House finch

Southern alligator lizard California kangaroo rat Tricolored blackbird - Lesser goldfinch

California ground squirrel Sora - Northern harrier

Columbian ground squirrel Virginia rail - Black-chinned hummingbird

Washington ground squirrel Eastern kingbird - American goldfinch

Montane vole Upland sandpiper - Allen`s hummingbird

Northern pocket gopher Red-necked grebe - White-crowned sparrow

Brush rabbit Short-eared owl - Red-eyed vireo

Pygmy nuthatch - Anna`s hummingbird

Killdeer - Purple finch

Solitary sandpiper - Chipping sparrow

Franklin`s gull - Mountain quail

Savannah sparrow - American kestrel

Canada goose - Black oystercatcher

Yellow-billed cuckoo - California quail

- Red-naped sapsucker

Table 6.2. Native species with more than 50% of predicted distribution in status 1 or 2. Taxa are

listed by relative degree of protection, with those at the top being least protected. 

Amphibians/reptiles Mammals Birds

Larch Mountain Salamander Kit fox Three-toed woodpecker

Spruce grouse

Snowy plover

Black swift

Gray-crowned rosy-finch

American pipit

Black rosy-finch
61

Table 6.3. Category 2 vertebrate species (taxa with between 1% and 10% of their distribution in

status 1 or 2 lands.) Taxa are listed by relative degree of protection, with those at the beginning

being least protected. 

Amphibians/Reptiles Mammals Birds

Sharptail snake Coyote Brandt`s cormorant - Spotted towhee

Woodhouse`s toad American badger Pelagic cormorant - Ring-billed gull

Racer Botta`s pocket gopher Pigeon guillemot - Wilson`s warbler

Great basin spadefoot Belding`s ground squirrel Lark sparrow - Bank swallow

Short-horned lizard Great Basin pocket mouse Common murre - Lincoln`s sparrow

Siskiyou mountains Western pipistrelle Leach`s storm-petrel - Bewick`s wren

Long-toed salamander Black-tailed jackrabbit Tufted puffin - Veery

Gopher snake Least chipmunk Glaucous-winged gull - White-headed woodpecker

Western rattlesnake Western small-footed bat American avocet - Lewis` woodpecker

Striped whipsnake Yellow-pine chipmunk Mourning dove - Sage thrasher

Western skink Western spotted skunk Barn owl - Orange-crowned warbler

Oregon spotted frog Common raccoon Brewer`s sparrow - Hutton`s vireo

Western fence lizard Sagebrush vole Vesper sparrow - California gull

Western terrestrial garter snake Nuttall`s cottontail Red-tailed hawk - White-breasted nuthatch

Rubber boa Pronghorn Red-shouldered hawk - Western screech-owl

Pacific treefrog Striped skunk Common poorwill - Brown-headed cowbird

Common garter snake Pinon mouse California towhee - Northern flicker

Western toad Townsend`s ground squirrel Western meadowlark - American robin

Side-blotched lizard White-tailed jackrabbit Gray flycatcher - Willow flycatcher

Night snake Pallid bat Oak titmouse - Common nighthawk

Sagebrush lizard Canyon mouse Horned lark - Great horned owl

Ringneck snake Yellow-bellied marmot Loggerhead shrike - Macgillivray`s warbler

Columbia spotted frog Southern red-backed vole Rock wren - Black-headed grosbeak

Dusky shrew White-throated swift - Turkey vulture

California myotis Western kingbird - Flammulated owl

Bushy-tailed woodrat Western gull - Western bluebird

Fringed bat House wren - Common raven

Western jumping mouse Ferruginous hawk - Green-tailed towhee

Townsend`s pocket gopher Black-capped chickadee - Violet-green swallow

Mule deer Long-eared owl - Nashville warbler

Dusky-footed woodrat Bushtit - Gray catbird

Long-tailed weasel Say`s phoebe - Long-billed curlew

Deer mouse Swainson`s hawk - Ruffed grouse

Big brown bat Black-billed magpie - Bald eagle

Red squirrel American crow - Cassin`s finch

Long-legged bat Song sparrow - Sage sparrow

Long-eared bat Nrn rough-winged sparrow - Vaux`s swift

Vagrant shrew American redstart - Mountain chickadee

Townsend`s mole Cliff swallow - Williamson`s sapsucker

Bobcat Lazuli bunting - Sage grouse

Coast mole Solitary vireo - Black-throated gray warbler

Merriam`s shrew Brewer`s blackbird - Dark-eyed junco

Preble`s shrew Downy woodpecker - American dipper

Ord`s kangaroo rat American bittern - Steller`s jay

Northern grasshopper mouse Barn swallow - Green heron

Common porcupine Wood duck - Brown creeper

Long-tailed vole Canyon wren - Hairy woodpecker

Broad-footed mole Yellow-breasted chat - Swainson`s thrush

Golden-mantled ground squirrel Burrowing owl - Dusky flycatcher

Pygmy rabbit Purple martin - Mountain bluebird

Red fox Golden eagle - Red-breasted nuthatch

Prairie falcon - Winter wren

Fork-tailed storm-petrel - Calliope hummingbird

Yellow-headed blackbird - Hooded merganser

Fox sparrow - Rufous hummingbird

- Black-throated sparrow
62

Index 1 =

1

1

−

 −











−

 −







































 −











c p

c

h p

h

c h

c

Figure 6.5. Formula 1, where hectares of historic habitat = h,

hectares of current habitat = c, and hectares currently

protected = p

Index 3 =











 +

+













p

c

c

c h

Figure 6.7. Formula 3, an index of change where h=historic

habitat, c=current habitat, and p = currently protected

Index 2 =

h c

h

p

c

−

−











 *−100

Figure 6.6. Formula 2, an index of change where

h=historic habitat, c=current habitat, and p=currently

protected lands.

Priority Species for Conservation

Species loss is not just related to habitat loss. If this were the case, management decisions could

focus on species which had the greatest habitat losses. To describe the change in vertebrate

distributions caused by anthropocentric changes in Oregon over the last century, both the loss of

habitat and how well the current and historic range of

the species is protected need to be evaluated. To

determine which species were most affected by habitat

loss/gain, and if protection status was low or high, three

indices which value species-area change and protection

differently were examined. The first index, Formula 1,

is shown as Figure 6.5. It incorporates the difference in

protection of current distribution and historic

distribution as a factor of habitat lost or habitat gained. 

Because the index is weighted by the change in habitat

area, the species identified by the index tend to be those

that lost, or gained the most habitat. Species with high

loss in habitat and a low ratio of current protected

habitat, have a negative value.

A second index (Formula 2) was suggested by Frank

Davis of UC Santa Barbara, somewhat similar to

Index 1 but with a greater focus on vulnerability of

the remaining, unprotected habitat. His index was

modified slightly, changing it from positive to

negative to match the other indices (Figure 6.6). 

 

Denis White of the Environmental Protection Agency

lab in Corvallis recommended the third additive

index which allows for weighting of how well areas

are protected and how much habitats have been lost. 

Denis noted that additive indices often work better

than multiplicative ones. Values for this index range

from 0 to 2. This is Formula 3, shown in Figure 6.7

to the left.

All three formulas have been applied to the entire set of species and habitats developed for this

project. As mentioned above, these range from negative to positive, with the species most in need

of attention having larger negative values, and those most secure having large positive values. 

Results are similar for the three indices, but not identical. Table 6.4, below shows the 20 bird

species most in need of protection based on the three formulas, in priority order. Certain species,

e.g. the yellow rail, the least flycatcher and the yellow-billed cuckoo show up as priorities using all

the indices, although the differences between them are intriguing. Appendices 6.2, 6.4 and 6.6

show the results of this analysis for all species, including hectares of habitat in the historic and

existing coverage, the percent change, area currently protected, the percentage of the historic and

current distribution this represents, the percent change in habitat from historic to current, and the

three indices.
63

Table 6.4. Top 20 priority bird species based on the three habitat loss/protected area formulas.

Formula 1 Formula 2 Formula 3

Yellow Rail

Yellow-billed Cuckoo

Peregrine Falcon

Fork-tailed Storm-petrel

Cassin`s Auklet

Grasshopper Sparrow

Bonaparte`s Gull

Lewis` Woodpecker

Marbled Murrelet

California Towhee

Black-necked Stilt

Red-eyed Vireo

Franklin`s Gull

Rhinoceros Auklet

Green-winged Teal

Hutton`s Vireo

Snowy Plover

Upland Sandpiper

Pacific Slope Flycatcher

Least Flycatcher

Yellow-billed Cuckoo

Grasshopper Sparrow

Fork-tailed Storm-petrel

Franklin`s Gull

Upland Sandpiper

Yellow Rail

Rhinoceros Auklet

Red-eyed Vireo

Wilson`s Phalarope

California Towhee

Cassin`s Auklet

Lewis` Woodpecker

Peregrine Falcon

Marbled Murrelet

Hutton`s Vireo

Yellow-headed Blackbird

Red-necked Grebe

Tufted Puffin

Least Flycatcher

Yellow-billed Cuckoo

Grasshopper Sparrow

Franklin`s Gull

Fork-tailed Storm-petrel

Upland Sandpiper

Wilson`s Phalarope

Rhinoceros Auklet

Red-eyed Vireo

California Towhee

Red-necked Grebe

Yellow Rail

Lewis` Woodpecker

Mockingbird

Cassin`s Auklet

Hutton`s Vireo

Common Murre

Leach`s Storm-petrel

Tufted Puffin

Similar results were obtained for mammals, reptiles and amphibians. The top 20 reptile and

amphibians are shown below in Table 6.5, and mammals in Table 6.6, both in priority order.

Table 6.5. Top 20 priority reptile and amphibian species based on the three habitat loss/protected

area formulas in priority order.

Formula 1 Formula 2 Formula 3

Common Kingsnake

Columbia Seep Salamander

Southern Seep Salamander

Red-legged Frog

Western Pond Turtle

Dunn`s Salamander

Pacific Cst Aquatic Garter Snake

Foothill Yellow-legged Frog

Cascade Seep Salamander

Pacific Giant Salamander

California Mountain Kingsnake

Oregon Slender Salamander

Ground Snake

Striped Whipsnake

Larch Mountain Salamander

Cope`s Giant Salamander

Night Snake

Side-blotched Lizard

Western Redback Salamander

Mojave Black-collared Lizard

Common Kingsnake

Columbia Seep Salamander

Western Pond Turtle

Southern Seep Salamander

Red-legged Frog

Dunn`s Salamander

Foothill Yellow-legged Frog

Pacific Cst Aquatic Garter Snake

Striped Whipsnake

Cascade Seep Salamander

Northern Leopard Frog

Side-blotched Lizard

Night Snake

Painted Turtle

Cope`s Giant Salamander

Western Redback Salamander

Columbia Spotted Frog

Western Skink

Oregon Spotted Frog

Short-horned Lizard

Common Kingsnake

Columbia Seep Salamander

Western Pond Turtle

Northern Leopard Frog

Painted Turtle

Striped Whipsnake

Red-legged Frog

Dunn`s Salamander

Southern Seep Salamander

Great Basin Spadefoot

Short-horned Lizard

Western Skink

Oregon Spotted Frog

Side-blotched Lizard

Racer

Night Snake

Long-toed Salamander

Foothill Yellow-legged Frog

Columbia Spotted Frog

Cope`s Giant Salamander

A potential use of these indices is to use them to define some group of species which are those most

in need of protection. Using the gap data and the indices, OR-GAP produced a species richness

map showing concentrations of these priority species. The question to be tested by this was
64

Table 6.6. Top 20 priority mammal species based on the three habitat loss/protected area formulas

in priority order.

Formula 1 Formula 2 Formula 3

Spotted Bat

White-tailed Deer

Washington Ground Squirrel

Canada Lynx

White-footed Vole

White-tailed Jack Rabbit

Mountain Lion

Townsend`s Big-eared Bat

Kit Fox

California Kangaroo Rat

Pacific Jumping Mouse

Fisher

American Marten

Wolverine

Brazilian Free-tailed Bat

Little Pocket Mouse

Pronghorn

Ringtail

Snowshoe Hare

Pinon Mouse

White-tailed Deer

Washington Ground Squirrel

Spotted Bat

White-tailed Jack Rabbit

Townsend`s Big-eared Bat

White-footed Vole

California Kangaroo Rat

Canada Lynx

Mountain Lion

Brazilian Free-tailed Bat

Pacific Jumping Mouse

Fisher

California Vole

Pronghorn

Pinon Mouse

American Marten

Western Small-footed Bat

Wolverine

Kit Fox

Belding`s Ground Squirrel

White-tailed Deer

Washington Ground Squirrel

Spotted Bat

White-tailed Jack Rabbit

California Kangaroo Rat

Townsend`s Big-eared Bat

Brazilian Free-tailed Bat

White-footed Vole

California Vole

Canada Lynx

Western Harvest Mouse

Mountain Lion

Columbian Ground Squirrel

Pronghorn

Western Small-footed Bat

Belding`s Ground Squirrel

Pinon Mouse

Northern Pocket Gopher

Great Basin Pocket Mouse

Western Pipistrelle

whether a species richness map generated using a prioritized subset of Oregon species would be

significantly different than the species richness map which used all species. Figure 6.8 compares

the total richness of all species (top) and the total richness of the subset of species needing

protection (bottom). We believe the priority species richness would be much more useful in

identifying areas which might provide the biggest return on conservation investments. 

For this richness sub-sample map (Figure 6.8, bottom), we used Index 2, with a cutoff value of 40. 

This value was selected somewhat arbitrarily, but represented the majority of the species which

either were not well represented in the network of conservation areas, or had declined significantly. 

Overall, a total of 333 of the 455 species (73%) were identified, of which most are birds (56%). 

However the percentage of the total birds selected (70%) is lower than the percentage of either

herps (75%) or mammals (79%), suggesting that birds are generally better protected in Oregon than

are the other groups. The color ramps used in the two maps (total species richness map and the

sub-sample or priority species richness map) represent the quantile distribution of total data points. 

Each of the ten color classes in each map contains exactly 10% of the total number of polygons (we

were unable to do this using total area instead of number of polygons, but it may be possible). 

These can also be viewed with an equal value distribution (each color class has the same number of

richness values), but we felt the two maps were more comparable using the quantile distributions. 

The major centers of species richness (areas with very high species diversity shown in yellow) are

the same in both the all species and the priority species richness maps: the Klamath Basin in southcentral Oregon, the Malheur Basin in east-central Oregon, and the Siskiyou Mountains in

southwestern Oregon. However, areas of high diversity (shown in yellow-green) change

dramatically in the sub-sample coverage, with high-richness areas highlighted in the western

Columbia River Gorge, the Alvord Basin, and southeastern Wasco County that were not important

in the overall species richness map.
65

CHAPTER 7: CONCLUSIONS AND MANAGEMENT IMPLICATIONS

OR-GAP has been a cooperative effort with numerous partners working over a 10 year period. It

started as an effort to answer the question, “Where are the best places to protect diversity in

Oregon?”. Over the project’s lifetime, it has changed significantly, and is now viewed as an effort

to provide both biodiversity information and analysis tools for answering the original question. 

The Version 1 products helped inspire the Oregon Biodiversity Project and led to the publication of

Oregon’s Living Landscape (OBP 1998).

In general, OR-GAP is hesitant to state that the results of the analysis included in this report

provide comprehensive information on either diversity patterns in Oregon, or sites where best

biodiversity most needs to be protected. As with many projects comprised of numerous

cooperators, much of the work has been pieced together. Some of the products and

accomplishments are significant, while others still need improvement.

The development of the stewardship coverage and the species distribution databases has improved

the ability for others to do statewide and local assessments. The land cover and species distribution

covers appear, in areas, to have high error rates. While an accuracy assessment was not done for

either of the two versions of the OR-GAP land coverage, both appear to be uneven, with detailed

mapping and classification in some areas, and coarser mapping and classification in others. ORGAP and ORNHP have started a cooperative effort with the U.S. Forest Service and BLM to

accumulate all their ecology plot data. When this data set is compiled, ORNHP and OR-GAP will

be able to assess the accuracy of both Version 1 and Version 2 land cover maps, as well as the

accuracy of the many other local and regional coverages being developed in Oregon.

The wildlife by habitat relationship models were developed for OR-GAP cooperatively by ODFW

and Blair Csuti, based on some preliminary analysis of wildlife needs, and a compilation of wildlife

habitat reports from a number of researchers. The need for additional work in this area led ODFW

and the Washington Department of Fish and Wildlife to seek and raise funds for a three year effort

to develop new models. It also, indirectly, led to the creation of a new non-governmental

organization, the Northwest Habitat Institute, in Corvallis, Oregon. Unfortunately, the new wildlife

by habitat relationship models were not available in time for this analysis. However, the analysis

tools OR-GAP developed to produce the species distribution coverage were designed to incorporate

new wildlife-habitat models and new vegetation coverages, whenever they become available. We

believe that using higher resolution vegetation coverages with more detailed classifications, and the

improved wildlife-habitat models would greatly improve the overall accuracy of the analysis. 

However, this may not change the basic identification of gaps (M. Scott, personal communication).

OR-GAP has been most valuable as a focus to develop and integrate these important data sets. 

More accurate species lists and species distribution maps will be developed using the species

distribution databases and the managed area coverage with the new wildlife-habitat models and

ecoregional or local vegetation maps which are currently being produced throughout the state. 

OR-GAP intends to continually update the managed area cover, the species distribution databases,

and to provide crosswalks between the new wildlife habitat models and any new vegetation or land

cover maps which become available. Oregon is exceptionally fortunate to have a number of

forward thinking agencies who are spending significant resources to map land cover and vegetation
66

at a fine scale, and to tie these maps to GPS labeled plot data. The Burns District BLM, the

Umatilla, Ochoco, Siuslaw and Willamette National Forests among others have developed

exceptional 1:24,000 vegetation coverages which are available to the public. OR-GAP and

ORNHP intends to aggregate these for the entire state, and to compare these to the coarser scale

maps based on satellite imagery. We feel that these fine scale maps will be more useful for

ecoregional and watershed analysis. ORNHP is working with TNC to complete ecoregional plans

for all of Oregon’s ecoregions, and working with the state of Oregon’s Watershed Enhancement

Board to assist in the development of watershed assessments. We believe the combination of fine

scale vegetation data, improved wildlife habitat matrices, and an updated GAP protected area cover

will greatly enhance these biodiversity planning efforts. And, ORNHP and OR-GAP intends to

remain a source of biodiversity information for anyone interested in studying or protecting

biodiversity in Oregon.

OR-GAP data has been used in a recent analysis to write a State of the Environment Report,

commissioned by the Governor and the Oregon Progress Board, and developed by a science team

headed by Dr. Paul Risser, President of Oregon State University. This project, and other

assessment projects in Oregon, has allowed OR-GAP to continue updating most of the data

developed. Annual updates of the Stewardship/Ownership coverage will be released, as will

updates to the vertebrate species distribution database. The Historic Vegetation coverage will be

updated one more time in the year 2000, to include new data from the eastern Oregon valleys and

from southwestern Oregon. 

One of the clear results of this analysis is the significance of the LSRs and the WSAs to the

protection of biodiversity in Oregon. The LSRs, designed to protect the northern spotted owl, do a

very good job at protecting other vertebrate species using western Oregon forests. Threats or

changes to the management of these LSRs would greatly change how well species are protected in

western Oregon, and increase the overall number of gaps. The BLM Wilderness Study areas are

also critical to the protection of wildlife and habitats, especially in southeastern Oregon. The

permanent protection of at least a significant portion of these lands is a critical strategy to assure we

do not have the endangered species problems we have had in western Oregon.

The National Gap Analysis Program is moving in two directions which OR-GAP fully intends to

assist. The first is to promote regional, multi-state GAP efforts. OR-GAP has worked with

adjacent states in a number of regional assessments, and especially sees the need to regionalize land

cover maps and other coverages which have varied significantly between programs. The second is

to complete aquatic gap analysis for states and the country. This report and the data are clearly

biased towards terrestrial systems and elements. Working to develop a coverage and classification

of aquatic habitats in Oregon will be a focus of future activities. 
67

PRODUCT USE AND AVAILABILITY

How To Obtain the Products

It is the goal of the Gap Analysis Program and the USGS Biological Resources Division (BRD) to

make the data and associated information as widely available as possible. Use of the data requires

specialized software called geographic information systems (GIS) and substantial computing

power. Additional information on how to use the data or obtain GIS services is provided below

and on the GAP homepage (URL below). While a CD-ROM of the data will be the most

convenient way to obtain the data, it may also be downloaded via the Internet from the national

GAP home page at:

 http://www.gap.uidaho.edu/gap

The home page will also provide, over the long term, the status of our state’s project, future

updates, data availability, and contacts. Within a few months of this project’s completion, CDROMs of the final report and data should be available at a nominal cost— the above home page

will provide ordering information. To find information on this state GAP project status and data,

follow the links to “project information” and then to the particular state of interest.

In Oregon, GIS information has been centralized at the State Service Center for GIS (SSCGIS).

While this agency has recently lost all of their state funding, they continue to attempt to post all of

the data layers available in the state, and with any associated metadata. All of the GIS datasets

created as part of OR-GAP, as well as most of the data created through the Oregon Biodiversity

Project are available on the SSCGIS’s FTP or Internet sites. If funding prohibits the SSCGIS from

continuing to post the data, ORNHP, OR-GAP or ODFW will assure they are posted. Until then,

the SSCGIS can be contacted through the internet at:

http://www.sscgis.state.or.us

ORNHP also maintains a homepage for the program and OR-GAP. All information produced as

part of the OR-GAP is available through this site as well. This includes an electronic copy of this

report (in PDF and word processing formats), lists of the rare, threatened and endangered species of

Oregon, a complete list of the habitats for Oregon (based on the current National Vegetation

Classification System), and a list of GIS data being developed by OR-GAP and ORNHP. The

current address is:

http://www.heritage.tnc.org/nhp/us/or

Three sets of species distribution covers were developed as part of OR-GAP. The first and the

second sets are the predicted distributions, and differ only in the vegetation cover which was used

to generate them. The first was developed from the first land cover map, which was created using

LANDSAT Multi-Spectral Scanner false-color infrared positive prints at a scale of 1:250,000 were

visually photo-interpreted to identify boundaries of different vegetation cover types. The second

set of distribution covers were developed using the second generation cover, which is described in

detail in this report. The last set was developed using a historic vegetation coverage developed by

ORNHP (cooperatively with the Defenders of Wildlife, ODFW, the USFS Forest Sciences Lab),

with significant funding from EPA, the BLM, and the State of Oregon.
68

All of the species coverages are available on CD-ROM. There are too many coverages, and they

are too large, to be all available on-line as grids or ARCINFO coverages. OR-GAP has developed

an ARCVIEW application which uses ESRI’s Internet Map Server (IMS) program to generate onthe-fly maps (shape files) of the historic and current distributions of all vertebrate taxa. As

currently developed, this application is currently too slow to be an efficient internet application. 

OR-GAP is working with the ODFW and the State of Oregon to streamline the existing databases

and to obtain new equipment to serve this data on line.

All of the data developed as part of the Oregon Biodiversity Project has been incorporated into the

Oregon Biodiversity Partnership. This is a cooperative effort between The Defenders of Wildlife,

ORNHP, and TNC to develop statewide partnerships to assist in the implementation of the results

of the Oregon Biodiversity Project. The Oregon Biodiversity Partnership has a website which

describes the partnership in detail, and provides access to data and data products:

http://www.biodiversitypartners.org

Minimum GIS Required For Data Use

Currently, ARC-INFO or ARCVIEW is needed to use the GIS Coverages. When the ARCVIEW -

Internet Map Server application discussed in the previous paragraph is completed, anyone with

internet access should be able to generate and download historic or current species distribution

maps using a free version of Arc Explorer. 

Disclaimer

Following is the official Biological Resources Division (BRD) disclaimer as of 29 January, 1996,

followed by additional disclaimers from GAP. Prior to using the data, you should consult the GAP

home page (see How to Obtain the Data, above) for the current disclaimer.

Although these data have been processed successfully on a computer system at the BRD, no

warranty expressed or implied is made regarding the accuracy or utility of the data on any other

system or for general or scientific purposes, nor shall the act of distribution constitute any such

warranty. This disclaimer applies both to individual use of the data and aggregate use with other

data. It is strongly recommended that these data are directly acquired from a BRD server [see

above for approved data providers] and not indirectly through other sources which may have

changed the data in some way. It is also strongly recommended that careful attention be paid to the

content of the metadata file associated with these data. The Biological Resources Division shall

not be held liable for improper or incorrect use of the data described and/or contained herein.

These data were compiled with regard to the following standards. Please be aware of the

limitations of the data. These data are meant to be used at a scale of 1:100,000 or smaller (such as

1:250,000 or 1:500,000) for the purpose of assessing the conservation status of vertebrate species

and vegetation types over large geographic regions. The data may or may not have been assessed

for statistical accuracy. Data evaluation and improvement may be ongoing. The Biological

Resources Division makes no claim as to the data's suitability for other purposes. This is writeable
69

data which may have been altered from the original product if not obtained from a designated data

distributor identified above.

Metadata

Proper documentation of all information sources used to assemble GAP data layers is central to the

scientific defensibility of GAP. The information used to describe GAP data is called metadata. 

Metadata are information about data. Metadata contain information about the source(s), lineage,

content, structure, and availability of a data set. Metadata also describe intentions, limitations, and

potential uses, allowing for the informed and appropriate application of the data. Descriptions of

metadata function have recently been published by the Federal Geographic Data Committee.

The GAP metadata standards have been closely matched to the FGDC standards to ensure current

and future compatibility. As the FGDC standards evolve beyond the current publication, we

anticipate corresponding refinements in GAP documentation. The format of the GAP metadata

consists of eight major documentation sections (Table 1) containing one or more metadata

elements. Each element is named (e.g. Map Projection Name), and the "Type" of entry (text,

integer, date, time) and "Domain" of the entry (i.e. x > 0) are also defined. 

Table 1. Metadata Data Element Categories: 

I Identification Information: What the data set is called, file format description.

II Data Quality Information: Accuracy, consistency, and data sources.

III Spatial Data Organization Information: Data structure--raster, vector, point, etc.

IV Spatial Reference Information: Coordinate units, map projection, spatial resolution.

V Entity and Attribute Information: Attribute codes and reference citations.

VI Distribution Information: How to order the data, on-line access, transfer size.

VII Metadata Reference Information: Date of the metadata, contact for metadata updates.

XIII Contact Information: General data contact, mail, voice, fax, web, e-mail.

Demands for metadata will increase as electronic networks expand across the national and

international scene, and more requests are made for distribution of information. As the number of

users and the diversity of disciplines and programs sharing the data expand, the information carried

by metadata will become increasingly important. One of the goals in defining today's metadata

standards is to anticipate these future needs.

For additional information via Internet: GAP home page address: http://www.gap.uidaho.edu/gap
70

Cogan, C.B., and T.C. Edwards. 1994. Metadata standards for GAP. Gap Analysis Technical

Bulletin 3. Idaho Cooperative Fish and Wildlife Research Unit, University of Idaho, Moscow,

Idaho. 28 pp. (A postscript file is available from the GAP web page listed above.)

For a postscript version of the current FGDC Metadata Standards (8 June 1994):

waisqvarsa.er.usgs.gov (anonymous ftp, cd to wais/docs, get FGDCmeta6894.ps)

Federal Geographic Data Committee. 1995. Content Standards for Digital Geospatial Metadata

workbook (March 24). FGDC. Washington D.C. (Describes the FGDC metadata standards.)

http://geochange.er.usgs.gov/pub/tools/metadata/standard/metadata.html 

Appropriate and Inappropriate Use of These Data

All information is created with a specific end use or uses in mind. This is especially true for GIS

data, which is expensive to produce and must be directed to meet the immediate program needs. 

