United States Department of Agriculture / Forest Service

Rocky Mountain Research Station

Research Paper RMRS-RP-85

June 2011

The 2002 Rodeo-Chediski Wildfire’s Impacts 

on Southwestern Ponderosa Pine Ecosystems, 

Hydrology, and Fuels

Peter F. Ffolliott

Cody L. Stropki

Hui Chen

Daniel G. Neary
Ffolliott, Peter F.; Stropki, Cody L.; Chen, Hui; Neary, Daniel G. 2011. The 2002 

Rodeo-Chediski Wildfire’s impacts on southwestern ponderosa pine ecosystems, 

hydrology, and fuels. Res. Pap. RMRS-RP-85. Fort Collins, CO: U.S. Department 

of Agriculture, Forest Service, Rocky Mountain Research Station. 36 p.

Abstract

The Rodeo-Chediski Wildfire burned nearly 462,600 acres in north-central Arizona 

in the summer of 2002. The wildfire damaged or destroyed ecosystem resources 

and disrupted the hydrologic functioning within the impacted ponderosa pine (Pinus 

ponderosa) forests in a largely mosaic pattern. Impacts of the wildfire on ecosystem 

resources, factors important to hydrologic functioning, peak stormflow events and 

water quality constituents, and loadings of flammable fuels were evaluated on two 

watersheds in a ponderosa pine forest that was exposed to the burn—one experienced 

a high severity (stand-replacing) fire (Watershed A), and the other was exposed to 

only a low severity (stand-modifying) fire (Watershed B). Cumulative impacts of the 

wildfire on ecosystem resources, hydrologic functioning, and flammable fuels were 

more pronounced on Watershed A. Recovery of the Stermer Ridge watersheds from 

the Rodeo-Chediski Wildfire has been related to the respective fire severities that the 

two watersheds experienced. Watershed A converted from ponderosa pine to grasses, 

forbs, and a few shrubs. Recovery of the hydrologic functioning on this watershed has 

begun on a limited scale, but it is anticipated that the overall hydrologic functioning 

of Watershed A will not approach pre-fire conditions for many years. Flammable 

fuels represented by standing trees have been eliminated on Watershed A, but there 

has been an increase in stem sections, branches, twigs, and herbaceous fuels on the 

forest floor. While the possibility of a future crown fire has declined, the potential for 

surface fire remains. Much of Watershed B is slowly recovering from the impacts of 

the wildfire. Much of the hydrologic functioning of this watershed is also returning 

slowly to its pre-fire level. The post-fire loadings of flammable fuels were largely 

unchanged from their pre-fire estimates. Watershed B remains vulnerable to future 

wildfire events as a consequence.

Keywords: flammable fuels, fire severity, hydrologic functioning, ponderosa pine, 

Rodeo-Chediski Wildfire
Authors

Peter F. Ffolliott, Professor, School of Natural Resources and the Environment, 

University of Arizona, Tucson, Arizona.

Cody L. Stropki, formerly Research Associate, School of Natural Resources and 

the Environment, University of Arizona, Tucson, Arizona; currently Environmental 

Scientist, SWCA, Albuquerque, New Mexico.

Hui Chen, Research Assistant, School of Natural Resources and the Environment, 

University of Arizona, Tucson, Arizona.

Daniel G. Neary, Research Soil Scientist and Science Team Leader, Air, Water, and 

Aquatic Environments Program, Rocky Mountain Research Station, U.S. Department 

of Agriculture, Forest Service, Flagstaff, Arizona.

Acknowledgments

This study and the preparation of this research paper were supported by the Southwest 

Watershed Sciences Team, Air, Water, and Aquatic Environments Science Program 

of the Rocky Mountain Research Station, U.S. Forest Service, Flagstaff, Arizona. 

Support from the U.S. Forest Service National Fire Plan; the Black Mesa Ranger 

District, Apache-Sitgreaves National Forest; and the Agricultural Experiment 

Station, University of Arizona, Tucson, Arizona, are gratefully acknowledged.
Contents

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

Rodeo-Chediski Wildfire................................................................................... 1

Stermer Ridge Watersheds............................................................................... 1

Study Protocols................................................................................................. 3

Ecosystem Resources............................................................................... 4

Hydrologic Functioning ............................................................................ 7

Loadings of Flammable Fuels................................................................... 9

Impacts on Ecosystem Resources................................................................... 10

Tree Overstories..................................................................................... 10

Stocking of Ponderosa Pine Seedlings ................................................... 11

Species Compositions of Herbaceous Plants and Shrubs ...................... 11

Production of Herbaceous Plants and Shrubs........................................ 12

Utilization of Forage Plants.................................................................... 17

Indigenous Ungulates and Small Mammals........................................... 17

Birds....................................................................................................... 19

Impacts on Hydrologic Functioning................................................................ 21

Water-Repellent Soils............................................................................. 21

Transpiration and Infiltration ................................................................. 22

Soil Movement....................................................................................... 22

Peak Stormflows.................................................................................... 25

Water Quality Characteristics ................................................................ 26

Impacts on Flammable Fuels.......................................................................... 26

Pre-Fire Fuel Loadings............................................................................ 26

Post-Fire Fuel Loadings .......................................................................... 26

Summary......................................................................................................... 28

Impacts on Ecosystem Resources .......................................................... 28

Impacts on Hydrologic Functioning ....................................................... 29

Impacts on Flammable Fuels ................................................................. 29

Management Implications.............................................................................. 30

References....................................................................................................... 30

ii
The 2002 Rodeo-Chediski Wildfire’s 

Impacts on Southwestern Ponderosa Pine 

Ecosystems, Hydrology, and Fuels

Peter F. Ffolliott

Cody L. Stropki

Hui Chen

Daniel G. Neary

iii
Figure 1—The Rodeo-Chediski Wildfire evolved from two separate human ignitions on the White Mountains-Fort Apache Reservation in northeastern 

Arizona that merged into one inferno. (Photo courtesy of the Apache-Sitgreaves National Forest.)

iv
USDA Forest Service RMRS-RP-85. 2011. 1

Introduction

The 462,600-acre Rodeo-Chediski Wildfire of 2002 was the largest known in Arizona’s history, and it 

was the ninth largest wildfire in the United States in 

terms of the acreage impacted (National Interagency 

Fire Center 2009). It damaged or destroyed ecosystem resources, disrupted hydrologic functioning, and 

altered the loadings of flammable fuels on much of the 

ponderosa pine forest that was exposed to the burn. 

Once a source of trees for processing into wood products, these forests are now vital in providing watershed 

protection in a water-deficient region, forage for domestic livestock and indigenous herbivores, habitats 

for mammals and avifauna, and sites for outdoor recreational activities.

An opportunity to study the impacts of this wildfire on ecosystem resources, hydrologic functioning, 

and flammable fuels presented itself on two first-order watersheds in a ponderosa pine forest. Watershed 

A was exposed to a high severity (stand-replacing) 

fire, and Watershed B was exposed to a low severity 

(stand-modifying) fire. The extensive area that was 

burned precluded establishment of a suitable unburned 

(control) area in the vicinity of the two watersheds 

for comparison purposes. This five-year study (2002 

through 2007) was initiated shortly after cessation of 

the Rodeo-Chediski Wildfire and continued through 

the implementation of salvage cutting and fuel reduction treatments on Watershed A. Impacts of the 

wildfire were evaluated on:

• Ecosystem resources including tree overstories; 

herbaceous understories and shrub species; and 

wildlife species and their habitats.

• Factors of importance to hydrologic functioning 

such as the formation of water-repellent soils; soil 

movement, including both soil erosion and soil 

deposition; and peak stormflow events and water 

quality constituents.

• Loadings of flammable fuels, including the 

fractions of standing trees, downed woody 

materials, litter and duff accumulations, and 

herbaceous plants.

The results of this study complement the findings from earlier studies on the impacts of wildfire 

on ecological resources, hydrologic functioning, 

and flammable fuels in southwestern ponderosa pine 

forests (Baker 1990; Campbell and others 1977; 

Harrington 1987; Ice and others 2004; McHugh and 

Kolb 2003; Neary and others 2005; Pearson and others 

1972). This report contains brief summaries of some 

of those studies. The information in this report should 

help managers evaluate the impacts of large-scale 

wildfires on ecosystem resources, hydrologic functioning, and flammable fuels and then plan effective 

post-fire rehabilitation activities.

Rodeo-Chediski Wildfire

The Rodeo-Chediski Wildfire evolved from two separate human-induced ignitions on the White 

Mountains-Fort Apache Reservation in northeastern 

Arizona that merged into one inferno (fig. 1). Arson 

was the cause of the Rodeo fire that started on June 18, 

2002, a few miles from Cibecue, a small village on the 

Reservation. The Chediski fire was set as a signal by 

a lost hiker a few days later. The second fire quickly 

spread out of control and eventually merged with the 

still out of control Rodeo wildfire on June 23rd. The 

re-named Rodeo-Chediski Wildfire then burned onto 

the adjacent Apache-Sitgreaves and Tonto National 

Forests and through many small communities before 

it was contained on July 7th at a suppression (fire 

fighting) cost of about $45 million (Morton and others 2003; Neary and Zieroth 2007). Nearly 500 homes 

and other buildings were destroyed and over 30,000 

people were forced to flee. Property losses, losses of 

ecosystem and cultural resources, and rehabilitation 

efforts increased the monetary costs of the wildfire to 

nearly $175 million.

Rehabilitation efforts began shortly after the wildfire was extinguished. Detention dams and other 

diversions were constructed to re-route (away from 

infrastructures) overland flows of water that originated from the post-fire summer rainstorms. Culverts 

were removed to reduce road damage during the anticipated flooding events. Helicopters ferried bales of 

straw to areas that were susceptible to increased soil 

erosion rates. Straw was spread onto the ground to reduce the impacts of the post-fire summer rains on the 

bare soil surface. Aerial seeding of grasses and other 

herbaceous plants on the erosion-prone sites proved 

ineffective. Most of the seed washed downslope into 

stream corridors in the initial post-fire rainstorms and 

few germinated on the slopes. Fire-damaged but salvageable trees 12 inches in diameter at breast height 

(dbh) and larger with merchantable value, but not 

expected to survive, were harvested on the White 

Mountains-Fort Apache Reservation beginning in the 

late fall of 2002. Salvage cutting and fuel reduction 

treatments were initiated on the Apache-Sitgreaves 

and Tonto National Forests in the summer of 2005. 

