CHAPTER 2 

Landscape Ecology 

Evaluation of the 

Preliminary Draft EIS 

Alternatives 

Wendel J. t-Iann 

Michael G. "Sherm" Karl 

Jeffrey L. Jones 

Rebecca A. Gravenmier 

Donald G. Long 

James P. Menakis 

Robert E. Keane 
Wendel J. Haim, Landscape Ecologist, USDA Forest Service and USDI Bureau of Land Management,

Interior Columbia Basin Ecosystem Management Project, Walla Walla, WA/Boise, ID

Michael G. "Sherm" Karl, Rangeland Management Specialist-Ecologist, USDA Forest Service, Pacific

Northwest Research Station, Interior Columbia Basin Ecosystem Management Project, Walla Walla, WA

Jeffrey L. Jones, Ecologist and Wildlife Biologist, USDA Forest Service, Northern Region, Missoula, MT

Donald G. Long, Forester, USDA Forest Service, Intermountain Fire Sciences Laboratory, Missoula, MT

Rebecca A. Gravenmier, Natural Resource Specialist/GIS, USDI Bureau of Land Management, Oregon

State Office, Portland, OR

James P. Menakis, Forester, USDA Forest Service, Intermountain Fire Sciences Laboratory, Missoula, MT

Robert E. Keane, Research Ecologist, USDA Forest Service, Intermountain Fire Sciences Laboratory,