For GAP, minimum standards were set (see A Handbook for Gap Analysis, Scott et al. 1993) to

meet program objectives. These standards include: scale or resolution (1:100,000 or 100 hectare

minimum mapping unit), accuracy (80% accurate at 95% confidence), and format (ARC/INFO

coverage tiled to the 30’ x 60’ USGS quadrangle). For complete project standards, refer to

Appendix 1.3.

Recognizing, however, that GAP would be the first, and for many years likely the only, source of

statewide biological GIS maps, the data were created with the expectation that they would be used

for other applications. Therefore, we list below both appropriate and inappropriate uses. This list is

in no way exhaustive but should serve as a guide to assess whether a proposed use can or cannot be

supported by GAP data. For most uses, it is unlikely that GAP will provide the only data needed,

and for uses with a regulatory outcome, field surveys should verify the result. In the end, it will be

the responsibility of each data user to determine if GAP data can answer the question being asked,

and if they are the best tool to answer that question.

Scale 

First we must address the issue of appropriate scale to which these data may be applied. The data

were produced with an intended application at the ecoregion level, that is, geographic areas from

several hundred thousand to millions of hectares in size. The data provide a coarse-filter approach

to analysis, meaning that not every occurrence of every plant community or animal habitat is

mapped, only larger, more generalized distributions. The data are also based on the USGS

1:100,000 scale of mapping in both detail and precision. When determining whether to apply GAP

data to a particular use, there are two primary questions: do you want to use the data as a map for

the particular geographic area, or do you wish to use the data to provide context for a particular

area? The distinction can be made with the following example: You could use GAP land cover to

determine the approximate amount of oak woodland occurring in a county, or you could map oak

woodland with aerial photography to obtain a more accurate estimate. You then could use GAP

data to determine the approximate percentage of all oak woodland in the region or state that occurs
71

in the county, and thus gain a sense of how important the county’s distribution is to maintaining

that plant community.

Appropriate Uses 

The above example illustrates two appropriate uses of the data: as a coarse map for a large area

such as a county, and to provide context for finer-level maps. Specific case-study examples are

provided in Appendix 1.1, but following is a general list of applications:

• Statewide biodiversity planning

• Regional (Councils of Government) planning

• Regional habitat conservation planning

• County comprehensive planning

• Large-area resource management planning

• Coarse-filter evaluation of potential impacts or benefits of major projects or plan initiatives

on biodiversity, such as utility or transportation corridors, wilderness proposals, regional

open space and recreation proposals, etc.

• Determining relative amounts of management responsibility for specific biological

resources among land stewards to facilitate cooperative management and planning.

• Basic research on regional distributions of plants and animals and to help target both

specific species and geographic areas for needed research.

• Environmental impact assessment for large projects or military activities.

• Estimation of potential economic impacts from loss of biological resource based activities.

• Education at all levels and for both students and citizens.

Inappropriate Uses

It is far easier to identify appropriate uses than inappropriate ones, however, there is a “fuzzy line”

that is eventually crossed when the differences in resolution of the data, size of geographic area

being analyzed, and precision of the answer required for the question are no longer compatible. 

Examples include:

• Use of the data to map small areas (less than thousands of hectares), typically requiring

mapping resolution at 1:24,000 scale and using aerial photographs or ground surveys.

• Combining GAP data with other data finer than 1:100,000 scale to produce new hybrid

maps or answer queries.

• Generating specific areal measurements from the data finer than the nearest thousand

hectares (minimum mapping unit size and accuracy affect this precision).

• Establishing exact boundaries for regulation or acquisition.

• Establishing definite occurrence or non-occurrence of any feature for an exact geographic

area (for land cover, the percent accuracy will provide a measure of probability).

• Determining abundance, health, or condition of any feature.

• Establishing a measure of accuracy of any other data by comparison with GAP data.

• Altering the data in any way and redistributing them as a GAP data product.

• Using the data without acquiring and reviewing the metadata and this report.
72

LITERATURE CITED

Anderson, J.R., E.E. Hardy, J.T. Roach, and R.E. Witmer. 1976. A land use and land cover

classification system for use with remote sensor data. Geological Survey Professional Paper

964. U.S. Geological Survey, Washington, DC.

AOU. 1998. Checklist of North America Birds, Seventh Edition. American Ornithologists’ Union,

Committee on Classification and Nomenclature, Washington, D.C.

Austin, M.P. 1991. Vegetation: Data collection and analysis. Pages 37-41 in: C.R. Margules

and M.P. Austin, eds., Nature conservation: Cost effective biological surveys and data

analysis. Australia CSIRO, East Melbourne.

Bailey, V. 1936. The mammals and life zones of Oregon. North American Fauna, 55:1-416.

Barrett, C.W., 1998. Airborne videography as a classification and validation technique for Landsat

TM-based vegetation mapping. Master Thesis. Oregon State University, Corvallis, Oregon. 

79 pp.

Bourgeron, P.S., H.C. Humphries, R.L. DeVelice, and M.E. Jensen. 1994. Ecological theory in

relation to landscape and ecosystem characterization. Pages 58-72 in: M.E. Jensen and

P.S. Bourgeron, eds., Ecosystem management: Principles and applications, Volume II. 

Gen. Tech. Rep. PNW-GTR-318. Portland, OR: USDA Forest Service, Pacific Northwest

Research Station. 376p.

Briggs, A. 1999. Conservation Status of Oregon Vegetation. Unpublished report, Oregon

Biodiversity Project. Defenders of Wildlife, Pacific Northwest Office, Lake Oswego, OR. 

182 pp.

Chappell, C.D., R.C. Crawford, J.S. Kagan and P.J.Doran. 1997. A Vegetation, Land Use, and

Habitat Classification System for the Terrestrial and Aquatic Systems of Oregon and

Washington. Progress Report # 3 of Wildlife Habitats and Species Associations in Oregon

and Washington: Building a common understanding for Management. D.H. Johnson and

T.A. O’Neil. Washington Department of Fish and Wildlife and the Northwest Habitat

Institute. 173 pp.

Cogan, C., Edwards, T.C., 1994. Metadata standards for Gap Analysis. Gap Analysis Technical

Bulletin 3. Idaho Cooperative Fish and Wildlife Research Unit, University of Idaho,

Moscow, Idaho.

Collins, J.T. 1990. Standard common and current scientific names for North American amphibians

and reptiles, Third Edition. Scoiety for the Study of Amphibians and Reptiles,

Herpetological Circular No. 19:i-iii, 1-41.

Crist, P., Thompson, B., Prior-Magee, J., 1995. A dichotomous key of land management

categorization, unpublished. New Mexico Cooperative Fish and Wildlife Research Unit,

Las Cruces, New Mexico.

Csuti, B., A.J. Kimerling, T.A. O’Neil, M.M. Shaughnessy, E.P. Gaines, and M. Huso. 1997a. 

Atlas of Oregon Wildlife. Oregon State University Press, Corvallis, OR. 492 pp.

Csuti, B., S. Polasky, P. H. Williams, R. L. Pressey, J. D. Camm, M. Kershaw, A. R. Kiester,

B. Downs, R. Hamilton, M. Huso, and K. Sahr. 1997b. A comparison of reserve

selection algorithms using data on terrestrial vertebrates in Oregon. Biological

Conservation, Vol. 80: 83-97.

.Csuti, B. 1994. Methods for developing terrestrial vertebrate distribution maps for Gap Analysis

(version 1). In J.M. Scott and M.D. Jennings, editors. A handbook for Gap Analysis. 

Idaho Cooperative Fish and Wildlife Research Unit, University of Idaho, Moscow.
73

Davis, F.W., P.A. Stine, D.M. Stoms, M.I. Borchert, and A.D. Hollander. 1995. Gap Analysis

of the actual vegetation of California - 1. The southwestern region. Madroño 42:40-78.

Davis, F.W., D.M. Stoms, M. Bueno, A.D. Hollander and J. Walsh. 1998. Gap Analysis of

Mainland California: An Interactive Atlas of Terrestrial Biodiversity and Land

Management. CD-ROM, Natural Heritage Division, CA Fish and Game, Sacramento.

Diamond, J. 1986. The design of a nature reserve system for Indonesian New Guinea. Pages 485-

503 in M.E. Soulé, editor. Conservation biology: The science of scarcity and diversity. 

Sinauer Associates, Sunderland, MA.

Driscoll, R.S., D.L. Merkel, D.L. Radloff, D.E. Snyder, and J.S. Hagihara. 1984. An ecological

land classification framework for the United States. Miscellaneous Publication 1439. 

USDA Forest Service, Washington, D.C.

Driscoll, R.S., D.L. Merkel, J.S. Hagihara, and D.L. Radloff. 1983. A component land

classification for the United States: Status report. Technical Note 360. U.S. Department of

the Interior, Bureau of Land Management, Denver.

Edwards, T.C., Jr., C.H. Homer, S.D. Bassett, A. Falconer, R.D. Ramsey, and D.W. Wight. 

1995. Utah Gap Analysis: An environmental information system. Technical Report 95-1,

Utah Cooperative Fish and Wildlife Research Unit, Utah State University, Logan, Utah.

Federal Geographic Data Committee (FGDC). 1994. Content standards for digital geospatial

metadata. 8 June 1994. Federal Geographic Data Committee, Washington, D.C.

____________. 1995. Content standards for digital geospatial metadata workbook, FGDC,

Washington, D.C.

Federal Geographic Data Committee, Vegetation Subcommittee. 1997. FGDC Vegetation

Classification and Information Standards--June 3, 1996 Draft. FGDC Secretariat, Reston,

VA. 35 pp.

FEMAT. 1993. Forest Ecosystem Management: An Ecological, Economic and Social Assessment.

U.S. Government Printing Office: 1993-793-071.

Forman, R.T.T., and M. Godron. 1986. Landscape ecology. John Wiley and Sons, New York,

NY.

Franklin, J.F. 1993. Preserving biodiversity: Species, ecosystems, or landscapes? Ecological

Applications, 3(2):202-205.

Freemark, K.E., C. Hummon, D. White, and D. Hulse. 1996. Modeling risks to biodiversity in

past, present, and future landscapes. Technical Report No. 268, Canadian Wildlife Service,

Headquarters, Environment Canada, Ottawa K1A 0H3. 60 pp.

Gabrielson, I.A. and S.G. Jewett. 1940. Birds of Oregon. Oregon State College, Corvallis, Oregon.

Gilligan, J. D. Rogers, M. Smith, and A. Contreras, eds. 1994. Birds of Oregon: Status and

Distribution. Cinclus Publications, McMinnville, Oregon.

Grossman, D., K.L Goodin, X. Li, C. Wisnewski, D. Faber-Langendoen, M. Anderson, L. 

Sneddon, D. Allard, M. Gallyoun, and A. Weakley. 1994. Standardized national

vegetation classification system. Report by The Nature Conservancy and Environmental

Systems Research Institute for the NBS/NPS Vegetation Mapping Program. National

Biological Service, Denver, Colorado.

Hall, E.R. and K.R. Kelson. 1959. The Mammals of North America. Ronals Press Company, New

York.

IRICC. 1994. Summary of Coordination Results. Unpublished document, Inter-organizational

Resource Information Coordination Council, Pacific Coast States, Portland, OR.

Jenkins, R.E. 1985. Information methods: Why the Heritage Programs work. The Nature

Conservancy News 35(6):21-23.
74

Jennings, M.D. 1993. Natural terrestrial cover classification: Assumptions and definitions. Gap

Analysis Technical Bulletin 2. Idaho Cooperative Fish and Wildlife Research Unit,

University of Idaho, Moscow.

Johnson, D.H. and T.A. O’Neil. 1997. A vegetation, land use, and habitat classification for the

terrestrial and aquatic systems of Oregon and Washington. Wildlife habitats and species 

associations in Oregon and Washington; Progress Report # 3. 167 pp.

Johnson, D., T. O’Neil, Bettinger, K. and M. VanderHeyden. 1999. Wildlife habitats and 

Species Associations in Oregon and Washington: Building a Common Understanding for 

Management. Book in preparation. Oregon State University Press; Corvallis, Oregon.

Kagan, J.S. and S. Caicco. 1992. Manual of the Actual Vegetation of Oregon. US Fish & Wildlife

Service, Biological Resources Division-GAP analysis program, Portland, Or.

Keisling, P. 1999. Oregon Blue Book, 1999-2000. Secretary of State’s Office, Salem, OR. Tim

Torgerson, editor. 431 pp.

Kiester, A.R,, J.M. Scott, B. Csuti, R. Noss, B. Butterfield, K. Sahr, and D. White. 1996. 

Conservation prioritization using GAP data. Conservation Biology 10(5):1332-1342.

Kiilsgaard, C.W. 1999. Land Cover Type Descriptions Oregon Gap Analysis 1998 Land Cover for

Oregon. Oregon Natural Heritage Program, Portland, OR. 72 pp.

Kirkpatrick, J.B. 1983. An iterative method for establishing priorities for the selection of nature

reserves: An example from Tasmania. Biological Conservation 25:127-134.

Küchler, A.W., and I.S. Zonneveld, eds. 1988. Vegetation mapping. Kluwer Academic

Publishers, Dordrecht, The Netherlands. 635p.

Levin, S.A. 1981. The problem of pattern and scale in ecology. Ecology, 73:1942-1968.

Lins, K.S., and R.L. Kleckner. 1997. Land cover mapping: An overview and history of the

concepts. In: J.M. Scott, T.H. Tear, and F. Davis, eds., Gap Analysis: A landscape

approach to biodiversity planning. American Society for Photogrammetry and Remote

Sensing, Bethesda, Maryland.

Loy, W.G. 1976. Atlas of Oregon. University of Oregon Books, Eugene, OR.

McNab, W.H. and P.E. Avers. 1994. Ecological Subregions of the United States: Section

Descriptions. USDA Forest Service, Ecosystem Management Publication, Washington,

DC. 

Margules, C.R., A.O. Nicholls, and R.L. Pressey. 1988. Selecting networks of reserves to maximize

biological diversity. Biological Conservation 43:63-76

Miller, K.R. 1994. In J.A. McNeely and K.R. Miller, editors. National parks conservation and 

development. Smithsonian Institution, Washington, D.C.

Miller, R.F. and P.E. Wigand. 1994. Holocene Changes in Semiarid Pinyon-Juniper Woodlands.

Bioscience, Vol. 44, No. 7: 465-474.

Mueller-Dombois, D., and H. Ellenberg. 1974. Aims and methods of vegetation ecology. John

Wiley & Sons, New York. 547pp.

Nicholls, A.O., and C.R. Margules. 1993. An upgraded reserve selection algorithm. Biological

Conservation 64:165-169.

Noss, R.F. 1987. From plant communities to landscapes in conservation inventories: A look at

The Nature Conservancy (USA). Biological Conservation 41:11-37.

Noss, R.F. 1990. Indicators for monitoring biodiversity: A hierarchical approach. Conservation

Biology, 4:355-364.

Noss, R.F. 1991. Report to the Fund for Animals in Washington, D.C.
75

Noss, R.F., and A.Y. Cooperrider. 1994. Saving nature’s legacy. Island Press, Washington, 

D.C.

Noss, R. F., E. T. LaRoe III, and J. M. Scott. 1995. Endangered ecosystems of the United

States: A preliminary assessment of loss and degradation. Biological Report 28, National

Biological Service, Washington, D.C. 

Nussbaum, R.A., E.D. Brodie and R.M. Storm. 1983. Amphibians and Reptiles of the Pacific

Northwest. University of Idaho Press, Moscow, Idaho.

Odum, E.D., and H.T. Odum. 1972. Proceedings of the North American Wildlife and Natural 

Resources Conference 39:178.

O’Neil, T.A., R.J. Steidl, W.D. Edge, and B. Csuti. 1995. Using wildlife communities to improve

vegetation classification for conserving biodiversity. Conservation Biology 9 (6):1482-1491

Oregon Biodiversity Project (OBP). 1998. Oregon’s Living Landscape: Strategies and

Opportunities to Conserve Biodiversity. Defenders of Wildlife, Portland, Oregon.

Oregon Ocean Policy Advisory Council. 1994. Territorial Sea Plan, State of Oregon. 800 NE

Oregon St. # 18, Portland, OR 97232. 250pp.

Pater, D.E., S.A. Bryce, T.D. Thorson, J. Kagan, C. Chappell, J.M. Omernik, S.H. Azevedo, and

A.J. Woods. 1998. Ecoregions of Western Washington and Oregon. US Environmental

Protection Agency, Corvallis, OR.

Pressey, R.L.,and A.O. Nicholls. 1989. Application of a numerical algorithm to the selection of

reserves in semi-arid New South Wales. Biological Conservation 50:263-278.

.Pressey, R.L., C. J. Humphries, C. R. Margules, R. I. Vane-Wright, and P. H. Williams. 1993. 

Beyond opportunism: Key principles for systematic reserve selection. Trends in Ecology

and Evolution 8:124-128.

Rathert, D., D. White, J.C. Sifneos and R.M. Hughes. 1999. Environmental correlates of species

richness for native freshwater fish in Oregon, U.S.A. Journal of Biogeography, 26, 257-273.

Ride, W.L.D. 1975. In F. Fenner, editor. A national system of ecological reserves in Australia. 

Australian Academy of Sciences Report No. 19. Canberra, Australia 64 pp.

Scott, J.M., and M.D. Jennings, editors. 1994. A handbook for Gap Analysis. Idaho Cooperative

Fish and Wildlife Research Unit, University of Idaho, Moscow, Idaho.

Scott, J.M., F. Davis, B. Csuti, R. Noss, B. Butterfield, C. Groves, H. Anderson, S. Caicco, F. 

D'Erchia, T.C. Edwards, Jr., J. Ulliman, and G. Wright. 1993. Gap analysis: A

geographic approach to protection of biological diversity. Wildlife Monographs 123.

Specht, R.L. 1975. The report and its recommendations. Pages 11-16 in: F.Fenner, ed., A

national system of ecological reserves in Australia. Australian Academy of Sciences Report

No. 19. Canberra, Australia.

Specht, R.L., E.M. Roe, and V.H. Boughlon. 1974. Australian Journal of Botany Supplement 

Series. Supplement No. 7.

Stoms, D.M. 1994. Actual vegetation layer. In J.M. Scott and M.D. Jennings, editors. A

handbook for Gap Analysis. Idaho Cooperative Fish and Wildlife Research Unit,

University of Idaho, Moscow.

.Stoms, D.M. and J. Estes. 1993. A remote sensing research agenda for mapping and monitoring

biodiversity. International Journal of Remote Sensing, 14:1839-1860.

UNESCO. 1973. International classification and mapping of vegetation. Paris.
76

Verts, B..J. and L.N. Carraway. 1984. Keys to the Mammals of Oregon. OSU Bookstores, Inc.

Corvallis, OR.178 pp.

 . 1998. Land Mammals of Oregon. University of California Press,

Berkeley and Los Angeles, CA. 667 pp.

Williams, P. H., D. Gibbons, C. Margules, A. Rebelo, C. Humphries, and R. Pressey. 1996. A

comparison of richness hotspots, rarity hotspots, and complementary areas for conserving

diversity of British birds. Conservation Biology 10:155-174.

Wilson, U.W. and D.M. Reeder. 1993. Mammal Species of the World: A taxonomic and geographic

reference, Second Edition. Smithsonian Institution Press, Washington, DC.

White D., A.J. Kimerling, and W.S. Overton. 1992. Cartographic and geometric components of a

global sampling design for environmental monitoring. Cartography and Geographic

Information Systems 19(1):5-22.

White, D., E.M. Preston, K.E. Freemark, and A. R. Kiester. 1999. A Hierachical Framework for

Conserving Biodiversity. Chapter 8, pages 127-153 in Landscape Ecological Analysis:

Issues and Applications, Jeffrey M. Klopatek and Robert H. Gardner, editors, SpringerVerlag, New York, 1999. ISBN 0-387-98325-2.

Whittaker, R.H. 1960. Vegetation of the Siskiyou mountains, Oregon and California. Ecological

Monographs 30(3):279-338.

Whittaker, R.H. 1965. Dominance and diversity in land plant communities. Science, 147: 250-

259.

Whittaker, R.H. 1977. Species diversity in land communities. Evolutionary Biology 10:1-67.
77

GLOSSARY OF TERMS

aerial videography - video images of the land surface taken from an airplane algorithm - a

procedure to solve a problem or model a solution (In GAP typically refers to a GIS procedure

used to model animal distributions.)

alliance level - a land unit made up of an "alliance" of natural communities that have the same

dominant or co-dominant plant species or, in the absence of vegetation, by the dominant land

cover typically described according to the Anderson land cover classification (see "Natural

Community Alliance" in Grossman et al. 1995) 

alpha diversity - a single within-habitat measure of species diversity regardless of internal

pattern, generally over an area of 0.1 to 1,000 hectares (see Whittaker 1960, 1977)

Anderson Level II - the second hierarchical level in the Anderson land cover classification

system (see Anderson et al. 1976)

anthropogenic - caused by man

assemblages - a group of ecologically interrelated plant and animal species

band, spectral - a segment of the electromagnetic spectrum defined by a range of wavelengths

(e.g. blue, green, red, near infrared, far infrared) that comprise the Landsat TM imagery

beta diversity - the change in species diversity among different natural communities of a

landscape; an index of between-habitat diversity (see Whittaker 1960, 1977) 

biodiversity - generally, the variety of life and its interrelated processes

biogeographic - relating to the geographical distribution of plants and animals

biological diversity - see biodiversity

cartographic - pertaining to the art or technique of making maps or charts

classify - to assign objects, features, or areas on an image to spectral classes based upon their

appearance as opposed to ‘classification’ referring to a scheme for describing the hierarchies of

vegetation or animal species for an area

coarse filter - the general conservation activities that conserve the common elements of the

landscape matrix, as opposed to the "fine filter" conservation activities that are aimed at special

cases such as rare elements (see Jenkins 1985) 

community - a group of interacting plants and animals

cover type - a non-technical higher-level floristic and structural description of vegetation cover
78

cross-walking - matching equivalent land cover categories between two or more classification

systems

delineate - identifying the boundaries between more or less homogenous areas on remotely

sensed images as visible from differences in tone and texture

delta diversity - the change in species diversity between landscapes along major climatic or

physiographic gradients (see Whittaker 1977) 

digitization - entering spatial data digitally into a Geographic Information System

ecoregion - a large region, usually spanning several million hectares, characterized by having

similar biota, climate, and physiography (topography, hydrology, etc.)

ecosystem - a biological community (ranging in scale from a single cave to millions of hectares),

its physical environment, and the processes through which matter and energy are transferred

among the components

edge-matching - the process of connecting polygons at the boundary between two independently

created maps, either between TM scenes or between state GAP data sets

element - a plant community or animal species mapped by GAP. May also be referred to as

"element of biodiversity"

error of commission - the occurrence of a species (or other map category) is erroneously

predicted in an area where it is in fact absent

error of omission - when a model fails to predict the occurrence of a species that is actually

present in an area

exact set coverage - a basic optimization problem to determine the best method for identifying

general areas that, when selected sequentially, would have the greatest positive cumulative

impact on attaining adequate representation of any or all biotic elements of interest 

extinction - disappearance of a species throughout its entire range

extirpation - disappearance of a species from part of its range 

fine filter - see "coarse filter" 

floristic - pertaining to the plant species that make up the vegetation of a given area

formation level - the level of land cover categorization between Group and Alliance describing

the structural attributes of a land unit, for example, "Evergreen Coniferous Woodlands with

Rounded Crowns" (see Jennings 1993)
79

gamma diversity - the species diversity of a landscape, generally covering 1,000 to 1,000,000

hectares, made up of more than one kind of natural community (see Whittaker 1977) 

gap analysis - a comparison of the distribution of elements of biodiversity with that of areas

managed for their long-term viability to identify elements with inadequate representation

geographic information systems - computer hardware and software for storing, retrieving,

manipulating, and analyzing spatial data

Global Positioning System (GPS) - an instrument that utilizes satellite signals to pinpoint its

location on the earth's surface

greedy heuristic - an algorithm for exact set cover analysis (see Kiester et al., 1996)

ground truthing - verifying maps by checking the actual occurrence of plant and animal species

in the field at representative sample locations

habitat - the physical structure, vegetational composition, and physiognomy of an area, the

characteristics of which determine its suitability for particular animal or plant species

hectare - a metric unit of area of 10,000 square meters and equal to 2.47 acres

hex/hexagon - typically refers to the EPA EMAP hexagonal grid of 635 square kilometer units

hyperclustering - an efficient, interactive method for accurately analyzing and classifying

remotely-sensed data that reduces data size and computational requirements while retaining the

integrity of the original data

lotic - flowing, e.g., water in a stream or river

metadata - information about data, e.g., their source, lineage, content, structure, and availability

minimum mapping unit - the smallest area that is depicted on a map

neotropics - the zoo-geographic region stretching southward from the Tropic of Cancer and

including southern Mexico, Central and South America, and the West Indies

phenology - the study of periodic biological phenomena, such as flowering, breeding, and

migration, especially as related to climate

phenotype - the environmentally and genetically determined observable appearance of an

organism, especially as considered with respect to all possible genetically influenced

expressions of one specific character 

physiognomic - based on physical features
80

physiographic province - a region having a pattern of relief features or land forms that differ

significantly from that of adjacent regions

pixel - the smallest spatial unit in a raster data structure 

polygon - an area enclosed by lines in a vector-based Geographic Information System data layer

or a region of contiguous homogeneous pixels in a raster system

preprocessing - those operations that prepare data for subsequent analysis, usually by attempts to

correct or compensate for systematic, radiometric, and geometric errors

pro-active - acting in anticipation of an event as opposed to reacting after the fact

range - the geographic limit of the species

range unit - a spatial, geographic unit to record and display species geographic range

reach - a stream or river segment between inflowing tributaries

registration, spatial - matching different images to each other by finding points on the images

that can be matched to known points on the ground

remote sensing - deriving information about the earth's surface from images acquired at a

distance, usually relying on measurement of electromagnetic radiation reflected or emitted from

the feature of interest

resolution - the ability of a remote sensing system to record and display fine detail in a

distinguishable manner, or the smallest feature that can be distinguished or resolved on a map or

image, such as a TM pixel

scale, map - the ratio of distance on a map to distance in the real word, expressed as a fraction;

the smaller the denominator, the larger the scale, e.g. 1:24,000 is larger than 1:100,000 

sensitivity analysis - the consideration of a number of factors involved in the mathematical

modeling of an ecosystem and its components. These include feedback and control, and the

stability and sensitivity of the system as a whole to changes in some part of the system.