Trees smaller than those harvested in the salvage cutting were cut in the fuel reduction treatments.

Stermer Ridge Watersheds

Two mostly homogeneous watersheds, 60 acres each, that are located along Stermer Ridge at the 

headwaters of the Little Colorado River were the sites 

chosen for this study (fig. 2). These watersheds, designated A (high severity wildfire) and B (low severity 

wildfire), are similar vegetatively, physiographically, 

and hydrologically. The watersheds were originally 

instrumented in 1972/1973 by the School of Natural 

Resources and the Environment, University of Arizona, 

and the Rocky Mountain Research Station, U.S. Forest 

Service, to obtain ecological and hydrologic information on ponderosa pine forests found on soils derived 

from sedimentary parent materials (Ffolliott and Baker 

1977). The information obtained on these watersheds 
2 USDA Forest Service RMRS-RP-85. 2011.

complemented the watershed-based research program 

on basaltic soils in the Southwestern Region (Baker 

1999; Fox and others 2000).

Pre-fire overstories of ponderosa pine trees on the 

two watersheds had been selectively harvested for 

merchantable timber in several earlier cuttings. The 

most recent timber harvesting operation before the 

Rodeo-Chediski Wildfire removed about 45 percent of 

the merchantable trees by group selection in the early 

1960s. A few intermingling Gambel oak (Quercus

gambelii) and alligator juniper (Juniperus deppeana) 

trees were also present on the watersheds. Graminoids, 

forbs, and shrubs found in southwestern ponderosa 

pine forests (Clary 1975; Ffolliott and Baker 1977; 

Ffolliott and Gottfried 2008, and others) comprised 

pre-fire herbaceous understories. Squirreltail (Elymus 

elymoides), muttongrass (Poa fendleriana), Arizona 

fescue (Festuca arizonica), blue grama (Bouteloua 

gracilis), prairie Junegrass (Koeleria macrantha), 

mountain muhly (Muhlenbergia montana), black 

dropseed (Sporobolus interruptus), and sedge (Carex

spp.) were the main grass and grasslike plants on the 

watersheds. Among the common forbs were showy 

goldeneye (Heliomeris multiflora), Cuman ragweed (Ambrosia psilostachya), Wright’s deervetch 

(Lotus wrightii), Cooley’s bundleflower (Desmanthus 

cooleyi), yellow sweetclover (Melilotus officinalis), 

trailing fleabane (Erigeron flagellaris), and western yarrow (Achillea millefolium var. occidentalis). 

Broom snakeweed (Gutierrezia sarothrae), the shrubform of Gambel oak; New Mexican locust (Robinia 

neomexicana); Mexican cliffrose (Purshia mexicana); 

and Fendler’s ceanothus (Ceanothus fendleri) were 

among the scattered half-shrubs and shrubs. The 

Stermer Ridge watersheds provided food resources 

and protective cover for a variety of wildlife species, 

including indigenous ungulates, small mammals, and 

birds.

Watersheds A and B are characterized by flat topographies with few slopes that exceed 10 percent. 

Elevations range from 6800 to 7000 ft. Soils derived from cretaceous materials lying beneath the 

Figure 2—The Stermer Ridge 

watersheds are located at the 

headwaters of the Little Colorado 

River on the Apache-Sitgreaves 

National Forest near Heber, 

Arizona.
USDA Forest Service RMRS-RP-85. 2011. 3

watersheds are classified in the McVickers series with 

sandy loam surface textures. According to Hendricks 

(1985), the soils in this series are moderately deep to 

deep and are well drained. They have a high available water capacity, a slow permeability, and a high 

shrink-swell potential; and are susceptible to slight to 

moderate erosion rates. The watersheds normally receive in excess of 20 inches of precipitation annually. 

Nearly 65 percent of this precipitation occurs from 

October to April, much of it as snow or low-intensity, long-duration winter rains (fig. 3). The remaining 

precipitation falls in mostly high-intensity, shortduration summer rainstorms from early July through 

the middle of September. However, a drought was 

impacting the watersheds and, more generally, the 

Southwestern Region before the onset of the RodeoChediski Wildfire and continued to prevail throughout 

the study period. Annual precipitation on the Stermer 

Ridge watersheds during this drought was less than 80 

percent of the normally expected precipitation. Nearly 

75 percent of the volume of the pre-fire intermittent 

stormflows from the Stermer Ridge watersheds occurred as a result of snowmelt-runoff events or winter 

rains, while the summer rains generated the highest 

peak stormflows.

A classification system that relates fire severity to the soil-resource response of burning (DeBano 

and others 1998; Hungerford 1996; Ice and others 

2004) was the basis for assessing fire severity at the 

primary sampling plots on the watersheds (see the 

Study Protocols section) shortly after cessation of the 

wildfire. These classifications were extrapolated to a 

watershed basis (Neary and others 2005; Ryan and 

Noste 1985; Wells and others 1979) to determine the 

portions of the watersheds that were unburned or had 

burned with a low, moderate, or high severity fire. This 

extrapolation procedure indicated that Watershed A 

had experienced a high severity (stand-replacing) fire, 

while Watershed B was exposed to only a low severity 

(stand-modifying) fire. A road between the two watersheds that was maintained by the U.S. Forest Service 

(FS-50) acted as a partial break by containing the high 

severity burn to only one of the watersheds.

Study Protocols

The Stermer Ridge watersheds were “moth-balled” in late 1977 after completion of the earlier studies (Ffolliott and Baker 1977). However, the control 

sections (3-ft H-flumes) on both watersheds that were 

used for monitoring stormflow events were left in 

place in anticipation of future needs. Following the 

Rodeo-Chediski Wildfire, the control sections were 

refurbished and re-instrumented with water-level recorders, and a weather station was re-established. A set 

of 30 sample plots were relocated that were originally 

installed on each of the watersheds in a systematic 

sampling scheme with multiple random starts (Shiue 

1960). These plots were used to obtain ecological and 

hydrologic information in the earlier studies (Ffolliott 

and Baker 1977). The sampling scheme combined random and systematic elements and, as such, allowed for 

computing measures of variation while ensuring that a 

representative sample was made of the area. The plots 

provided the primary sampling framework in evaluating the impacts of the wildfire on the ecosystem 

0

0.5

1

1.5

2

2.5

3

3.5

Average precipitation (inches)

1970-1990

1996-2007

Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sept. Oct. Nov. Dec.

Figure 3—Average monthly precipitation amounts in the vicinity of the Stermer Ridge watersheds before (1970 

to 1990) and during (1996 to 2007) the drought conditions that prevailed in the study. The data compiled 

for this figure were obtained from the Black Mesa Ranger Station, U.S. Forest Service—the nearest long-term 

weather station (approximately 7 miles) to the watersheds.
4 USDA Forest Service RMRS-RP-85. 2011.

resources, hydrologic functioning, and flammable fuels of the watersheds.

Ecosystem Resources

Tree Overstories

It was necessary to reconstruct the tree overstory 

structures on the Stermer Ridge watersheds before the 

Rodeo-Chediski Wildfire to form a basis for evaluating 

impacts of the fire on the overstories. Two approaches 

were taken to obtain these reconstructions. One approach consisted of tallying trees (both alive and killed 

outright by the fire) that were 6 inches and larger in 

dbh at the sample plots by point sampling techniques 

(Avery and Burkhart 2002) with a basal area factor 

of 25. The tallies included burned-out root cavities of 

trees consumed by the wildfire (fig. 4). The dbh of prefire trees that occupied those cavities was estimated 

from previously established relationships between dbh 

and stump diameters (Myers 1963). Diameters of the 

cavities were assumed to approximate the stump diameters of the pre-fire trees.

The second approach involved sequential interpretations of a series of computer-simulated stand-table 

projections from 1977, when the watersheds were retired from active use, to before the wildlfire occurred 

in 2002. The STAND simulator used in this effort 

(Ffolliott and others 1988) was a simplified version 

of the Timber Resource Analysis System (TRAS), a 

widely used computer program for estimating forest 

resources in the United States (Alig and others 1982; 

Larson and Goforth 1970).

Reconstructions obtained by point sampling techniques and reconstructions simulated by the simplified 

version of TRAS were similar in their tree distributions 

by dbh classes and had only insignificant discrepancies 

(Ffolliott and others 2008). Therefore, the average of 

the tree distributions obtained by the two reconstructions was selected to represent the structures of the 

pre-fire tree overstories. The reconstructed overstory 

structures were summarized in terms of the number of 

trees per acre by 2-inch dbh classes (that is, the 6-inch 

dbh class included trees 5.0 to 6.9 inches, the 8-inch 

dbh class included trees 7.0 to 8.9 inches in dbh, and 

so forth), and were then grouped into two size classes 

for analysis purposes. The size classes coincided with 

the categories specified by Smith and others (2004) for 

poles (at least 6 inches in dbh but smaller than sawtimber) and sawtimber (12 inches in dbh and larger). 

Sawtimber trees were further classified into small 

sawtimber (up to 18 inches in dbh) and large sawtimber (20 inches in dbh and larger). Small and large 

sawtimber trees are often tallied separately in timber 

inventories and in other mensurational studies in the 

Southwestern Region because of their different forms.

Trees that initially survived the wildfire were classified by crown damage in four categories:

• No crown damage.

• Less than one-third of the crown scorched.

• Between one-third and two-thirds of the crown 

scorched.

• More than two-thirds of the crown scorched.

Similar criteria have been used in classifying fire 

damage and to predict post-fire mortality of southwestern ponderosa pine trees by Dieterich (1979), 

Herman (1954), and McHugh and Kolb (2003), and 

in other studies reviewed by Fowler and Sieg (2004). 

Annual observations of the subsequent mortality of 

the fire-damaged trees were made from 2002 through 

2006. However, the estimates of mortality in 2006 

were confounded because of the salvage cutting and 

fuel reduction treatments that were initiated on the watershed that was burned by a high severity fire.