Missoula, MT

30 Landscape Ecology
TABLE OF 

CONTENTS 

Introduction 37 

Landscape Evaluation Process 37 

Assumptions About Landscape Integrity and Management Approaches 38 

Landscape Integrity Assumption 1 38 

Landscape Integrity Assumption 2 41 

Landscape Integrity Assumption 3 42 

Landscape Integrity Assumption 4 43 

Landscape Integrity Assumption 5 44 

Landscape Integrity Assumption 6 45 

Landscape Integrity Assumption 7 45 

Landscape Integrity Assumption 8 45 

Landscape Integrity Assumption 9 46 

Simulation Strategies Used for Evaluation of Alternatives 47 

Prescription Models 47 

Alternative Emphasis and Prescription Assignments 51 

Preliminary Draft EIS Alternative Disturbances and Simulated Disturbances 52 

Implementation and Allocation of Activity Levels from Preliminary Draft EIS 79 

Alternative 1 and 2 79 

Alternatives 3 through 7 79 

Summary of Cont~dence in Predictions and Qualifiers 79 

Evaluation of Landscape Disturbances 91 

Relation of Disturbance Levels and Standards in Preliminary Draft EISs to 

Evaluation of Alternatives 91 

Forest Disturbances 92 

Prescribed Fire 92 

Thinning and Harvest 92 

Wildt~re 92 

Forest Crown Wildfire 98 

Forest Mortality Susceptibility 98 

Forest Disturbance Summary 101 

Landscape Ecology 
Rangeland Disturbances 101

Prescribed Fire 101

Range Improvements and Plan Revision/Implementation 102

Grazing 102

Exotics 102

Rangeland Wildfire 102

Rangeland Disturbance Summary 106

Landscape Scale Disturbances 106

Total Direct Disturbance 106

Wildfire 107

Soil Disturbances 109

Ability to Mimic Native Composition and Structure 109

Spatial Distribution of Disturbances 110

Alternative Management Activity Levels 112

Simulations Compared to Alternative Management Activities 114

Terrestrial Communities 119

Methods for Evaluating Terrestrial Communities 120

Assumptions and Notes About Simulation Methods and Results 120

Riparian Communities 120

Exotic Herbland 122

Terrestrial Communities in Alternative 7 122

Results of Evaluating Terrestrial Communities by Alternative 122

Alternative 1 122

Alternative 2 129

Alternative 3 137

Alternative 4 139

Alternative 5 140

Alternative 6 142

Alternative 7 143

Discussion 145

Eastside EIS Area 146

Montane Forests 146

Subalpine Forests 154

Upland Communities 154

Riparian Communities 162

Exotic Herbland Communities 162

Upper Columbia River Basin 162

Montane Forests 162

Subalpine Forests 163

Upland Communities 169

32 Landscape Ecology
Riparian Communities 169

Exotic Herbland Communities 169

Summary 170

Terrestrial Community Departures 171

Methods of Evaluating Terrestrial Community Departures 171

Results of Evaluating Terrestrial Community Departures 172

Alternative 1 Departures 172

Montane Community Departures in Alternative 1 172

Subalpine Community Departures in Alternative 1 173

Upland Community Departures in Alternative 1 174

Alternative 2 Departures 175

Montane Community Departures in Alternative 2 176

Subalpine Community Departures in Alternative 2 181

Upland Community Departures in Alternative 2 182

Alternative 3 Departures 182

Montane Community Departures in Alternative 3 183

Subalpine Community Departures in Alternative 3 184

Upland Community Departures in Alternative 3 184

Alternative 4 Departures 184

Montane Community Departures in Alternative 4 185

Subalpine Community Departures in Alternative 4 186

Upland Community Departures in Alternative 4 186

Alternative 5 Departures 187

Montane Community Departures in Alternative 5 187

Subalpine Community Departures in Alternative 5 188

Upland Community Departures in Alternative 5 188

Alternative 6 Departures 189

Montane Community Departures in Alternative 6 189

Subalpine Community Departures in Alternative 6 190

Upland Community Departures in Alternative 6 190

Alternative 7 Departures 191

Montane Community Departures in Alternative 7 191

Subalpine Community Departures in Alternative 7 192

Upland Community Departures in Alternative 7 192

Discussion on Departures of the Alternatives 193

Departure Discussion by Community 193

Montane Departures 193

Subalpine Departures 194

Upland Departures 195

Summary of Terrestrial Community Departures 196

Landscape Ecology 33
Vegetation Response and Disturbance Patterns 197

Forest Potential Vegetation Groups 197

Lower Montane Forest Response 198

Early-Serai Lower Montane Forest 198

Mid-Serai Lower montane Forest 200

Late-serai Multi-layer Lower montane Forest 203

Late-serai Single-layer Lower Montane Forest 206

Montane Forest Response 209

Early-serai Montane Forest 209

Mid-serai Montane Forest 212

Late-serai Multi-layer Montane Forest 216

Late-serai Single-layer Montane Forest 220

Subalpine Forest Response 223

Early-Serai Subalpine Forest 223

Mid-serai Subalpine Forest 225

Late-serai Multi-layer Subalpine Forest 228

Late-serai Single-layer Subalpine Forest 230

Rangeland Potential Vegetation Groups 232

Upland Herbland 234

Exotic Herbland 236

Upland Shrubland 238

Upland Woodland 240

Rangeland Riparian 241

Alpine 241

Summary 241

Effects of Alternatives on Selected Noxious Weeds and

Cheatgrass on Rangeland 243

Methods Used in Evaluating the Effects of Alternatives on Noxious Weeds

