In Cooperation with The Nature Conservancy 

High-Severity Fire in Forests of the Southwest: 

Conservation Implications 

Progress Report, August 2005 

By Sandra Haire 

Open-File Report 2006–1077 

U.S. Department of the Interior 

U.S. Geological Survey 
U.S. Department of the Interior 

Gale A. Norton, Secretary 

U.S. Geological Survey 

P. Patrick Leahy, Acting Director 

U.S. Geological Survey, Reston, Virginia 2006 

For product and ordering information: 


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Suggested citation: 


Haire, Sandra, 2006, High severity fire in forests of the southwest: Conservation implications, Progress 


report August 2005: U.S. Geological Survey, Biological Resources Discipline, Open-File Report 2006-1077, 9p. 


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Although this report is in the public domain, permission must be secured from the individual copyright 


owners to reproduce any copyrighted material contained within this report. 


Cover photograph: Short-horned lizard (Phrynosoma douglassii) on a Field Map, Saddle Mountain Study 


Site, Spring 2005


ii 
Acknowledgments 

The Nature Conservancy, U.S. Geological Survey, and University of Massachusetts provided 

funding for operations and salaries. Janice Stone conducted photograph interpretation and digitizing; 

Rebecca Franklin, John Riling, and Dave Lively were field technicians for the 2005 season; Matt Sperry 

and Micah Brachman assisted with field work in the Dome Wilderness. Brad Compton developed the 

computer program for kernel analysis and provided consultation on related programming efforts. Research 

permits were granted to us by Bandelier National Monument, Santa Fe National Forest, Kaibab National 

Forest, and Grand Canyon National Park. Los Alamos National Laboratory allowed access to our plots 

near the T-49 Interagency Fire Center. Managers and scientists at these agencies assisted with critical 

logistical support, shared GIS data and aerial photography, and aided us in plant identification. We 

appreciate the generosity of our funding agencies, the hard and careful work of our mapping and field 

crews, and the support of our collaborators at the National Forests and Parks. 

A project funded by The Nature Conservancy under the title, “Disturbance Ecology of Rocky Mountain 


Pine Forests: Conservation Implications” 


Principal Investigators: Sandra Haire and Kevin McGarigal (University of Massachusetts) 


Contact: Sandra Haire, tel 413-577-3304, e-mail shaire@forwild.umass.edu


Consultants: Patrick McCarthy (The Nature Conservancy), Melissa Savage (The Four Corners Institute, 


New Mexico), and Bill Romme (Colorado State University) 


iii 
 Contents 

Introduction .........................................................................................................................................................................1 


Acknowledgments .........................................................................................................................................................iii 


Objective 1. .........................................................................................................................................................................1 


Mapping Burn Severity for the Field Sites .................................................................................................................1 


Selection of Plot Locations ...........................................................................................................................................2 


Field Data Collection ..................................................................................................................................................... 2 


Objective 2. .........................................................................................................................................................................3 


Site Selection and Mapping .........................................................................................................................................3 


General Observations ........................................................................................................................................................6 


Data Analysis and Products .............................................................................................................................................9 


References Cited ................................................................................................................................................................9 


Tables 

1. Data collected at La Mesa and Saddle Mountain field plots .................................................................................5 


2. Mapping status of burns in the three geographic regions .....................................................................................8 


Figures 

1. Potential sample points based on distance from high severity and a model of ponderosa pine seed 


density, La Mesa.................................................................................................................................................................3 


2. Potential sample points based on distance from high severity and a model of ponderosa pine seed 


density, Saddle Mountain .................................................................................................................................................4 


3. Plot locations at the field sites, La Mesa ...................................................................................................................6 


4. Plot locations at the field sites, Saddle Mountain ....................................................................................................7 


5. Diagram of plot layout....................................................................................................................................................8


iv
High-Severity Fire in Forests of the Southwest: 

Conservation Implications 

Progress Report, August 2005 

By Sandra Haire 

Introduction 

The occurrence of large, severe fires in southwestern ponderosa pine (Pinus ponderosa) forests has 

resulted in concern that these forests may not persist under such an extreme disturbance regime. In our 

research, we are examining the outcomes of high-severity fire in ponderosa pine forests and their 

neighboring communities across an elevational gradient. One goal of our work is to contribute to 

understanding the resiliency of these systems, but we also want to investigate the conservation values 

intrinsic to the diverse communities that represent alternative successional trajectories after severe fire. 