Stocking of Ponderosa Pine Seedlings

Ponderosa pine seedlings (trees less than 1inch in 

dbh) were tallied on 30 mil-acre plots superimposed 

on the primary sample plots to determine the impact 

of the wildfire on stocking of this reproduction. A 

plot was classified as stocked if (at least) one seedling 

was tallied. Otherwise, the plot was considered as not 

stocked. The stocking of ponderosa pine seedlings was 

recorded shortly after the wildfire was extinguished 

and then again in 2004 and 2006, two and four years 

after the burn, to assess the longer-term post-fire stocking conditions on the watersheds.

Species Compositions and Production of 

Herbaceous Plants and Shrubs

Species were noted, and production (above-ground 

biomass) of the herbaceous plants (grasses and forbs 

combined), grass and forb components (considered individually) of the herbage, and shrubs in the 

understories of the Stermer Ridge watersheds was 

estimated on 9.6-ft2 plots centered over the primary 

sample plots. Estimates of production were obtained 

by applying the double-sampling method outlined 

originally by Pechanec and Pickford (1937) and later by Cook and Stubbendieck (1986), Holechek and 

others (2004), and Shoop and McIlvain (1963). Field 

estimates of green weights of the plants were made in 

late spring and early fall to reflect the production of 

Figure 4—Burned-out root cavities of trees consumed 

by the Rodeo-Chediski Wildfire on the Stermer Ridge 

watershed that was burned by a high severity fire. 

(Photo by Peter F. Ffolliott).
USDA Forest Service RMRS-RP-85. 2011. 5

early-growing (cool-season) and late-growing (warmseason) plants, respectively. Growth of early-growing 

plants is responsive largely to winter precipitation and 

the consequent soil moisture conditions, while the 

growth of late-growing plants is related mostly to summer rainstorms (McPherson 1992, 1997). Estimates of 

herbage production were obtained initially in the fall 

of 2002, after the wildfire had been extinguished, and 

continued through the spring of 2007. Samples of the 

plants tallied were collected on 15 temporary 9.6-ft2

plots located adjacent to a sub-sample of the primary 

sample plots at the time that production estimates were 

made to develop the correction factors necessary to 

convert the field estimates of green weights to actual 

(oven-dried) weights.

Frequency distributions of the estimated production of the herbaceous plants and grass and forb 

components of the herbage were mostly non-normal 

according to Shapiro-Wilk tests of normality (Yazici 

and Yolacan 2007). Transformations of the data sets 

failed to normalize the non-normal frequency distributions. Occurrences of statistical differences in the 

production of the plant groups sampled, therefore, 

were evaluated by distribution-free non-parametric 

tests. Applications of these non-parametric tests are 

independent of the structure of the frequency distributions involved. The non-parametric tests applied in 

this study are analogues to corresponding parametric 

methods of data analyses (table 1). Details of the tests 

and their interpretations are outlined in Zar (1999) and 

other references on non-parametric methods of statistical analysis.

Separate analyses were conducted to determine 

whether there were statistical differences in the postfire production of the herbaceous plants combined and 

grass and forb components of herbage on the Stermer 

Ridge watersheds. These analyses were conducted 

by applying Mann-Witney tests for each season that 

the production estimates were obtained. This test was 

deemed appropriate because the representative data 

sets obtained on the two watersheds were considered 

to be independent of each other. Differences between 

the production of early-growing and late-growing 

herbaceous plants, grasses, and forbs on each of the 

watersheds were evaluated by using the Wilcoxonpaired-sample test in each year of the study that the 

production of both the early-growing and late-growing plant groups were estimated on the watersheds (in 

2003, 2004, 2005, and 2006). This test was considered 

appropriate for this purpose because the production of 

early-growing plants was not totally independent of the 

production of late-growing plants. Some of the plant 

species that were sampled initiated their growth in early spring and then continued to grow into late summer 

or early fall and, as a consequence, were included in 

both seasonal estimates of production. Nemenyi tests 

were used to determine whether statistical differences 

occurred in the production of early-growing plants 

for each season that the production of the plants was 

estimated. This test was also applied in analyzing differences in the production of late-growing plants when 

the production was estimated.

All tests of statistical differences in the production 

of the plant groups were evaluated at a 0.10 significance level. However, because the grass and forb 

components of the herbage were nested within the 

overall tests of all herbaceous plants combined, the individual tests of those two components were evaluated 

separately at a 0.05 level of significance to maintain 

the overall 0.10 level of significance in accordance 

with a Bonferroni adjustment.

Differences in the production of shrub species 

on the Stermer Ridge watersheds were not analyzed 

analytically because of the limited frequencies of 

occurrence and low levels of production of the plants 

that only occurred in the latter stages of the study.

Utilization of Forage Plants

Utilization of forage plants, that is, the herbaceous plants and shrubs that provide food for grazing 

livestock and indigenous ungulates, was estimated 

ocularly (Cook and Stubbendieck 1986; Holechek 

and others 2004) on the 9.6-ft2 plots at the time that 

the plant production was estimated. No differentiation 

was made among the kinds of herbivores that consumed the forage.

Indigenous Ungulates and Small Mammals

Use of the post-fire habitats on the Stermer Ridge 

watersheds by elk (Cervus elaphus) and mule deer 

(Odocoileus hemionus) was estimated by counting 

the accumulations of their fecal pellet groups in the 

0.01-acre plots centered over the primary sample 

plots. Pellet group counts had also been used to estimate population numbers of these ungulates in 

earlier studies (Clary and Larson 1971; Eberhardt 

and White 1979; Larson and others 1986; Neff 

1968, 1972; Rowland and others 1984; Smith 1968). 

However, problems in obtaining reliable estimates of 

population numbers using this technique have been 

pointed out by Braun (2005), Collins and Urness 

(1979), Davis (1982), Neff (1968), Rowland and others (1984), and others.

Table 1—Non-parametric tests used in this study and corresponding parametric methods of data analyses.

Sample Non-parametric test Parametric method

Two independent samples Mann-Witney test Two-sample t-test

Two dependent samples Wilcoxon-paired-sample test Paired-sample t-test

Multiple Comparison Nemenyi test Tukey test
6 USDA Forest Service RMRS-RP-85. 2011.

One reason that the counting pellet groups can lead 

to inaccuracies in estimating population numbers is 

that it is necessary to assume a constant defecation 

rate between the sexes and within age classes of the 

species in the population to be estimated. This assumption is not always valid. For example, seasonal 

diets of elk and mule deer often vary, with less moisture and digestible matter in winter foods than foods 

in summer, resulting in lower defecation rates in the 

winter. Furthermore, it is not always known whether 

a count of 10 pellet groups represents 10 elk or mule 

deer that defecated once or 1 elk or mule deer that 

defecated 10 times without validation information 

such as that obtained from a sub-sample of radiomarked animals. Because of these and other possible 

problems encountered with the use of this technique, 

the counts of elk and mule deer pellet groups obtained 

in this study were interpreted only as indices of presence (occurrence) of the ungulates on the watersheds.

Earlier depositions of elk and mule deer pellet 

groups were cleared from the 0.01-acre plots when 

the primary sample plots were re-located in the fall 

of 2002 because the time of their accumulation was 

unknown. Elk and mule deer pellet groups were then 

counted on, and cleared from, the plots beginning 

in the spring and fall of 2003 and continuing to the 

spring of 2007. Differentiating elk from mule deer 

pellet groups was not a problem in this study.

Counts of the elk and mule deer pellet groups obtained in this study fit negative binomial frequency 

distributions. This frequency distribution had been 

determined by other researchers to be appropriate 

in earlier studies involving elk and mule deer pellet 

group counts (Bowden and others 1969; McConnell 

and Smith 1970; Rowland and others 1984). Two parameters, m (the average frequency of pellet groups 

per plot) and k (a positive exponent that measures 

dispersion), characterize a negative binomial distribution. Procedures outlined by White and Bennetts 

(1996) and White and Eberhardt (1980) for analyzing 

the differences in count data fitting the negative binomial frequency distribution, such as the counts of elk 

and mule deer pellet groups in 

this study, were applied. It was 

assumed that the m and k values 

differed in the analyses because 

it was anticipated that the elk 

and mule deer use of the habitats on the two watersheds might 

also differ. Tests for statistical 

differences in the total counts 

of the pellet groups on each of 

the watersheds for a sampling 

period were evaluated at a 0.10 

level of significance.

Occurrences of cottontail 

(Sylvilagus auduboni) on the watersheds following the wildfire 

were estimated by counting the 

individual fecal pellets deposited on the 0.01-acre plots that 

were used to count the elk and 

mule deer pellet groups. This 

technique had been used in earlier studies (Cochran and Stains 

1961; Kundaeli and Reynolds 1972; and others) to 

obtain estimates of cottontail population numbers. 

However, the problems encountered in obtaining reliable estimates of population numbers for elk and 

mule deer from counts of fecal pellets also applied 

to the cottontail pellet counts. Similar to interpretations of the counts of elk and mule deer pellet groups, 

therefore, the cottontail pellet counts obtained in this 

study were also interpreted as indices of presence.

After earlier accumulations of individual pellets 

were cleared from the 0.01-acre plots when the primary sample plots were re-located, cottontail pellets 

were counted on and cleared from the plots from the 

spring and fall of 2003 through the spring of 2007. 

However, the few cottontail pellets that were eventually counted in the study precluded a statistical 

analysis of the data sets obtained.

Twigs of ponderosa pine trees clipped in feeding activities by Abert’s squirrel (Sciurus aberti), 

the common tree squirrel in southwestern ponderosa 

pine forests, were noted when found beneath trees 

that survived the Rodeo-Chediski Wildfire (fig. 5) 

at the time that elk, mule deer, and cottontail pellets 

were counted. The presence of the squirrel after the 

wildfire and its post-fire selection of feed trees, a key 

habitat component (Brown 1984; Ffolliott and Patton 

1978; States and others 1988), were then inputted 

from this information.

Birds

Birds sighted in five-minute observation-periods 

at each primary sample plot on the watersheds were 

tallied by species and numbers according to established procedures (Braun 2005; Davis 1982; Ralph 

and others 1995). These tallies began a few minutes 

after the observer arrived at a plot to minimize the effects of disturbances caused by the observer moving 

Figure 5—Twigs clipped in feeding by Abert’s squirrel (Sciurus aberti) 

beneath trees that survived the Rodeo-Chediski Wildfire on the 

Stermer Ridge Watershed B. (Photo by Peter F. Ffolliott)
USDA Forest Service RMRS-RP-85. 2011. 7

onto the plot. Fall sightings were initiated in 2002 

and continued in 2003, 2004, and 2005. Spring tallies were made from 2003 through 2007. All of the 

bird observations were obtained between 0800 and 

1130 on clear or partly cloudy days with minimal 

wind movement. Summaries of these tallies provided 

a snap-shot picture of the birds on the watersheds at 

the time of their observations.