and Cheatgrass 243

Assumptions for Rangelands 244

Rangeland Assumption 1 244

Rangeland Assumption 2 245

Rangeland Assumption 3 246

Rangeland Assumption 4 246

Rangeland Assumption 5 246

Rangeland Assumption 6 246

Rangeland Assumption 7 246

Rangeland Assumption 8 246

Rangeland Assumption 9 247

34 Landscape Ecology
Discussions on Effectiveness of Alternatives in Integrated Weed Management 247

Dry Grass Potential Vegetation Group, EEIS 247

Dry Grass Potential Vegetation Group, UCRB 252

Dry Shrub Potential Vegetation Group, EEIS 258

Dry Shrub Potential Vegetation Group, UCRB 264

Cool Shrub Potential Vegetation Group, EEIS 268

Cool Shrub Potential Vegetation Group, UCRB 275

Summary and Synthesis of Landscape Findings 281

Results and Discussion 281

Forests 281

Rangeland 282

Summary of Response 283

Succession/Disturbance Regime 283

Vegetation Change 288

Consistency of Standards 289

Landscape Integrity Summary Ratings 289

Simulations Compared to Alternative Management Activities 290

Terrestrial Communities 292

Acknowledgments 294

References 295

Appendix 2-A 299

Appendix 2-B 305

Appendix 2-C 321

Appendix 2-D 327

Appendix 2-E 329

Appendix 2-F 331

Appendix 2-G 341

Appendix 2-H 347

Appendix 2-1 349

Appendix 2-J 351

Appendix 2-K 365

Appendix 2-L 405

Appendix 2-M 419

Appendix 2-N 429

Landscape Ecology 35
36 Landscape Ecology
Introduction

The landscape evaluation of alternatives for the

Eastside and Upper Columbia Preliminary Draft

Environmental Impact Statements (PDEISs) presents a comparison of outcomes for key landscape

variables across the seven alternatives for the

Basin.1 The evaluation process involved simulation

and analyses of predicted effects, and also qualitative evaluation, of the alternatives as described in

direction to the Science Integration Team (SIT) in

a letter dated February 26, 1996.2 The relationship of the Evaluation of Alternatives to both the

assessment and the EIS alternatives is shown in

figure 2.1. The relation between the assessment

data and EIS scale is shown in figure 2.2.

This chapter has seven sections:

1) Overview of the landscape ecology evaluation

of alternatives, including a statement of

assumptions.

2) Overview of the simulation methods used for

predicting spatial and temporal responses to

different levels of management treatments and

disturbances.

3) Responses of vegetation to management and

other disturbances.

4) Responses of terrestrial vegetation and habitats,

and their interrelationships.

5) Evaluation of vegetation response and disturbance patterns.

6) Effects of selected noxious weeds and cheatgrass on rangeland in the Basin.

7) Summary, including conclusions.

The methods used for the evaluation of alternatives involved mapping land management and disturbance prescription response and assumptions

based on alternatives developed by the EIS teams.

Background information on the development,

characteristics, and response of various landscapes

to the different types of prescriptions is documented in Landscape Dynamics of the Basin (Hann

and others, in press), Chapter 3 of the Assessment

of Ecosystem Components in the Interior Columbia

Basin and Portions of the Klamath and Great Basins

(Quigley and others, in press). Vegetation and disturbance responses are modeled using the Columbia River Basin SUccession Model (CRBSUM)

(Keane and others 1996), in association with the

Columbia River Basin Landscape Analysis Data

Base (CRBLAD) (Gravenmier and others, in

press), and a variety of associated simulation

methods (Hann and others 1997).

The purpose of landscape dynamics evaluation is

to predict the effects of the alternatives on landscape components (table 2.1). These components

vary depending on the management emphasis of

the alternatives (table 2.2; appendix 2-C). The

seven different alternative themes in the preliminary draft EIS have a broad range of outcomes

considering the variation in landscape components and the differences in spacial location and

effects through time.

Landscape Evaluation Process

Direct linkages between each alternative's desired

future conditions (DFCs),3 objectives and standards (appendix I), and the emphasis areas by

'The Basin is defined as those portions of the Columbia River basin inside the United States east of the crest of the Cascades and

those portions of the Klamath River basin and the Great Basin in Oregon.

The version of the EIS alternatives under evaluation here was presented to the SIT on February 26, 1996 in a package titled

"Alternatives Package for SIT Evaluation for Eastside and UCRB EISs." On file with: U.S. Department of Agriculture, Forest

Service; U.S. Department of Interior, Bureau of Land Management; Interior Columbia Basin Ecosystem Management Project,

112 E. Poplar, Walla Walla, Washington, 99362.

3Desired Future Condition (DFC) is a portrayal of the land, resource, or social and economic conditions that are expected to

result in 50 to 100 years if objectives are achieved; in this document, portrayed as a range of conditions. A vision of the long-term

condition of the land. See appendix I for a description of the DFCs for each of the alternatives.