One assumption of our research is that the spatial pattern of a disturbance becomes increasingly important 

when the disturbance is large and biological legacies are few and sparse. We ask, therefore, what spectrum 

of plant communities results from high severity fire, and what is their relationship to spatial patterns of 

severity mapped in early post fire timeframes? Also, do spatial patterns of older burns (1950–80) differ 

from recent burns (1998–present) in ways that make us expect successional changes years from now to 

differ from those we observed at our older burn field sites? 

Here, we describe the first stages of our work in mapping burn severity at old and new burns as 

well as the work we have recently completed at our two field sites. The report is organized under our two 

main objectives with the purpose of summarizing the steps we have taken in working toward these 

objectives, as well as changes we have made in methodologies since the original study plan. We present 

some general observations and plans for the next steps in data analysis and product generation. This 

report, the study plan, a photograph gallery, slide presentations, and our contact information are available 

on the project Web site http://www.umass.edu/landeco/research/swfire/swfire.html . 

Objective 1 

Determine the persistent and ephemeral effects of the spatial heterogeneity of burn severity in areas 

affected by high-severity fire over decadal timeframes. 

Mapping Burn Severity for the Field Sites 

Last fall and winter, we obtained pre- and post fire aerial photographs for our field sites, delineated 

areas of high severity, and created GIS coverages of the burned areas. The first field site, La Mesa, burned 

in 1977. The burn is located primarily in Bandelier National Monument with some areas on the Los 

Alamos National Laboratory and also Santa Fe National Forest. La Mesa, thought to be a human-caused 

fire, burned across an elevational gradient, which generally increases from southeast to northwest, 

1 
encompassing approximately 6,000 ha of pinion-juniper (Pinus edulis-Juniperus spp.), ponderosa pine, 

and mixed conifer forest. For this burn, we had access to aerial photographs taken in 1973, 1975, 1977, 

1981, and 1983, courtesy of Kay Beeley, National Park Service. The photographs vary in scale from 

1:6,000 to 1:24,000. 

Our second field site is Saddle Mountain, a 4,000-ha burn that occurred in 1960. The fire started by 

lightning in Grand Canyon National Park and spread northeast across a similar range of forest types to that 

at La Mesa, with elevation increasing from northeast to southwest. The area is almost entirely within the 

Saddle Mountain Wilderness and is accessible by foot from dirt roads at the southwest, southeast, and 

northern wilderness boundaries. Aerial photographs taken before and after the fire (1957 and 1963; 

1:15,840 scale) were purchased from the U.S. Department of Agriculture Aerial Photography Field Office. 

The aerial photographs were interpreted in stereo and digitized with an Optem Digitizing Transfer 

Scope onto digital black and white orthophoto quads taken in the late 1990s and early 2000s. Mapping 

areas of high-severity burn was relatively straightforward where standing dead trees were visible in the 

photographs. In other cases, openings on the post fire photographs were compared to conditions on pre fire 

photographs to distinguish preexisting openings from new openings created by fire, although this was very 

rarely a source of confusion in our study areas. Moderate severity was mapped where a mix of dead and 

live trees was visible. In this case, standing trees commonly had brown needles but were too intermingled 

with live trees to delineate separate patches. The minimum mapping unit is defined by groups of two or 

more trees that survived the fire. These patches may have experienced low-severity (for example, surface) 

fire or may represent unburned islands. 

Selection of Field Plot Locations 

In our analysis of the maps to determine field site selection, we used a simplified map with high 

and low/unburned classes. Moderate areas in which live trees were too scattered to delineate were 

included in the high category. Before the field season, we devised a scheme for selecting sample locations 

with the goal of capturing variation in gradients of (1) distance from within high-severity patches to an 

edge of lower severity and (2) landscape context of forest cover/potential seed sources. The variation in 

ponderosa pine cover at La Mesa was modeled using percent cover values from a map created soon after 

the fire by Craig Allen for his dissertation work. For Saddle Mountain, we estimated percent cover of 

ponderosa pine from the post fire aerial photograph in a buffer zone around each high severity polygon. 