Predictions can be made from the analysis.

simulated annealing - an algorithm used for set coverage analysis (see Kiester et al. 1996)

species richness - the number of species of a particular interest group found in a given area

spectral cluster - a group of adjacent pixels that are uniform with respect to their brightness

values
81

supervised classification - the process of classifying TM pixels of unknown identity by using

samples of known identity (i.e., pixels already assigned to informational classes by ground

truthing or registration with known land cover) as training data 

synoptic - constituting a brief statement or outline of a subject; presenting a summary

tessellation - the division of a map into areas of equal and uniform shape such as the EPAEMAP hexagon

Thematic Mapper - a sensor on LANDSAT 4 and 5 satellites that records information in seven

spectral bands, has a spatial resolution of about 30 m x 30 m, and represents digital values in

256 levels of brightness per band

transect - a transversely cut line along which physical and biological observations are made

trophic structure - the various levels in a food chain, such as producers (plants), primary

consumers (herbivores), and secondary consumers (carnivores)

Universal Transverse Mercator - one of several map projections or systems of transformations

that enables locations on the spherical earth to be represented systematically on a flat map 

Universal Transverse Mercator grid - a geographic reference system used as the basis for

worldwide locational coding of information in a GIS or on a map

unsupervised classification - the definition, identification, labeling, and mapping of natural

groups, or classes, of spectral values within a scene. These spectral classes are reasonably

uniform in brightness in several spectral channels. 

vector format - a data structure that uses polygons, arcs (lines), and points as fundamental units

for analysis and manipulation in a Geographic Information System 

virtual reality - a computer-generated simulation of reality with which users can interact using

specialized peripherals such as data gloves and head-mounted computer graphic displays

wildlife habitat relationship model - a method of linking patterns of known habitat use by animal

species with maps of existing vegetation, thereby identifying the spatial extent of important

habitat features for use in conservation and management.
82

GLOSSARY OF ACRONYMS

ACSM American Congress on Surveying and Mapping

ADAMAS Aquatic Database Management System

AML ARC/INFO Macro Language

ASPRS American Society for Photogrammetry & Remote Sensing

AVHRR Advanced Very High Resolution Radiometer (satellite system)

BEST Biomonitoring of Environmental Status and Trends

BLM Bureau of Land Management

CAFF Conservation of Arctic Flora and Fauna

C-CAP Coastwatch Change Analysis Program (NOAA)

CDC Conservation Data Center

CEC Council on Environmental Cooperation

CENR Committee on Environment and Natural Resources

CERES California Environmental Resources Evaluation System

CIESIN Consortium for Internat'l Earth Science Information Network

CODA Conservation Options and Decision Analysis (software)

CRMP Coordinated Resource Management Plan

CRUC Cooperative Research Unit Center

DLG-E Digital line graph - enhanced

DOI Department of the Interior

EDC EROS Data Center

ECOMAP National Hierarchical Framework of Ecological Units mapping project of the USFS

EMAP Environmental Monitoring & Assessment Program

EMAP-LC EMAP-Landscape Characterization (USEPA)

EMSL Environmental Monitoring & Systems Laboratory (USEPA)

EMTC Environmental Management Technical Center (NBS)

EOS Earth Observing System

EOSAT Earth Observation Satellite Company (the operator of the Landsat satellite system)

EOSDIS EOS Data & Information System

ERL Environmental Research Laboratory, Corvallis (USEPA)

EROS Earth Resources Observation Systems (USGS)

ESRI Environmental Systems Research Institute

ETM+ Enhanced Thematic Mapper plus

FGDC Federal Geographic Data Committee

FTP file transfer protocol

FY Fiscal Year

GAO General Accounting Office (Congress)

GAP Gap Analysis Program

GCDIS Global Change Data and Information System

GLIS Global Land Information System (USGS)

GLOBE Global Learning and Observations to Benefit the Environment

GPS Global Positioning System

GRASS Geographic Resources Analysis Support System

GRIS Geographic Resource Information Systems
83

HRMSI High Resolution Multispectral Stereo Imager

IALE International Association of Landscape Ecology

IDRISI A GIS developed by Clark University

LAPS Land Acquisition Priority System

LC/LU Land Cover/Land Use (USGS)

MIPS Map and Image Processing System

MMU Minimum mapping unit

MOU Memorandum of Understanding

MRLC Multi-Resolution Land Characteristics Consortium 

MSS Multi-Spectral Scanner

MTPE Mission to Planet Earth

NAFTA North American Free Trade Agreement

NALC North American Landscape Characterization (USEPA, USGS)

NAWQA National Water Quality Assessment (USGS)

NBII National Biological Information Infrastructure

NBS National Biological Service

NCCP Natural Communities Conservation Planning program (in CA)

NDCDB National Digital Cartographic Data Base

NERC National Ecology Research Center (Ft. Collins, CO)

NMD National Mapping Division

NPS National Park Service

NSDI National Spatial Data Infrastructure

NSTC National Science and Technology Council

NWI National Wetlands Inventory (USFWS)

OMB Office of Management and Budget (Administration)

PARC Public Access Resource Center

PI Principal Investigator

RMSE Root mean square error

SAB Science Advisory Board (USEPA)

SCICOLL Scientific Collections Permit Database

SDTS Spatial Data Transfer Standard

SGID State Geographic Information Database

SNEP Sierra Nevada Ecosystem Project

SOFIA Southern Forest Inventory and Analysis

SPOT Système Pour l'Observation de la Terre

TIGER Topologically Integrated Geographic Encoding and Referencing (used for U.S. census)

TM Thematic Mapper

TNC The Nature Conservancy

UNESCO United Nations Educational, Scientific, and Cultural Organization

URISA Urban and Regional Information Systems Association.

URL Universal Resource Locator

USFS US Forest Service

USFWS US Fish & Wildlife Service

UTM Universal Transverse Mercator

WHRM Wildlife/habitat relationship model
84

Appendix 1.1 - List of Example GAP Applications

Businesses and Non-government Organizations:

The following are some examples of applications of GAP data by the private sector:

• The Wyoming Natural Heritage Program (a private non-government organization)

transformed the endangered and sensitive species database into a spatially referenced digital

geographic information system using the GAP digital base map and other GAP spatial data.

• Hughes Corp. is experimenting with the Utah and Nevada GAP digital base maps,

simulating images to aid the development of new space-based remote sensing devices.

• The Nature Conservancy used the Wyoming GAP data to develop a map of ecoregions of

Wyoming.

• Weyerhaeuser Corp. is using the Arkansas GAP data in managing their lands in Arkansas.

• IBM Corp. is funding a project at the University of California, Santa Barbara, that, in part,

uses GAP data in the development of visualization software.

• NM-GAP vegetation data is being used for an environmental assessment of a proposed

spaceport, a state/private venture.

County and City Planning:

Some other examples of the use of GAP by local governments are:

• CA-GAP biological data were combined with the Southern California Association of

Governments (SCAG) land ownership data to show which ownerships and jurisdictions

were needed for joint conservation planning and management of a particular natural

community or species, maximizing efficiency and minimizing the potential for yet another

conservation crisis.

• In California, county and city planners of several jurisdictions, wildlife agencies, developers

of the 4S Ranch property, and the state Natural Communities Conservation Planning

program used the GAP regional data, as well as more detailed information, to conserve

1,640 acres of habitat within a 2,900-acre planned development.

• County planners in Piute County, Utah used GAP data to optimize the siting of a proposed

sawmill for aspen with respect to the distribution of aspen stands.

• Missoula County, Montana, used the GAP land cover map of the area as a base map for its

comprehensive long-range plan.

• Snohomish County, Washington, used the GAP land cover map in meeting state

requirements for a growth management plan.

• The City of Bainbridge Island, Washington, used GAP data to assist them in development

of a watershed planning project.

State Uses:

The following are some examples of uses of GAP data by state agencies.

• The GAP database of species habitats was used by the Tennessee Wildlife Resources

Agency (TWRA) to update its book “Species in Need of Management.”

• Images of land cover derived from GAP TM data are used by TWRA for locating particular

habitat types. Information on the locations of these habitat types is provided by TWRA to

the public for a wide variety of public service functions, from education to cooperative

resource management.

• Early GAP data developed by TWRA were used to help identify an important area of the

state with high biodiversity that was subsequently purchased by the state for conservation.
85

• Preliminary findings from GAP were used by TWRA to develop three resource management

initiatives.

• The Tennessee GAP project, which is being carried out primarily by TWRA, is the

foundation of a multi-agency, long-term biodiversity program for Tennessee.

• GAP data have been used by the Tennessee Forestry Stewardship Program to help develop a

district program for nine conservation planning districts, outlining Best Management

Practices (BMPs) for biological conservation on private lands.

• GAP data are being used extensively by TWRA in the preparation of project proposals to

the North American Waterfowl Conservation Program. These proposals require that

biodiversity issues are addressed in specific detail. The use of GAP data on occurrence of

land cover types and terrestrial vertebrates has made this possible.

• The Wyoming Department of Fish and Game (WYF&G) used GAP data to assist them in

transforming the Wildlife Observation System database into a spatially referenced

geographic information system.

• The Utah Division of Wildlife Resources and the Bear River Water Conservancy District

used the Utah GAP land cover map in a resource management assessment for mitigating

conflicts between a proposed groundwater withdrawal project and the maintenance of an elk

calving area in the Uinta Mountains.

• The Utah Division of Wildlife Resources, the Rocky Mountain Elk Foundation, and Sheik

Safari International used the Utah GAP land cover map to identify critical elk habitat. The

environmental profile of these areas was then used to identify other similar areas for elk

habitat enhancement.

• The Utah Division of Wildlife Resources used the Utah GAP land cover map for a rapid

ecological assessment of the Echo Henefer Wildlife Management Area.

• The Washington Department of Fish and Wildlife used GAP data to develop a breeding bird

atlas and an atlas of mammals of Washington State.

• The Washington Department of Fish and Wildlife uses GAP data to operate an integrated

landscape management program.

• The Washington Department of Fish and Wildlife uses GAP data from Eastern Washington

to assist with an innovative program that brings the forest products industry, state agency

biologists, non-government organizations, and tribal biologists together in the field to

jointly determine the appropriate management practices for any particular site of concern

(Timber, Fish & Wildlife Program).

• The Idaho Department of Fish and Game used GAP data to evaluate the impact from

expanded military training activities on public lands in Southern Idaho.

• The Idaho Department of Fish and Game uses GAP data for regional planning efforts on a

regular basis.

Statewide Planning:

Biodiversity planning programs or projects are now under way or have been completed in

Arizona, California, Colorado, Maine, Missouri, Nevada, Oregon, and Tennessee. It is likely

that similar efforts will develop in other states. In some cases, these efforts grew out of the state

GAP project, however, in most cases, the GAP data are being used to meet a previously defined

need. In all cases, GAP data are central to their development and operations. The goals of each

of these programs or projects are presented briefly below.
86

Federal Agency Applications:

Some examples of applications of GAP data by federal agencies follow:

• GAP data are being supplied to all military installations in the Great Basin ecoregion for

integrated management of the natural resources. These installations constitute a very large

amount of land area. Much of it is of high value for native species.

• The Ouachita National Forest used the Arkansas GAP data to help them develop an

ecosystem management plan.

• The Wyoming GAP data were used by NASA to calibrate a model that predicts vegetation

types based on climate and soil variables.

• The potential contributions to biodiversity conservation of four different options proposed

for new wilderness designation in Idaho were quantified by the Idaho Cooperative Fish and

Wildlife Research Unit in cooperation with the Park Studies Unit.

• The potential contributions to biodiversity conservation of four different options proposed

for new national park designation in Idaho were quantified by the Idaho Cooperative Park

Studies Unit.

• The U.S. Forest Service in Booneville, Arkansas, used the Arkansas GAP data land cover

maps in a 3-dimensional presentation to provide the public with a visual representation of

the region and to enhance the public’s involvement with the National Forest planning

process.

• The U.S. Fish and Wildlife Service regularly uses the GAP data for Southern California for

habitat evaluation and management.

• The U.S. Forest Service, Bureau of Land Management, and National Park Service are using

the GAP data for a wide variety of natural resource management operations in Utah. For

example, the entire Utah GAP database is directly linked with existing National Park

Service databases for use by National Parks.

• The Bureau of Land Management uses the Wyoming GAP data for managing the Buffalo

Resource Area.

• The U.S. Forest Service used the Utah GAP data to help assist them in evaluating humaninduced impacts to forested lands surrounding ski resorts in central Utah.

• The U.S. Fish and Wildlife Service in Delaware used GAP data to help identify potential

habitat for the federally endangered Delmarva fox squirrel. These maps were displayed and

served as a catalyst for bringing together people with a stake in the issue.

• The U.S. Fish and Wildlife Service used the Indiana GAP data as part of a biological

assessment for the base closure of the Jefferson Proving Grounds and its conversion to a

National Wildlife Refuge. This 58,000-acre installation has restricted human access due to

unexploded ordinance and contains some of the highest quality natural habitat in Indiana.

• The U.S. Fish and Wildlife Service in Louisiana used GAP data to avoid conflict over the

designation of critical habitat of the federally endangered Louisiana black bear.

• The U.S. Natural Resources Conservation Service in New Mexico is using a GAP

clustered imagery as a base for their land cover mapping activities.

• The Department of Defense (DoD) is funding the development of an electronic

environmental information system for the Mojave ecoregion, which would use GAP data as

a foundation or base layer of information. The system will link 29 DoD installations to a

common source of environmental information.
87

Appendix 1.2 - Descriptions of Oregon’s Ecoregions

Coast Range

The Coast Range Ecoregion includes the entire Oregon coastline and the northern and central

Oregon Coast Range Mountains, and extends north though the state of Washington to

southwestern British Columbia on Vancouver Island, and south into California. Elevations in

the Oregon Coast Range Ecoregion range from sea level to 4,000 feet, and the marine climate

creates the most moderate and wettest habitats in the state. Average annual precipitation of 60

to 180 inches supports spectacular stands of temperate rainforests. Vegetation is characterized

by forests of Sitka spruce, western hemlock, Douglas fir and red alder.

The Oregon coast has other unique ecological features. Sand deposits from coastal streams and

rivers (primarily the Umpqua and Columbia Rivers) have created major coastal dune systems,

the largest located at the Oregon Dunes National Recreation Area. In the north coast, steep

headlands and cliffs are separated by stretches of flat coastal plain and large estuaries. The

south coast includes the warmest areas, with rugged headlands and very mild winters, supporting

local endemic species such as the coast redwood and Port Orford cedar.

Almost 40% of the region is in public ownership, primarily in National Forest and State Forest

lands. Population is dispersed in many small towns, most located within a few miles of the

ocean. Forest products, tourism and fisheries are the mainstays of the local economy. The

Coast Range Ecoregion includes all of Oregon’s coastal resources, including all of the intertidal,

marine and estuarine habitats. These resources are currently not well represented in Oregon’s

system of natural areas. The publication of the Territorial Sea Plan (Oregon Ocean Policy

Advisory Council,1994) has created an excellent opportunity to better protect Oregon's marine

and intertidal resources.

Willamette Valley

The Willamette Valley Ecoregion is located between the Coast Range and the Western Cascades

in northwestern Oregon and includes Oregon’s largest river valley. From Oregon it extends

north to include the Vancouver, Washington bottomlands. The valley is characterized by broad,

alluvial flats and low basalt hills. Soils include deep alluvial silts from river deposits and dense

heavy clays from pluvial deposits in the valley bottom's numerous oxbow lakes and ponds. 

The abundant rainfall and fertile soils make the valley Oregon’s most important agricultural

region. This has been the case since the first settlers began arriving via the Oregon trail. As a

result, the Willamette Valley is Oregon’s most altered ecoregion.

Originally, the valley was a mosaic of gallery riparian forests and wetlands, open white oak

savannas and prairie, with valley margins of oak, ponderosa pine and Douglas fir woodlands. 

Native Americans maintained the prairies, oak savannas and woodlands by regularly burning

most of the valley. With settlement, the prairies have been largely farmed and the open oak

savannas and oak-conifer woodlands have been logged or become closed canopy forests.
88

The Willamette Valley is home to most Oregonians, with more than 70% of the state's

population, the majority of its industry, and almost half of its farmland. It is also the fastest

growing ecoregion, with the human population expected to double in the next 25 years.

The Willamette Valley's location on the Pacific Flyway makes it an important area for migrating

and wintering waterfowl. Geese and shorebirds benefit from flooded agricultural lands, and the

Willamette River and its many tributaries support salmon and steelhead runs, mostly of hatchery

origin due to the large number of dams in the system. The valley’s few remaining fragments of

native prairie support many special plant species and endemic invertebrates, while the

remaining wetlands provide habitat to the Oregon chub, the western pond turtle and many other

sensitive animal species.

Klamath Mountains

The Klamath Mountains Ecoregion covers most of southwestern Oregon and northwestern

California and includes the Siskiyou Mountains, California’s Marble Mountains and Trinity

Alps and the interior valleys and foothills between these mountain ranges. Elevations range from

100 to over 7,500 feet. Valley bottoms in the interior generally range between 450 feet elevation

in the north around Roseburg to almost 2,000 feet at Ashland near the California border.

The ecoregion has the oldest landscapes in Oregon and is one of the few areas of the state not

shaped largely by volcanism. It also is by far the most geologically diverse, having large areas

of metamorphic and sedimentary rocks such as serpentine, limestone and gabbro, as well as

granites and basalt. Topography ranges from steep, dissected mountains and canyons to gentle

foothills and flat valley bottoms. The ecoregion also has major climatic extremes. Far western

portions receive more than 100 inches of rain per year, with relatively mild temperatures yearround. The southern interior valleys are much drier, with locations receiving less than 20 inches

of rain per year and summer high temperatures averaging more than 90E F. 

The combination of exceptional climatic, geologic, and topographic diversity supports the most

diverse habitats in Oregon. In addition to diverse habitats, the Klamath Mountain Ecoregion is a

floristic crossroads, including elements of the Sierra Nevada Mountains, Sacramento Valley and

Coast Range Mountains of California; the Cascade Mountains of Oregon and Washington; and

the Great Basin to the east. 

Because of its geologic age, stable climate, and many unusual habitats, the ecoregion is a major

center of species endemism for vascular plants. Of the 4,000 native plant species or subspecies

occurring in Oregon, about half are found in this ecoregion, with about a quarter of these known

only here. The region is also known for its diversity of conifers, with 30 different species. (In

Oregon, the West Cascades has the second largest number of conifer species, with 18 species). 

Prior to European settlement, the landscape was dominated by three major vegetation types: 

Douglas-fir forests, oak woodlands and ponderosa pine woodlands. Other significant

communities include native grasslands and chaparral which dominated the historic valley

bottoms, and Port Orford cedar forests, which have been decimated by logging and disease. All
89

of the natural habitats have changed since fire suppression became effective in the early

twentieth century. The region has a high frequency of dry, summer lightning storms, leading to

natural fire frequency of less than 40 years for most of the region, and closer to 20 years in the

valleys and eastern portions of the region. Over fifty years of fire suppression have dramatically

altered the ecology of the forests, savannas and shrublands in this region.

The human population of the ecoregion is concentrated in the valleys along the Interstate 5

corridor. Forest products, agriculture and tourism are the foundations of the local economy. 

The region is currently growing at a rate second only to the Willamette Valley.

West Cascades and Crest

The West Cascades Ecoregion extends from southern British Columbia south almost to the

California border. This mountainous, heavily forested ecoregion is bounded on the west by the

farms and woodlands of the Puget Trough and the Willamette Valley or the drier forests and

valleys of the Klamath Mountains. To the east, it spills over the crest of the Cascade Mountains

to the drier ponderosa pine forests of the East Cascades Ecoregion. 

The crest of the Cascade Range is dominated by a series of volcanic peaks. Mount Hood is the

highest peak in the state at 11,240 feet, but a dozen others top 8,000 feet. The western slopes of

the range feature long ridges with steep sides and wide, glaciated valleys. Most of the rivers

draining the northern two-thirds of the ecoregion flow into the Willamette Valley and then to the

Columbia River system; the southern third drains to the Pacific Ocean through the Umpqua and

Rogue River systems. The climate varies with elevation and, to a lesser extent, latitude. Higher

elevations receive heavy winter snows. The drier southern half has a fire regime similar to the

Klamath Mountains, with frequent lightning-caused fires. In the northern half, the natural fire

regime has historically produced less frequent but more severe fires.

The ecoregion is almost entirely forested and the flora and fauna are similar to that of the Coast

Range Ecoregion. Douglas-fir-western hemlock forests dominate large areas up to elevations of

about 3,300 feet. However, most of the previously-harvested forests of the lowlands and lower

slopes now support mixed conifer-deciduous forests, with young Douglas-fir and western

hemlock found in a mosaic with hardwood species such as bigleaf maple and red alder. Silver

fir-mountain hemlock forests occur at mid-elevations. Silver fir is common between 2,600 and

4,200 feet. Mountain hemlock is most common between 2,200 and 6,000 feet. In the higher

areas, mountain hemlock or occasionally Alaska yellow cedar, subalpine fir, or whitebark pine

woodlands open into alpine parklands with patches of forest interspersed with shrub and

meadow communities. Alpine areas feature a variety of habitats ranging from dwarf shrubs,

grasses and forbs to wetlands and barren expanses of rocks and ice. 

Forests have long been the foundation of the local economy in the West Cascades, and decades

of logging put the region at the center of controversies over the northern spotted owl, logging of

old growth forests and management of federal lands. Most of the ecoregion’s population is

found in small towns in the river valleys where increasing recreation use supplements the

traditional timber-based economy.
90

East Cascades

The East Cascades Ecoregion is a transition zone that extends from below the crest of the

Cascade Range east to where the ponderosa pine zone meets the sagebrush-juniper steppe. The

ecoregion also extends north into Washington and south into California. In Oregon, the

ecoregion is variable, including extensive lodgepole forests on deep Mazama ash, the montane

and foothill Ponderosa pine forests, Klamath Basin lakes and wetlands, and many diverse

montane forests. 

The eastern slopes of the Cascades are drier than the western slopes, with annual rainfall ranging

from 14-26 inches per year. The ecoregion is less steep and cut by fewer streams than the west

side of the mountain range. It is also predominantly covered by conifer forests growing on

volcanic soils. The northern two-thirds of the East Cascades is drained by the Deschutes River

system, which includes a series of large lakes and reservoirs near its headwaters. The southern

third is drained by the Klamath River, which flows south and west into California. 

The Klamath Basin, which extends into the Modoc Plateau in California, is a broad, relatively

flat mid-elevation valley that historically supported a vast expanse of lakes and marshes.

Oregon’s largest lake, Upper Klamath Lake, is the biggest remnant of this wetland system. Most

of the basin’s wetlands have been drained and converted to agriculture.

The mountains on the northern and eastern edges of the Klamath Basin lack a generally accepted

name, but include a series of peaks and ridges extending from Paulina Peak near Bend

southward through the headwaters of the Williamson, Sprague and Chewaucan Rivers to the

Warner Mountains east of Lakeview. These mountains are generally forested, but the valleys and

flats between them include large marshes, irrigated meadows and pastures, and arid juniper and

sagebrush steppes. These habitats are a critical part of the Pacific Flyway, supporting vast

number of shorebirds and waterfowl, the densest wintering concentration of bald eagles in the

world, and many other wildlife species.

Also of significance is the broad ecological zone found at the northern end of this region in

Oregon, where the Columbia River Gorge created the only Oregon white oak zone in eastern

Oregon - and a wealth of diversity. This Columbia Gorge transition zone, the extensive

Ponderosa pine forests and woodlands, and the vast wetlands of the Klamath and upper

Deschutes basin characterize this region.

The ecoregion’s human population is concentrated in the cities of Hood River, Bend and

Klamath Falls. Forest products, agriculture, recreation and tourism are the biggest contributors

to local economies.

Columbia Basin

The Oregon portion of the Columbia Basin Ecoregion (sometimes referred to as the Umatilla

Plateau) extends from the eastern slopes of the Cascades Mountains south and east from the

Columbia River to the Blue Mountains. The ecoregion also extends northward throughout most

of eastern Washington, including a small portion of west central Idaho. The region includes the
91

Columbia Basin proper, and the Palouse, which is recognized by many geographers as a separate

region.

The Columbia River, with its historic floods and large deposits of loess (wind-borne silt and

sand) from the end of the last ice age, has greatly influenced the region. Most of the Oregon

portion of the ecoregion is a lava plateau broken by basalt canyons carved out by the Deschutes,

John Day, and Umatilla rivers and other streams that flow into the Columbia River. The climate

is arid, with cold winters and hot summers. Most of the ecoregion receives less than 15 inches

of precipitation per year (some areas as little as eight inches), much of that in the form of snow. 

The majority of the ecoregion’s natural vegetation is native bunchgrass prairie, often called

palouse prairie because of the deep, loess soils and plentiful bunchgrass. The majority of the

ecoregion in Washington was originally sagebrush steppe. Sandy deposits along the Columbia

River support open dunes, grasslands, bitterbrush and sagebrush steppe, and western juniper. A

few species of ground-squirrel and plants (milkvetch species among others) adapted to these

habitats. The rivers are generally characterized by intermountain riparian vegetation, with black

cottonwood, willows, chokecherry and aspen dominating riverbanks. Less common are riparian

habitats dominated by black hawthorn and white alder.

Early travelers along the Oregon trail found vast natural grasslands broken by brushy draws and

tree- and rimrock-bordered streams with numerous springs. Because of the deep loess soils,

mild climate (due to low elevations) and the presence of adequate water (either from wells or

from the Columbia, Snake and Umatilla rivers), much of this region provided model farmland. 

The human population is concentrated in the northeastern portion of the ecoregion, where

Pendleton, Hermiston and other smaller communities serve as commercial centers for the

agricultural economy.

The Columbia Basin Ecoregion is second only to the Willamette Valley in the percentage of

landscape converted to non-native habitats and human uses. Protected areas and public lands are

very limited in this region -- with the only vegetation types that have not declined dramatically

found on lands that cannot be farmed: the steep canyon grasslands and scablands.

Blue Mountains

The Blue Mountains Ecoregion occupies nearly all of northeastern Oregon and extends into

small portions of southern Washington and western Idaho. It encompasses three major mountain

ranges -- the Ochoco, Blue and Wallowa Mountains. Landscapes include deep, rocky-walled

canyons, glacially cut gorges, dissected plateaus, broad alluvial river valleys, and numerous

mountain lakes, forests and meadows. Due to sharp elevational differences, the climate varies

over broad temperature and precipitation ranges. Overall, the ecoregion is characterized by

short, dry summers and long, cold winters. 

The flora is intermediate between the east Cascades and the western Rocky Mountains of Idaho

and Montana. Species composition changes with altitude. Sagebrush and grassland steppes

dominate the entire eastern length of the region along with significant areas along the south, and

include some of the largest and best quality bunchgrass prairies and canyon grasslands
92

remaining in North America. Ponderosa pine woodlands are characteristic at mid-elevations and

mixed coniferous forests dominate at higher altitudes. Barely half the ecoregion is forested, but

vast sections at all elevations are treeless due to dry conditions and the harsh climate.

Most of the region is thinly populated, with small towns in the major valleys and rural residents

scattered throughout the smaller valleys among the mountains. Timber, ranching, agriculture

and tourism provide the foundations for the local economy in most areas. 

The diversity in elevation, soils and climate yields diverse habitats and many endemic plant

species. The Wallowa Mountains alone have more than ten plants species found nowhere else. 

Bighorn sheep, elk and large mammal populations are among the largest in the state. The variety

in habitats, including low, mid and high elevation grasslands, shrublands and forests results in

this ecoregion having more habitat diversity than all but the Klamath Mountains Ecoregion. The

region is the headwaters for most of eastern Oregon’s rivers, and provides critical riparian and

fish habitat for more than half of the state.

High Lava Plains

The High Lava Plains is the only ecoregion contained entirely within Oregon’s borders. It is

essentially a lava plateau dissected by canyons of the Deschutes, John Day and Crooked Rivers.

Elevations in most areas are between 3,500 and 4,500 feet, but range from as low as 1,400 feet

in the Deschutes River canyon at Warm Springs to as high as 6,500 feet on higher basalt rims

and buttes rising from the plateau.

The climate is arid, with 10-20 inches of precipitation per year. Although some of eastern

Oregon’s major rivers cross the Lava Plains, most of the water originates in adjoining

ecoregions. Before the advent of modern reservoirs and irrigation systems, the plateau had no

major lakes and few large wetlands. 

Western juniper achieves its greatest dominance and diversity in this area, where it occurs in

more than 30 plant communities. Before European settlement, basin big sagebrush, native

grasslands and riparian woodlands were widespread in this region. Today, it is more common to

find irrigated alfalfa, grains and mint occupying the region’s valley bottoms and plains, while

juniper has expanded into many former shrub-steppe vegetation types.