Landscape Ecology 37
forest and range clusters in the EISs were not

always clear. For example, many of the objectives

and standards were written for fine-scale features

that were not necessarily linked, in either a spatial

or temporal context, with the broad-mid-fine

scale hierarchy depicted in figure 2.2. Many of the

standards apply single size/state conditions to ecological functions that are inherently variable. As

such, standards applicable to the finer scales may

be unrelated to the mid and broad scale. As an

alternative is implemented, potential for conflict

between the overall theme, objective, forest and

range cluster emphasis, activity levels, mid-scale

patterns, and the finer-scale standards exists. To

reduce this potential for conflict and proceed with

outcome projections, it was necessary to make

assumptions relative to management prescriptions,

management activities, and ecological "fit" of the

single size/state standards. The purpose of the

assumptions was to provide clarity about implementation of an alternative.

Treatment prescriptions were assumed to be either

traditional or ecological, or to have minimal treatment (as in the reserves) (table 2.3). Treatment

emphasis differs among alternatives. Management

prescriptions emphasized in Alternatives 1 and 2

are traditional, Alternatives 3 through 6 are ecological, and Alternative 7 is a mix of reserve and ecological. It was also assumed that Alternatives 1 and

2 would be implemented in a traditional programmatic allocation with no emphasis on multi-scale

relationships, while Alternatives 3 through 7 would

be implemented with varying emphasis on interconnected spatial and temporal scales (figure 2.2).

Assumptions About Landscape

Integrity4 and Management

Approaches

Two important measures of landscape integrity at

all scales are: (1) ecosystem integrity (both ecological and socioeconomic), and (2) diversity of

native habitats and associated processes. Generally,

in wildland environments, native communities are

more productive and more resilient to disturbances such as fire, drought, and insects/disease,

than are communities that have been simplified

by traditional agricultural, forest, or range management, or by conversion to exotic5

 communities. As native habitats are simplified or converted

to exotics, there is a decline in the native fauna

and flora that depend on these habitats. Management that conserves native habitats avoids further

declines in native species, productivity and

resiliency.

Listed below are the assumptions about the types

of management that would be used to implement

the alternatives. The assumptions are expectations

of how management would sustain landscape

integrity on BLM- and FS-administered lands.

Landscape Integrity Assumption 1:

Landscape Approach to Management —

Through time, the management of BLM- and FSadministered lands shifts increasingly toward a

landscape approach. Under this assumption, the

BLM- and FS-administered lands are managed as

a whole within watersheds and as connected lands

between watersheds. Forests and rangelands intermingled within or between watersheds are managed on an integrated basis for both resources and

habitats. Hydrologic and riparian regimes within

watersheds are managed as integral networks.

Managers recognize that ownership pattern strongly affects implementation of a landscape approach.

Watersheds dominated by continuous BLM and

FS oversight would have the best chance for

achieving long-term desired patterns, while watersheds with mosaic or mixed ownership would have

less chance. In contrast, managers recognize that

disjunct BLM or FS parcels in environments with

little BLM or FS ownership may be highly valuable for remnant native habitats.

'Landscape integrity is synonymous to landscape health based on proper functioning systems at a landscape scale. See Chapter 3

of the landscape assessment (Hann and others, in press) for definitions and discussion.

^Exotics are non-native plants; biota from a different area or environment that migrated to the area with the assistance of humans.

38 Landscape Ecology
Science

Assessment

ElSand

Decision

Evaluation of

Alternatives

Figure 2.1 — Relationship of Evaluation of Alternatives to the Science Assessment and EISs.

Landscape Ecology
Scale EIS Assessment

Broad

Theme, DFCs,

Strategic emphases,

Objectives, Activity

standards and

guidelines >

Forest/Range clusters

Management

prescription models

predicted response

I (from CRBSUM)

Standards,

Guidelines,

Subbasins and

watershed type

priorities

Patterns of fragmentaiton,

Patch size/shape,

Potential disturbance

(from watershed sample

data), Assumptions in

management prescription

models

Fine

Mid

Standards and

guidelines,

Species habitats,

Snags, Riparian,

Soil productivity <

Composition and

structure, Species, Snags

(from Stand, Patch, Plot

Data), Assumptions in

management prescription

3 models

Figure 2.2 — Relationship between Assessment data and EIS scales.