Using the cover values, we developed a surface that represented potential for seed dispersal within the 

high severity polygons using kernels (Worton, 1989; figs. 1 and 2). Local peaks in distance within highseverity patches were identified, and a subset of these locations was chosen to represent variation in kernel 

values. Approximately 60 priority locations were chosen at each site; extra points that could be substituted 

or added were available to use if needed. 

Field Data Collection 

We collected data at 68 plots at La Mesa and 80 plots at Saddle Mountain between May 16 and 

June 30, 2005. Plots were located throughout the burns (figs. 3 and 4), except where access was limited by 

private ownership (for example, Los Alamos National Laboratory properties). We also avoided locations 

where tree planting was documented, for example, on the Mesa del Rito (New Mexico). According to our 

contacts at the Forest Service, trees were planted at Saddle Mountain; however, we had no information on 

the specific location of the planting. Therefore, we continually looked for evidence of planting and found 

none in our plots (that is, no trees near in age to the burn). The plots were circular with a 25-m radius; 

data collected at each plot include physical characteristics, point-intercept cover estimates, tree species, 

size, age, and shrub and understory species lists (table 1; fig. 5). 

2 
Figure 1. The field map of potential plot locations at La Mesa chosen relative to (1) distance from high 

severity (blue areas) to nonhigh and (2) variation in ponderosa pine seed sources outside the high-severity 

patches (represented by shades of blue). A large portion of the burn is located within Bandelier National 

Monument, but parts of the Santa Fe National Forest to the southwest and Los Alamos National Laboratory 

property to the northeast also burned in the fire. 

Some changes were made in the data-collection procedures from our original proposal. We made a 

complete survey of woody species at all plots; however, due to several factors (visibility of flowers 

because of season, time constraints, and limitations of our expertise in botany) we could not realistically 

identify all herbaceous and grassy species at the plots. Instead, we identified the most visible species (that 

is, those that were flowering) at a subset of the plots and added a narrow belt along the line transects in 

which to quantify presence/absence of high-priority “invasive” plants. Some of the invasive species of 

interest, identified by local managers, were cheatgrass (Bromus tectorum), smooth brome (Bromus 

inermis), mullein (Verbascum thapsus), sheep fescue (Festuca ovina), Kentucky bluegrass (Poa 

pratensis), and diffuse knapweed (Centaurea diffusa), among others. 

Objective 2 

Determine the differences in spatial heterogeneity in older and newer burns of similar and different sizes 

and, using our findings from Objective 1, evaluate the cumulative effects of high-severity burns on 

biodiversity within the broader regional landscape. 

3 
Study Site Selection and Mapping 

We have identified a set of fires that meet our criteria in the older and newer timeframes (table 2). 

The fires are distributed among three regions: Jemez Mountains in New Mexico, Gila Mountains in New 

Mexico, and the Kaibab Plateau (including Grand Canyon North Rim) in Arizona. In the older burn 

category, mapping is in progress for the Lookout Canyon, Little Creek, and McKnight burns, and we are 

working with cooperators 

Figure 2. The field map of potential plot locations at Saddle Mountain, chosen relative to (1) distance from 

high severity (blue areas) to nonhigh and (2) variation in ponderosa pine seed sources outside the highseverity patches (represented by shades of blue). The southern edge of the high-severity patches borders 

on Grand Canyon National Park (Forest Road 610 of the Kaibab National Forest). The majority of the burn is 

in the Saddle Mountain Wilderness, North Kaibab Ranger District. 

4 
at the Los Alamos Laboratory to obtain photographs for American Springs. The size of the McKnight fire 

may prevent its completion in the timeframe and budget of our project, but we will optimistically keep it 

in the plan until the work on the other burns is near completion. There are many possibilities for newer 

burns, and we may yet substitute one for another in some cases. For example, several large burns have 

recently been mapped in the Gila Mountains. Burn severity maps are available for all of the recent fires 

either through the National Burn Severity Mapping Project (http://burnseverity.cr.usgs.gov/fire_main.asp) 

or from collaborators (for example, at the local National Forest). 

Table 1. Data collected at La Mesa and Saddle Mountain field plots. Plots were 25-meter radius, with 

transects running north-south and east-west. 