Species richness, that is, the number of bird species sighted (MacArthur and MacArthur 1961), was 

determined for each of the observation periods. 

Knowledge of the species richness of birds was supplemented by obtaining a number that represented 

species diversity (Shannon and Weaver 1948). The 

number (H’) was calculated by:

S

H’ = - 3 pi ln (pi) i=1

The variable pi represents the proportion of the i

th

species in a population of birds composed of s species. 

Larger numbers represent higher species diversities. 

Evenness (E) of the species tallied, or how equally 

abundant were the species, was determined by:

E = H’/ln s

Larger values for species evenness were equated 

with higher diversity conditions. Values approaching 

1 represented the highest level of species diversity.

Hydrologic Functioning

Water-Repellent Soils

Water-repellent (hydrophobic) soils impact the infiltration process of the hydrologic cycle in a similar 

manner as a hardpan layer might. Infiltration of water 

into the soil can be inhibited and often completely impeded, with much of the precipitation that reaches the 

soil surface accelerating the magnitudes and velocities 

of the resulting overland flows of water (Brooks and 

others 2003; DeBano and others 1998; Erickson and 

White 2008; Neary and others 2005). One 

mechanism that causes the formation of 

water- repellent soils is the distillation of 

organic compounds in the litter layer on 

the soil surface in the combustion phase 

of a fire (DeBano 1981, 2003; Doerr and 

others 2000; Neary and others 2005). It 

was assumed that this mechanism caused 

the formation of water-repellent soils on 

the Stermer Ridge watersheds following 

the Rodeo-Chediski Wildfire.

Occurrence of water-repellent soils 

was determined at each primary sample 

plot on the two watersheds using the 

water-drop penetration method outlined 

by Letey and others (2000). The initial 

measurements of water repellency were 

obtained in the fall of 2002, and continued until measurable water-repellent 

soils ceased to exist on each watershed. 

Measurements of water repellency were 

made in the spring and fall throughout 

the study to reflect occurrences and levels of the repellency following the periods 

of snowmelt runoff and winter rains (combined) and 

summer rainstorms, respectively, and were then summarized accordingly. Litter and duff accumulations 

were cleared to expose mineral soil for each measurement. A drop of distilled water was placed on the soil 

surface, and the time for the water drop to penetrate 

the soil surface was recorded (fig. 6). This procedure 

was then repeated because the precise location of a 

water- repellent layer at the plot (if a layer existed) 

was not known. The longest duration of the two times 

measured for the water drop to penetrate into the soil 

was related to the following criteria of the National 

Wildfire Coordinating Group (Clark 2001) to determine the level of water repellency:

• No repellency.

• Slight repellency, less than 10 seconds.

• Moderate repellency, 10 to 40 seconds.

• Strong repellency, more than 40 seconds.

Transpiration and Infiltration

Transpiration was another component of the water budget that was altered by the Rodeo-Chediski 

Wildfire. To estimate the magnitude of this component, 

measurements of instantaneous transpiration rates 

were obtained by the sap flow method (Swanson 1994) 

shortly after the fire on three severely damaged and 

three undamaged ponderosa pine trees, 18 to 24 inches 

in dbh, on each of the watersheds.

The major impact of wildfire on water infiltration 

into the soil comes from the formation of water- repellent layers. Infiltration rates commonly decline from 

levels exceeding most peak rainfall intensities to zero. 

It was assumed that formation of water-repellent soils 

in the early years of the Stermer Ridge study inhibited 

Figure 6—Time for a drop of water (arrow) placed on the soil 

surface to penetrate into the soil was a measure of waterrepellent (hydrophobic) soils at a sample plot on Watershed 

A. (Photo by Cody L. Stropki)
8 USDA Forest Service RMRS-RP-85. 2011.

the infiltration rates on the watersheds, with most of 

the precipitation reaching the soil surface contributing 

to surface runoff, thereby increasing the flows of overland water and movement of soil particles. Infiltration 

of rainfall into the soil was not measured directly in the 

study, and only by proxy as water repellency.

Soil Movement

The cumulative impacts of the loss of protective 

vegetation, formation of water-repellent soils, and increase in overland flows of water following a wildfire 

often result in increased soil erosion and soil deposition on the hillslopes of a burned watershed (Brooks 

and others 2003; Chang 2006; DeBano and others 

1998; Neary and others 2005). Soil particles that are 

eroded from one site are either deposited downslope 

on another site or are transported into a stream channel 

to become sediment when water flows. The transport 

of soil particles and their eventual deposition within 

a watershed after a wildfire is linked closely to the 

matrix of severities within the fire perimeter and to 

the magnitudes, velocities, and timing of consequent 

overland flows of water. Though sediment accumulations in the stream channels were not measured in this 

study, measurements of post-fire soil erosion and soil 

deposition on the hillslopes of the watersheds were 

obtained.

Initial estimates of soil erosion were obtained 

on the Stermer Ridge watersheds shortly after the 

Rodeo-Chediski Wildfire occurred from the measurement of 23 soil pedestals on Watershed A and from 

18 soil pedestals on Watershed B. Three capped pins 

were subsequently placed around each of the primary sample plots on the watersheds to obtain more 

precise measurements of soil erosion and deposition. 

Two pins were placed 3 ft upslope and one pin 3 ft 

downslope of a plot. Once these pins were installed, 

seasonal measurements of soil loss beneath the cap of 

the pins (soil erosion) or soil accumulation on top of 

the cap (soil deposition) were made in the spring and 

fall to characterize post-fire soil movements following 

periods of snowmelt runoff, winter rains (combined), 

and summer rainfalls, respectively. On occasion, there 

was no measurable change in the soil surface beneath 

the cap. It was assumed in these cases that either the 

magnitudes of soil erosion and soil deposition in the 

time interval between the measurements equaled each 

other or, what was less likely, neither soil erosion nor 

deposition occurred in the measurement interval.

The capped pins were re-set flush to the soil surface 

after each measurement to facilitate the subsequent 

measurements. Measurements obtained from the three 

pins surrounding a plot were averaged to estimate soil 

movement at the plot. A bulk density value that was 

developed from a set of soil samples collected on unburned sites near the Stermer Ridge watersheds was 

applied in converting the measurements of soil erosion 

and deposition to tons per acre on a watershed basis.

Measurements of soil erosion and deposition obtained in the study were analyzed separately because 

they represented separate processes of soil movement 

on a hillslope. Interpretations of the results of ShapiroWilk tests of normality indicated that the frequency 

distributions for both soil erosion and deposition were 

mostly non-normal in structure. Transformations of 

the data sets did not normalize these distributions. As 

a consequence, two of the non-parametric tests used in 

analyzing the production of herbaceous plants (MannWhitney and Nemenyi) were also applied in analyzing 

the measurements of soil erosion and deposition in 

this study. A minimum number of 12 plots with measurable soil erosion and a minimum of 4 plots with 

measurable soil deposition in each of the measurement 

periods were selected arbitrarily as a requirement to 

conduct statistical analyses of the respective processes. Plots with no measurable change in soil movement 

were excluded from the analyses.

Occurrences of statistical differences in the measurements of soil erosion rates and soil deposition 

between the two Stermer Ridge watersheds were determined by the Mann-Whitney test for each season 

in the study that the minimum numbers of measurements of these processes were available. This test 

was considered appropriate because estimates of the 

respective processes on the two watersheds were independent of each other. Differences between the 

measurements of soil erosion in the spring and in the 

fall and differences between the measurements of soil 

deposition in the spring and in the fall, on each of the 

watersheds were also analyzed by the Mann-Witney 

test for each year that the required number of measurements had been made. Because the respective 

measurements were considered independent of each 

other, the Mann-Whitney test was deemed suitable for 

the evaluations. Differences in the soil erosion measurements obtained in the spring and differences in the 

soil erosion measurements obtained in the fall on each 

watershed were evaluated (separately) by the Nemenyi 

test when the required measurements were available. 

The respective differences in seasonal measurements 

of soil deposition were also analyzed by the Nemenyi 

test. All of the tests of differences in soil movement 

were evaluated at an α = 0.10 level of significance.

Peak Stormflows

Initial estimates of peak stormflows (ft3/sec) following the Rodeo-Chediski Wildfire were obtained from 

observed high-water marks in or above the H-flumes 

on the watersheds following the rainfall events that 

occurred before the control sections could be reinstrumented with water-level recorders. Following 

the re-instrumentation, the depths of stormflows that 

passed through the flumes were obtained on the water-stage recorders. All estimated and recorded depth 

measurements were converted to rates of peak stormflow through interpretations of the established rating 

curve for the flumes. Only measurements of peak 

stormflows from early April through late November 

were obtained in this study because of the limited 

accessibility to the Stermer Ridge watersheds in the 

winter months and because of a lack of electronic 

recorders. Loss of the winter stormflows was not considered to be critical to the study since these flows had 

been generally low in the past in the Southwest unless 
USDA Forest Service RMRS-RP-85. 2011. 9

a rare rain-on-snow event occurred. The highest peak 

stormflows originating on ponderosa pine watersheds 

of the Mogollon Rim are normally generated from 

high-intensity, short-duration summer rainfall events 

(Ffolliott and Baker 1977).

Water Quality Characteristics

Concentrations of sediment particles and dissolved 

nutrients are among the water quality characteristics 

of primary interest to hydrologists and watershed 

managers in the Southwestern Region. Unfortunately, 

it was not possible in this study to collect samples 

of stormflow water to measure those concentrations. 

The intermittent post-fire stormflows that originated 

on the watersheds generally occurred when people 

were not on-site, and collection basins for obtaining stormflow samples in the absence of people were 

not part of the instrumentation on the watersheds. 

However, samples of water flowing off of the larger 

area burned by the Rodeo-Chediski Wildfire were obtained intermittently by hydrologists and watershed 

managers further downstream to provide a general 

analysis of selected water quality constituents.