Landscape Ecology
Landscape Integrity Assumption 2:

Successful Ability to Mimic/Represent

Processes — Managers develop the ability to

assess and implement landscape management to

more closely resemble native landscape mosaics,

biotic community structure and composition, and

processes over space and time. This does not infer

that these conditions are representative of the historical range of variability (HRV), which is the

variability of regional or landscape composition,

structure, and disturbances during a period of

time for several cycles of the common disturbance

intervals and for similar environmental gradients.6

In essence, managers promote a balance of land

use and ecosystem integrity that sustains native

habitats while producing human resource values

within the limitations of biophysical systems and

inherent disturbance processes.

Emphasis should be placed on understanding and

managing within the limitations and options of

the biophysical template (BPT)7 to conserve

processes associated with native composition and

structure. The biophysical template refers to an

area's mosaic of inherent patterns of composition

and structure, including environmental gradients

and dynamics of disturbance that developed

through evolutionary time. This concept, developed from work by Jenny (1958) and Major

(1951), is described in detail by Hann and others

(in press).

The historical range of variability provides an

assessment tool to monitor biodiversity for either

departure, or similarity of conditions or processes,

to native pre-Euro-American settlement. HRV

also provides a useful tool for understanding cause

and effect, and thus, risk of undesired outcomes.

Managing for HRV in a regime that has a substantially unbalanced biophysical composition

could cause changes detrimental to native conditions and processes. Unbalanced regimes include

areas having: exotic species, historically common

species that are now rare, disrupted hydrologic

systems, high fuel loading, simplified native diversity, composition and structure that are incompatible with the biophysical succession/disturbance8

regime, or have degraded soils. Management for

HRV is not appropriate for many types of land

use that balance restoration and mitigation to sustain ecological integrity and native habitats with

socioeconomic resiliency.

Representation of native conditions and processes

is generally most successful in natural and natural/

human-influenced management areas. In these

areas, managers utilize planned and unplanned

prescribed fire and flexible wildfire suppression

strategies to represent native landscape patterns

and represent native fire regime severity and intervals. Livestock grazing is managed in these areas to

generally preclude departure from the native

succession/disturbance regimes. However, the transition to native patterns occurs carefully to avoid

loss of key elements (such as large trees or stronghold rare aquatic populations), site capability, or

invasion of exotic species.

On human-influenced management areas, managers use various treatments to produce the types

of communities and landscape structures somewhat characteristic of the native regime. These

''Historical range of variability (HRV) refers to the "pre-Euro-American settlement" or "native" regime. It is not synonymous with

the historic or historical time period which we define as beginning circa 1850.

'The biophysical template can be visualized as the biological, physical, and disturbance characteristics of an environment over a

period of relatively stable climate. It is the current expression of the collective adaptations of species to competition, disturbances,

and the physical environment. It is also the current expression of the soils, landform, and hydrologic system development in

response to biotic and geomorphologic processes. Biophysical templates have characteristic succession and disturbance regimes

that are governed by the interaction oetween biotic and abiotic components. They may be altered by any disturbance (or repeated

disturbances) that change the relationships between the biotic and abiotic systems.

"We provide a classification that integrates aquatic and terrestrial systems, and succession/disturbance. We classified succession/

disturbance regimes according to 1) the severity of the disturbance relative to the subsequent change of community composition

and structure, 2) the time interval between disturbances, 3) the resiliency or rate of community development in response to the

disturbance, and 4) the mosaic created by disturbance through time.

Landscape Ecology 43.
Table 2.1 — Landscape components evaluated for alternatives.

Landscape Component

• Management prescription assumptions.

• Succession/disturbance trends and regimes.

• General trends of fine-scale variables such as snags, upland down wood, riparian down wood, forest riparian,

range riparian, and vegetation mosaic patterns.

• Similarity of current vegetation and alternative vegetation to historical range of variability.

• Physiognomic types by potential vegetation group changes.

• Physiognomic type transitions from historical to current and current to 100 years.

• Terrestrial community changes.

• Terrestrial community departure of current from historical range and alternatives from historical range.

• Forest harvest.

• Forest thinning.

• Forest prescribed fire.

• Forest insect/disease susceptibility.

• Forest wildfire.