The ecoregion can be divided into three general sections: the western high plateaus, the John

Day River basin and the upper Crooked River steppe. The western-most section, the plateau

lands along the Deschutes and lower Crooked Rivers between Bend and Madras, includes

substantial areas that have been converted to irrigated agriculture and urbanization. Rapid

population growth and increasing recreational uses have increased development pressures

dramatically in the juniper woodlands and sagebrush steppes of this area. Agriculture and

recreation are key components of an increasingly diversified economy.

The northeastern arm of the ecoregion extends from the sagebrush steppe and juniper-dominated

hills east of the Deschutes plateau to the valleys along the main stem John Day River and the

lower reaches of its north and south forks. Most of the bottomlands along the rivers have been
93

converted to agriculture. Small communities along the John Day River are supported by

agriculture, grazing, timber processing from the forests of the Ochoco and Blue Mountains and

tourism. 

The southeastern portion of the ecoregion, along the tributaries of the South Fork and mainstem

Crooked River, is made up of more arid sagebrush steppe. Livestock grazing is the primary land

use in this sparsely populated area.

Basin and Range

The Basin and Range Ecoregion is the Oregon portion of the Northern Basin and Range

Ecoregion. It includes southeastern Oregon’s high desert and extends south into Nevada to

Reno and extreme northeastern California. The ecoregion’s name reflects its topography and

geology, with numerous flat basins separated by isolated, generally north-south mountain ranges. 

Many of the mountains are fault blocks, with gradual slopes on one side and precipitous basalt

rims on the other. In Oregon, elevations range from 4,100 feet in the lowest basin to more than

9,700 feet on Steens Mountain. Soils are generally rocky and thin, low in organic matter and

high in minerals.

The climate is arid, with extreme ranges of daily and seasonal temperatures -- with the Alvord

Desert (Oregon's driest location) receiving less than 7 inches of rain annually. Runoff from

precipitation and mountain snowpacks the basins often flows into flat, alkaline playas, where it

forms seasonal shallow lakes and marshes. 

Also known as the sagebrush desert or high desert, the Basin and Range Ecoregion contains

many diverse habitats. The most significant of these are the sagebrush steppe types, salt desert

scrub, riparian and wetland types, and mountain mahogany and aspen woodlands. Sagebrush

steppe communities include Wyoming big sagebrush, basin big sagebrush, mountain big

sagebrush, silver sagebrush, black sagebrush, low sagebrush and rigid sagebrush types. The

region has Oregon’s best examples of salt desert scrub, as well as its largest playas. The large

wildlife refuges and closed basin wetlands here support some of the largest populations of

pronghorn antelope, sage grouse, white pelicans, waterfowl, and are well known for their

wildlife diversity.

This is the most sparsely inhabited ecoregion, with the small towns of Burns and Lakeview

being the only population centers. Livestock, agriculture and tourism are the foundations of the

regional economy. Lumber production, formerly a major source of employment in the Burns

and Lakeview areas, has declined with lower harvests on nearby national forests.

Owyhee Uplands

The Owyhee Uplands Ecoregion covers the extreme southeast corner of Oregon, occupying the

entire Owyhee River drainage, as well as the lower basin of the Malheur River. The ecoregion

also extends into southwestern Idaho and northern Nevada. The ecoregion has similar

vegetation as the adjacent Basin and Range Ecoregion, but differs markedly in its terrain. The
94

Owyhee Uplands landscape is basically a broad, undulating plateau cut by deep riverine

canyons. Elevations range from 2,100 to 6,500 feet, with the average elevation of the plateau at

about 4,000 feet. The climate is one of extremes, with generally moist springs and cold winters

bringing moisture in the form of snow, resulting in annual precipitation of only 8-12 inches. 

Summers are hot and dry with temperatures regularly exceeding 90o F, and the occasional

thunderstorms producing more lightning than rain.

Another important influence in the ecoregion is the geology, which is mostly of volcanic origin.

Over large portions of the landscape, soils have been derived from underlying layers of basalt

and rhyolite, or occasionally from sedimentary layers that have been exposed by erosion. Of

more interest than these ?normal soils” are soils derived from volcanic ash and welded tuffs,

which are found in distinct sites such as Leslie Gulch and Succor Creek near the Idaho border,

or the extensive recent lava flows such as Jordan Craters or Saddle Butte Lava Field. 

The weathering of the exposed volcanic ash has resulted in unique soils with a high clay content

and an unusual chemical composition. The adaptational challenge these peculiar soils present for

plants has given rise to a relatively rich flora of endemic species. The welded tuffs in these areas

have also produced remarkable rock formations that rival more well-known erosional formations

in the national parks of Utah’s Colorado Plateau country.

Diverse sagebrush steppe communities dominate most of the ecoregion, including Wyoming big

sagebrush, basin big sagebrush, mountain big sagebrush, silver sagebrush, black sagebrush, low

sagebrush and rigid sagebrush communities. Curl-leaf mountain mahogany woodlands achieve

their greatest diversity in the Mahogany Mountain area of this ecoregion. 

The ecoregion’s population is concentrated in the northeastern corner, where irrigated

agriculture in the fertile lowlands along the Snake and Malheur Rivers is the foundation of the

local economy. This area is occasionally considered part of a separate ecoregion called the

Snake River Plains. In the remainder of the region, the economy is almost entirely based on

local ranching.
95

Appendix 1.3. National Gap Analysis Project Standards - 10/26/1999

Patrick Crist and Michael Jennings

Idaho Cooperative Fish and Wildlife Research Unit

University of Idaho, Moscow, ID

Introduction

This document provides a summary of standards for conducting a Gap Analysis Project. As a

collaborative "bottom-up" effort, the National Gap Analysis Program recognizes the need for a

flexible approach at the state level. However, in order to provide ecologically meaningful

information at the bioregional and national levels, certain minimum project standards are

essential. The standards described below apply to all products delivered to the national program.

Detailed descriptions of standards for individual components are provided in the Handbook for

Gap Analysis (Scott and Jennings 1994), but note that this section references information in

specific chapters that may be in progress and therefore not yet available. For clarification,

contact the National GAP office. Projects shall indicate in their proposals, contracts, and

modifications the standards in effect at the time the agreement is developed (version number and

date). They will not be subject to later revisions of the standards but are strongly encouraged to

meet the standards in effect at the time of project completion when doing so will not result in

delay of completion or increase in project cost. In particular, this applies to file and database

field names and attribute codes which are easily revised and critical for regionalization of the

data.

A note on terminology: Because this is a summary chapter, we do not define terms or provide

citations or sources of information that are already provided in the Handbook chapters for those

specific items. See also the Glossary in the Handbook for definitions of many terms and

acronyms. We introduce with this chapter the use of the term "resolution" which replaces

Minimum Mapping Unit (MMU). GAP previously required land cover to be aggregated to a

MMU of 100 ha which suggested that nothing smaller than 100 ha should be portrayed. We no

longer make that requirement and instead state that "the resolution of this coverage is at least X

ha" to indicate the smallest mapped unit that a project should be able to portray, but it may

portray smaller features as well. This is further explained in this chapter and will be treated in

detail in the forthcoming revision of the Land Cover chapter (see Handbook table of contents for

chapter status).

Basic GAP Components and Deliverables:

The basic GIS coverages and associated databases required to complete Gap Analysis are

identified below. The list of deliverables is substantially expanded to: a) support data

regionalization and analyses, b) provide a permanent archive for the entire set of data needed for

replication, and c) provide an adequate starting point should a different facility be required to

complete the project, and d) provide a more user-friendly and complete CD-ROM distribution

product. All items are required deliverables unless otherwise described: 

1. Land Cover Data:
96

a. A GIS coverage of actual land cover by NVCS (alliance level or aggregation of alliances). 

b. The digital reference data (ground points, aerial video, etc.) used to label and assess the map.

Generally these are a deliverable if they can be delivered in a compact digital form (CD or

tape). Consult with National GAP for your particular situation. 

c. A digital manual describing the mapped land cover types. 

d. Any imagery obtained with project funds and not included in the MRLC set. 

2. Animal Modeling Data:

a. A database file of predicted species occurrence in EMAP hexagons. 

b. A database of specimen collection or sighting localities, if available. 

c. A database of species habitat associations with references. 

d. GIS coverages of the individual predicted distributions of each terrestrial vertebrate species. 

e. A "hyperdistribution" of all species in a single coverage. 

3. Land Stewardship Data:

a. A GIS coverage of land stewardship (ownership and management). 

b. A database or lookup table of all status 1 & 2 management areas with reference data. 

4. Analysis Data:

a. A database of the analysis statistics for land cover and animal species.

5. Ancillary GIS coverages and digital tabular data used to create GAP coverages, including the

USGS 30 x 60 minute quadrangle coverage.

6. A paper and digital copy of the final project report according to the standard template.

7. Graphic image files of all coverages, including all individual animal species distribution

maps, tables, charts, and outcome analyses maps produced for the written report.

Additional General Requirements:

The following are not meant to replace specific project contract language but to inform potential

GAP investigators of performance expectations.

1.Projects shall deliver a CD-ROM of all interim or completed data with their annual and final

reports. Annual deliveries prior to the final delivery do not require ancillary data or imagery,

only data actually produced by the project. 

2.Projects shall deliver all coverages according to the standards in the Data Delivery Standards,

(Appendix 1.3). 
97

3.Projects shall follow all applicable rules of the USGS Biological Resources Division (BRD) as

stated in their RWO or Cooperative Agreement when conducting Gap Analysis. 

4.Projects shall make substantial efforts to involve all organizations that can likely contribute to

the project in financial, in-kind, or advisory roles. At a minimum, workshops should be held for

all potential cooperators with invitations going to the directors as well as key program and GIS

leaders within the institutions. A newsletter is also highly recommended. They must also

participate in regional GAP coordination efforts to achieve thematic and cartographic match

between states. 

5.Projects shall make substantial effort to identify an institution in-state to serve and maintain

the GAP data. Data distribution shall include metadata and the final report, including the BRD

data disclaimer. 

6.Projects shall maintain a fire-safe backup of all data current to within one week of the last

update. 

7.In addition to the final report, projects shall produce progress reports according to their project

agreement. The Principal Investigator will also modify the Online GAP Tracking Survey

whenever there is a significant change in the status of: principal and secondary investigators;

staff and affiliated investigators; cooperators; project funding; equipment and imagery; mapping;

and analysis and data archive. 

8.Projects shall follow the project close-out protocol to achieve sign-off on project completion. 

Data Production Standards:

General:

a. Follow the overall Gap Analysis process described in A Handbook of Gap Analysis using

the version current on the GAP home page (http://www.gap.uidaho.edu/gap/) or in

consultation with the national office if a chapter is not current or available. 

b. Projects may exceed these standards (e.g., use finer resolution, more detailed classification

levels) provided that: 1) the refinements do not increase the original project budget or are

funded by others; and 2) do not cause extension of the project time-line without prior

consultation with National GAP. 

c. For digital spatial data (GIS coverages), geographic position accuracy will meet or exceed

the standards of the USGS for 1:100,000 scale products (see

http://mapping.usgs.gov/www/html/ 2nmpgds.html#dlgs), or follow standards identified in

the Handbook chapters. Because production of GAP data products requires the incorporation

or "overlay" of numerous data layers, it is critical that they align such that the total spatial

variation between all data does not exceed that allowed by the 1:100,000 standard. 

d. When digitizing, it is suggested that each 1:100,000 tile should have a maximum root mean

square error tolerance of <.005 digitizing inches (±13). Imbedded, missing, or extra polygons

in vector coverages must be corrected and cleaned. 
98

1a. Land Cover Coverage:

1.Use the National Vegetation Classification System (NVCS) to identify alliances or

aggregations of alliances to be mapped in the project area. Note that descriptions of alliances

are currently available for the East and will be available for the West approximately end of

calendar year 1998. See the Land Cover chapter for additional information on application of

the NVCS, or contact the national office. 

2.Use Landsat TM imagery at 30 meter pixel resolution as the data source for map

development. Do not resample the imagery to a different pixel size. 

3.Use the methodology and standards described in the Land Cover Mapping chapter of the

Handbook for both rendering a digital base map of land cover pattern and deriving thematic

data with a by-type accuracy objective of 80%. 

4.Map nonvegetated cover to the minimum categories described in the Land Cover Mapping

chapter of the Handbook. 

5.Resolution is at least 2 ha*, although a tiled, vectorized version of the coverage must be

provided that may use a coarser resolution to achieve vectorization and allow efficient

operation of a tile on the current version of PC ArcView. The "Merge" program available

from National GAP is recommended for aggregation as needed. 

* Note that spatial versus thematic resolution will be discussed in detail in the

updated Land Cover Mapping chapter. Spatial resolution will generally be a

result of the thematic level mapped and the nature of the plant community itself.

The goal should be to achieve a reasonable portrayal of the mapped units 

geographic extent and distribution patterns which may result in variable spatial

resolutions by type, ranging from a few pixels to several hundred hectares. 

6.Projects shall map land cover beyond their project boundary for a distance of 10 kilometers

or to the edge of their TM imagery, whichever is less, provided the entire project area is

mapped. Projects may map further than this requirement if they wish and are encouraged to

discuss an appropriate amount of overlap with adjoining states. 

7.Conduct an accuracy assessment of the land cover map to provide a measure of accuracy

by mapped type. Follow the Land Cover Assessment chapter guidelines in the Handbook. 

1b. Land Cover Reference Data:

1.Obtain data that represents "ground truth" for use in map creation and assessment (see 1a

above). This can be near-remote-sensing-based data such as aerial photographs or

videography (digital is recommended), accuracy-assessed large-scale vegetation maps, or

field-gathered data. Digital data gathered by the GAP project is considered a deliverable and

should be documented and archived as described in this chapter and the Information

Archiving and Distribution chapter. 
99

1c. Land Cover Manual:

1.Produce a Land Cover Manual that describes the mapped types in the context of the

hierarchical classification scheme. Refer to the Land Cover section of the Handbook for

minimum Manual components. 

1d. TM Imagery:

1.Generally, projects will be supplied with sufficient imagery to create the land cover map.

However, many projects obtain additional imagery. If this imagery is obtained with project

funds, it must be delivered to the National GAP office. For more details see the Land Cover

Mapping chapter or contact the National GAP office. 

2a. Database File of Predicted Species Occurrence in EMAP Hexagons:

1.Use the TNC standard list of names and codes available from the TNC home page (see the

link on the GAP home page). Note that around 1/98 we anticipate switching to the Integrated

Taxonomic Information System (ITIS) system (http://biology.usgs.gov/cbi2/programs/

itis.html) and will update this standard at that time. This caveat applies also to all other

animal naming and coding standards in this chapter. 

2.Include, at a minimum, all terrestrial vertebrates that breed or use habitat for a substantial

part of their life history in the study area, including migration stopovers. 

3.Use the Environmental Protection Agency (EPA) Ecological Mapping and Assessment

Program (EMAP) hexagon grid (~635 km2) as the geographic unit (available from the GAP

home page). 

4.If using the hexagons as the source for delimiting range extent in the predicted vertebrate

distributions, follow the attributing protocols found as an appendix in the animal modeling

chapter of the Handbook. 

5.If not using the hexagons in the predicted distribution modeling process, then at a

minimum intersect the predicted distribution maps with the hexagon coverage to attribute the

grid with GAP-predicted occurrence of each species mapped. 

6.Export the resulting INFO file to dBASE such that each hexagon cell is represented by its

ID number followed by the occurrence attribute for each modeled animal species. 

2b. Database of Specimen Collection or Sighting Localities (if available):

1.Obtain available digital vertebrate point locations to use in vertebrate range mapping and

verification (see Vertebrate Modeling and Assessment chapters). 

2.Develop a digital database of locations from hard copy tabular or map products when this

can be done in partnership with other institutions. 
100

2c. Database of Species Habitat Associations: 

1.Use the peer-reviewed literature, existing habitat association databases, and expert opinion

to attribute each species with its known habitat associations. 

2.Enter all associations into a database such that each association for each species is

referenced to the source of that information. 

2d. Predicted Distributions of Terrestrial Vertebrate Species:

1.Use the ECOMAP sections or subsections as available from USFS to bound regional

differences in habitat associations for each species if they are known. 

2.Develop a distribution map for each species with an accuracy objective of 80% based on

comparison to high-confidence checklists for sample areas.

3.Resolution will be variable and a consequence of the resolution of the various coverages

used in the modeling. 

4.Conduct an accuracy assessment of the species distributions according to the guidelines in

the Animal Distribution Assessment chapter of the Handbook. 

2e. A "hyperdistribution" of all species in a single coverage:

1.Create a raster coverage such that each cell is attributed for presence/absence of each

modeled species. This coverage allows simple queries of richness or coincidence of any

group of species. Other attributes are allowed but not required at this time (see the vertebrate

modeling chapter). 

3a. Land Stewardship Coverage: 

1.Map land management authority by the major categories of 

a. Publicly owned lands, attributed by the name of the agency that is responsible for

managing the land parcel, and secondarily with the actual owner if different from

the managing entity. 

b. Privately owned lands categorized in status 3 or higher when identified

voluntarily by the land owner. 

c. All other privately owned lands are to be attributed "private." 

d. Subdivide general ownership/management categories with internal management

boundaries that will have a different management status ranking, for instance, a

Research Natural Area is an internal management boundary within Forest

Service lands. 

2.The resolution is at least 16 ha (40 acres), but smaller units may be used. 
101

3.The management authority and management status attributes shall occur as one GIS

coverage that can be queried to produce separate maps. Use the code system in the

Stewardship chapter. 

4.Categorize management according to the methods described in the Stewardship chapter of

the Handbook using the status levels 1-4 described therein. You may attribute with

subcategories as described in that chapter. 

3b. Status 1 & 2 Management Areas:

1.Document the name of the area, date of establishment under its current status (an area may

have been established as a national monument and then upgraded to national park; use the

date of establishment of the latter), managing entity, owner if different than the managing

entity, and source of management information for status 1 & 2 areas. Documentation for

status 3 tracts is encouraged but not required. 

2.Enter the data in a database program. 

4a. Analysis Statistics for Land Cover and Animal Species:

1.Intersect the land cover and animal distribution coverages with the stewardship coverage

and export the resulting coverage table to a database file. 

2.For each element (land cover type and animal species), report its total project area

distribution in square kilometers and the area and percent of its total distribution for each

major land steward by management status level (see example in the Analysis chapter of the

Handbook). Identify elements that have less than 10%, 20%, and 50% of their distribution in

status 1 & 2 areas. Identify the measured accuracy level of each element. 

5. Ancillary Data Used to Create Gap Coverages:

1.All data must be obtained from a referenced source with known methods used to create it

and the location where the original data may be obtained. 

2.Text, tabular, and hard copy map data must be referenced as typical for literature citations

(see the GAP Handbook citations for style). 

3.GIS data must include metadata sufficient to determine its fitness for use in deriving GAP

products. 

6. The Final Project Report:

1.Develop the final project report using the standard final report template available from the

National GAP office (see Report chapter in this Handbook). 
102

2.It is recommended that projects use the template during project production phases and

annual reporting so that all pertinent information is captured when it is fresh and production

staff are still available. 

7. Graphic Image Files of All Coverages:

1. All coverages, including individual animal ranges by hexagon and predicted distribution

shall be provided as a graphic image in addition to the GIS coverages. This is for CD-ROM

production.

Acknowledgments:

We thank the following reviewers for their contributions to this document.

 Robert Deitner 

 Daniel Fitzpatrick 

 Liza Fox 

 Steve Hartley 

 Frederick Limp 

 Leonard Pearlstine 

 Roly Redmond 

 Kathryn Thomas 

Literature Cited:

Anderson, J. R., E. E. Hardy, J. T. Roach, and R. E. Witmer. 1976. A land use and land cover

classification system for use with remote sensor data. U.S. Geological Survey Professional

Paper 964, U.S. Government Printing Office, Washington, D.C. 28 pp.

Cowardin, L. M., V. Carter, F. C. Golet, and E. T. LaRoe. 1979. Classification of wetlands and

deepwater habitats of the United States. U.S. Fish and Wildlife Service Office of Biological

Services No. 79/31. U.S. Government Printing Office, Washington, D.C., stock number GPO

024-010-00524-6. 103 pp. 

Scott, J. M., F. Davis, B. Csuti, R. Noss, B. Butterfield, C. Groves, H. Anderson, S. Caicco, F. D

Erchia, T. C. Edwards Jr., J. Ulliman, and R. G. Wright. 1993. Gap Analysis: A geographic

approach to protection of biological diversity. Wildlife Monograph 123. 41 pp

Scott, J. M., and M.D. Jennings. 1994. A Handbook for Gap Analysis. National Gap Analysis

Program, University of Idaho, Moscow, ID 83843, http://www.gap.uidaho.edu/gap/.
103

Appendix 2.1. Land Cover Type Descriptions, OR-GAP Version 2 Land Cover

FOREST AND WOODLAND COVER TYPES

SITKA SPRUCE-WESTERN HEMLOCK MARITIME FOREST (32)

Geographic Distribution. This conifer dominant forest extends the length of the Oregon coast but

is narrowly restricted in its distribution. Frequently this cover type will be no more than a 2 mile

wide from the coastal margin to its bordering cover type. This maritime forest is most widely

distributed in the rolling hills and coastal plain of the northwest coast. Along the south coast this

cover type is restricted to the windward sides of hills on the narrow coastal plain. Sitka spruce

(Picea sitchensis) and to a lesser extent western hemlock (Tsuga heterophylla), along with various

willows (Salix spp.) also form palustrine forests in the tidewater reaches of the northwest coast and

in the islands of the Columbia River east of Astoria.

Structure and Appearance. Closed canopy, multi-story conifer forest typically with a dense

understory of shrubs, forbs and ferns.

Composition. Sitka spruce and western hemlock dominate the overstory with Douglas fir

(Pseudotsuga menziesii), and western red cedar (Thuja plicata), becoming more frequent as the

type grades into inland forest covers. 

Shrub cover is diverse and often dominates the understory. Evergreen huckleberry (Vaccinium

ovatum), salal (Gaultheria shallon), vine maple (Acer circinatum), pacific rhododenron

(Rhododendron macrophyllum), salmonberry (Rubus spectabilis), and elderberry (Sambucus

racemosa) are common associates.

Herbaceous cover is diverse and typically contains several fern species. Swordfern (Polystichum

munitum) is the most common fern with deerfern (Blechnum spicant), bracken (Pteridium

aquilinum), and chainfern (Woodwardia fimbriata). Other common forbs are devils club

(Oplopanax horridum), false lily-of-the-valley (Maianthemum dilatatum), inside-out-flower

(Vancouveria hexandra), and Oregon oxalis (Oxalis oregana).

Landscape Setting. The Sitka spruce-western hemlock forest is bordered inland by the Douglas

fir/western hemlock/western red cedar forests. This forest type is frequently battered by high winds

from Pacific Ocean storms with overstory trees showing evidence of wind shear and the effects of

salt spray along the coastal margin. This type will also extend inland for several miles on river

floodplains.

References. Hemstrom and Logan 1986, Wiedemann et al. 1974, Ripley 1983.

MOUNTAIN HEMLOCK SUBALPINE FOREST (33)

Geographic Distribution. Mountain hemlock (Tsuga mertensiana) ranges throughout the Cascades

at higher elevations (generally above 4500 ft). In the southern Cascades and Siskiyou Mountain
104

ranges the mountain hemlock cover type grades into the Shasta red fir (Abies magnifica var.

shastensis)/mountain hemlock forest cover type. Mountain hemlock is also found in the Wallowa

Mountains of northeastern Oregon. In both the Siskiyous and Wallowas, mountains hemlock is not

as common, nor as extensive, as in the Cascades.

Structure and Appearance. At the lower elevation range of mountain hemlock this cover type is a

forest that can have a multi-storied canopy, although it typically tends to single story. In these

conifer dominant forests tree size is considerably smaller and regeneration difficult than lower

elevation conifer cover types due to persistent snowpack and short growing season. Mountain

hemlock, at its upper elevation range, grades into alpine parkland. Parkland settings are considered

as a mosaic of treeless openings with clumps of closed canopy trees.

Composition. Mountain hemlock typically dominates the overstory in this upper elevation conifer

forest. Pacific silver fir (Abies amabilis), lodgepole pine (Pinus contorta), western white pine

(Pinus monticola), western hemlock (Tsuga heterophylla), and Douglas fir (Pseudotsuga menziesii)

may be present in the overstory. In parkland mosaics mountain hemlock may appear in pure

clumps, or mixed with subalpine fir (Abies lasiocarpa) or whitebark pine (Pinus albicaulis).

Shrubs and forb layer are typically sparse and species poor. Several of the Vaccinium genus are the

most commonly found shrubs, big huckleberry, (V. membranaceum), grouse whortleberry (V.

scoparium), and Alaska huckleberry (V. alaskaense). Dwarf bramble (Rubus lasiococcus), and

prince’s pine (Chimaphila umbellata) also occurs commonly in this type.

Beargrass (Xerophyllum tenax) is the dominant herb in most places. Other associated herbs are:

sidebells pyrola (Pyrola picta), beadlily (Clintonia uniflora), and sickletop pedicularis (Pedicularis

racemosa).

Landscape Setting. In the Cascade Range mountain hemlock occupies the elevation zone between

the true fir dominant montane forests, and the alpine parkland forest types. Mountain hemlock also

occurs as high elevation savanna in pure clumps or mixed with whitebark pine in the volcanic soils

of the southern Cascades.

References. Atzet et al. 1996, Hemstrom et al. 1987, Volland 1985, Crawford et al. 1999, Johnson

and Simon 1987

TRUE FIR/HEMLOCK MONTANE FOREST (34)

Geographic Distribution. Found throughout the northern and central Cascade Range at middle to

higher elevations, especially west of the Cascade crest. The true fir/hemlock type reaches its

southern limit in the upper Rogue River drainage, east of Prospect. This type is also found in

disjunct populations in the Coast Range. 

 

Structure and Appearance. Multi-story closed canopy forests. Trees can grow to large stature

barring disturbance in these fertile, mid-elevation forests. Snags and large woody debris are

commonly found. Understory vegetation is rich in species with a diversity of forms.
105

Composition. Canopy co-dominance of pacific silver fir (Abies amabilis), and/or noble fir (A.

procera) along with both western and mountain hemlock characterize this conifer forest type. 

Other canopy trees found in this type include: Douglas fir (Pseudotsuga menziesii), western white

pine (Pinus monticola), subalpine fir (Abies lasiocarpa), Alaska yellow cedar (Chamaecyparis

nootkatensis) and grand fir (Abies grandis).

The shrub layer in this cover type is dense and diverse with a number of deciduous and evergreen

shrubs commonly found. Shrubs associated with this cover type are: pacific rhododendron

(Rhododendron macrophyllum), Cascade azalea (R. albiflorum), salal (Gaultheria shallon), fools

huckleberry (Menziesia ferruginea), big huckleberry (Vaccinium membranaceum), Alaska

huckleberry (V. alaskaense), dwarf Oregongrape (Mahonia nervosa), and vine maple (Acer

circinatum).

The forb layer in these forests is also rich in species and abundance. Indicator species of wet and

mesic sites include: skunk cabbage (Lysichitum americanum) devils club (Oplopanax horridum),

beadlily (Clintonia uniflora), foamflower (Tiarella unifoliata) wild ginger (Asarum caudatum)

Oregon oxalis (Oxalis oregana), vanillaleaf (Achlys triphylla), bunchberry (Cornus canadensis) and

beargrass (Xerophyllum tenax).