Loadings of Flammable Fuels

Knowledge of the impacts of the Rodeo-Chediski 

Wildfire on flammable fuels is helpful to managers in 

anticipating the frequency of occurrences, severities, 

and impacts of future wildfire events in southwestern ponderosa pine forests. However, the loadings 

of flammable fuels on the Stermer Ridge watersheds 

at the time of the wildfire were unknown. Therefore, 

estimates of those loadings were obtained from the 

information available from earlier studies on the 

watersheds (Ffolliott and Baker 1977; Ffolliott and 

others 1971). Loadings reported earlier in the literature provided an additional source of data (Harrington 

1986; Sackett 1979; Sackett and Haase 1996). New 

measurements made in this study made up the third 

source of fuel loadings data. Estimates of the pre-fire 

fractions of standing trees, downed woody materials, 

litter and duff accumulations, and herbaceous plants 

and shrubs were compared to post-fire estimates of 

those fractions to evaluate the impacts of the RodeoChediski Wildfire.

Standing Trees

Cubic-foot volumes of standing trees were tallied 

on the watersheds (Ffolliott and others 2008) and 

were converted to oven-dry weights by multiplying 

the volumes by the appropriate species-specific wood 

density values (Barger and Ffolliott 1964, 1965, 

1971) to estimate the loadings of this fraction. Prefire approximations of the fraction were based on 

the reconstructions of tree overstories structures before the wildfire (see the Tree Overstories section). 

Post-fire estimates of the fraction obtained one and 

three years after the fire were based on knowledge 

of the impacts of the Rodeo-Chediski Wildfire on 

the reconstructions. Loadings of this fraction were 

separated into live trees and dead trees because the 

higher moisture contents of living trees increase their 

ignition time and decrease their rates of burning relative to dead trees (DeBano and others 1998; Pyne 

and others 1996). Moist fuels either do not burn or 

burn slowly and at lower temperatures than dry fuels, 

while dry fuels tend to burn hot, more completely, 

and quickly. It was not possible to separate live trees 

from dead trees in estimating the pre-fire loadings 

of the fraction. However, the portion represented by 

dead trees was assumed to be negligible because the 

occurrence of dead trees (snags) in cutover southwestern ponderosa pine forests such as the pre-fire 

forests on the Stermer Ridge watersheds before the 

wildfire was generally insignificant (Ffolliott 1983a).

Downed Woody Materials

Loadings of downed woody materials consisting 

of the accumulations of stems, branches, and twigs 

on the forest floor before the wildfire were estimated by the value for this fraction reported earlier 

by Sackett (1979) and Sackett and Haase (1996). 

Measurements of downed woody materials included 

in this value were obtained on 14 sites in the vicinity 

of the Stermer Ridge watersheds. The post-fire loadings of this fraction on the Stermer Ridge watersheds 

were estimated by applying the planar-intersect procedure (Brown 1974; Brown and others 1982) at the 

plot. This procedure involved counting the intersections of stems, branches, and twigs on the forest floor 

with a vertical sampling frame that resembles a guillotine that is dropped through the accumulated fuels. 

The procedure has the same theoretical basis as the 

line-intersect method of sampling flammable fuels 

(Van Wagner 1968). Converting the counts obtained 

with the planar-intersect procedure to estimates of 

weight is outlined in the publications cited for this 

procedure. The standing trees killed outright by the 

fire or severely damaged by the burn that had fallen 

to the ground were included in the post-fire estimates 

of this fraction. Estimates of the downed woody materials were obtained in 2003 and 2005 to assess the 

impacts of the wildfire on the loadings of the fraction. An estimate of this fraction was also obtained 

after the salvage cutting and fuel reduction treatments were applied to Watershed A to evaluate the 

impacts of the treatments.

Litter and Duff Accumulations

Obtaining estimates of the pre-fire loadings of fine 

fuels consisting of litter and duff accumulations on the 

forest floor involved two steps. A derived ratio of annual 

litter fall (Davis and others 1968) to annual litter decomposition (Klemmedson and others 1985) was used 

in projecting the depths of litter and duff layers reported 

earlier by Ffolliott and others (1976) to estimates of 

corresponding depths at the time of the wildfire. These 

estimates of depths were then converted to estimates 

of weights by applying the appropriate density values 

(Ffolliott and others 1976) to represent the loadings of 
10 USDA Forest Service RMRS-RP-85. 2011.

this fraction. Post-fire estimates of the fraction were 

obtained in 2003 and 2005 by the planar-intersect procedure (Brown 1974; Brown and others 1982).

Herbaceous Plants and Shrubs

Production of herbaceous plants and shrubs reported in the earlier studies on the watersheds (Ffolliott 

and Baker 1977) represented the pre-fire estimates of 

this fine fuel fraction. Production estimates that were 

obtained at the lower end of the annual precipitation 

regimes encompassed in the earlier studies were selected as the bases for comparison with the post-fire 

estimates of the production of the plants obtained on 

the watersheds during the drought conditions that 

prevailed throughout this study. Because estimates of 

only the late-growing herbaceous plants and shrubs 

were available from the earlier studies, the estimates 

of the production of late-growing plants obtained in 

2003 and 2005 represented the post-fire loadings of 

this fraction.

Statistical analyses of differences in the estimated 

loadings of flammable fuels on the Stermer Ridge 

watersheds were not undertaken. The varying measurement methods and sampling procedures involved 

in estimating the pre- and post-fire loadings of the 

respective fractions precluded these analyses. Only 

general statements on the pre- and post-fire comparisons, therefore, have been made.

Impacts on Ecosystem 

Resources

Tree Overstories

Ponderosa Pine Trees

Nearly 50 percent of the ponderosa pine trees on Watershed A that were burned by high severity fire were killed outright by the wildfire (fig. 7A). 

There was higher mortality in the pole class than the 

sawtimber classes of trees, a common finding following wildfires in coniferous forests of the western 

United States (Arno 2000). Almost 55 percent of the 

[A] 

0

10

20

30

40

50

60

70

80

90

100

Poles

(6 in to 10 in)

Small sawtimber

(12 in to 18 in)

Large sawtimber

(20 in +)

All trees

Number of trees/acre

Pre-fire 

Post-fire 

[B] 

0

20

40

60

80

100

120

Number of trees/acre 

Pre-fire

Post-fire

Poles

(6 in to 10 in)

Small sawtimber

(12 in to 18 in)

Large sawtimber

(20 in +)

All trees

Figure 7—Initial mortality of the Rodeo-Chediski Wildfire on the overstories 

of ponderosa pine trees on the Stermer Ridge watersheds burned by (A) a 

high severity fire and (B) a low severity fire in terms of number of trees per 

acre. Scales of the Y-axis are unique for each graph.

poles suffered immediate mortality, 

while about 35 percent of the trees 

in the sawtimber classes were killed. 

All of the trees that survived the initial impact of the burn were severely 

damaged, with more than two-thirds 

of each tree’s crown scorched. 

Almost two-thirds of those trees died 

within two years. Continuing rates 

of tree mortality averaged nearly 5 

percent annually until the salvage 

cutting and fuel reduction treatments 

were implemented on the watershed.

Only 17 percent of the ponderosa pine trees on Watershed B were 

killed in the burn due low fire severity (fig. 7B). The pole class once 

again suffered the greatest mortality, while mortality in the sawtimber 

classes was less than 10 percent. Of 

the trees that survived the wildfire, 

70 percent were undamaged by the 

burn, and most of the remaining 

trees exhibited only limited crown 

damage. Less than 3 percent of the 

fire-damaged trees that survived the 

initial impact of the wildfire died by 

2004, with only minimal tree mortality observed thereafter. Post-fire 

mortality of trees on this watershed was similar to that reported by 

O’Brien (2002) for unburned southwestern ponderosa pine forests.

Impacts of the Rodeo-Chediski 

Wildfire in terms of basal area and 

volume losses of ponderosa pine 

trees have been reported in a more 

comprehensive paper on the effects 

of the wildfire on the tree overstories of the Stermer 

Ridge watershed by Ffolliott and others (2008) and, 

therefore, are not detailed here. Very briefly, however, almost 45 percent of both the basal area and 
USDA Forest Service RMRS-RP-85. 2011. 11

volume of the ponderosa pine trees on Watershed A 

were lost initially to the wildfire. The largest losses 

of basal area occurred in the large sawtimber class, 

while trees in the pole class suffered the largest 

volume losses. Basal area and volume losses of ponderosa pine trees on Watershed B were minimal.

Other Tree Species

Almost 90 percent of the Gambel oak trees on 

Watershed A suffered complete crown-kill as a result 

of the high severity fire. However, basal sprouting was 

observed around most of these trees within one year of 

the wildfire, indicating that many of the trees had not 

been root-killed by the burn. Nearly all of the Gambel 

oak trees on Watershed B survived the wildfire with 

little or no fire damage. While none were tallied by 

point sampling on either of the Stermer Ridge watersheds, the few alligator juniper trees observed on 

Watershed A were either killed by the wildfire or suffered severe crown damage. Only limited post-fire 

basal sprouting of alligator juniper occurred. Most of 

the alligator juniper on the Watershed B were not affected by the burn.

Other Studies on Impacts of Wildfire on Tree 

Overstories

Similar impacts of wildfire on tree overstories 

have been reported in coniferous forests of the western United States in general (Arno 2000) and, more 

specifically, other southwestern ponderosa pine forests 

(Campbell and others 1977; Dieterich 1979; Fowler 

and Sieg 2004; Harrington 1987; McHugh and Kolb 

2003; Pearson and others 1972). These studies collectively show that the effects of a wildfire on the 

tree overstories impacted are determined largely by 

the pre-fire stand structures of the burned forests and 

severity of the wildfire. Monitoring impacts of the 

Rodeo-Chediski Wildfire on the tree overstories of 

the Stermer Ridge watersheds represents one of the 

more continuous and longer-term evaluations of the 

post-fire impacts of wildfire on tree overstories in the 

Southwestern Region.