• Forest wildfire crown susceptibility.

• Range improvements such as seeding, spraying, and woodland cutting.

• Range allotment plan revision assumptions.

• Range prescribed fire.

• Range wildfire.

• Range grazing effects.

• Exotic plants, noxious and undesirable weeds.

• Total wildfire.

• Total prescribed fire.

• Wildfire cost.

• Prescribed fire cost.

• Total fire management cost.

• Wildfire intensity.

• Prescribed fire smoke.

• Wildfire smoke.

• Total smoke and effect on visual condition.

• Ecosystem productivity processes.

treatments may include timber harvest, livestock

grazing, prescribed fire, wildfire suppression

strategies, range cultural treatments, and forest

cultural treatments. Monitoring and evaluation

are conducted to compare the outcomes and make

improvements in the landscape and communitylevel treatments.

Landscape Integrity Assumption 3:

Hierarchical Assessment, Implementation,

Monitoring, and Evaluation — Inventory

programs and methods are redesigned based on

landscape processes and gradients to integrate ecological conditions and resource values. Vegetation

mapping emphasizes techniques such as remote

sensing using multi-scale satellite imagery to

Landscape Ecology
provide information that is consistent, continuous, and current. Classification methods for mapping vegetation use hierarchies based on the vegetation's composition and structure. Landscape

planning is accomplished in a hierarchical manner

reflecting integrated broad- to fine-scale findings

in project design. Activities and changes are monitored by sampling mid- and fine-scale data, and

then statistically extrapolated to support broadscale monitoring. The evaluation process integrates broad- to fine-scale landscape conditions to

evaluate change, as well as the effects of cumulative activities.

Landscape Integrity Assumption 4:

Prioritization and Integration of

Activities — Through time, activities that produce commodities and restore landscape conditions are prioritized and then implemented

with emphasis on achieving an integrated landscape and maintaining aquatic, terrestrial, and

Table 2.2 — Alternatives by management emphasis and ecological interpretation.

Alternative Management

Alternative Group1 Emphasis2 Management Interpretation

Alt. 1

Alt. 2

Existing BLM/FS

Plans. Commodity

with minimal reserves.

Interim BLM/FS

Plans. Commodity

with reserves.

Traditional prescriptions: Produce and sustain commodity

values. Traditional commodity and wilderness management and wildfire suppression.

Traditional prescriptions: Provide protection in aquatic

riparian ecosystems; same as Alternative 1 in other areas.

Reduce traditional commodity and continue traditional

wilderness management and wildfire suppression.

Alt. 3 B

Alt. 4 C

Alt. 5 B

Alt. 6 C

Alt. 7 B

Restore/produce with

local priority.

Restore with Basin

priority.

Restore/produce with

economic

efficiency priority.

Restore with

adaptive management

and with Basin

priority.

Reserve the

undeveloped areas;

restore/ produce in

other areas.

Ecological prescriptions: Restore, produce, and conserve.

Restore and/or conserve areas that have local high

priority and produce commodities.

Ecological prescriptions: Restore, produce, and conserve.

Restore and/or conserve areas according to Basin priorities and produce commodities.

Ecological prescriptions: Conserve, produce, and restore.

Produce and/or restore where economically efficient in the

Basin and conserve with Basin priorities.

Ecological prescriptions: Restore, produce, and conserve

with adaptive management. Restore and/or conserve

areas based on Basin priorities, and produce commodities

with reduced rates in higher risk areas.

Ecological/reserve prescriptions: Minor management in

reserves with minimal investment in fire suppression and

restoration; same as Alternative 3 in other areas.

'Alternative Group:

A = Alternatives with traditional prescriptions that have high departure from native succession/disturbance regimes.

B = Alternatives with ecological prescriptions that have moderate departure from native succession/disturbance regimes due to spatial and temporal

fragmentation in response to emphasis on local priorities (alternative 3); economic priorities (alternative 5), or reserve management (alternative 7).

C = Alternatives with ecological prescriptions that have low departure from native succession/disturbance regimes.

Management emphasis - see appendix 2-C for description of catagories; see table 2.4 footnote 1 for definitions.