Landscape Setting. This cover type is adjacent to Douglas fir/western hemlock/western red cedar

at its lower elevation range and subalpine forest types at its upper limits. These are cool site, fertile

soil forests with winter snowpack and moist soils during the growing season. The long droughty

summers of southern Oregon are likely the limiting factor in its southern distribution.

References. Hemstrom et al. (1982, 1987), Atzet and Wheeler 1984, Atzet et al. 1996, Halvorson

et al. 1986, Crawford et al. 1999.

SHASTA RED FIR-MOUNTAIN HEMLOCK MONTANE FOREST (36)

Geographic Distribution. Mid-to-upper elevation conifer forest found in the Siskiyou Mountains

and southern Cascades, especially south of Crater Lake.

Structure and Appearance. Closed canopy, multi-story conifer forest typically with a dense

understory of shrubs, forbs and ferns.

Composition. Overstory species include: Shasta red fir (Abies magnifica var. shastensis), mountain

hemlock (Tsuga mertensiana), with white fir (Abies concolor), lodgepole pine (Pinus contorta),

Shrubs associated with this type are: dwarf bramble (Rubus lasiococcus), Oregon boxwood

(Pachistima myrsinites), pinemat manzanita (Arctostaphylos nevadensis), saddler oak (Quercus

sadleriana), and baldhip rose (Rosa gymnocarpa).

Herbs associated with this type are: false Solomon’s seal (Smilacina racemosa), rattlesnake

plantain (Goodyera oblongiflora), woods strawberry (Fragaria vesca), white flowered hawkweed

(Hieracium albiflorum).
106

Structure and Appearance. This forest type takes on a variety of forms, ranging from multi-story

closed canopy forests to open canopy alpine parkland type forest.

Landscape Setting. This montane forest cover type is found at elevations mostly above 4,000 ft.

with a tendency towards north aspects, especially when occurring at lower elevations.

References. Atzet and Wheeler, 1984, Atzet et al. 1996, Jimerson et al. 1996, Frenkel and

Kiilsgaard 1984.

WHITEBARK-LODGEPOLE PINE ALPINE FOREST (39)

Geographic Distribution. The whitebark-lodgepole pine type has a sporadic distribution in the

high elevation zone of the eastern Cascades. The forest cover type is found mainly in the southern

reaches of the eastern Cascades, especially around the Gearhart Mt. Wilderness Area.

Structure and Appearance. This conifer forest has generally open to moderately closed canopy

(less than 60% crown closure). Stands are of moderate stature with sparse shrub and forb layers. 

Regeneration of conifer trees is minimal.

Composition. Whitebark pine (Pinus albicaulis) and lodgepole pine (Pinus contorta) dominate the

overstory. Occasional white fir (Abies concolor) and western white pine (Pinus monticola) are

found in the overstory.

Shrub layer is sparse with little diversity, occasional pinemat manzanita (Arctostaphylos

nevadensis), and sticky currant (Ribes viscosissimum).

Forb layer is predominantly grasses, with Wheeler’s bluegrass (Poa nervosa), western needlegrass

(Stipa occidentalis), bottlebrush squirreltail (Sitanion hystrix), and long stolon sedge (Carex

pensylvanica). Forbs are gay penstemon (Penstemon laetus), and tailcup lupine (Lupinus

caudatus).

Landscape Setting. This type is not readily mapped because of its non-contiguous cover and its

occurrence as a mosaic with alpine grassland and shrubland types.

References. Hopkins 1979.

PONDEROSA PINE DOMINANT- MIXED CONIFER FOREST (40)

Geographic Distribution. The ponderosa pine dominant-mixed conifer forest is found primarily in

the southern half of the eastern Cascades, ranging from the California border to Bend. 

Structure and Appearance. This type is typically a two story conifer forest with the predominance

of the overstory canopy (greater than 60%) being ponderosa pine (Pinus ponderosa). White fir
107

(Abies grandis and A. concolor), is the other common overstory tree with occasional incense cedar

(Calocedrus decurrens), and sugar pine (Pinus lambertiana). Understory regeneration can be

dense, or sparse, based on intensity of cattle grazing, fire frequency, and ecological site conditions. 

Composition. Overstory conifers are ponderosa pine, white fir, with lesser contribution from

incense cedar and sugar pine. Understory trees are similar in composition to overstory although

generally white fir predominates over ponderosa and lodgepole pine (Pinus contorta) is a common

understory occupant.

The shrub and herb layers form a diverse and prominent ground cover component in this forest type

especially when compared to adjacent cover types. Commonly associated shrubs include

snowberry (Symphoricarpos albus), creeping snowberry (S. mollis), dwarf Oregongrape (Mahonia

nervosa), wax currant (Ribes cereum), and serviceberry (Amelanchier alnifolia). 

Indicator cover type herbs are: heartleaf arnica (Arnica cordifolia), long stolon sedge (Carex

pensylvanica), squirreltail bottlebrush (Sitanion hystrix), starwort (Stellaria jamesiana), white

hawkweed (Hieracium albiflorum), and broadleaf strawberry (Fragaria virginiana).

Landscape Setting. This mid elevation cover type occupies the zone between the drier low

elevation types, primarily ponderosa-western juniper cover type, and higher elevation mixed conifer

or sub-alpine types. This type, with its mesic site conditions, is transitional in its ecological setting

bridging the gap between drier, low elevation types and the colder, wetter higher elevation types. 

This type also warrants distinction because of its lack of Douglas fir (Pseudotsuga menziesii) in its

stands and the consistent presence, but lack of co-dominance by associated conifers.

References. Hopkins, 1979, Volland, 1988, Kovalchik, 1987.

NORTHEASTERN OREGON MIXED CONIFER FOREST (41)

Geographic Distribution. Common mid-elevation forest cover type found throughout the various

mountain ranges of northeastern Oregon. More common on north and east facing slopes.

Structure and Appearance. This cover type can take on a variety of structural and canopy

appearances based on site history. In its unaltered form stands are typically two storied with an

overstory of ponderosa pine (Pinus ponderosa) over smaller ponderosa, or grand fir (Abies

grandis), western larch (Larix occidentalis), lodgepole pine (P. contorta), western white pine (P.

monticola), Douglas fir (Pseudotsuga menziesii), or Engelmann spruce (Picea engelmannii)

depending on local environment. Selective logging, grazing, and fire suppression effects have

significantly changed the appearance of this forest type. 

Composition. Overstory conifers can be ponderosa pine, grand fir, western white pine, lodgepole

pine, western larch, Engelmann spruce, and Douglas fir. Forest regeneration after wildfires favors

recruitment of western larch and lodgepole pine. Cool, moist sites within this type typically contain

Engelmann spruce and grand fir. Understory trees reflect the same species of conifers and

occasionally will have western yew (Taxus brevifolia).
108

Shrub layer is prominent and diverse. Common tall shrubs include bigleaf huckleberry (Vaccinium

membranaceum), rocky mountain maple (Acer glabrum), ninebark (Physocarpus malvaceus),

Scouler’s willow (Salix scouleriana) serviceberry (Amelanchier alnifolia). Mid and low shrubs

include shiny-leaf spirea (Spiraea betulifolia), myrtle pachistima (Pachistima myrsinites),

snowbrush (Ceanothus velutinus), grouse whortleberry (Vaccinium scoparium), bog blueberry (V.

ulignosum), dwarf Oregon grape (Mahonia nervosa), and the prostrate manzanitas (Arctostaphylos

nevadensis and A. uva-ursi).

Commonly encountered forbs in this cover type include: false Solomon’s seal (Smilacina

racemosa), heartleaf arnica (Arnica cordifolia), rattlesnake plantain (Goodyera oblongifolia), white

hawkweed (Hieracium albiflorum), Wilcox’s penstemon (Penstemon wilcoxii), bigleaf sandwort

(Arenaria macrophylla), woods strawberry (Fragaria vesca), meadowrue (Thalictrum occidentale),

sweet cicely (Osmorhiza chilensis), sidebells pyrola (Pyrola picta), and trail plant (Adenocaulon

bicolor).

Landscape Setting. This type can extend to grassland or shrubland cover types on its low elevation

end but usually it is transitional between ponderosa pine on its lower end and subalpine

fir/lodgepole pine at higher elevations.

References. Hall 1973, Johnson and Simon 1987, Johnson and Clausnitzer 1989, Kagan and Caicco

1992, Chappell et al. 1999.

JEFFREY PINE WOODLANDS (42)

Geographic Distribution. Jeffrey pine (Pinus jeffreyi), while common in the mountains of

California, is at the northern extension of its range in Oregon and is found only in Josephine, Curry,

Jackson Counties and small, scattered patches in the south fork of the Umpqua River drainage in

Douglas County. Closely associated with ultramafic rocks this open woodland is a good indicator

of parent material and is most readily found west of the Illinois River by Cave Junction. Ultramafic

rock, serpentine and peridotite have such high concentrations of nickel, chromium and magnesium

that soils derived from this substrate are toxic to most plants. Those plants which are tolerant to the

heavy metal concentrations form a unique and diverse flora within southwestern Oregon.

Structure and Appearance. Jeffery pine woodlands are open canopy, (less than 30% crown closure

in most stands), single story, conifer dominant cover type. Floristic composition is diverse, but

sparse in appearance. This type tends to have a lot exposed bedrock and gravel scattered amongst

the vegetation.

Composition. Jeffrey pine is the dominant overstory tree species in this cover type. Incense cedar

(Calocedrus decurrens) is commonly found but rarely does it have sufficient cover to be considered

co-dominant. In moist areas Port Orford cedar (Chamaecyparis lawsoniana) replaces incense

cedar. Understory trees are Jeffrey pine, incense cedar, Douglas fir (Pseudotsuga menziesii) and

California laurel (Umbellaria californica).
109

Shrubs are prominent and diverse in this type. Commonly associated shrubs are coffeeberry

(Rhamnus californica), hoary manzanita (Arctostaphylos canescens), whiteleaf manzanita (A.

viscida), squaw carpet (Ceanothus prostratus), dwarf ceanothus (C. pumilus), silk tassel (Garrya

buxifolia), and the shrub form of tanoak (Lithocarpus densiflora).

Grasses and forbs are also prominent. Lemmon’s needlegrass (Stipa lemmonii), Idaho fescue

(Festuca idahoensis), Roemer’s fescue (F. roemeri) and California fescue (F. californica) are

common. Commonly associated forbs are: rock fern (Aspidotis densa), Tolmie’s mariposa

(Calochortus tolmeii), death camas (Zigadenus venenosus), yarrow (Achillea millefolium) and

beargrass (Xerophyllum tenax).

Landscape Setting. Because of the unique relationship this cover type has with parent material its

setting is largely a function of local geology. Jeffrey pine woodlands are interspersed with the other

two ultramafic rock influenced cover types, serpentine conifer woodland and Siskiyou Mountains

serpentine shrubland. Jeffrey pine woodlands often are found in low to mid elevation, southerly

exposure settings. 

References. Plant classification and ecology works that describe this cover type include: Atzet et

al. 1996, Jimerson et al. 1995, Kruckeburg 1984, Frenkel and Kiilsgaard 1984, Atzet and Wheeler

1984, and Zobel and Hawk 1980.

SERPENTINE CONIFER WOODLAND (43)

Geographic Distribution. Similar in distribution pattern and environmental relationship as the

Jeffrey pine woodlands. This conifer woodland is most common in California and reaches its

northern extent in southwestern Oregon.

Structure and Appearance. This cover type, responding to recent fire by serotinous cone

regeneration, is relatively short lived and responds well to disturbances, or disturbed soils. Stands

are open to dense, even-aged, and low in stature.

Composition. Knobcone (Pinus attenuata) and lodgepole pine (P. contorta) are the most

commonly associated conifers in this type. Western white pine (P. monticola), sugar pine (P.

lambertiana), Jeffrey pine (P. jeffreyi) incense cedar (Calocedrus decurrens), madrone (Arbutus

menziesii), and occasionally, brewers spruce (Picea breweriana) form the regeneration and

overstory layers in these short stature (most trees are less than 20 ft tall) stands.

Shrub layers typically have moderate to high cover. Huckleberry oak (Quercus vaccinifolia),

tanoak (Lithocarpus densiflora), chinquapin (Castanopsis chrysophylla), creambrush oceanspray

(Holodiscus discolor), and red huckleberry (Vaccinium parvifolium).

Forb layers are diverse and rich in species. Commonly found species being: beargrass

(Xerophyllum tenax), western starflower (Trientalis latifolia), wild ginger (Asarum hartwegii),

creeping Oregongrape (Mahonia repens), spreading dogbane (Apocynum androsaemifolium),
110

spotted coralroot (Corallorhiza maculata), Tolmies mariposa lily (Calochortus tolmiei), fawn lily

(Erythronium grandiflorum), and woodland tarweed (Madia madioides).

Landscape Setting. This type is primarily associated with the distribution of serpentine soils within

southwestern Oregon. It most commonly occurs on higher elevation benches, slopes and ridges and

is a pioneer forest community following fire or mining disturbance.

References. Frenkel and Kiilsgaard 1984, Jimerson et al. 1995, Atzet et al. 1996.

LODGEPOLE PINE FOREST AND WOODLAND (44)

Geographic Distribution. A common forest cover type found throughout the central and southern

Cascades, east of the crest; and in smaller, scattered mosaics throughout the mountains of

northeastern Oregon, and along the crest of the Cascades.

This cover type is most extensive in the same geographic area as the ponderosa-lodgepole pine on

pumice type; but warrants distinction because it occurs on mid-slopes and ridges and is a forest type

responding from wild fires, not soil conditions.

Structure and Appearance. Single layer, open to closed canopies, dominated by lodgepole pine

(Pinus contorta). A typical post-fire successional path for this cover type is to have dense

reproduction of short stature lodgepole. As the stand matures lodgepole cover thins to scattered

overstory lodgepole with regeneration layers of other conifers. These other conifers, regionally

important replacement trees would be: Douglas-fir (Pseudotsuga menziesii), grand fir (Abies

grandis), white fir (A. concolor), incense cedar (Calocedrus decurrens), and western white pine

(Pinus monticola) will eventually form the overstory and eliminate lodgepole from the stand

entirely.

Composition. Lodgepole dominates the overstory in early to mid successional stands. Western

larch (Larix occidentalis), another post-fire colonizing conifer, can be co-dominant in this cover

type, especially in the northeastern Oregon mountains. Regeneration layers are composed of

conifers listed in the structure and appearance section.

Shrubs are common and diverse in this cover type: common snowberry (Symphoricarpos albus),

mountain snowberry (S. mollis), serviceberry (Amelanchier alnifolia), ninebark (Physocarpus

malvaceus), shiny-leaf spirea (Spiraea betulifolia), bitterbrush, (Purshia tridentata), baldhip rose

(Rosa gymnocarpa), myrtle pachistima (Pachistima myrsinites), and several huckleberries (V.

membranaceum, V. scoparium, V. uliginosum, and V. caespitosum).

Grasses dominate some understories with few shrubs. Pine grass (Calamagrostis rubescens), Ross’

sedge (Carex rossii), elk sedge (Carex geyeri), bluebunch wheatgrass (Agropyron spicatum),

western needlegrass (Stipa occidentalis), Idaho fescue (Festuca idahoensis), prairie junegrass

(Koeleria macrantha), and mountain brome (Bromus carinatus) are commonly found.
111

Landscape Setting. Since this forest cover type usually is the response following wild fires there is

no environmental relationship that controls its distribution. This cover type appears as a mosaic

within the larger, regionally important cover types.

References. Hopkins 1979, Johnson and Clausnitzer 1986, Johnson and Simon 1987, Crawford et

al. 1999, Kagan and Caicco 1992.

SUBALPINE FIR-LODGEPOLE PINE MONTANE FOREST (45)

Geographic Distribution. A common mid to high elevation conifer forest cover type in the

mountains of northeastern Oregon, and along the crest of the Cascades.

Structure and Appearance. Short stature single story canopy forests. Crown closure ranges from

open to closed. At its lower elevation range, this cover type grades into various montane forest

types and maintains a continuous canopy. At its upper elevation range, (which can be the

timberline), the type grades into subalpine parkland, or it takes on the clumpy appearance of a

parkland cover type.

Composition. Subalpine fir (Abies lasiocarpa) and lodgepole pine (Pinus contorta) dominate the

canopy overstory. Engelmann spruce (Picea engelmannii) can be a locally important overstory tree,

especially in northeastern Oregon. Understory tree composition usually is dominated by subalpine

fir.

Shrub cover in this type can be extensive and is typified by big huckleberry (Vaccinium

membranaceum), and grouse huckleberry (V. scoparium). Other commonly associated shrubs

include: gooseberry (Ribes lacustre), shiny-leaf spirea (Spiraea betulifolia), and prince’s pine

(Chimaphila umbellata).

Forb cover is often low but diverse in species. Common indicator forbs would be strawberries,

(Fragaria vesca and F. virginiana), roundleaf violet (Viola oreganum), heartleaf arnica (Arnica

cordifolia), sidebells pyrola (Pyrola secunda), skunkleaf polemonium (Polemonium pulcherrimum),

sweet cicely (Osmorhiza chilensis) and meadowrue (Thalictrum occidentalis).

Landscape Setting. Occupies the upper elevation range of continuous forest cover for much of

northeastern Oregon. As discussed in the structure and appearance section, this type grades into, or

takes on the appearance of parkland cover types. Lodgepole pine is successional to subalpine fir,

but remains a common component on harsher sites and ridgetops. Successional change is slow in

this cover type with its short growing season and persistent snow cover.

References. Hall 1973, Johnson and Simon 1987, Johnson and Clausnitzer 1989, Kagan and Caicco

1992.
112

COASTAL LODGEPOLE FOREST (46)

Geographic Distribution. Most commonly found along the south-central coastline near Florence,

this type can be found throughout the length of the Oregon coast. It is uncommon to find this type

more than a mile or so off the coastline and primarily located in deflation plain settings.

Structure and Appearance. Low stature, single story conifer stands, with moderate to closed

canopies. Overstory is predominantly lodgepole pine (Pinus contorta) on newly colonized dunes

and deflation plains. As the habitat matures Sitka spruce (Picea sitchensis) increases in abundance,

becoming the successional forest. Sitka spruce will also co-dominate with lodgepole on wet places

in the deflation plain. South of Coos Bay, Port Orford cedar (Chamaecyparis lawsoniana) can be

found in this forest type in the wet deflation and dune places.

Understory vegetation is often a dense, impenetrable shrub layer in stable, late successional stands. 

Early succession stands, and places with active sand movement, have sparse understories.

Composition. Conifer overstories of lodgepole pine and locally abundant Sitka spruce. Shrub layer

is dominated by salal (Gaultheria shallon), pacific rhododendron (Rhododendron macrophyllum),

and evergreen huckleberry (Vaccinium ovatum). Forb layer is sparse to non-existent under the

heavy shrub covers

Landscape Setting. Lodgepole pine is the early colonizer of dunes and deflation plains. This cover

type can exist as a narrow strip bordering on the Sitka spruce-western hemlock type along the

northern coast; or it can become fairly extensive on the dune sheets between Florence and Coos

Bay.

References. Wiedemann et al. 1974, Ripley 1983.

DOUGLAS FIR/WESTERN HEMLOCK/WESTERN RED CEDAR FOREST(49)

Geographic Distribution. The most common low to mid elevation forest found in western Oregon. 

Extends from the foothills of the western Cascades to approx. 4,500 ft and is ubiquitous throughout

the Coast Range to the coastal margin forests. Its distribution becomes scattered in southwestern

Oregon and the southern Cascades and is replaced by Douglas fir-mixed conifer mixed deciduous

types.

Structure and Appearance. In its mature form this conifer forest type contains numerous large

trees, multi-story tree canopies, numerous snags and downed logs. Sub-canopies are composed of

shade tolerant conifer species and deciduous trees where there is discontinuous overstory canopy

cover. Early seral and commercial forests have dense accumulations of smaller trees, (typically

dominated by Douglas fir, Pseudotsuga menziesii) and single story canopies. 

 Shrub and herbaceous layers are dense and rich in species in mid-to-late successional forest stands
113

Composition. Douglas fir dominates most of the overstory in these stands, with western hemlock

(Tsuga heterophylla), western red cedar (Thuja plicata) and grand fir (Abies grandis) present to

locally co-dominant. Western hemlock and western red cedar form the bulk of the subordinate tree

and regeneration layers. Pacific yew (Taxus brevifolia) is another conifer that shows up in the subcanopy tree layers. Big leaf maple (Acer macrophyllum), and to a lesser extent, red alder (Alnus

rubra) are common in riparian strips and stands that do not have continuous conifer overstories.

Large stature shrubs are common in the Cascades stands. Vine maple (Acer circinatum), pacific

rhododendron (Rhododendron macrophyllum), and fools huckleberry (Menziesia ferruginea) and

red huckleberry (Vaccinium parvifolium) are frequently found. Coast Range shrub layers are

dominated by salal (Gaultheria shallon), evergreen huckleberry (V. ovatum), elderberry (Sambucus

racemosa) and salmonberry (Rubus spectabilis).

Herbaceous layers are rich in species and abundance. Swordfern (Polystichum munitum) and other

ferns, bracken (Pteridium aquilinum), deer fern (Blechnum spicant), and lady fern (Athyrium filixfemina) are commonly found and can dominate the herb layer. Other forbs associated with this

cover type include: inside-out flower (Vancouveria hexandra), twinflower (Linnea borealis),

Siberian springbeauty (Claytonia sibirica), vanillaleaf (Achlys triphylla), bedstraw (Galium

triflorum), western iris (Iris tenax), and Oregon oxalis (Oxalis oregana).

Landscape Setting. In the interior valleys of western Oregon at low elevations this forest type

grades into agriculture, or Douglas fir/deciduous types. Bordering this cover type at upper

elevations are the true fir dominant montane forest types. This type extends west of the Coast

Range onto the coastal plains where it borders the coastal margin forests.

References. Hemstrom et al. 1987, Hemstrom and Logan 1986, Franklin and Dyrness 1974, Atzet

et al. 1996, Atzet and McCrimmon 1990, Chappell et al. 1999, Halverson et al. 1986

DOUGLAS FIR-PORT ORFORD CEDAR FOREST (50)

Geographic Distribution. A low to mid elevation forest type found mainly in the Coast Range and

Siskiyou Mountains of Curry County of southwestern Oregon. This type does not grow north of

Coos Bay on the Oregon coast and Roseburg in the interior valleys. Common west of the Coast

Range Crest, but is largely restricted to moist ultramafic soil environments inland. This cover type

is mostly confined to moist habitats of moderate elevation and steep riparian situations.

Structure and Appearance. This conifer forest type is characterized by, multi-story tree canopies,

co-dominated by Port Orford cedar (Chamaecyparis lawsoniana) and Douglas fir (Pseudotsuga

menziesii). Sub-canopies are composed of conifers and evergreen deciduous trees where there is

discontinuous overstory canopy cover. 

Composition. Douglas fir and Port Orford cedar dominate canopy overstory in these stands. 

Western hemlock (Tsuga heterophylla) is common west of the Coast Range, and sugar pine (Pinus

lambertiana) and grand fir (Abies grandis) present in the overstory of interior stands. 
114

Understory conifers are Douglas fir, western hemlock, western yew (Taxus brevifolia) and Port

Orford cedar. On ultramafic substrates, sugar pine and western white pine (Pinus monticola) are

frequent associates. Evergreen deciduous trees are California laurel (Umbellaria californica),

tanoak (Lithocarpus densiflora), and chinquapin (Castanopsis chrysophylla).

Large stature shrubs are common west of the Coast Range crest, vine maple (Acer circinatum),

pacific rhododendron (Rhododendron macrophyllum), and red huckleberry (Vaccinium

parvifolium), and evergreen huckleberry (V. ovatum). Interior stands shrub layers contain western

azalea (Rhododendron occidentalis), Sadler oak (Quercus sadleriana), and dwarf Oregongrape

(Mahonia nervosa).

Herbaceous layers are rich in species and abundance. Swordfern (Polystichum munitum) and other

ferns, bracken (Pteridium aquilinum), deer fern (Blechnum spicant), and lady fern (Athyrium filixfemina) are common. Other forbs include: vanillaleaf (Achlys triphylla), bedstraw (Galium

triflorum), western iris (Iris tenax), Oregon oxalis (Oxalis oregana), redwoods violet (Viola

sempervirens), western starflower (Trientalis latifolia), rattlesnake plantain (Goodyera

oblongifolia), and white trillium (Trillium ovatum).

Landscape Setting. This cover type is under-represented in the mapping effort because it often

exists as a coniferous riparian type that is not extensive enough to be mapped. It is largely

transitional to the other Douglas fir conifer types found in the region.

References. Atzet and Wheeler 1983, Jimerson et al. 1995, Atzet et al. 1996, Frenkel and

Kiilsgaard 1984, Hawk 1978, Hawk and Zobel 1980

DOUGLAS FIR / MIXED DECIDUOUS FOREST (51)

Geographic Distribution. Low to mid-elevation conifer and mixed deciduous forest. Found

primarily in the southwestern Oregon counties of Douglas, Coos, northern Curry, Josephine, and

Jackson. Also extends north into southern Lane County. This type is most common on the eastern

side of the Coast Range and in mesic microsites in the Siskiyou Mountains.

Structure and Appearance. This conifer/mixed deciduous forest type in its mature form is a large

structure multi-canopy forest. Upper tree layer always contains Douglas fir (Pseudotsuga

menziesii). Sub-canopies are mixes of shade tolerant conifers, with deciduous and evergreen

deciduous trees in discontinuous conifer canopies. Shrub and herb layers are prominent and rich in

species.

Composition. The overstory canopy is largely Douglas fir (Pseudotsuga menziesii). Sub-canopy

trees include: tanoak (Lithocarpus densiflora), madrone (Arbutus menziesii), chinquapin

(Castanopsis chrysophylla), and pacific dogwood (Cornus nuttallii) in the Siskiyou Mountains. 

Deciduous sub-canopies in the Coast Range will also include madrone, some chinquapin, and some

Oregon white oak (Quercus garryana) but will mostly contain big leaf maple (Acer macrophyllum),

and red alder (Alnus rubra).
115

Indicative shrubs of this cover type include: dwarf Oregongrape (Mahonia nervosa), pacific

blackberry (Rubus ursinus), oceanspray (Holodiscus discolor), California hazelnut (Corylus

cornuta), baldhip rose (Rosa gymnocarpa), pacific rhododendron (Rhododendron macrophyllum),

salal (Gaultheria shallon), red huckleberry (Vaccinium parvifolium), creeping snowberry

(Symphoricarpos mollis), and snow bramble (Rubus nivalis).

Commonly associated herbs include: cutleaf goldthread (Coptis laciniata), coolwort foamflower

(Tiarella trifoliata), white trillium (Trillium ovatum), western starflower (Trientalis latifolia),

swordfern (Polystichum munitum), trail plant (Adenocaulon bicolor), prince’s pine (Chimaphila

umbellata), Scouler’s harebell (Campanula scouleri), vanillaleaf (Achlys triphylla), streamside

violet (Viola glabella), Oregon fairybell (Disporum hookeri), and inside-out-flower (Vancouveria

hexandra).

Landscape Setting. This cover type occurs at intermediate elevations with moderate amounts of

precipitation. The abundant understory and sub-canopy layer distinguishes this type from other

regional conifer/deciduous cover types. 

References. Atzet et al. 1996, White 1996, Frenkel and Kiilsgaard 1984, Smith et al. 1987.

DOUGLAS FIR-WHITE FIR/TANOAK-MADRONE MIXED FOREST (52)

Geographic Distribution. Low to mid-elevation mixed conifer and mixed deciduous forest. Found

primarily in Jackson, Curry, and Josephine Counties of southwestern Oregon. This type is common

in the Siskiyou and Klamath Mountains and to a lesser extent, the southern Cascades.