Field data collected Description of methods 

Plot characteristics 

Location 

GPS error 

Slope 

Aspect 

Topographic position 

Navigated to point using Garmin 12 GPS, map, and compass, then 

marked the location in the GPS unit and recorded error. 

Slope of the land in degrees. 

Aspect in compass degrees describing the predominant direction 

face. 

Classified relative to the local condition: summit or mesa top, flat 

side-slope, shoulder, toe, or bottom. 

Cover data 

Grass 

Forb 

Soil 

Rock 

Organic 

Shrubs (by species) 

Trees (by species) 

Point intercept recorded at 100 1-m intervals along North-South and 

East-West line transect through center of plot. 

Live trees 

Diameter (or seedling, sapling class) 

Species 

Age if ponderosa pine (whorl count and coring) 

Health rating 

Downed wood 

Length in belt 

Average diameter in belt 

Decay class 

Stumps and snags 

Diameter 

Species if identifiable 

Trees and dead wood were measured in a belt along either side of 

the line transect. At each plot, width was chosen to optimize 

number of coniferous trees while maximizing efficiency in areas 

with dense trees. Width of the belt varied from 2 to 10 meters. 

Trees were cored selectively (approximately 20-30 per site) to 

determine confidence in age estimates based on whorl counts. 

Health of trees was rated on a scale of 1 (healthy) to 3 (unhealthy). 

Downed wood and stump decay class was rated using a standard 

scheme, considering state of bark and stems and softness of 

wood. 

Diameters were measured at 1.5-meters up from the ground. 

Soil data 

Stoniness 

Development 

Texture 

Soil was characterized onsite using categories of stoniness, degree 

of development, and texture based on properties when wet. 

Plant species diversity and abundance 

Woody species identification 

Herbaceous and grassy species identification 

“Invasive” species abundance 

All woody plants were identified to genus and in most cases, to 

species. Herbaceous and grassy species were identified at a 

subset of plots as time and expertise allowed. 

Presence/absence of priority “invasive” species, specified by local 

managers, was quantified in 200 1-m 2

 plots, which were located 

along the line transects. 

Photographs Digital photographs were taken from plot center, one in each 

cardinal direction. 

5 
For the newer burns, a change detection index called the Normalized Burn Ratio (deltaNBR) 

provides a template for modeling burn severity. Landsat Thematic Mapper or Enhanced Thematic Mapper 

imagery band 4 and band 7 are used in a normalized ratio; then, the prefire NBR and postfire NBR are 

differenced to calculate the deltaNBR (Key and Benson, 2005). The method incorporates bands 

Showing substantial change from pre to postfire in a change detection algorithm with the objective of 

providing a clear distinction between burned and unburned areas while mapping burn severity as a 

gradient of values representing increasing degree of change on the burned landscape. The deltaNBR has 

been related to a field measure that represents a composite of effects across vertical strata of vegetation 

and soils (Key and Benson, 2005). We are using burn severity ratings and (or) fire-effects data (Kotliar 

and Haire, unpubl. data (USGS 2001); Omi and Martinson, 2002, unpubl. data) from several recent fires 

(Outlet, Pumpkin, Cerro Grande, Viveash) to determine the expected accuracy of severity maps that are 

derived using the deltaNBR alone (that is, without field data). 

Figure 3. Sample plot locations at La Mesa (n = 68). Mesa del Rito (southwest) and areas near the 

Ponderosa Campground (north-central) were avoided due to known tree plantings after the fire. Two plots 

were located on Los Alamos Laboratory properties, with permission from the local authorities. 

General Observations 

The past year of work on the project has increased our enthusiasm for the original ideas in the 

proposal. Initial uncertainty regarding the availability of historical photographs, taken at the desired place 

and time, was replaced by excitement when we acquired the photographs and began to work out the 

protocols for severity mapping. Our field season, with all its logistical challenges, was endowed with 

extreme good luck in terms of weather (the monsoons only began in the last week), an amiable and 

compatible field crew, and equipment (GPS and palm pilots, especially) that got through the season 

without incident. We continually looked for verification and (or) problems with the burn severity maps as 

6 
we hiked to the plots, but found only a few places where adjustments were needed. We often used the 

severity maps for navigation because the patterns of trees that survived the fire were clearly visible on the 

landscape. As expected, we observed a wide spectrum of vegetation communities in high-severity areas at 

both sites (see the Web site Photograph Gallery for a sample). Dense shrub communities with manzanita 

(Archtostaphylos spp.), oak (Quercus spp.), New Mexico locust (Robinia neomexicana), grassy meadows, 

and aspen (Populus tremuloides) with conifers in the understory/openings and ponderosa pine in varying 

densities and stages of growth were all represented in the suite of successional outcomes. 