Landscape Ecology 43
hydrologic integrity and social and economic

resiliency. These priorities are set regionally using

assessment results at the subbasin [4th-field

Hydrologic Unit (HUC)9] level and associated

interpretations (see Quigley and others 1996).

These priorities are placed in context with national and international integrated priorities scaled at

the Basin level. Priorities are set at the watershed

and subwatershed scale using a similar analytical

process for 5th- and 6th-field HUCs within subbasins. The process of ecosystem risk and opportunity analysis follows the concepts of assessment

for proper functioning landscape patterns as

described in the Landscape Dynamics assessment

by Hann and others (in press).

Landscape Integrity Assumption 5:

Concentration of Activities Temporally

and Spatially — Through time, the implementation of activities such as access for timber harvest, use of prescribed fire, and road access management tends to be concentrated in time and

space to better reflect patterns of the inherent disturbance regimes and biophysical template. In

general, disturbances at the watershed level are

consistent with the template and concentrated

within periods of a few years, across a relatively

large part of the watershed, and with relatively

long time intervals of little or no disturbance.

Management for individual activities occurs over

larger areas to represent natural disturbances and

'As part of the need to integrate terrestrial and aquatic ecosystem information to address many of the issues related to the biophysical and social ecosystem components within the Basin, it was necessary to develop consistent and continuous delineations of

watersheds across the assessment area. A total of approximately 7,500 base unit subwatersheds (6th-field HUCS) were identified

within the Basin. Watersheds by their very nature are a nested hierarchy; a small watershed is contained within a larger watershed,

which, in turn, is contained within a still larger one. The numeric coding system was based on the one prepared by the USGS in

cooperation with the Water Resources Council. This system consists of fields of paired digits referred to as Hydrologic Unit Code

(HUC). The first four fields (8 digits) are assigned and published by the USGS and are commonly referred to as 4th-field HUCs.

The ICBEMP watershed delineation further subdivides 4th-field hydrologic code units into smaller, nested 5th-field and 6th-field

hydrologic units. It is the 6th-field hydrologic unit (referred to as 6th-field HUC or subwatershed) that was used as the basic

characterization unit for the ICBEMP assessment effort.

Table 2.3 — General descriptions of traditional, ecological, and reserve management prescriptions.

Management

Prescription Description

Traditional Emphasis on managing primary natural resource variables related to providing for human needs

(such as wood production, livestock, recreation, visual condition, water, and big game). Manage

as an aggregation of effects from a fine scale (such as stands, allotments, campgrounds, and

point source) with no broader scale context. Measure sustainability directly from the variables.

Manage to control landscape dynamics to maximize production of primary natural resource

variables.

Ecological Emphasis on managing relationships of humans and other species with their environments (recognizing primary natural resource variables and their relationship with ecological composition,

structure, and function). Manage using broad spatial and temporal scales to provide context for

management of finer scale patterns. Measure sustainability from both primary natural resource

variables and ecological processes. Manage landscape succession/disturbance regimes to shift

current spatial patterns and temporal trajectories to fit the basic biophysical template and represent native succession/disturbance regimes.

Reserve Emphasis on minimal production of natural resource commodity variables and minimal direct

management treatments. Manage landscape dynamics to allow the current spatial patterns to

achieve their own balance with the environment through time.

44 Landscape Ecology
to maintain structures that "fit" the biophysical

template. This management shift, prioritized

through time, would result in improved landscape

integrity and more efficient production of

resource values.

Landscape Integrity Assumption 6:

Road Management — New road construction

is prioritized for low sensitivity landtypes and 6thfield HUC subwatersheds within the context of

objectives specifying no net increase in road densities in any cluster or in applicable subwatersheds.

Road management prioritizes reductions in road

density in moderate-to-high sensitivity watersheds

and landtypes. Permanent roads are surfaced with

asphalt or stable aggregate to reduce the need for

grading and cut/fill slopes, and ditches are stabilized with herbaceous cover. Drainage systems and

culverts are reconstructed, as needed, and maintained to eliminate delivery of sediment into

streams. Bridges and culverts are reconstructed, as

needed, in locations that reduce impacts on the

river and stream channel dynamics.