Stocking of Ponderosa 

Pine Seedlings

Impacts of Fire Severity

Only two of the 30 mil-acre plots on Watershed A 

were stocked with ponderosa pine seedlings that were 

alive before the wildfire in the fall of 2002, while no 

plots were stocked with seedlings that had germinated after the fire. This latter finding was not expected, 

however, because of the large number of newly germinated ponderosa pine seedlings that were observed on 

the watershed shortly after the wildfire. No plots were 

stocked with either pre- or post-fire seedlings in 2004 

or 2006, indicating that the post-fire environmental 

conditions on this watershed were (apparently) not 

conducive to the survival of ponderosa pine seedlings 

in the immediate aftermath of the burn.

Ponderosa pine seedlings that were presumed to be 

alive before the wildfire stocked one-half of the 30 milacre plots on Watershed B in the fall of 2002, although 

some of the plantlets had been scorched. However, the 

condition of the seedlings at that time indicated that 

many had also suffered from the prevailing drought 

conditions. It was not surprising, therefore, that only 

two of the plots were stocked with pre-fire seedlings 

in 2004 and none was stocked with seedlings in 2006. 

No plots were stocked at any time with ponderosa pine 

seedlings that had germinated after the wildfire.

Stocking of ponderosa pine seedlings after the 

Rodeo-Chediski Wildfire was insufficient in both 

number and distribution to maintain the forest at a 

stocking level necessary to ensure for future sustainability (Pearson 1950; Schmidt 1988; Schubert 1974; 

Tecle and Hamre 1989; and others) on either of the 

Stermer Ridge watersheds. The prolonged drought 

that prevailed at the time of the wildfire and thereafter 

also impacted obtaining and then sustaining post-fire 

natural reproduction. Moreover, natural reproduction 

of ponderosa pine in the Southwestern Region is episodic in nature (Pearson 1950; Schubert 1974), which 

must also be considered in the assessment of post-fire 

stocking conditions.

Other Studies on Impacts of Wildfire on Stocking of 

Ponderosa Pine Seedlings

Campbell and others (1977) found no ponderosa 

pine seedlings in their three-year evaluation of the impacts of a wildfire in a southwestern ponderosa pine 

forest. However, the impacts of that wildfire on natural reproduction were inclusive because there also was 

a lack of established seedlings on adjacent unburned 

sites. In comparing the stocking conditions of ponderosa pine seedlings on four sites that had burned 

within 20 years of each other near Flagstaff, Arizona, 

with an unburned area, Lowe and others (1978) reported that ponderosa pine seedlings were found on 

all of the burned sites. Peak tallies of these seedlings 

occurred within two years of a wildfire event and then 

leveled off but still remained higher than the stocking 

of seedlings on the unburned site. To place this finding into proper perspective, the annual precipitation 

amounts throughout the 20-year study period were 

above average.

Species Compositions of 

Herbaceous Plants and Shrubs

Among the herbaceous plants and shrubs affected 

by high severity fire on Watershed A was an assemblage 

of grasses dominated by squirreltail, muttongrass, blue 

grama, and mountain muhly. Other grasses of less 

common occurrence were prairie Junegrass, Arizona 

fescue, and black dropseed. Mullein (Verbascum thapsus), a short-lived biennial plant naturalized from 

Europe (Epple 1995; Sieg and others 2003), dominated 

the forb component of the herbaceous plants on both of 

the Stermer Ridge watersheds in the early years after 
12 USDA Forest Service RMRS-RP-85. 2011.

the wildfire (fig. 8). Cooley’s bundleflower, Cuman’s 

ragweed, and western yarrow replaced mullein in the 

latter years of the study. The limited occurrences of 

post-fire shrubs on the watersheds were mostly basal 

sprouts from the crown-killed Gambel oak trees with 

scattered Fendler’s ceanothus.

The post-fire composition of herbaceous plants 

and shrubs on Watershed B was similar to the pre-fire 

composition (Ffolliott and Baker 1977). The frequent 

occurrence of mullein in the early years of the study 

was the main exception.

Production of Herbaceous 

Plants and Shrubs

Production of herbaceous plants and the grass 

and forb components of the herbaceous plants are illustrated in this paper by bar graphs that show the 

respective production of these 

plant groups in the sampling 

periods (see figs. 9, 10, and 

11). Because the data sets that 

formed the basis for constructing the bar graphs were mostly 

non-normal in their frequency 

distributions, however, inferences relating to the apparent 

differences among the levels 

of production are not necessarily valid. Occurrences of 

statistical differences in production in the plant groups 

were determined through interpretations of the results that 

were obtained from the nonparametric tests applied in the 

study.

Herbaceous Plants

Production of herbaceous 

plants was generally greater throughout the study 

period on Watershed A than on Watershed B where 

fire severity was low (fig. 9). The only exception to 

this finding occurred in the fall of 2002, shortly after cessation of the wildfire, when the low levels of 

herbage production that were estimated on the two 

watersheds were similar. The situation was probably 

a consequence of the initial impacts of the wildfire. 

Infiltration of water into the soil at that time was inhibited by the formation of water-repellent soils on 

the two watersheds (Stropki and others 2005) that, 

in turn, limited the amount of soil moisture available 

for plant growth. Though not measured in this study, 

the possibility of accelerated losses of on-site nutrients in the initially high overland flows of water that 

occurred shortly after the wildfire (Garcia-Chevesich 

and others 2004) could have been another causal 

factor.

The greater production of herbaceous plants for 

most of the study period on Watershed A was attributed largely to the greater loss of the tree overstory 

on this watershed than on the other watershed. Earlier 

studies in southwestern ponderosa pine forests have 

shown that the production of herbaceous plants 

increases when densities of the competing tree overstory decrease (Bojorquez-Tapia and others 1990; 

Clary 1975; Ffolliott 1983b; and others). Burning 

intensities that consume the litter and large amounts 

of the duff layers can also result in increased herbage 

production in these forests (Clary and others 1968; 

Davis and others 1968). Such a fire occurred on the 

severely burned watershed.

Another reason for the post-fire pattern of production of the herbaceous plants on the severely 

burned watershed could be that a large pool of available nutrients was formed where large quantities of 

vegetation, litter, and duff were combusted by the 

fire. The trend of the post-fire production illustrated 

in fig. 9 agrees with the effects that one might anticipate from a flush of available nutrients following 

fire (Bond and van Wilgen 1996; DeBano and others 

1998; Whelan 1997). While production of the herbaceous plants in the fall of 2002 and the spring of 

2003 might not have been affected by a post-fire nutrient pulse, an increase in the production could be 

expected following the summer rains in 2003. Such 

an increase would likely be sustained for a couple of 

years and then would start to decline along with the 

nutrients made available by the wildfire. The increase 

in production of herbaceous plants on Watershed B 

was less because a smaller pool of nutrients was 

released.

Production of early-growing herbaceous plants 

was less each year than the production of lategrowing herbaceous plants on Watershed A, with 

the exception of 2005, when production of the 

two groups of plant was similar (fig. 9). However, 

comparisons of the differences in production of early-growing plants to the production of late-growing 

Figure 8—Mullein (Verbascum thapsus) was the main forb component of 

herbaceous plants on both of the Stermer Ridge watersheds in the early 

years following the wildfire. (Photo by Peter F. Ffolliott.)
USDA Forest Service RMRS-RP-85. 2011. 13

plants on Watershed B were inconsistent, with production of early-growing plants greater than that of 

late-growing plants in some years and vice versa in 

other years.

There were significant but inconsistent differences 

in the production of early-growing herbaceous plants 

on the two watersheds throughout the study (table 2). 

While there were significant differences in the production of late-growing plants on the watersheds, the 

differences were also inconsistent. The time of recovery since the Rodeo-Chediski Wildfire occurred and 

the seasonal precipitation amounts that affected the 

production of the respective plant groups were evaluated in attempting to explain these inconsistencies. 

However, the time since the wildfire occurred was 

not a significant contributing factor. But the production of the two plant groups was favorably related to 

the seasonal precipitation amounts on one of the two 

watersheds.

Production of early-growing and late-growing 

herbaceous plants was not related to the seasonal precipitation amounts on Watershed A. The more severe 

impacts of the Rodeo-Chediski Wildfire on ecosystem functioning of this watershed may have obscured 

any influence that seasonal precipitation might have 

had on the production of herbaceous plants. However, 

the production of both early-growing and late-growing plants on Watershed B related linearly to the 

amount of seasonal precipitation. On this watershed, 

the correlation coefficient between the production 

of early-growing plants and precipitation between 

October 15 and April 14 and the correlation coefficient between the production of late-growing plants 

and precipitation between April 15 and October 14 

were significant, similar in magnitude, and, therefore, combined. The resulting correlation coefficient 

(+0.748) indicated that 56 percent of the variation 

in the production of both early-growing and lategrowing herbaceous plants on Watershed B could be 

attributed to the precipitation amount that affected 

the production of herbaceous plants for that season.

Table 2—Differences in the production of early-growing herbaceous plants and in 

the production of late-growing herbaceous plants (considered separately) on the 

Stermer Ridge watersheds that were burned by a high severity fire and a low 

severity fire. Higher levels of production of herbaceous plants are indicated by 

the years to the left on the table with lower levels of production progressing to 

the right. Years not underscored by the same line are significantly different, while 

years underscored by the same line are not significantly different.

High severity fire

Early-growing herbage

Spring 2005 Spring 2004 Spring 2006 Spring 2007 Spring 2003

Late-growing herbage

Fall 2004 Fall 2005 Fall 2003 Fall 2006 Fall 2002

Low severity fire

Early-growing herbage

Spring 2005 Spring 2007 Spring 2006 Spring 2004 Spring 2003

Late-growing herbage

Fall 2005 Fall 2004 Fall 2006 Fall 2003 Fall 2002

Figure 9—Production of herbaceous plants on the Stermer Ridge watersheds after the 

Rodeo-Chediski Wildfire. Estimates of average production are shown in this figure.

0

100

200

250

300

350

400

450

Herbage production (lbs/acre)

High severity fire

Low severity fire

150

50

Fall

2002

Spring

2003

Fall

2003

Spring

2004

Fall

2004

Spring

2005

Fall

2005

Spring

2006

Fall

2006

Spring

2007
14 USDA Forest Service RMRS-RP-85. 2011.