Figure 4. Sample plot locations at Saddle Mountain (n = 80). The plots were accessed by hiking from forest 

roads (primarily Road 8910 on the north and Road 610 on the south) that border the Saddle Mountain 

Wilderness. 

7 
Figure 5. Diagram of plot layout. At each plot location, two 50-meter line transects were oriented in 

cardinal directions, and ground cover was recorded at 1-meter intervals. Tree and downed wood data 

were collected within in a belt varying in width from 2 to 10 m along the line transects. Photographs were 

taken, and physical characteristics of each plot were recorded at plot center. 

Table 2. Burns in the older and newer timeframes from the three regions: Jemez, Gila, and Kaibab 

(including Grand Canyon North Rim). 

Fire name Region Approximate size 

(ha, hectare) 

Date Status of mapping/comments 

American Springs Jemez 600 1954 Working with Los Alamos National Laboratory to 

obtain photographs. 

Jerky #5 Gila 700 1956 Photographs acquired. 

Lookout Canyon Gila 2,400 1951 Photograph interpretation and mapping in progress. 

Saddle Mountain Kaibab 4,000 1960 Mapping complete (field site). 

Little Creek Gila 6,000 1951 Photographs acquired. 

McKnight Gila 16,000 1951 Photographs acquired; may be too large to complete. 

La Mesa Jemez 6,000 1977 Mapping complete (field site). 

Oso Jemez 2,000 1998 Landsat burn-severity map available. 

Vista Kaibab 1,500 2001 Landsat burn-severity map available. 

Outlet Kaibab 6,000 2000 Landsat burn-severity map available. 

Pumpkin Kaibab 3,500 2000 Landsat burn-severity map available. 

Cerro Grande Jemez 17,000 2000 Landsat burn-severity map available. 

Dry Lakes Gila 26,000 2003 Landsat burn-severity map available for this and 

other recent burns in the Gila Mountains. 

8 
Data Analysis and Products 

We are in the process of determining the best ways to present the results of the project. Our current 

plans include several peer-reviewed publications, and we will maintain the project Web page as a way to 

distribute reports, photographs, and presentations, in addition to data products (for example, maps). 

Here are a few ideas for working titles of manuscripts we hope to develop as the data analysis 

progresses: 

1.	 “Plant community diversity decades after high-severity fire: Assessing conservation value.” 

Possible journal outlet: The Southwestern Naturalist 

2.	 “A characterization of plant communities relative to spatial patterns of high-severity fire in the 

Southwestern U.S.” Possible journal outlet: Forest Ecology and Management 

3.	 “Spatial patterns after high-severity fire and their implications for long-term successional 

changes at broad temporal and geographic scales.” Possible journal outlet: Landscape Ecology 

4.	 “A spatial model of ponderosa pine regeneration after high-severity fire.” Possible journal 

outlet: Conservation Biology 

References Cited: 

Key, C.H., and Benson, N.C., 2005, Landscape assessment: Remote sensing of severity, the Normalized 

Burn Ratio; and ground measure of severity, the composite burn index. In Lutes, D.C., Keane, R.E., 

Caratti, J.F., Key, C.H., Benson, N.C, and Gangi, L.J., Eds., FIREMON, Fire effects monitoring and 

incentory system: General Technical Report, RMRS-GTR-164-CD: LA1-LA51. USDA Forest Service, 

Rocky Mountain Research Station, Ogden, Utah. 

Omi, P.N. and Martinson, E.J., 2002, Effects of fuels treatment on wildfire severity. Final Report to the 

Joint Fire Science Governing Board. Western Forest Fire Research Center, Colorado State University. 

March 25, 2002. 

Worton, B.J., 1989, Kernel methods for estimating the utilization distribution in home-range studies: 

Ecology, v. 70, p. #164-168. 

9