Landscape Integrity Assumption 7:

Fire Management — The fire suppression and

fuels programs are managed to attain landscape

conditions consistent with inherent disturbance

processes and within the capabilities of the biophysical system. Fire suppression resources are

maintained to manage wildfires when needed.

During periods when wildfire activity is low, these

resources are used for prescribed fire and fuel

management. Large wildfires are managed in the

context of the total landscape and risk to lives,

property, and resource investments, with a full

range of strategies capable of achieving landscape

vegetation and fuel management objectives, as

well as wildfire suppression.

Wildfire management strategies fully recognize the

dangers of various fuel and weather conditions

and place emphasis on the safety of firefighters, as

well as the need to meet fire suppression objectives. Fuels in wilderness and semi-primitive areas

are managed with an active prescribed fire program that includes unplanned ignitions where

appropriate, and planned ignitions where needed,

to trend toward the appropriate landscape pattern

of succession/disturbance regimes and to meet

resource objectives.

Landscape Integrity Assumption 8:

Forest and Range Integrated Landscape

Management — Management activities are

designed and implemented to integrate planning,

implementation, and monitoring for ecological

integrity, while considering social and economic

resiliency. Management emphasis shifts towards

managing landscape processes to provide the most

effective "fit" with the biophysical template and

associated pattern of succession/disturbance

regimes.

Management would improve the integrity of many

processes by managing activities such as harvest,

prescribed fire, wildfire, and grazing to mimic or

represent effects of native succession and disturbance processes at .the physiognomic level. Key

processes include photosynthesis, decay, fire,

insect/disease, and herbivory. Landscape patterns

of succession/disturbance regimes provide a basis

for integrated improvement of integrity by "best

fit" of treatments to their appropriate landscape

position and scale. Through time, management

activities that affect these processes would provide

for a supply of dead and live standing and down

wood that structurally represent the essential range

of associated habitats and conditions for nutrient

cycling.

By considering net primary productivity and

water/nutrient balance at levels consistent with

the native system, management would provide for

productivity and stress levels consistent with biophysical limitations. Managing for soil cover and

structure as appropriate for the biophysical template would provide for long-term soil productivity, and also limit erosion and sediment delivery.

Designing roads that reduce sediment delivery

and bare soil would improve hydrologic integrity.

Monitoring of multi-scale landscape patterns

and adjusting for landscape processes would

change the trends in community and landscape

patterns to be more consistent with inherent disturbance processes. The broad-scale composition

Landscape Ecology 45
of physiognomic types would become more similar to the biophysical template, in both structure

and composition of communities, and landscape

patterns of succession/disturbance regimes, at the

watershed scale.

Landscape Integrity Assumption 9:

Management of Different Potential

Vegetation Groups (PVGs)10 — Management

of potential vegetation groups is done in a landscape context with their adjacent PVGs. There is

emphasis to avoid both the introduction and

spread of exotic plants and noxious weeds. Any

seeding that is deemed necessary would use native

species whenever possible; any non-native species

used should, when possible, be ones that do not

produce viable seed. Desired non-native species

are used for restoration only if there are no native

species that can compete with undesirable exotics

or that will stabilize the site.

Over time, the integrity of potential vegetation

groups would improve by addressing conditions

related to current integrity problems. By improving inventory, remote sensing, and ecological

modeling, management would develop a better

understanding of potential vegetation groups and

their relationships to landscape patterns and succession/disturbance regimes at finer scales.

Through time and with die use of prescribed fire,

flexible strategies on wildfire management, noncommercial tree cutting, commercial harvest, livestock grazing, and other treatments, the mix of

physiognomic types would show a trend toward a

mix consistent with properly functioning landscape systems (also equivalent to landscape health).

Additional information about assumed management of potential vegetation groups is included in

appendix 2-A.

10A PVG is a group of potential vegetation types (PVTs) that have similar environmental conditions and are dominated by similar

types of plants. A potential vegetation type is a physical and biological environment that produces a kind of vegetation, such as

the dry Douglas-fir type.

46 Landscape Ecology