Structure and Appearance. This mixed conifer/mixed deciduous forest type in its mature form is a

large structure multi-canopy forest. Upper tree layer always contains Douglas fir (Pseudotsuga

menziesii), with co-dominant to lesser amounts of fir (Abies grandis or Abies concolor) and usually

some representation of incense cedar (Calocedrus decurrens). Sub-canopies are mixes of shade

tolerant conifers with evergreen deciduous and deciduous trees. Shrub and herb layers are well

represented.

Composition. The proportion of overstory composition may vary by microsite and disturbance

history, but there will always be some mix of Douglas fir, white fir, and incense cedar in the stand. 

Sugar pine (Pinus lambertiana) and western white pine (P. monticola) are infrequent overstory

occupants. Sub-canopy trees include: tanoak (Lithocarpus densiflora), madrone (Arbutus

menziesii), chinquapin (Castanopsis chrysophylla), and lesser amounts of pacific dogwood (Cornus

nuttallii) and California laurel (Umbellaria californica).

Indicative shrubs of this cover type include: baldhip rose (Rosa gymnocarpa), dwarf Oregongrape

(Mahonia nervosa), pacific blackberry (Rubus ursinus), oceanspray (Holodiscus discolor),

California hazelnut (Corylus cornuta), and hairy honeysuckle (Lonicera hispidula).

Commonly associated herbs include: western starflower (Trientalis latifolia), rattlesnake plantain

(Goodyera oblongifolia), trail plant (Adenocaulon bicolor), prince’s pine (Chimaphila umbellata),
116

Scouler’s harebell (Campanula scouleri), vanillaleaf (Achlys triphylla), whipplevine (Whipplea

modesta), and Oregon fairybell (Disporum hookeri).

Landscape Setting. Common California mid-elevation forest type that reaches it northern extent in

southwestern Oregon. Logging, fires, and other stand disturbances promote the deciduous tree

component. Shasta red fir types typically border the type at its upper elevation. Lower elevation by

deciduous dominant cover types.

References. Atzet et al. 1996; Atzet and McCrimmon 1990; Jimerson et al. 1996

DOUGLAS FIR-OREGON WHITE OAK FOREST (53)

Geographic Distribution. Foothills forest type found in the Willamette and western interior

valleys of western Oregon. The type is also found in diminishing frequency in the Puget Trough of

western Washington. This particular cover type description will pertain to the Willamette Valley

communities. 

Structure and Appearance. Mosaic cover type where patterns of dominance and co-dominance

between Douglas fir (Pseudotsuga menziesii) and Oregon white oak (Quercus garryana) vary based

on local environment and stand history. Understory vegetation conditions range widely as well. 

Ungrazed stands can have prominent shrub and herbaceous layers, while stands that are part of

unmanaged pasture mosaics typically have understories where introduced annual grasses dominate.

Composition. Douglas fir and Oregon white oak are the dominant overstory trees. Grand fir (Abies

grandis) and Pacific madrone (Arbutus menziesii) may be present, but limited in numbers. Subcanopy tree layers can be dense in some stands and dominated by California hazelnut (Corylus

cornuta), the invasive sweet cherry (Prunus avium), black hawthorn (Crataegus douglasii), and

Indian plum (Oemleria cerasiformis).

Commonly associated shrubs for this type include poison oak (Rhus diversiloba), tall Oregongrape

(Mahonia aquifolium), snowberry (Symphoricarpos mollis), trailing blackberry (Rubus ursinus),

serviceberry (Amelanchier alnifolia), and baldhip rose (Rosa gymnocarpa).

The grass and forb layer typically includes cleavers (Galium aparine), blue wildrye (Elymus

glaucus), western iris (Iris tenax), bracken (Pteridium aquilinum), hairy honeysuckle (Lonicera

hispidula), and a variety of introduced grasses that seed in from adjacent pasturelands.

Landscape Setting. Hot, dry forests on the fringe between coniferous and valley bottom. Moisture

is probably the most limiting characteristic. Douglas fir is invading these predominantly white Oak

stands so stand composition typically grades from white oak dominance at lower treeline to codominance as the type merges with adjacent conifer forests. The hot, dry conditions of this cover

type preclude seedling establishment of shade tolerant conifers, i.e. western hemlock (Tsuga

heterophylla) and western red cedar (Thuja plicata). It is the lack of regeneration (and eventual

stand succession), of shade tolerant species that distinguishes this cover type from the more mesic

upslope conifer forest types.
117

References. Chappell et al. 1998

PONDEROSA PINE FOREST AND WOODLAND (54)

Geographic Distribution. This conifer forest and woodland is a major cover type in mid to lower

elevation zones along the flanks of the eastern Cascades and the mountain ranges of central and

northeastern Oregon.

Structure and Appearance. In its mature form this forest type is typified by large structure, widely

spaced ponderosa pine (Pinus ponderosa). The overstory is predominantly ponderosa with white

fir (Abies concolor), grand fir (A. grandis), incense cedar (Calocedrus decurrens), and Douglas fir

(Pseudotsuga menziesii) minor overstory trees based on location within the state.

Regeneration and understory tree layers are comparatively sparse in this cover type with regards to

other regional forest cover types. A variety of forest related grasses and grass-like forbs are

frequently found in this type.

Composition. Overstory tree along low elevation is exclusively ponderosa pine. At higher

elevation margin and transition to mixed conifer types, overstory conifers can be white fir, grand fir,

western larch (Larix occidentalis), incense cedar, Douglas fir, sub-alpine fir (Abies lasiocarpa), and

Engelmann spruce (Picea engelmannii). Understory and regeneration layers reflect similar

composition as overstory.

Shrubs are commonly found and reflect the same environmental trend as associated conifers; lower

elevations have fewer shrubs and sparse appearance, increasing in diversity and abundance with

elevation and improved soil moisture conditions. Indicative shrubs are bitterbrush (Purshia

tridentata), big sagebrush (Artemisia tridentata), snowberry (Symphoricarpos albus), serviceberry

(Amelanchier alnifolia), mountain mahogany (Cercocarpus ledifolius), greenleaf manzanita

(Arctostaphylos patula), and squaw carpet (Ceanothus prostratus).

Grasses and grass-like vegetation are common and dominate the understory in many stands. Idaho

fescue (Festuca idahoensis), prairie junegrass (Koeleria macrantha), bluebunch wheatgrass

(Agropyron spicatum), Kentucky bluegrass (Poa pratensis), mountain brome (Bromus carinatus),

elk sedge (Carex geyeri), Ross’ sedge (C. rossii) and western needlegrass (Stipa occidentalis).

Landscape Setting. Ponderosa pine is the most tolerant of hot, dry environments of Oregon’s

conifers and forms the boundary zone between forest and rangeland cover types for much of

Oregon. Its presence along the transition zone at lower elevations usually marks the adequacy of

soil moisture to grow large stature vegetation. The exception to ponderosa pines types forming the

forest/rangeland boundary is in central Oregon where western Juniper (Juniperus occidentalis)

occupies the transition between sagebrush and ponderosa pine cover types.

Ponderosa pine can also tolerate cold conditions so it occupies a wide elevational range, but in the

higher elevations it is restricted to southerly aspects. At these higher elevations ponderosa stands
118

usually are not large enough to form mappable units. Similarly, ponderosa pine stands can be found

in the low elevation, western Cascade forests but are not large enough to be mapped.

References. Volland, 1985, Johnson and Simon, 1987, Topik et al., 1988, Hopkins, 1979, Atzet et

al., 1996.

DOUGLAS FIR DOMINANT/MIXED CONIFER FOREST (56)

Geographic Distribution. Common mid elevation forest type in southwestern Oregon. This type

also extends north to the Columbia River in a narrow band along the eastern side of the Cascades.

Structure and Appearance. Stand structure can be diverse in undisturbed late seral stands although

single story forest canopies typify the type. Overstory tree layer ranges widely in canopy closure

based on management practice, disturbance history, and microsite. Understory vegetation is usually

diverse and rich in species.

Composition. This cover type contains a diverse array of conifers that complement the ever-present

Douglas fir (Pseudotsuga menziesii). Fir (Abies grandis and/or A. concolor), incense cedar

(Calocedrus decurrens), western white pine (Pinus monticola), and ponderosa pine (P. ponderosa)

are found throughout the range. Sugar pine (P. lambertiana) occurs only in southwestern Oregon,

and western red cedar (Thuja plicata), and Engelmann spruce (Picea engelmannii) only in the

central and northern regions of the Cascades. Sub-canopy layer generally has the shade tolerant

components of the overstory. Western yew (Taxus brevifolia) is a frequent sub-canopy component

in southwestern Oregon.

Indicator shrubs in this cover type include: vine maple (Acer circinatum), Rocky mountain maple

(A. glabrum var. douglasii), serviceberry (Amelanchier alnifolia), greenleaf manzanita

(Arctostaphylos patula), pinemat manzanita (A. nevadensis), red huckleberry (Vaccinium

parvifolium), Oregon grape (Mahonia nervosa), snowberry (Symphoricarpos albus), oceanspray

(Holodiscus discolor), sticky currant (Ribes viscosissimum), and squaw currant (R. cereum).

Common herbs in this cover type include western yarrow (Achillea millefolium), silvery lupine

(Lupinus argenteus), tailcup lupine (L. caudatus), strawberry (Fragaria virginiana), bull thistle

(Cirsium vulgare), heartleaf arnica (Arnica cordifolia), peavine (Lathyrus lanszwertii), starry

solomon-plume (Smilacina stellata), and white vein pyrola (Pyrola picta).

Landscape Setting. In southwestern Oregon this mid-elevation forest transitions between the

deciduous dominant foothill forests and the true fir dominant montane conifers. Along the slopes

of the eastern Cascades it is also transitional to the ponderosa pine and ponderosa/western juniper

at its low end and montane forests at upper elevations.

References. Hopkins and Rawlings 1985, Atzet et al. 1996, Atzet and Wheeler 1983, Chappell et

al. 1999, Kovalchik 1986, Volland 1985.
119

PONDEROSA PINE-OREGON WHITE OAK FOREST (57)

Geographic Distribution. A low elevation forest found on the eastern flanks of Mount Hood and

into the Columbia River Gorge. The type extends south to the Mutton Mountains of Wasco

County. This type is also found in the foothills vegetation of southwestern Oregon, especially in

the Rogue River Valley around White City.

Structure and Appearance. Open to closed canopy forest with small stature ponderosa pine (Pinus

ponderosa), co-dominant with Oregon white oak (Quercus garryana). Ponderosa may be the

canopy dominant but is considerably smaller than ponderosa grown in other environments. Except

for an occasional Douglas fir (Pseudotsuga menziesii) around Mt. Hood and incense cedar

(Calocedrus decurrens) in the Rogue River Valley other trees are absent from this type. Locally,

white oak can be very dense. Shrub cover is typically sparse in this type, but rich in herbs and

grasses.

Composition. Overstory tree species are ponderosa and white oak. Commonly associated shrubs

with the type include: squaw carpet (Ceanothus prostratus), deerbrush (C. integerrimus),

snowberry (Symphoricarpos mollis), serviceberry (Amelanchier alnifolia) and bitterbrush (Purshia

tridentata).

Commonly associated forbs include western yarrow (Achillea millefolium), hawkweed (Hieracium

albiflorum), smooth prariestar (Lithophragma glabra), American vetch (Vicia americana), tailcup

lupine (Lupinus caudatus), arrowleaf balsamroot (Balsamorhiza sagittata), and nineleaf lomatium

(Lomatium triternatum). Indicator grasses include: prairie junegrass (Koeleria macrantha), Idaho

fescue (Festuca idahoensis), California brome (Bromus carinatus), cheatgrass (B. tectorum),

bluebunch wheatgrass (Agropyron spicatum), elk sedge (Carex geyeri), and bulbous bluegrass (Poa

bulbosa).

Landscape Setting. The ponderosa/white oak type is an indicator of warm, dry environments. 

This type usually forms the lower treeline zone and grades into unimproved pastures that were

formerly grasslands. Grazing and selective logging pressure is high in these easily accessible

environments. Frequent disturbance will decrease abundance of ponderosa and promote the spread

of white oak.

References. Eyre 1980, Kagan and Caicco 1992, Topik et al. 1988, Williams, 1978.

PONDEROSA PINE/WESTERN JUNIPER WOODLAND (58)

Geographic Distribution. Widespread conifer woodland forest type in eastern Oregon. This cover

type is usually found in the foothills margin bordering upland conifer types and sagebrush dominant

lowlands for most of the regions mountain ranges.

Structure and Appearance. Woodland conifer forest cover type. Two-story canopy with widely

spaced overstory ponderosa pine (Pinus ponderosa) over the sub-canopies of western juniper
120

(Juniperus occidentalis). Combined canopy layers generally ranges from 10-50 percent. The shrub

layer, interspersed with annual and bunch grasses typically dominates understory vegetation.

Composition. Ponderosa pine and western juniper dominate the overstory in this cover type. 

Dominance of the tree layer between Ponderosa and juniper shifts by microsite and elevation. 

Improved site productivity favors dominance by Ponderosa. In lower elevations with warmer, drier

microclimates, or sites with thin soils, dominance shifts to western juniper.

Indicator shrubs in this type include big sagebrush (Artemisia tridentata), low sagebrush (A.

arbuscula), rabbitbrush (Chrysothamnus nauseous and C. viscidiflorus), mountain mahogany

(Cercocarpus ledifolius), and bitterbrush (Purshia tridentata).

Grasses dominate the herbaceous layer. Overgrazing in the cover type usually leads to the

proliferation of cheatgrass (Bromus tectorum), bottlebrush squirreltail (Sitanion hystrix), or bulbous

bluegrass (Poa bulbosa). Native bunchgrasses commonly found in this cover type include:

Sandberg’s bluegrass (Poa secunda), Idaho fescue (Festuca idahoensis), bluebunch wheatgrass

(Agropyron spicatum), Great Basin wildrye (Elymus cinereus), and Indian ricegrass (Oryzopsis

hymenoides).

Landscape Setting. Similar to the western juniper woodland cover type, the ponderosa/juniper type

occupies the transition between upland conifer forests and lowland sagebrush communities.

References. Shiftlet, 1994, Johnson and Clausnitzer 1992, Johnson and Simon, 1987, Dealy et al.

1981.

PONDEROSA-LODGEPOLE PINE ON PUMICE (59)

Geographic Distribution. The most common forest and/or woodland cover type in the southern

half of the eastern Cascades ecoregion. The long taproots of lodgepole (Pinus contorta) and

ponderosa (P. ponderosa) make them especially well adapted to the droughty pumice soils of this

region. Pumice soils are derived from the volcanic eruptions of prehistoric Mount Mazama and

numerous cinder cones throughout the region. This forest type forms a nearly continuous cover

from LaPine to the northern edge of the Klamath Marsh.

Structure and Appearance. Ponderosa and lodgepole dominate the overstory canopy and

regeneration layers in these forests. In its mature, undisturbed form, these forests are distinctly two

story canopies with large ponderosa over the shorter lodgepole. Due to extensive selective logging

in this type most of the large ponderosa have been removed leaving large tracts of single story

lodgepole forests. Regeneration and tree growth are slow in these infertile forests. These forests

have an active fire history and have evolved with frequent fires.

Shrub and herb layers are poorly developed in this forest type.
121

Composition. Ponderosa and lodgepole are the most commonly encountered trees. In wet places

and riparian strips, Engelmann spruce (Picea engelmannii), quaking aspen (Populus tremuloides),

and white fir (Abies concolor) can be found.

The shrub layer in this cover type is poorly developed. The most commonly associated shrubs are

bitterbrush (Purshia tridentata), greenleaf manzanita (Arctostaphylos patula), kinnikinnik (A. uvaursi), and serviceberry (Amelanchier alnifolia).

The herb layer in most stands has sparse cover with few species. Several grasses, western

needlegrass (Stipa occidentalis), squirreltail (Sitanion hystrix), Wheeler’s bluegrass (Poa nervosa),

and Idaho fescue (Festuca idahoensis) are commonly found. Other forbs can be: wooly wyethia

(Wyethia mollis), white hawkweed (Hieracium albiflorum), and Ross’ sedge (Carex rossii).

Landscape Setting. The distribution of the ponderosa-lodgepole pine on pumice cover type closely

corresponds to the distribution of deep tephra layers from the regions volcanic activity. As such, it

doesn’t necessarily relate to environment or climatic conditions.

References. Volland 1988, Kovalchik 1987, Hopkins 1979.

WESTERN JUNIPER WOODLAND (61)

Geographic Distribution. Western juniper (Juniperus occidentalis) is a common foothills

vegetation type for many of the mountain ranges of eastern Oregon. Juniper reaches its greatest

extent in the High Lava Plains Ecoregion centered on Bend, Oregon.

Structure and Appearance. This woodland type is typified by its open canopy (less than 30%

crown closure), single story, short stature (6-20 feet tall) trees. Understory vegetation in these

stands tends to be dominated by sagebrush species, although introduced annual grasses and native

bunchgrasses can be important depending on site history and disturbance. As site productivity

conditions improve, or as soil moisture availability increases, the pure stands of juniper give way to

mixed stands of juniper and ponderosa pine (Pinus ponderosa).

Composition. In most stands western juniper dominates the tree layer. The most frequently

encountered shrubs in this cover type are sagebrush species. Big sagebrush (Artemisia tridentata)

is the most common with rigid sagebrush (A. rigida) and low sagebrush (A. arbuscula) also

commonly found. Other shrubs associated with this type are mountain mahogany (Cercocarpus

ledifolius), bitterbrush (Purshia tridentata), and rabbitbrush (Chrysothamnus nauseous and C.

viscidiflorus).

 Grasses characterize the herbaceous layer. Cheatgrass (Bromus tectorum) and bottlebrush

squirreltail (Sitanion hystrix) are typical and dominant on overgrazed or disturbed sites. Native

bunchgrasses can usually be found. Idaho fescue (Festuca idahoensis), bluebunch wheatgrass

(Agropyron spicatum), Thurber’s needlegrass (Stipa thurberiana), and Sandberg’s bluegrass (Poa

secunda) are the most commonly encountered.
122

Landscape Setting. Western juniper occupies the transition zone between conifer dominant

uplands and the shrub-steppe basins of eastern Oregon. In the driest mountain ranges of

southeastern Oregon, i.e. the Trout Creek and Pueblo Mountains, juniper is found at all elevational

ranges. Western juniper’s range is increasing in Oregon. Overgrazing and fire suppression are

considered to be the primary factors for the spread of this type.

References. Crawford and Chappell 1999, Dealy et al. 1981, Monzingo 1986, Kagan and Caicco

1991.

RED ALDER (63) & RED ALDER/BIG LEAF MAPLE FOREST (64)

Geographic Distribution. Lowland riparian and low montane forest common in northwestern

Oregon and found throughout the Coast Range mountains and the low elevation forests along the

western margin of the Cascades. Big leaf maple (Acer macrophyllum) is most prevalent in the

foothills region of the Cascades and the eastern side of the Coast Range. Maple is a minor

deciduous component along the coastal margin.

Structure and Appearance. Moderate height (20-50 feet) closed canopy deciduous forest. Upland

red alder (Alnus rubra) and alder/big leaf maple forests are early seral forests to the low elevation

conifer forests of Douglas fir (Pseudotsuga menziesii), western hemlock (Tsuga heterophylla), and

western red cedar (Thuja plicata). Red alder also is a common overstory tree along many

streamside corridors within the Coast Range.

Composition. In early seral stages red alder and big leaf maple dominate the overstory. As the

stand matures conifers overtop the deciduous trees and dominate the crown layer. In this advanced

forest successional stage maintain a hold within the stand as sub-canopy trees in the large gaps

among the overstory conifers.

Understory vegetation is prominent and diverse. Indicator shrubs are vine maple (Acer circinatum),

salmonberry (Rubus spectabilis), thimbleberry (R. parviflorus), evergreen huckleberry (Vaccinium

ovatum), and salal (Gaultheria shallon).

Herbaceous layer is rich in species and usually has one or more of the following moist site

indicators: oxalis (Oxalis oregana), swordfern (Polystichum munitum), foamflower (Tiarella

trifoliata), vanillaleaf (Achlys triphylla), beadlily (Clintonia uniflora), skunk cabbage (Lysichitum

americanum), coltsfoot (Petasites frigidus), and twinflower (Linnaea borealis).

Landscape Setting. Alder stands are important colonizers of sites following timber harvest and act

to stabilize hill slopes and retard erosion. Alder and big leaf maple stands are indicative of warm,

moist sites. Alder regeneration and establishment is always better on southerly exposures.
123

ALDER-COTTONWOOD (65) & COTTONWOOD RIPARIAN GALLERY FOREST (68)

Geographic Distribution. Alder-cottonwood riparian forest is found along the margin of flowing

streams in the foothills and mountains throughout much of Oregon. West of the Cascade crest the

alder species is red alder (Alnus rubra); east of the crest it is typically white alder (Alnus

rhombifolia). The type is especially prevalent along high gradient stream systems that flood

frequently and deposit bed-load sand and gravel. The description of this type follows closely that of

palustrine forest. 

Structure and Appearance. Tall deciduous forest with partial-to-closed overstory canopy. Stands

are often multi-layered. Cottonwood riparian stands are often mosaics of partial overstory canopy

with dense understory reproduction to open areas dominated by willows (Salix spp.) to closed

forests that may include conifers in the overstory.

Composition. Black cottonwood (Populus trichocarpa) is always present in the overstory. West of

the Cascade crest red alder and big leaf maple (Acer macrophyllum) can be co-dominant with

cottonwood. Conifers found in the western Oregon version of this type are Douglas fir

(Pseudotsuga menziesii), western hemlock (Tsuga heterophylla), western red cedar (Thuja plicata),

and Port Orford Cedar (Chamaecyparis lawsoniana) in southwestern Oregon.

Eastern Oregon deciduous overstory trees besides cottonwood include white alder, mountain alder

(Alnus incana), pacific willow (Salix lasiandra), non-native black locust (Robinia pseudo-acacia),

and quaking aspen (Populus tremuloides). Conifers associated with the eastern Oregon cottonwood

gallery forests are ponderosa pine (Pinus ponderosa), Douglas fir, and in mountain settings

Engelmann spruce (Picea engelmannii), and lodgepole pine (Pinus contorta).

Shrub and herb layers are prominent and diverse. Douglas spiraea (Spiraea douglasii), red osier

dogwood (Cornus sericea), Nutka rose (Rosa nutkana), chokecherry (Prunus virginiana), and a

variety of willow species (Salix boothii, S. exigua, S. geyeriana, S. lemmonii, and S. bebbiana). 

Forbs include speedwell (Veronica americana), cow parsnip (Hieracleum lanatum), skunk cabbage

(Lysichitum americanum), pioneer violet (Viola glabella), stinging nettle (Urtica dioica), wide-fruit

sedge (Carex eurycarpa) and wooly sedge (C. lanuginosa).

Landscape Setting. Generally a narrow, linear cover type. Mostly bordering agriculture, the type

also fingers into uplands and mountains along the larger watercourses.

References. Kovalchik 1986, Crawford et al. 1999, Kagan and Caicco 1992.

ASPEN GROVES (66)

Geographic Distribution. Scattered throughout the coniferous forests of eastern Oregon in clonal

clumps that are too small to map in most cases. Aspen (Populus tremuloides) groves are most

extensive in the Steens Mountains of southeastern Oregon.
124

Structure and Appearance. Short stature (most aspen are less than 50 feet tall) deciduous trees that

dominate the overstory. Lacking cattle grazing pressure aspen groves can be dense with numerous

stems, most stands however are open with widely spaced aspen clumps with well-developed shrub

and forb layers.

Composition. Aspen is the dominant tree in this cover type, although scattered conifers, or western

juniper (Juniperus occidentalis) may be present.

Shrub layer is conspicuous and usually includes snowberry (Symphoricarpos mollis) and

serviceberry (Amelanchier alnifolia). Other shrubs can be mountain big sagebrush (Artemisia

tridentata var. vaseyana), bitterbrush (Purshia tridentata), and mountain mahogany (Cercocarpus

ledifolius).

Forb layer is dominated by grasses, both native and introduced. Bluebunch wheatgrass (Agropyron

spicatum), pinegrass (Calamagrostis rubescens), California brome (Bromus carinatus), blue

wildrye (Elymus glaucus) and Idaho fescue (Festuca idahoensis), along with a variety of introduced

grasses are common.

Landscape Setting. Aspen groves can be found in a variety of environmental settings in eastern

Oregon. However, they mostly occupy mid to upper elevation ranges on the various mountain

ranges.

References. Franklin and Dyrness 1973, Kagan and Caicco 1992, Kovalchik, 1987.

CONIFER-DECIDUOUS FOREST (67)

Geographic Distribution. Low to mid elevation early successional forest found throughout the

Coast Range and Cascade Mountains of western Oregon.

Structure and Appearance. Overstory canopy is composed of co-dominant conifer (generally

Douglas fir (Pseudotsuga menziesii) and deciduous (generally red alder (Alnus rubra), and/or big

leaf maple (Acer macrophyllum) trees. This type is classed as an old clear-cut, or young forest. 

Canopies are single story and closed. The deciduous component is a remnant of earlier clear-cut

succession where red alder and big leaf maple can dominate the overstory. Over time conifers out

compete the deciduous trees relegating them to a minor component in the mature conifer forests of

western Oregon.

Composition. The most common overstory conifer in this type is Douglas fir as it is replanted in

monotypic stands following timber harvest. Western hemlock (Tsuga heterophylla), western red

cedar (Thuja plicata), grand fir (Abies grandis), and Sitka spruce (Picea sitchensis) will naturally

reseed into the clear-cuts depending on geographic location within the types regional distribution. 

Deciduous trees are primarily red alder and big leaf maple.

Understory vegetation is negligible as the tightly crowded canopy casts deep and continuous shade

upon the forest floor.
125

Landscape Setting. Common throughout the Coast Range and its coastal plain forests. Also

common in the Douglas fir dominant- low elevation forests of the Cascades. Exists as a patchwork

mosaic with younger clear-cuts and established forests.

SISKIYOU MOUNTAINS MIXED DECIDUOUS (72)

Geographic Distribution. A common foothills forest type in the interior valleys of southwestern

Oregon. Most readily found in the Rogue River valley between Grants Pass and Ashland. This

type is also common in the Illinois River and other valley stream courses south to the California

border. North of Grants Pass the type can be found in diminishing frequency in Douglas County to

the Drain/Curtin divide.

Structure and Appearance. Dominant canopy layer is a low to mid stature (20-60 feet) deciduous

and evergreen deciduous trees. Widely scattered emergent conifers, Douglas fir (Pseudotsuga

menziesii) and incense cedar (Calocedrus decurrens) are common in stands that have not been

selectively harvested, or have had recent fire activity.

Composition. Pacific madrone (Arbutus menziesii) and Oregon white oak (Quercus garryana) are

generally co-dominant with less frequent representation from canyon live oak (Q. chrysolepis),

black oak (Q. kelloggii), tan oak (Lithocarpus densiflorus), California laurel (Umbellaria

californica), and chinquapin (Castanopsis chrysophylla). 

Deciduous shrubs that are commonly associated with this cover type are poison oak (Rhus

diversiloba), baldhip rose (Rosa gymnocarpa), common snowberry (Symphoricarpos albus),

California hazelnut (Corylus cornuta), buckbrush (Ceanothus cuneatus), and hairy honeysuckle

(Lonicera hispidula).

Commonly associated herbs include sweet cicely (Osmorhiza chilensis), bedstraw (Galium

aparine), Sierra sanicle (Sanicula graviolens), blue wildrye (Elymus glaucus), bottlebrush

squirreltail (Sitanion hystrix), and an assortment of naturalized annual grasses including the often

dominant hedgehog dogtail (Cynosorus echinatus).