Grasses

Grass production was also greater on Watershed 

A despite high severity fire, with the exception of 

the fall shortly after the wildfire when the levels of 

production were similar (fig. 10). The greater loss of 

the tree overstory, more complete consumption of the 

litter and duff layers, and (possibly) greater pool of 

available nutrients on this watershed were among the 

factors assumed to have contributed to the difference.

Production of early-growing grasses was less than 

the production of late-growing grasses on Watershed A 

throughout the study, with the exception of 2006 when 

the production of the two groups of grasses was similar 

(fig. 10). Production of early-growing grasses was also 

less than that of the late-growing grass for most of the 

study period on Watershed B. An exception to this finding occurred in 2005, when the levels of production for 

the respective grasses were similar for unknown reasons.

Production of early-growing grasses on Watershed 

A in 2003 was significantly lower from the production 

of early-growing grasses in the other years of the study 

for unknown reasons (table 3). There also were significant differences in the production of late-growing 

plants on this watershed, but the pattern of production of these plants was inconsistent. Production of 

early-growing grasses on Watershed B differed inconsistently, while the production of late-growing grasses 

was similar throughout the study. The time since the 

wildfire was not a factor in that contributed to those 

differences. However, the seasonal amount of precipitation that regulated the production of the two groups 

of grasses was a significant factor on Watershed B.

There was no relationship between either the production of early-growing grasses or the production 

of late-growing grasses and the seasonal precipitation amounts on Watershed A. But the production of 

early-growing and late-growing grasses was related 

linearly to the amount of seasonal precipitation associated with their production levels on Watershed B. The 

correlation coefficient between the production of the 

early-growing grasses and precipitation amounts for 

October 15 to April 14 and the correlation coefficient 

between the production of the late-growing grasses 

and precipitation between April 15 and October 14 

Table 3—Differences in the production of early-growing grasses and in the 

production of late-growing grasses (considered separately) on the Stermer 

Ridge watersheds that were burned by a high severity fire and a low severity 

fire. Higher levels of production of grasses are indicated by the years to the left 

on the table with lower levels of production progressing to the right. Years not 

underscored by the same line are significantly different, while years underscored 

by the same line are not significantly different.

High severity fire

Early-growing grasses

Spring 2005 Spring 2004 Spring 2006 Spring 2007 Spring 2003

Late-growing grasses

Fall 2005 Fall 2004 Fall 2006 Fall 2003 Fall 2002

Low severity fire

Early-growing grasses

Spring 2005 Spring 2007 Spring 2006 Spring 2004 Spring 2003

Late-growing grasses

Fall 2005 Fall 2006 Fall 2004 Fall 2003 Fall 2002

0

50

100

150

200

250

Grass production (lbs/acre)

High severity fire

Low severity fire

Fall

2002

Spring

2003

Fall

2003

Spring

2004

Fall

2004

Spring

2005

Fall

2005

Spring

2006

Fall

2006

Spring

2007

Figure 10—Production of the grass component of herbaceous plants on the Stermer Ridge 

watersheds after the Rodeo-Chediski Wildfire. Estimates of average production are shown 

in this figure.
USDA Forest Service RMRS-RP-85. 2011. 15

were significant, similar, and combined. The resulting 

correlation coefficient (+0.686) indicated that 47 percent of the variation in the production of grasses could 

be attributed to the amount of precipitation that influenced grass growth in that season.

Forbs

Production of forbs was consistently higher throughout the study on Watershed A than on Watershed B 

(fig. 11). The greater reduction of the tree overstory, 

more complete consumption of the litter and duff layers, and availability of nutrients on Watershed A were 

again the probable reasons for this finding.

Production of early-growing forbs was less than the 

production of late-growing forbs throughout the study 

on Watershed A, with the exception of 2005 when 

the two levels of production were similar (fig. 11). 

However, the differences in production of the two 

groups of forbs on Watershed B were inconsistent, 

with similar levels of production in 2003 and 2006 but 

different levels of production in 2004 and 2005.

Differences in the production of early-growing 

forbs were insignificant on both of the watersheds 

throughout the study period. However, the production of late-growing forbs differed significantly but 

inconsistently on the two watersheds (table 4). The 

time since the wildfire occurred was not related to 

the production of the two groups of forbs. Seasonal 

precipitation amounts were related to the level of production of the two groups on one of the watersheds but 

not on the other.

Neither the production of early-growing nor lategrowing forbs on Watershed A was correlated with the 

influencing seasonal precipitation amounts. However, 

the production of these forb groups was related linearly to the amount of seasonal precipitation linked to 

their production on Watershed B. The correlation coefficient between production of the early-growing forbs 

and seasonal precipitation amounts and the correlation 

coefficient between production of the late-growing 

forbs and seasonal precipitation were significant, similar, and combined. The resulting correlation coefficient 

(+0.693) indicated that 48 percent of the variation in 

the production of forbs was attributed to seasonal precipitation. This amount of accountable variation was 

similar to the amount associated with the production 

of grasses and seasonal precipitation.

Table 4—Differences in the production of early-growing forbs and the production 

of late-growing forbs (considered separately) on the Stermer Ridge watersheds 

that were burned by a high severity fire and a low severity fire. Higher levels of 

production of forbs are indicated by the years to the left on the table with lower 

levels of production progressing to the right. Years not underscored by the same 

line are significantly different, while years underscored by the same line are not 

significantly different.

High severity fire

Early-growing forbs

Spring 2005 Spring 2004 Spring 2007 Spring 2006 Spring 2003

Late-growing forbs

Fall 2003 Fall 2004 Fall 2005 Fall 2006 Fall 2002

Low severity fire

Early-growing forbs

Spring 2005 Spring 2004 Spring 2007 Spring 2006 Spring 2003

Late-growing forbs

Fall 2004 Fall 2005 Fall 2006 Fall 2003 Fall 2002

Figure 11—Production of the forb component of herbaceous plants on the Stermer Ridge 

watersheds after the Rodeo-Chediski Wildfire. Estimates of average production are shown 

in this figure.

0

50

100

150

200

250

Forb production (lbs/acre)

High severity fire

Low severity fire

Fall

2002

Spring

2003

Fall

2003

Spring

2004

Fall

2004

Spring

2005

Fall

2005

Spring

2006

Fall

2006

Spring

2007
16 USDA Forest Service RMRS-RP-85. 2011.

Mullein

Mullein often establishes itself on a site in southwestern ponderosa pine forests following a fire (Epple 

1995; Ffolliott and others 1977; Sackett and others 

1994; Sieg and others 2003). This was also the case on 

the Stermer Ridge watersheds following the RodeoChediski Wildfire. This early-seral species was found 

on 25 percent of the 9.6-ft2 plots and contributed nearly 50 percent to the production of the forb component 

at its peak establishment on Watershed A in the fall 

of 2004 (fig. 12A). Mullein occurred on 10 percent of 

the plots and represented about 40 percent of the comparatively lower level of forb production at its peak on 

Watershed B in the following spring (fig. 12B). The 

early dominance of the plant declined on both of the 

watersheds thereafter.

Mullein has been reported to be a major component 

of the early production of herbaceous plants in other 

studies on the effects of wildfire in southwestern ponderosa pine forests (Davis and others 1968; Ffolliott 

and others 1977; Sackett and others 1994). The plant 

rarely becomes overly aggressive, however, because 

bare soil is required for its seeds to germinate (Sackett 

and others 1994; Sieg and others 2003). Mullein is 

intolerant of the shade from competing herbaceous 

plants. It was expected, therefore, that the species 

would decline in its occurrence and level of production after peaking on the Stermer Ridge watersheds 

following the Rodeo-Chediski Wildfire as the amount 

of bare ground and availability of light decreased and 

other herbaceous species recovered from the burn.

Shrubs

The infrequent post-fire occurrence of shrubs on 

Watershed A contributed little to the production of 

understory plants (less than 10 lbs/acre), and this limited amount of production occurred in only the spring 

and fall of 2006 and the spring of 2007. Basal sprouts 

of crown-killed Gambel oak trees comprised most 

of this understory component. Only a trace of shrub 

Spring

2007

Fall

2006

Spring

2006

Fall

2005

Spring

2005

Fall

2004

Spring

2004

Fall

2003

Spring

2003

Fall

2002

Spring

2007

Fall

2006

Spring

2006

Fall

2005

Spring

2005

Fall

2004

Spring

2004

Fall

2003

Spring

2003

[A] 

0

20

40

60

80

100

120

140

160

180

200

220

240

Fall

2002

Production (lbs/acre)

Non-mullein forbs

Mullein

[B] 

0

20

40

60

80

100

120

Production (lbs/acre)

Non-mullein forbs

Mullein

Figure 12—Proportions of the forb component of herbage represented by mullein (Verbascum 

thapsus) on the Stermer Ridge watersheds burned by (A) a high severity fire and (B) a low 

severity fire. Scales of the Y-axis are unique for each graph.
USDA Forest Service RMRS-RP-85. 2011. 17

production occurred on Watershed B even though 

it was burned by a low severity fire. Otherwise, the 

shrub production was insignificant on this watershed 

throughout the study period.

Other Studies on Impacts of Wildfire on Species 

Compositions and Production of Herbaceous Plants 

and Shrubs

Impacts of wildfire on herbaceous plants and 

shrubs in the coniferous forests of the western United 

States have been reported generally by Arno (2000) 

and, more specifically, in southwestern ponderosa 

pine forests by Campbell and others (1977), Lowe 

and others (1978), Oswald and Covington (1983), 

Pearson and others (1972), and others. In reference 

to the impacts of fire on species compositions, a shift 

from a largely mullein composition in the initial years 

following fire to other herbaceous species as post-fire 

time progresses has also been found in other studies in 

southwestern ponderosa pine forests (Davis and others 1968; Ffolliott and others 1977). Results also show 

that compositions of herbaceous plants and shrubs remain mostly unchanged after mullein declines in its 

post-fire occurrence.

In a study similar to that on the Stermer Ridge 

watersheds following the Rodeo-Chediski Wildfire, 

Campbell and others (1977) estimated the production 

of late-growing herbaceous plants and shrubs on three 

watersheds in north-central Arizona that had been (respectively) severely burned, moderately burned, and 

unburned by a wildfire. The basis for classifying the 

fire severity of the watersheds was not specified by 

Campbell and others (1977), but it was not the classification system of Hungerford (1996) that evolved 

later. The researchers found that the levels of plant 

production on the three watersheds six months after 

the wildfire were not different—a finding not unlike 

that obtained on the Stermer Ridge watersheds in the 

fall of 2002 shortly after the Rodeo-Chediski Wildfire. 