Landscape Setting. Siskiyou Mountains mixed deciduous forest is a transition forest type to

associated regional upland conifer types. Its presence denotes warm, dry microclimates. Fire and

grazing are frequent perturbations in this cover type.

References. Atzet and Wheeler 1983, Atzet et al. 1996, Jimerson et al. 1996, Hawk and Zobel

1983.
126

OREGON WHITE OAK FOREST (75)

Geographic Distribution. Common throughout the western Oregon interior valleys of the Rogue,

Umpqua and Willamette River valleys and the eastern end of the Columbia River Gorge. Oregon

white oak (Quercus garryana) is a low elevation, warm site deciduous tree species. This cover type

is rapidly disappearing throughout its range in Oregon due to urban expansion.

Structure and Appearance. Oregon white oak dominates the overstory in this deciduous forest that

ranges from woodland to forest based on ecological site and site history. Understories in these

forests typically contain tall deciduous shrubs and smaller stature deciduous trees. In southwestern

Oregon the subcanopy is often California black oak (Quercus kelloggii), while in the Willamette

Valley it is sweet cherry (Prunus avium). 

Composition. The canopy layer is dominated by Oregon white oak. Other canopy trees can be

Douglas fir (Pseudotsuga menziesii), ponderosa pine (Pinus ponderosa) in upland settings. On the

valley floor, overstories can be mixed with Oregon ash (Fraxinus latifolia), cottonwood (Populus

trichocarpa), and big leaf maple (Acer macrophyllum).

Shrub layer is prominent and diverse. Commonly encountered shrubs being: poison oak (Rhus

diversiloba), baldhip rose (Rosa gymnocarpa), California hazelnut (Corylus cornuta), common

snowberry (Symphoricarpos albus), oceanspray (Holodiscus discolor), Indian plum (Oemleria

cerasiformis), and trailing blackberry (Rubus ursinus).

Landscape Setting. Through most of the interior western valley settings Oregon white oak is the

transitional forest from the agriculture dominant valley floor to the conifer forest uplands. Oregon

white oak is a vigorous sprouter after fires and this cover type benefited from frequent fires. 

Increased fire suppression in this last century has led to invasion of the Oregon white oak stands by

upland conifers. Oregon white oak produces an abundance of acorns and is a highly desirable

wildlife habitat.

References. Atzet et al. 1996, Kagan and Caicco 1992, Franklin and Dyrness 1973, Habeck 1961.

SOUTH COAST MIXED DECIDUOUS (77)

Geographic Distribution. Low to middle elevation deciduous forest restricted to the western side

of the Coast Range from Coos Bay south to the California border. This type is most prevalent in

coastal northwestern California.

Structure and Appearance. Multi-story canopy composed of well-spaced large bole conifers

(primarily Douglas fir (Pseudotsuga menziesii), over a densely stocked evergreen deciduous and

deciduous sub-canopy. Understory is diverse and dominated by the shrub layer.

Composition. Overstory conifer is usually Douglas fir although western hemlock (Tsuga

heterophylla), and Port Orford cedar (Chamaecyparis lawsoniana) can be important. Sub-canopy

deciduous trees are tanoak (Lithocarpus densiflorus), California laurel (Umbellaria californica),
127

Pacific dogwood (Cornus nuttallii), golden chinquapin (Castanopsis chrysophylla) and to a lesser

extent, big leaf maple (Acer macrophyllum).

Representative shrubs are evergreen huckleberry (Vaccinium ovatum), Pacific rhododendron

(Rhododendron macrophyllum), Oregon grape (Mahonia nervosa), salal (Gaultheria shallon),

California hazelnut (Corylus cornuta), and red huckleberry (Vaccinium parvifolium).

Western sword fern (Polystichum munitum) dominates the herb layer and often is the only

prominent herbaceous species due to the dense cover of shrubs.

Landscape Setting. The south coast mixed deciduous cover type is common in the southwestern

Coast Range where frost, drought and fire are less likely to occur, namely the coastal margin and

low elevation forests. Tanoak, California laurel, and Pacific dogwood are susceptible to frost and

cannot compete with higher elevation forest types when they are continually set by frost damage. 

Similarly, the Coast Range north of Coos Bay is too cold for this cover type to thrive.

References. Atzet and Wheeler 1984, Atzet .et al. 1996, Jimerson et al. 1996, Frenkel and

Kiilsgaard 1984.

SHRUBLAND AND GRASSLAND TYPES

SISKIYOU MOUNTAINS SERPENTINE SHRUBLAND (85)

Geographic Distribution. Occurs throughout southwestern Oregon in scattered mosaics with the

Jeffrey Pine type. Most abundant in the foothills of the Illinois River Valley, also found in the

Rogue Valley. This type is also associated with serpentine soil plant communities and its

distribution and occurrence closely follows the Jeffrey Pine Forest and Woodlands type.

Structure and Appearance. Medium to tall shrubland that may have shrub canopy closures greater

than 60% although most stands have canopies that are less dense with dispersed overstory. 

Scattered Jeffrey pine (Pinus jeffreyi) and incense cedar (Calocedrus decurrens) commonly occur

in the type, at less than 10% canopy cover.

Forb layer is diverse, but sparse in appearance. Like the Jeffrey Pine type, these shrublands tend to

have a lot of exposed bedrock and gravel scattered among the vegetation.

Composition. Shrub layer is dominated by hoary manzanita (Arctostaphylos canescens), white leaf

manzanita (A. viscida), and buckbrush ceanothus (Ceanothus cuneatus). Other associated shrubs

are huckleberry oak (Quercus vaccinifolia), dwarf ceanothus (Ceanothus pumilus) and coffeeberry

(Rhamnus californica).

Forbs are diverse, but most of forb cover comes from grasses. Red fescue (Festuca rubra), Idaho

fescue (F. idahoensis), Lemmon’s needlegrass (Stipa lemmonii), blue wildrye (Elymus glaucus), big

squirreltail (Sitanion jubatum), and pacific bluegrass (Poa gracillima) are commonly found. Other

forbs are rock fern (Aspidotis densa), common yarrow (Achillea millefolium), spreading phlox
128

(Phlox diffusa), deadly zigadenus (Zigadenus venenosus), and sulphurflower (Eriophyllum

umbellatum).

Landscape Setting. These shrublands typically are found at low elevations on southerly aspects. 

They are successional to Jeffrey Pine woodlands. However, slow plant growth due to general poor

site quality and an active fire frequency maintain these shrublands as persistent features in the

regions vegetation.

References. Jimerson et al. 1995, Atzet et al. 1996, Frenkel and Kiilsgaard 1984, Kagan and Caicco

1992.

WILLOW-HAWTHORN SHRUBLAND (87)

Geographic Distribution. Valley bottom riparian shrubland formerly widespread along low

gradient streams. Currently most prevalent in the Willamette and Grand Ronde River Valleys.

Structure and Appearance. Tall shrubland with dense cover of willows (Salix spp.) and/or black

hawthorn (Crataegus douglasii). Shrubs are interspersed with dense patches of spirea and sedge

meadows in poorly drained reaches and tufted hairgrass (Deschampsia caespitosa) prairie on better

drained soils.

Composition. Overstory willow species include (Salix sitchensis, S. rigida, S. fluviatilis, in western

Oregon, and S. lasiandra, S. exigua, S. geyeriana, and S. lutea) in eastern Oregon. Black hawthorn

is generally present in varying degrees of dominance. Other western Oregon shrubs include

blackberry (Rubus ursinus and R. spectabilis), sticky currant (Ribes lacustre), Indian plum

(Oemleria cerasiformis), and Douglas spirea (Spiraea douglasii).

Eastern Oregon shrubs include western birch (Betula occidentalis), snowberry (Symphoricarpos

albus), mockorange (Philadelphus lewisii), and red osier dogwood (Cornus sericea).

Forbs and grasses common to this type include cowparsnip (Hieracleum lanatum), stinging nettle

(Urtica dioica), common rush (Juncus effusus), horsetail (Equisetum arvense), camas (Camassia

quamash), tufted hairgrass, buttercup (Ranunculus occidentalis), marsh sedge (Carex obnupta),

bluejoint reedgrass (Calamagrostis canadensis), and blue wildrye (Elymus glaucus).

Landscape Setting. This type occurs on broad, low elevation floodplains that seasonally flood and

maintain high water tables. Agriculture or other wetland/riparian types usually border this shrub

dominant type.

References. Klock 1998, Chappell et al. 1998, Kagan and Caicco 1992, Kovalchik 1986.
129

MANZANITA DOMINANT SHRUBLAND (89)

Geographic Distribution. This is a primary colonizing vegetation type following fires both wild in

southern margin of the eastern Cascades, and to lesser extent in the Siskiyou Mountains along the

California border.

Structure and Appearance. Shrub layer dominates the early successional development of this

cover type. Older stands have emergent conifers gradually to be replaced by conifer overstory. 

Composition. Greenleaf manzanita (Arctostaphylos patula) dominates the shrub layer in this cover

type. Other associated shrubs would be bitterbrush (Purshia tridentata), chokecherry (Prunus

virginiana), pinemat manzanita (A. nevadensis), and snowbrush (Ceanothus velutinus).

Landscape Setting. Forms a mosaic with mixed conifer, lodgepole, and ponderosa pine forest

cover types. This type is not prominent on the map because many of the stands are excluded

because they are less than 250 acres in size.

References. Hopkins 1979, Mozingo 1986.

MOUNTAIN MAHOGANY SHRUBLAND (90)

Geographic Distribution. Mainly found in the mountain ranges of southeastern Oregon, i.e. Steens,

Trout Creek and Pueblo Mountains. This cover type is commonly encountered but generally exists

as units that are too small to be mapped. The most extensive representation of this is found on the

rimrock canyons of the Steens Mountain.

Structure and Appearance. Widely dispersed tall shrubland with rock talus and rock outcrops

between shrubs. Mountain mahogany (Cercocarpus ledifolius) grows in the soil pockets within the

rocky slopes along with big sagebrush (Artemisia tridentata), bitterbrush (Purshia tridentata) and

purple sage (Salvia dorrii).

Composition. Mountain mahogany is the dominant overstory vegetation with occasional western

juniper (Juniperus occidentalis). Shrub layer also contains big sagebrush, bitterbrush, purple sage,

low sage (Artemisia arbuscula or A. cana), and several buckwheats (Eriogonum strictum and E.

caespitosum).

Landscape Setting. Occurs on the steep, rocky slopes of mountains in southeastern Oregon. It

usually appears as a minor component within the western juniper woodland type, or it grades in and

out of sagebrush steppe.

References. Kagan and Caicco, 1992, Mozingo 1986.
130

SAGEBRUSH STEPPE (91)

Geographic Distribution. The predominant cover type of the Owyhee Uplands ecoregion of

southeastern Oregon. Sagebrush steppe is a common vegetation element in the watersheds of the

Malheur, Powder, and Burnt Rivers. Sagebrush steppe is also commonly found in the noncultivated portions of the Columbia River basin.

Structure and Appearance. Complicated mosaic of grasses (mostly introduced) and shrubs (mostly

the differing varieties of big sagebrush). Historically, this type contained a predominance of

bunchgrasses with scattered shrubs. Overgrazing has shifted the composition to favor sagebrush. 

Composition. Shrub layer always contains some mixture of sagebrush and sagebrush-like

vegetation. The three common subspecies of big sagebrush, Wyoming (Artemisia tridentata var.

wyomingensis), basin (A. tridentata var. tridentata), and mountain (A. tridentata var. vaseyana) will

grow with shorter varieties of sagebrush (rigid (Artemisia rigida), low (A. arbuscula), silver (A.

cana) and three-tip (A. tripartata)) along with rabbitbrush (Chrysothamnus viscidiflorus and C.

nausosus), based on local environment and site history. 

A variety of bunchgrasses are associated with this type although they rarely comprise much of the

stand due to grazing pressure. Some of the characteristic native grasses of this type are Great Basin

wildrye (Elymus cinereus), Thurber needlegrass (Stipa thurberiana), Indian ricegrass (Oryzopsis

hymenoides), blue bunch wheatgrass (Agropyron spicatum), Idaho fescue (Festuca idahoensis),

bluegrass (Poa secunda), and sand dropseed (Sporobolus cryptandrus). In many areas, these have

given way to cheatgrass (Bromus tectorum), and crested wheatgrass (Agropyron cristatum).

Landscape Setting. The sagebrush steppe primarily is adjacent to the big sagebrush type. These

two types may, in fact, weave together in complicated mosaics at the edges of the Basin and Range

ecoregion and in the interior uplands. Distinction between the two types is complicated and

therefore somewhat crude and inexact in its depiction on the map.

References. Johnson and Simon 1986, Johnson and Clausnitzer 1987, Crawford et al. 1999,

Franklin and Dyrness 1973.

LOW-DWARF SHRUBLAND (93)

Geographic Distribution. These dwarf sagebrush types are sporadically found throughout eastern

Oregon, generally on areas with shallow basalt soils. The low sagebrush (Artemisia arbuscula)

cover type is most extensive east of the Guano Valley in Lake and Harney counties and in the

ancient pluvial lake basins of northern Lake County. Rigid sagebrush (Artemisia rigida) is

common in Oregon’s Basin and Range along the Columbia River between Arlington and

Boardman, and along the margins of the Blue Mountains. Black sagebrush (Artemisia nova)

dominates scabland flats in extreme southeastern Oregon, in Malheur and southeastern Harney

Counties. Low and rigid sagebrush are both infrequently found in the forests of the eastern

Cascades and northeastern Oregon, where soils are too shallow to permit tree growth.
131

Structure and Appearance. Low sagebrush (A. arbuscula) or rigid sagebrush (Artemisia rigida)

are the primary dominants and often the only shrubs in the stand. Sandberg bluegrass (Poa

secunda) is common. 

Composition. A dwarf sagebrush shrub (black sagebrush, rigid sagebrush, low sagebrush, or silver

sagebrush [Artemisia cana]) dominates the shrub layer with occasional big sagebrush (A.

tridentata) and bitterbrush (Purshia tridentata). Several shrubby buckwheat species (Eriogonum

douglasii and E. strictum) and purple sage (Salvia dorrii) are prominent on steep, rocky slopes

within the cover type.

The forb layer is diverse, but usually composed of ephemeral annual forbs, or scabland perennials

(Lomatium cous, Balsamorhiza serrata, B. hookeri, Lewisia rediviva, Erigeron and Phlox spp.),

although grasses provide most of the forb cover. Cheatgrass, Sandberg bluegrass, bottlebrush

squirreltail (Sitanion hystrix) and onespike oatgrass (Danthonia unispicata) are the most frequently

encountered.

Landscape Setting. The dwarf sagebrush usually are the dominant vegetation in shallow soil, rocky

conditions that exclude the formation of other sagebrush and shrub types. In most cases, they do

not form extensive landscape-level covers but rather are part of the larger big sagebrush and

sagebrush steppe mosaic.

References. Hopkins 1979, Kagan and Caicco 1992, Shiftlet 1994, Dealy et al. 1981.

SALT DESERT SCRUB SHRUBLAND (95)

Geographic Distribution. Most extensive in the alkaline playa lake basins of the Great Basin

ecoregion of Harney, Lake and Malheur Counties. Especially prominent around Lake Abert,

Malheur, Alvord, and the Warner Lakes.

Structure and Appearance. Low to tall shrub communities comprised of dispersed alkali-tolerant

vegetation. Salt desert scrub is a catchall term that describes several differing environments. On

the most saline sites, that also are seasonally flooded, black greasewood (Sarcobatus vermiculatus)

and winterfat (Erotia lanata) dominate. Sites with better drainage support a variety of shrubs and

several grasses.

Composition. Characteristic shrubs that are commonly associated with salt desert scrub complexes

are shadscale (Atriplex confertifolia), hopsage (Grayia spinosa), budsage (Artemisia spinescens),

Mormon tea (Ephedra viridis), rabbitbrush (Chrysothamnus nauseous), saltbush (Atriplex nuttallii)

and greenmolly (Kochia americana).

Landscape Setting. Salt desert scrub is surrounded by big sagebrush or sagebrush steppe cover

types. The most extensive areas are always associated with the large, ephemeral lakes of the region. 

However, there are numerous, small pockets of this cover type scattered sporadically throughout

southeastern Oregon.
132

References. Mozingo 1986, Demming et al. 1978, Shiftlet 1994, Dealy et al. 1981.

BIG SAGEBRUSH SHRUBLAND (96)

Geographic Distribution. The most common vegetative cover type in eastern Oregon. It appears

as a mosaic with shrub-steppe communities along mountain range foothills, basins and along the

valley floor.

Structure and Appearance. Medium to tall shrub community dominated by the three varieties of

big sagebrush, mountain big sagebrush (Artemisia tridentata var. vaseyana), basin big sage (A.

tridentata var. tridentata), and Wyoming big sage (A. tridentata var. wyomingensis). Some stands

support a diversity of forbs and grass species; however, due to grazing pressure the dominant forb is

cheatgrass (Bromus tectorum). Crested wheat grass (Agropyron cristatum) from nearby CRP (Crop

Reserve Program) lands can seed into these stands.

Composition. Artemisia tridentata varieties dominate the canopy layer. Other shrubs found in this

type include: bitterbrush (Purshia tridentata), rabbitbrush (Chrysothamnus nauseous and C.

viscidiflorus), threetip sagebrush (Artemisia tripartata), silver sagebrush (Artemisia cana) and

shadscale (Atriplex confertifolia).

Herbaceous plants found in this type include pussytoes (Antennaria corymbosa), spreading phlox

(Phlox diffusa), Hoods phlox (P. hoodii), and longleaf phlox (P. longifolia), starved milk vetch

(Astragalus miser), bigseed lomatium (Lomatium macrocarpum), nineleaf lomatium (Lomatium

triternatum) Cusick’s penstemon (Penstemon cusickii), and arrowleaf balsamroot (Balsamorhiza

sagittata).

Native grasses range from present to abundant based on site history and beneficial soil/water

relations. Commonly encountered native bunchgrasses include bluebunch wheatgrass (Agropyron

spicatum), Sandberg’s bluegrass (Poa secunda), junegrass (Koeleria macrantha), Idaho fescue

(Festuca idahoensis), Great Basin wildrye (Elymus cinereus) and in more disturbed situations

bottlebrush squirreltail (Sitanion hystrix). Introduced annual grasses are primarily cheatgrass and

crested wheatgrass. 

Landscape Setting. Big sagebrush occurs throughout the arid basins and valleys of western United

States. In Oregon, it is the 2nd largest (to Douglas fir/western hemlock/western red cedar) cover

type mapped in this study. Big sagebrush thrives in regions of low precipitation (mostly in the 8 to

14 inch range). The big sage type is bordered on its upland margin by western juniper, eastside

mixed conifer, or ponderosa pine types.

References. Tisdale 1994, Shiftlet 1994, Dealy et al 1981, Dobler et al. 1996.
133

BIG SAGEBRUSH - BITTERBRUSH SHRUBLAND (97)

Geographic Distribution. Occurs throughout eastern and central Oregon east of the Cascade crest. 

While widespread in its occurrence, the big sagebrush (Artemisia tridentata)-bitterbrush (Purshia

tridentata) is largely restricted to porous, well-drained, sandy soils.

Structure and Appearance. Medium-tall shrubland steppe with grass dominant understory. Big

sagebrush and bitterbrush are co-dominant in the canopy layer. 

Composition. Other shrubs commonly encountered in this type besides big sagebrush and

bitterbrush would be low sagebrush (Artemisia arbuscula), rigid sage (A. rigida), gray and green

rabbitbrush (Chrysothamnus nauseosus and C. viscidiflorus). Mountain mahogany (Cercocarpus

ledifolius) and purple sage (Salvia dorrii) are associated with this type in southwestern Oregon.

The herbaceous layer in this type ranges widely in composition and coverage. Associated plants

include northern mule ears (Wyethia amplexicaulis), cluster tarweed (Madia glomerata), line-leaf

fleabane (Erigeron filifolius), sagebrush mariposa (Calochortus macrocarpus), death-camas

(Zigadenus venenosus), primrose (Oenothera pallida), desert parsley (Lomatium macrocarpum),

and several species of buckwheat (Eriogonum spp.). Commonly encountered grasses are several

species of wheatgrass, crested, downy and bluebunch (Agropyron cristata, A. dasytachyum, and A.

spicatum), cheatgrass (Bromus tectorum), Indian ricegrass (Oryzopsis hymenoides), needle-andthread grass (Stipa comata), and Sandberg’s bluegrass (Poa secunda).

Landscape Setting. Because of the close relationship this cover type has with sandy, alluvial soils

it is mostly found on deposition features; primarily alluvial terraces above streams and on bajadas at

the base of the arid mountain ranges in southeastern Oregon. The type generally appears as a small

component of the larger big sagebrush and sagebrush-steppe types.

References. Shiftlet 1994, Taylor 1994, Mozingo 1986, Kagan and Caicco 1992, Dealy et al. 1981.

NORTHEASTERN OREGON CANYON GRASSLAND AND SHRUBLAND (103)

Geographic Distribution. Occurs on steep canyon slopes in the mountains of northeastern Oregon. 

This type is most extensive in the Hell’s Canyon and the Grand Ronde River canyon of Baker and

Wallowa Counties.

Structure and Appearance. Bunchgrasses and shrub dominant patches form a mosaic vegetation

cover type. On steep slopes with poor soil development, grasses dominate with stringers of shrubs,

especially mockorange (Philadelphus lewisii), oceanspray (Holodiscus discolor), and Rocky

Mountain maple (Acer glabrum). Where deeper soils exist, shrub development is usually more

extensive along with widely scattered ponderosa pine (Pinus ponderosa) and Douglas fir

(Pseudotsuga menziesii).

Composition. Predominant grasses found in this cover type are Idaho fescue (Festuca idahoensis),

blue bunch wheatgrass (Agropyron spicatum), Wheeler’s bluegrass (Poa nervosa), Sandberg’s
134

bluegrass (P. secunda), mountain brome (Bromus carinatus), cheatgrass (B. tectorum), junegrass

(Koeleria nitida), western needlegrass (Stipa occidentalis), sand dropseed (Sporobolus

cryptandrus) and red three awngrass (Aristida longiseta).

Predominant shrubs are: mountain big sagebrush (Artemisia tridentata var. vaseyana), bitterbrush

(Purshia tridentata), ninebark (Physocarpus malvaceus), hackberry (Celtis reticulata), snowberry

(Symphoricarpos albus), buffaloberry (Shepherdia canadensis), and sumac (Rhus glabrum),

Landscape Setting. Occupies the hot, dry environments of the river canyons of northeastern

Oregon. This type grades in and out of ponderosa pine and/or mixed conifer forest that occupy the

benches and more suitable environments.

References. Johnson and Simon 1987, Kagan and Caicco 1992.

ALPINE GRASSLANDS AND SHRUBLANDS (105)

Geographic Distribution. This cover type depicts the vegetated areas above upper treeline in the

highest mountains throughout Oregon.

Structure and Appearance. Dwarf shrubs dominate this cover type, and thickly compacted Carex

species that form a grass-like cover called sedge turf. Widely scattered, low stature conifers are

also common in this type.

Composition. Shrub layer is dominated by several prostrate shrubs; red mountain heather

(Phyllodoce empetriformis), green mountain heather (P. glanduliflora), white mountain heather

(Cassiope mertensiana), or crowberry (Empetrum nigrum). Other dwarf shrubs found in this cover

type include cinquefoil (Potentilla fruticosa), juniper (Juniperus communis), bearberry

(Arctostaphylos uva-ursi) and willows (Salix spp.).

Alpine sedge turf usually contains one or more of the following: alpine black sedge (Carex

nigricans), capitate sedge (C. capitata), dunhead sedge (C. phaeocephala), or showy sedge (C.

spectabilis).

Landscape Setting. This cover type always occurs above timberline. Typically this type occurs as a

mosaic with alpine parkland and alpine fell and snowfields. These types usually are not very

extensive and therefore not mapped.

FOREST GRASSLAND MOSAIC (106)

Geographic Distribution. Common in ponderosa pine and mixed conifer types of northeastern

Oregon, and in the eastern Cascades.

Structure and Appearance. Mosaic of bunchgrass grasslands and conifer forest. Most common in

the foothills and lower elevation ranges, this type is indicative of the hottest and driest forested

conditions. In mid elevations this type is almost always found on southerly aspects.
135

Composition. Ponderosa pine (Pinus ponderosa), Douglas fir (Pseudotsuga menziesii), lodgepole

pine (P. contorta) and grand fir (Abies grandis) are the most common overstory trees in

northeastern Oregon. While in the eastern Cascades, ponderosa pine, Douglas fir, white fir (Abies

concolor), and incense cedar (Calocedrus decurrens) are the common overstory conifers.

The shrub layer is poorly represented in this type. Birchleaf spirea (Spiraea betulifolia), baldhip

rose (Rosa gymnocarpa), and snowberry (Symphoricarpos albus) can be found but typically are not

present in significant amounts.

Grasses and grass-like plants dominate the forb layer. Idaho fescue (Festuca idahoensis) usually is

the dominant grass. Other grasses that in combination can form co-dominance within the stand are

bluebunch wheatgrass (Agropyron spicatum), junegrass (Koeleria macrantha), Sandberg bluegrass

(Poa secunda) and western needlegrass (Stipa occidentalis). Cheatgrass (Bromus tectorum), and

bottlebrush squirreltail (Sitanion hystrix) are also present to co-dominant in most stands, especially

those stands which are heavily grazed by cattle. Ross’ and elk sedge (Carex rossii and C. geyeri)

are common associates in this type.

Landscape Setting. The type can inter-grade with several conifer forest and woodland types,

typically those most tolerant of hot, dry conditions. At lower elevations the type can grade into

western juniper woodlands, particularly in the eastern Cascades.

References. Volland 1985, Johnson and Simon 1987, Topik et al. 1988, Hopkins 1979, Atzet et al.

1996.

SUBALPINE PARKLAND (110)

Geographic Distribution. The highest elevation forest zone in the Cascades, Blues, and Wallowa

Mountain ranges of Oregon. 

Structure and Appearance. Subalpine parkland is distinctive from subalpine grassland and

shrublands due to the presence of the clumpy, scattered tree pockets throughout the cover type.

Conifer overstory typically ranges from 10 to 30% cover. Ground layer can be a dense layer of lowlying shrubs, sedge or grass turf, or montane wetland bogs.

Composition. Subalpine parkland conifer composition varies by region. In the Blues and

Wallowas the parkland is usually subalpine fir (Abies lasiocarpa), Engelmann spruce (Picea

engelmannii), or lodgepole pine (Pinus contorta). In the Cascades, mountain hemlock (Tsuga

mertensiana), subalpine fir, silver fir (Abies amabilis), and to a lesser extent Alaska yellow cedar

(Chamaecyparis nootkatensis). In the southern Cascades mountain hemlock, Shasta red fir (Abies

magnifica var. shastensis), and whitebark pine (Pinus albicaulis).

The shrub layer is similar in composition to the subalpine shrubland and grassland cover type,

where commonly associated shrubs are: red mountain heather (Phyllodoce empetriformis), green

mountain heather (P. glanduliflora), white mountain heather (Cassiope mertensiana), or crowberry

(Empetrum nigrum). Other dwarf shrubs found in this cover type include cinquefoil (Potentilla
136

fruticosa), juniper (Juniperus communis), bearberry (Arctostaphylos uva-ursi) and willows (Salix

spp.).

Alpine sedge turf usually indicates poorly drained soils, or persistent snow pack well into the

growing season, and contains one or more of the following; alpine black sedge (Carex nigricans),

capitate sedge (C. capitata), dunhead sedge (C. phaeocephala), or showy sedge (C. spectabilis).

On drier sites, the forb layer is characterized by either elk or Ross’ sedge (Carex geyeri or C.

rossii), smooth woodrush (Luzula hitchcockii), Drummond’s rush (Juncus drummondii), or green

fescue (Festuca viridula).

Landscape Setting. Forms the high elevation limit to tree growth. Usually is a mosaic with alpine

fell and snowfields and the alpine shrubland and grassland.

References. Hopkins 1979, Johnson and Simon 1986, Johnson and Clausnitzer 1987, Hemstrom et

al. 1987, Volland 1988, Atzet et al. 1996, Crawford et al. 1999.

MODIFIED GRASSLAND (112)

Geographic Distribution. Extensive grasslands of northeastern Oregon that formerly were

composed of native bunchgrasses. Presently, these grasslands are used primarily for pasture. Most

lands in this type are seeded to cultivated grasses. This type is common in the foothills of the

Wallowa and Blue Mountains in Grant, Union, and Wallowa Counties.

Structure and Appearance. Medium-tall grasslands composed of a variety of orchard and perennial

bunch grasses. Shrubs are virtually nonexistent and a negligible part of total plant cover. Forbs can

be diverse, but largely inconspicuous amongst the grasses.

Composition. Undisturbed remnants of this type are typically dominated by bluebunch wheatgrass

(Agropyron spicatum). Idaho fescue (Festuca idahoensis), Sandberg’s bluegrass (Poa secunda),

and prairie junegrass (Koeleria macrantha) are common associates. Less abundant, but common in

the type are sand dropseed (Sporobolus cryptandrus), threeawn (Aristida longiseta), and needleand-thread grass (Stipa comata).

Native forbs commonly found in this type include yarrow (Achillea millefolium), milk vetch

(Astragalus spp.), arrowleaf balsamroot (Balsamorhiza sagittata), biscuitroot (Lomatium

macrocarpum), and spreading phlox (Phlox longifolia). Common, exotic species include salsify

(Tragopogon dubius), mullein (Verbascum thapsus), knapweed (Centurea spp.), cheatgrass

(Bromus tectorum) and Kentucky bluegrass (Poa pratensis).

Landscape Setting. Generally restricted to foothill margins of northeastern Oregon mountains. 

Native bunchgrasses are more prevalent on steep hillsides and remote sections of the type. With

gentle terrain and proximity to valley bottom agriculture grass species composition shifts to

introduced orchard grasses.
137

References. Mayfield and Kjelmyr 1982, Johnson and Simon 1987, Johnson and Klausnitzer,

Tisdale 1994, Johnson 1994

COASTAL STRAND AND HEADLANDS (113)

Geographic Distribution. This narrow strip of vegetation borders the coastline from Oregon to

California.

Structure and Appearance. This cover type combines several distinct vegetation types, deflation

plains, and headlands. Deflation plain vegetation types can be lumped into two general situations,

1) dry meadow, and 2) marsh community. Hummocky ridges of European beach grass (Ammophila

arenaria) and wet reaches, which contain a variety of herbaceous plants and willows, characterize

deflation plains. Headland vegetation is a mosaic of grass and shrublands that grow on

promontories adjacent to the shoreline and grade into coastal forest cover types.

Composition. The hummocky ridges that separate the sandy beaches from the wet deflation plains

are dominated by European beach grass, an introduced grass that was originally planted for dune

stabilization purposes and has spread throughout the coastal strand to become a dominating

influence on vegetation development. Other herbaceous vegetation commonly found on these

ridges is seashore bluegrass (Poa macrantha), beach pea (Lathyrus littoralis), and seashore lupine

(Lupinus littoralis). The marshy deflation plain vegetation includes: Hooker’s willow (Salix

hookeriana), slough sedge (Carex obnupta), Pacific silver weed (Potentilla pacifica), and salt rush

(Juncus lesueurii).

Headland vegetation shrub layer includes: salal (Gaultheria shallon), evergreen huckleberry

(Vaccinium ovatum), salmonberry (Rubus spectabilis), and elderberry (Sambucus racemosa). South

coast shrublands will also contain, or be dominated by, coyote bush (Baccharis pilularis) and the

introduced gorse (Ulex europaeus) and Scotch broom (Cytisus scoparius).

Grasses dominate the forb layer in headland vegetation. Native dominant grasses are red fescue

(Festuca rubra), and pacific reedgrass (Calamagrostis nutkatensis). Blue wildrye (Elymus

glaucus), California danthonia (Danthonia californica), and Sitka brome (Bromus sitchensis) can

be found. These grasslands also contain a variety of introduced grasses as they were managed for

sheep grazing earlier in this century.

Landscape Setting. This type is poorly represented on the map because its distribution is not

extensive enough to be mapped in most areas. The type grades in and out of coastal forest types

and estuarine and palustrine wetland types.

References. Crawford et al. 1999, Weideman 1974, Ripley 1984
138

WET MEADOW (114)

Geographic Distribution. Montane herbaceous meadows of grass-like plants, primarily members

of the Carex tribe. Soil must be saturated to moist throughout the growing season for the Carex to

dominate. Soil surface is seasonally flooded from May-June from snowmelt. Occurs throughout

most mountain ranges in eastern Oregon. This type is poorly represented on the map because these

meadows typically are smaller than the minimum map unit

Structure and Appearance. Carex dominant meadows with dense sedge turf the primary vegetation

layer. If the area is not grazed there are a number of Carex species that will occupy these sites. 

Grazing reduces species complexity and shifts dominance to Nebraska sedge (Carex nebraskensis).

Composition. Sedge species form the majority of species diversity in this type. Commonly

occurring sedges include beaked sedge (Carex rostrata), water sedge (C. aquatilis), wooly sedge

(C. lanuginosa), thickheaded sedge (C. pachystachya), and lenticular sedge (C. lenticularis). Drier

microsites will typically contain tufted hair grass (Deschampsia caespitosa). Forbs are not

abundant in this type.

Landscape Setting. Montane meadows where sub-surface soil conditions, or shallow ground water

table maintain moist soils through the growing season. The type exists as small, discrete entities

through the mountains of eastern Oregon and the eastern Cascades.

References. Kovalchik 1986, Johnson and Simon 1987, Johnson and Clausnitzer 1992, Kagan and

Caicco 1992.

GRASS-SHRUB-SAPLING or REGENERATING YOUNG FOREST (121)

Geographic Distribution. Common throughout the mountains of Oregon.

Structure and Appearance. Captures the range of successional conditions following timber harvest. 

Site preparation following timber harvest is a ground scarification and burning of slash and large

woody debris, followed by seeding of a mix of annual grasses to retard soil erosion and planting

conifer seedlings. As the stand matures there may be a phase where resprouting shrub vegetation,

or dormant shrub seeds germinated by prescription fire, dominate the overstory canopy layer. Later

in the successional phase the conifer saplings have emerged through the shrub canopy and formed

continuous canopies

Composition. A variety of shrubs and forbs can be present in this cover type based on regional

flora and site history.

Landscape Setting. Appears as a patchwork mosaic woven into surrounding local forest cover

types. The several large, continuous polygons that appear on the map in south-central and

northeastern Oregon are burned over lands from fires in the 1980's.
139

OTHER TYPES 

ALKALI PLAYA (122)

Geographic Distribution. Found in Harney, Lake, and Malheur Counties of southeastern Oregon.

These barren flats are commonly associated with the larger pluvial lake basins of Alvord, Summer,

Malheur, Catlow, and Pueblo Lakes.

Structure and Appearance. Barren, alkali flats that are seasonally flooded.

Composition. Alkali playas are largely devoid of vegetation.

Landscape Setting. This cover type is surrounded by the salt desert scrub, big sagebrush, or

sagebrush steppe cover types.

References. Kagan and Caicco 1992, Mozingo 1987

URBAN (124)

Geographic Distribution. Urban areas depicted on the map are those cities and municipalities

identified in the Oregon state service center digital urban area coverage.

AGRICULTURE (125)

Geographic Distribution. Found throughout Oregon. Agriculture is identified as those lands that

have been modified for growing crops and/or animal husbandry.

TIDAL FLATS (126)

Geographic Distribution. Tidal flats are features associated with bays and estuaries along the

Oregon coast. There are also a number of tidal flats in the lower Columbia River extending east to

about Clatskanie.

Structure and Appearance. These are the sand-soil-muck surfaces that becomes exposed during

low tide. 

Composition. Tidal flats are basically devoid of significant amounts of rooted vegetation.

Landscape Setting. Forms the boundary layer between estuarine, or palustrine wetlands and open

water habitats in Oregon’s bays, estuaries, and the lower reaches of the Columbia and many coastal

rivers. 

References. Cowardin et al. 1978
140

LAVA FLOWS (127)

Geographic Distribution. This cover type is found mostly in southeastern Oregon and eastern

Cascades Mountains.

Structure and Appearance. Surface lava flows that are largely unvegetated (less than 15%

vegetation cover). In eastern Oregon, lava flows may be thinly vegetated with sagebrush, primarily

big sagebrush (Artemisia tridentata) and annual grasses, especially cheatgrass (Bromus tectorum).

The lava flows in the Cascades tend to be largely unvegetated with scattered pockets of soil that are

deep enough to sustain vegetation. In these soil pockets, shrubs such as gooseberry (Ribes cereum),

or snowbush (Ceanothus velutinus), or conifers, especially lodgepole pine (Pinus contorta) can

survive.

COASTAL DUNES (128)

Geographic Distribution. The coastal dunes of Oregon attain their greatest development between

Florence and Coos Bay where they form a continuous surface that extends several miles inland. 

Dunes can form through a variety of processes that are influenced by local topography, prevailing

wind direction, and source supply of sand. While dunes can be found throughout the length of the

Oregon coast they mostly are small, discrete features that do not show up in the vegetation map.

Structure and Appearance. Coastal dunes, as they relate to this vegetation description, are sparsely

vegetated. Dunes are regions of actively moving sand and only a few types of plants do well in this

environment, and typically are grasses or grass-like plants.

Composition. The most commonly encountered plants encountered on these dunes are European

beach grass (Ammophila arenaria), seashore bluegrass (Poa macrantha), American dune grass

(Elymus mollis) and large-headed sedge (Carex macrocephala). Other forbs are beach morning

glory (Convolvulus soldanella), beach knotweed (Polygonum paronychia), yellow abronia (Abronia

latifolia) and silver beach weed (Franseria chamissonis).

Landscape Setting. Coastal dunes can appear as a mosaic with coastal forest, estuarine and

palustrine wetlands and coastal strand vegetation.

References. Weideman et al. 1974, Ripley 1984

ALPINE FELL and SNOWFIELDS (129)

Geographic Distribution. This cover type depicts the non-vegetated areas above upper treeline in

the highest mountains throughout the state. Persistent snow cover and rock talus slopes dominate

the local landscape. Found in above timberline environments on the higher peaks and ranges of the

Cascades, Steens, and ranges in northeastern Oregon.
141

OPEN WATER (130)

Geographic Distribution. Lakes, ponds, and reservoirs larger than 10 acres that occur throughout

Oregon.

NATIONAL WETLAND INVENTORY (135) & GAP PALUSTRINE FOREST (200)

Geographic Distribution. Palustrine forest wetlands are characterized by overstory canopy

vegetation greater than 18 feet in height. All water regime influences: lacustrine, riverine, and tidal

margin is included. Palustrine forests, indeed all riparian vegetation systems, occur along the

interface between aquatic and terrestrial ecosystems. The distribution of this type is a function of

surface hydrologic features.

Structure and Appearance. Dominant overstory vegetation is trees. Canopies range from open to

closed and in well-developed stands are typically multi-storied. The tree layer can be dominated by

deciduous, conifer, or mixed canopies. The shrub layer, both tall and low, generally forms dense

thickets. Forb layer is abundant and diverse.

Composition. Common eastern Oregon deciduous canopy trees in this type are: black cottonwood

(Populus trichocarpa), white alder (Alnus rhombifolia), quaking aspen (Populus tremuloides), and

peachleaf willow (Salix amygdaloides). Conifer trees in eastern Oregon palustrine forests typically

do not dominate the overstory. Ponderosa pine (Pinus ponderosa), lodgepole pine (P. contorta),

and Douglas fir (Pseudotsuga menziesii) are the most commonly encountered overstory conifers.

Western Oregon palustrine forests common deciduous trees include: big leaf maple (Acer

macrophyllum), red alder (Alnus rubra), western ash (Fraxinus latifolia), black cottonwood Oregon

white oak (Quercus garryana), and pacific willow (Salix lucida). Conifers commonly dominate the

overstory in many western Oregon palustrine forest conditions. Lodgepole pine is common in bogs

and deflation plains in the coastal margin. Western red cedar (Thuja plicata), western hemlock

(Tsuga heterophylla), Douglas fir, and grand fir (Abies grandis).

Landscape Setting. Palustrine forests tend to be narrow, linear features that closely follow the

moving watercourse.

References. Chappell et al. 1999, Kagan and Caicco 1992, Kovalchik 1986 

NATIONAL WETLAND INVENTORY (136) & GAP PALUSTRINE SHRUBLAND (201)

Geographic Distribution. Palustrine shrublands, like palustrine forests, are vegetation cover types

closely associated with surface hydrologic features. These tall shrub riparian areas are most

prominent along low gradient streams that meander through the broad valleys and pluvial basins of

eastern Oregon. The type is very common in the Silvies and Woods River basins.

Structure and Appearance. Dense, tall shrubs dominate the canopy layer of this type.
142

Composition. Eastern Oregon palustrine shrublands tend to be dominated by willow species (Salix

spp.). Other shrubs found in these settings include chokecherry (Prunus virginiana), bog birch

(Betula glandulosa), bog blueberry (Vaccinium occidentale), snowberry (Symphoricarpos albus),

wax currant (Ribes cereum), and Douglas spirea (Spiraea douglasii).

Western Oregon palustrine shrublands are also dominated by willow species, especially Sitka

willow (Salix sitchensis) and Hooker's willow (S. hookeriana), Douglas spirea, red-osier dogwood

(Cornus sericea), snowberry, and black hawthorn (Crataegus douglasii).

References. Cowardin et al. 1979, Kovalchik 1986, Franklin 1972.

NWI (137) & GAP ESTUARINE EMERGENT WETLAND (202)

Geographic Distribution. Common wetland vegetation that borders Oregon’s coastal river mouths,

bays, and estuaries. Estuarine emergent vegetation is occupied by plants that can withstand

inundation by salt and brackish water.

Structure and Appearance. Herbaceous wetlands composed of grass, grass-like, and forbs. 

Vegetation composition and pattern is strongly influenced by tidal inundation and elevation within

the salt marsh.

Composition. The lowest salt marsh plant community occupies exposed tidal flats during periods of

low tides and is characterized by such halophytic plants as seashore saltgrass (Distichlis spicata),

pickleweed (Salicornia virginica), jaumea (Jaumea carnosa), shore podgrass (Triglochin

maritimum), and saltmarsh sedge (Carex lyngbyei).

The intermarsh community (higher elevation, less flooding) commonly associated plants include

redtop bentgrass (Agrostis alba), rush (Juncus articulatus), Pacific potentilla (Potentilla pacifica),

yarrow (Achillea millefolium), sea-watch angelica (Angelica lucida), giant vetch (Vicia gigantea),

Pacific waterwort (Oenanthe sarmentosa), and Douglas aster (Aster subspicatus).

The transition zone (upper elevation saltmarsh to terrestrial upland) is characterized by salmonberry

(Rubus spectabilis), bracken (Pteridium aquilinum), sword fern (Polystichum munitum), common

velvetgrass (Holcus lanatus), Alaska fringecup (Tellima grandiflora), red alder (Alnus rubra), Sitka

spruce (Picea sitchensis), and western hemlock (Tsuga heterophylla).

Landscape Setting. Borders the cover types of open water and adjacent upland types. Agriculture

is a common bordering cover type as many of Oregon’s estuaries are diked to permit dairy cattle

grazing.

References. Weideman 1986, Frenkel and Eilers 1976, Mitchell 1981, Cowardin et al. 1982.
143

NWI (138) & GAP PALUSTRINE EMERGENT WETLAND (203)

Geographic Distribution. Freshwater herbaceous wetlands distributed throughout the state. 

Especially prevalent in the Klamath Basin, Malheur-Harney and Warner Lakes basins, the Grande

Ronde Valley, Willamette Valley, and the coastal margin.

Structure and Appearance. Medium tall (2-4 feet) to tall (>4 feet) grass, or grass-like plants that

occur in dense mosaics depending on substrate and water depth.

Composition. Commonly associated herbaceous plants in this type, cattail (Typha latifolia), several

bulrush species (Scirpus olneyi, S. acutus, S. validus, and S. americanus), burreed (Sparganium

emersum and S. eurycarpum), flourish in shallow standing water situations. In the drier reaches of

this type where the surface may dry out but subsurface is persistently wet numerous sedge (Carex

spp.) and rush (Juncus spp.) dominate. Spikerush, (Eleocharis spp.) also can be an important

component in this seasonal flooded margin.

Grasses that are commonly associated with this type are blue wildrye (Elymus glaucus), tufted hair

grass (Deschampsia caespitosa), bluejoint reedgrass (Calamagrostis canadensis), reed canary grass

(Phalaris arundinacea), American sloughgrass (Beckmannia syzigachne) and northern mannagrass

(Glycera borealis).

Landscape Setting. This type is restricted to perennially flooded regions, or where the ground water

lies just below the soil surface. Some type of agriculture typically borders emergent wetlands. 

Their silty soils are very fertile and are drained and converted to agriculture wherever possible.

References. Chappell et al. 1998, Christy and Titus 1996, Kovalchik 1986.
144

REFERENCES

Atzet, T. and D. Wheeler. 1984. Preliminary plant associations of the Siskiyou Mountain

Province. USDA Forest Service, Portland, Or. 315pp.

Atzet T., D. White, L. McCrimmon, P. Martinez, P. Fong, V. Randal. 1996. Field Guide to the

Forested Plant Associations of Southwestern Oregon. USDA Forest Service, Portland, Or. 

Atzet, T. and L. McCrimmon. 1990. Preliminary plant associations of the southern Oregon

Cascades Mountain Province. USDA Forest Service, Siskiyou National Forest.

Christy, J. and J. Titus. 1996. Wetland plant communities of Oregon. Unpublished manuscript.

Oregon Natural Heritage Program, Portland, Or. 87 pp.

Cowardin, L., V. Carter, F. Golet, E. LaRoe. 1979. Classification of Wetlands and Deepwater

Habitats of the United States. US Fish & Wildlife Service. FWS OBS-79/31. Washington,

D.C.

Dealy, J., D. Leckenby, D. Concannon. 1981. Wildlife habitats in managed rangelands - the Great

Basin of southeastern Oregon. USDA Forest Service, Portland, Or. GTR-PNW-120.

Eyre, F. 1980. Forest Cover Types of the United States and Canada. Society of American

Foresters, Washington, D.C. 235 pp.

Franklin, J. and T. Dyrness. 1973. Natural vegetation of Oregon and Washington. USDA Forest

Service, GTR-PNW-8. 417 pp.

Frenkel, R. and C. Kiilsgaard. 1984. Vegetation classification and map of the central Siskiyou

Mountains, Oregon. NASA technical report # SEA-1600/T-4885. NASA Ames Research

Center, Moffett Field, California.

Frenkel, R. and P. Eilers. 1976. Tidal datums and characteristics of coastal marshes in selected

Oregon estuaries. Oregon State Univ., Corvallis, Or.

Grossman, D.H., D. Faber-Langendoen, A.S. Weakley, M. Anderson, P.Bourgeron, R. Crawford, K.

Goodin, S. Landaal, K. Metzler, K. Patterson, M. Pyne, M. Reid, and L. Sneddon. 1998.

International Classification of Ecological Communities: Terrestrial Vegetation of the United

Sates. Volume 1. National Vegetation Classification System: Development, Status, and

Applications. The Nature Conservancy, Arlington, VA, USA.

Habeck, J. 1961. Original vegetation of the Willamette Valley. Northwest Science. Vol. 35 #2.

Hall, F. 1973. Plant communities of the Blue Mountains in eastern Oregon and southeastern

Washington. USDA Forest Service, PNW Portland, Or. R6- Area Guide 3-1.
145

Halverson, N., C. Topik, R. Van Vickle. 1986. Plant associations and management guide for the

western hemlock zone, Mt. Hood National Forest. USDA Forest Service, PNW, Portland, Or.

Halverson, N. 1986. Major indicator shrubs and herbs on national forests of western Oregon and

southwestern Washington. USDA Forest Service, PNW, Portland, Or. R6-Tm-229-1986.

Hawk, G. 1976. Comparative study of the temperate Chamaecyparis forests. Unpublished thesis. 

Oregon St. Univ., Corvallis, Or.

Hemstrom, M., W. Emmingham, N. Halverson, S. Logan, C. Topik. 1982. Plant association and

management guide for the pacific silver fir zone, Mt. Hood and Willamette National Forests. 

USDA Forest Service, PNW, Portland, Or.

Hemstrom, M., S. Logan. 1986. Plant association and management guide Siuslaw National Forest. 

USDA Forest Service, PNW, Portland, Or. R6-ECOL-220-1986a.

Hemstrom, M., S. Logan, W. Pavlat. 1987. Plant association and management guide, Willamette

National Forest. USDA Forest Service, PNW, Portland, Or. R6-ECOL-257-B-86.

Hopkins, W. 1979. Plant associations of the Fremont National Forest. USDA Forest Service, PNW,

Portland, Or. R6-ECOL-79-004.

Hopkins, W. and R. Rawlings. 1985. Major indicator shrubs and herbs on national forests in

eastern Oregon. USDA Forest Service, PNW, Portland, Or. R6-TM-190-1985.

Johnson, C. and S. Simon. 1986. Plant associations of the Wallowa-Snake Province WallowaWhitman National Forest. USDA Forest Service, PNW, Portland, Or. R6-ECOL-1986.

Johnson, C. and R. Clausnitzer. 1992. Plant associations of the Blue and Ochoco Mountains. 

USDA Forest Service, PNW, Portland, Or. R6-ERW-TP036-92.

Kagan, J. and S. Caicco. 1992. Manual of Oregon actual vegetation. US Fish & Wildlife Service,

Biological Resources Division-GAP analysis program, Portland, Or.

Kovalchik, B. 1987. Riparian zone associations; Deschutes, Winema, Ochoco, and Fremont

National Forests. USDA Forest Service, PNW, Portland, Or. R6-ECOL-TP-279-87.

Kruckeberg, A. 1984. The ecology of serpentine soils: plant species in relation to serpentine soils. 

Ecology 35:267-274.

Mayfield, M. and J. Kjelmar. 1981. Boardman research natural area, supplement #17. Supplement

to Federal Research Natural Areas in Oregon and Washington. USDA Forest Service, PNW,

Portland, Or.
146

Mitchell, D. 1981. Ecology of salt marsh communities in the Salmon River Estuary, Oregon. 

Unpublished thesis. Oregon St. Univ., Corvallis, Or.

Mozingo, H. 1987. Shrubs of the Great Basin. Univ. of Nevada Press, Reno, NV.

Ripley, D. 1984. Description of plant communities and succession of the Oregon coast grasslands. 

Unpublished thesis, Oregon St. Univ. Corvallis, Or.

Shiftlet, T. 1994. Rangeland cover types of the United States. Society for range management.

Denver, Col.

Taylor, B. 1994. Rangeland cover of the Pacific Northwest: IN Rangeland cover types of the

United States. T. Shiftlet ed. Society for Range Management. Denver, Col.

Topik, C., N. Halverson, and T. High. 1988. Plant associations and management guide for the

ponderosa pine, Douglas fir, and grand fir zones, Mt. Hood National Forest. USDA Forest

Service, PNW, Portland, Or. R6-ECOL-TP-004-88.

Volland, L. 1988. Plant associations of the central Oregon pumice zone. USDA Forest Service,

PNW, Portland, Or. R6-ECOL-104-1985.

Weideman, A. 1984. The ecology of Pacific Northwest coastal sand dunes: a community profile. 

US Fish & Wildlife Service. FWS/OBS-84/04.

Zobel, D. and G. Hawk. 1980. The environment of Chamaecyparis lawsoniana. American

Midland Naturalist. 103:280-297.
147

Appendix 2.2. Discussion of ODFW’s Use of Aerial Videography for OR-GAP

Airborne Videography 

ODFW had airborne videography recorded between August 25 and September 3, 1993.

Approximately 4% of Oregon was sampled by flying north-south transects at approximately 30-km

intervals (Figure 2.2). In areas of high vegetation diversity and variability, transects were flown at

15 km intervals. The video was shot from an airplane flying approximately 600m above the ground

with a zoom camera activated every nine seconds for five seconds. Hence, the video has coverage

at two scales: approximately 1:1,800 and 1:150 when displayed on a 25-inch diagonal television. 

The video acquisition system integrated a digital color video camera, a laptop computer, a Super

VHS (S-VHS) VCR, a Trimble Pathfinder GPS, and a Horita time code generator/recorder/encoder

to record real-time location data as well as the video imagery. The Horita time code

generator/recorder/encoder recorded the GPS time onto the audio track of the videocassette and

dubbed the time in a window directly on the imagery as well. Simultaneously, GPS time and the

corresponding location were recorded once per second in a digital file on the laptop computer. At

the 1:150 scale, there are more than 18,000 reference points that are GPS linked to ground

coordinates. These GPS points are not differentially corrected. Therefore, the GPS acquired

geodetic measurement could be 0 to 140 meters from the true location of each reference point

(Graham 1993). 

Results

Results from our research evaluating airborne videography were not encouraging (Barrett, 1998). 

Our analysis indicates that airborne videography has limited usefulness as a tool for Landsat TMbased vegetation map validation. Despite the fact that collecting it can be substantially faster than

field work and that it allows remote, inaccessible-by-ground areas to be sampled, we did not find 

airborne videography to be an efficient method for assessing the accuracy of our satellite derived

vegetation maps.

There were a number of reasons airborne videography was not efficient. First, the cost of acquiring

airborne videography, while cheaper than traditional aerial photography, is still quite expensive. 

For example, the ODFW video acquired in this study cost $30,000 in 1993. A more costly,

increased-density of flight-lines in a more complex sampling scheme would be necessary to

sufficiently assess the accuracy of the 1998 OR-GAP state vegetation map. Second, the accuracy of

the video interpretation must be assessed before it can be used to assess the accuracy of the

satellite-based map - thus, a certain amount of field work must still be performed. The collection of

enough field points to perform this assessment will likely be difficult as it depends on having a

sufficient number of video sample points for each vegetation class within observation distance of an

accessible road. Additionally, this substitution of interpreted videography for "ground-truth" data

will yield a more complex, if not questionable, statistical analysis in the final assessment. Finally,

the inferior spectral resolution of our airborne video made successful interpretation of vegetation

classes difficult. 
148

In this study, a misleading overall interpretation accuracy of nearly 95 percent was obtained for the

higher resolution ODFW video. However, this video was recorded in a relatively small area of low

vegetation diversity, and interpretation accuracy was substantially lower for mixed species classes

in this video as well as in supplemental video. These findings indicate that airborne videography

will be less suitable for accuracy assessment as the vegetation classification and landscapes increase

in complexity (southwestern Oregon for example).

Despite its limited value as an accuracy assessment tool, airborne videography would be a valuable

classification aid in the development of a satellite-based vegetation map. GPS geo-referenced

airborne video could be used to quickly generate training areas for supervised classifications or to

help label classes resulting from unsupervised classifications of satellite imagery. Proper planning

of video acquisition is the key to its successful use for these purposes.

Chris Kiilsgaard