However, the production of herbaceous plants 

and shrubs on the moderately and severely burned 

watersheds increased nearly three-fold 30 months later 

in comparison to that estimated on the unburned watershed. Similar results of increased herbage production 

were also observed on the Stermer Ridge watersheds 

following the Rodeo-Chediski Wildfire, with the largest increases in herbage production on Watershed A.

Utilization of Forage Plants

Only limited amounts of forage plants were utilized by herbivores in the study period. Cattle had 

been removed by local ranchers from the Stermer 

Ridge watersheds and, more generally, from the larger 

area burned by the Rodeo-Chediski Wildfire when the 

magnitude of the fire became evident. A small (but unknown) number of cattle were allowed back onto the 

watersheds and nearby vicinity in the summer of 2005. 

Utilization of forage by the indigenous ungulates was 

variable throughout the study. The overall utilization 

of forage species by all of the herbivores averaged 3 

percent annually on a watershed basis.

Indigenous Ungulates and 

Small Mammals

Information on the elk and mule deer populations 

in the Stermer Ridge watersheds before the RodeoChediski Wildfire was incomplete. It was known, 

however, that an “exceptionally large” elk population 

inhabited the general area before the wildfire, while 

the mule deer population was below the “long-term 

norm” for the area (U.S. Forest Service 2002). Whether 

these two populations of indigenous ungulates were 

expanding, declining, or stable was unknown. Little 

was known about the small mammal populations on 

the watersheds.

Elk

The initial disruptive impact of the Rodeo-Chediski 

Wildfire was the assumed cause of the limited and 

similar presence of elk on the two Stermer Ridge watersheds in the fall of 2002 (fig. 13). However, in the 

Spring

2007

Fall

2006

Spring

2006

Fall

2005

Spring

2005

Fall

2004

Spring

2004

Fall

2003

Spring

2003

Fall

2002

0

10

20

30

40

50

60

Elk pellet groups (number)

High severity fire

Low severity fire Figure 13—Presence 

of elk (Cervus 

elaphus) on the 

Stermer Ridge 

watersheds 

after the RodeoChediski Wildfire, 

as indicated by 

indicated by pellet 

group counts. Total 

pellet group counts 

in the respective 

sampling periods 

on the watersheds 

are shown in this 

figure.
18 USDA Forest Service RMRS-RP-85. 2011.

spring of 2004, the occurrence of elk on Watershed 

A increased significantly in relation to the occurrence 

observed on Watershed B. This difference continued 

through the following spring, after which the post-fire 

presence of elk on the two watersheds was similar to 

the end of the study.

It was assumed that the increase in the production of forage plants preferred by elk (Clary and 

Larson 1971; Kufeld 1973; Thill and others 1983) on 

Watershed A in the middle years of the study contributed to the comparatively high presence of elk on the 

watershed at that time. Included among the preferred 

forage plants were muttongrass, squirreltail, Cooley’s 

bundleflower, and Fender’s ceanothus. Availability of 

the protective cover provided by standing trees at that 

time was possibly a secondary factor of importance. 

While the production of the preferred forage plants 

was sustained at a relatively high level to the end of 

the study, the cover of standing trees killed outright 

or severely damaged by the Rodeo-Chediski Wildfire 

started to decline by the summer of 2005 when those 

trees started falling to the ground. The loss of standing 

trees increased further into 2006 when the salvage cutting and fuel reduction treatments were implemented. 

Disturbances caused by the activities associated with 

post-fire interventions such as the felling, skidding, 

and piling of the larger trees might have also contributed to the declining presence of elk on this watershed.

The lower occurrences of elk on Watershed B remained largely unchanged throughout most of the 

study (fig. 13). Availability of preferred forage species 

and protective cover on this watershed was impacted less by the wildfire. Also, salvage cutting and 

fuel reduction treatments were not imposed on this 

watershed.

Elk populations in northern Arizona generally 

migrate from their summer habitats in the higher 

mountains to winter habitats at the lower elevations. 

However, because of the low snow accumulations 

and above-average temperatures in the winters of 

the study, many elk remained on or near the Stermer 

Ridge watersheds throughout the year, as indicated by 

the seasonal pellet group counts.

Mule Deer

The presence of mule deer on the two Stermer 

Ridge watersheds was less than the elk presence 

throughout the study. Whether the lower occurrences 

were a reflection of the small mule deer population in 

the area before the wildfire or a consequence of the 

burn lowering the habitat qualities for the ungulate on 

the watersheds is unknown. Within the perspective of 

their lower occurrence on the Stermer Ridge watersheds, the presence of mule deer in the fall of 2004 

and spring of 2005 on Watershed A was greater than 

the occurrences on Watershed B (fig. 14). It should be 

noted that no mule deer pellet groups were counted on 

Watershed B in the fall of 2004, the fall of 2005, and 

the spring of 2007.

The greater 

presence of mule 

deer in the fall 

of 2004 and the 

spring of 2005 on 

Watershed A was 

attributed largely 

to the relatively 

short-term increases in production of 

the browse species 

preferred by mule 

deer (Clary and 

Larson 1971; Neff 

1974; Severson 

1981; Thill and 

others 1983) during those times 

compared to the 

decreased production of the species 

in other sampling 

periods. The basal sprouts that originated from crownkilled Gambel oak trees in the later stages of this study 

were the only browse of significance on either of the 

watersheds after the wildfire. The protective cover of 

the standing trees had little apparent impact on the 

movements of mule deer.

Mule deer populations also remained in the general 

area of the Stermer Ridge watersheds throughout most 

of the study period, as suggested by the seasonal pellet group counts. The limited snow accumulations and 

above average temperatures apparently precluded the 

need for mule deer to move to habitats at lower elevations in the winter.

Small Mammals

It was assumed that most of the cottontail and 

Abert’s squirrels that inhabited the Stermer Ridge watersheds were unable to escape the Rodeo-Chediski 

Fall

2004

Fall

2003

Spring

2003

Fall

2002

Spring

2007

Fall

2006

Spring

2006

Fall

2005

Spring

2004

High severity fire

Low severity fire

0

1

2

3

4

5

6

7

8

9

10

Mule deer pellet groups (number)

Spring

2005

Figure 14—Presence of mule deer (Odocoileus hemionus) on the Stermer Ridge watersheds after 

the Rodeo-Chediski Wildfire, as indicated by pellet group counts. Total counts of pellet groups 

in the respective sampling periods on the watersheds are shown in this figure. (The scale of 

the Y-axis in this figure differs from the scale of the Y-axis in fig. 13 for elk.)
USDA Forest Service RMRS-RP-85. 2011. 19

Wildfire because of their small home ranges (Brown 

1984; Patton 1975b; U.S. Natural Resources 

Conservation Service 1999) and the extensive area of 

the burn. Therefore, the limited presence of cottontail 

in the area was expected. Insufficient food sources 

(U.S. Natural Resources Conservation Service 1999) 

and a lack of sufficient cover conditions (Costa and 

others 1976) for most of the study were the probable 

reasons for the low cottontail presence on either of the 

watersheds after the wildfire.

Abert’s squirrels were not observed throughout the 

study period on Watershed A due to the high severity fire. Most of the feed trees preferred by squirrel 

(Brown 1984; Ffolliott and Patton 1978; Keith 1965; 

Patton 1975a) had been killed by the wildfire or died 

shortly thereafter. As a consequence, this key habitat 

requirement was lost in the burn. However, following 

their initial displacement on Watershed B, scattered 

twig clippings indicated that the squirrel was feeding 

on this watershed two years after the wildfire. Many 

of the feed trees preferred by the squirrel had survived 

the burn and, therefore, were available to the returning 

small mammal.

Other Studies on Impacts of Wildfire on 

Mammalians

Impacts of wildfire on the ungulates and small 

mammals that inhabit southwestern ponderosa pine 

forests have long been a concern of wildlife managers 

in the Region. It is hoped, therefore, that the impacts of 

the Rodeo-Chediski Wildfire on these wildlife groups 

reported in this paper will contribute to the existing 

information already available on wildfire impacts on 

wildlife (Campbell and others 1977; Clary and Larson 

1971; Finch and others 1997; Kruse 1972; Kufeld 

1973; Lowe and others 1978; Thill and others 1983). 

This information should add to the database on the 

effects of wildfire on the mammalians inhabiting the 

coniferous forests of the western United States (Smith 

2000). The results obtained on the Stermer Ridge watersheds, combined with the conclusions from earlier 

studies, indicate that the impacts of a wildfire in these 

forests are usually greater on mammal habitats than 

on mammal mortality. Small mammals with limited 

mobility are most vulnerable to a wildfire, while mammals with comparatively large home ranges are more 

likely to survive a wildfire, responding negatively or 

positively to changes in habitat conditions depending 

on the severity, uniformity, and duration of the fire and 

the extent of the area burned. Changes in the availability of food and amount of protective cover for these 

animals were especially notable in the stand-replacing, high severity wildfire.

Birds

The number of species and total numbers of birds tallied on the Stermer Ridge watersheds after the wildfire 

were less than counts generally reported in unburned 

southwestern ponderosa pine forests (Brawn and others 1987; Hurteau and others 2008; Rosenstock 1996; 

Szaro and Balda 1979). The widespread impacts of the 

Rodeo-Chediski Wildfire, when coupled with the ongoing drought in the Southwestern Region, probably 

contributed to the limited numbers of birds sighted. 

Birds in the foliage-gleaning guild of species (Ehrlich 

and others 1988) declined in numbers because of the 

loss of food items such as invertebrates and fruit on 

the foliage and branches of trees killed by the wildfire 

(fig. 15). Birds whose nests are supported by trees also 

declined on the severely burned sites. However, birds 

that were nested in the cavities of standing dead trees 

benefited from the fire until the trees fell to the ground. 

Birds scavenging food from the ground surface were 

likely affected less by the wildfire.

Figure 15—Birds in 

the foliage-gleaning 

guild of species likely 

declined in numbers 

on severely burned 

sites on the Stermer 

Ridge watersheds 

because of the loss 

of food items such 

as invertebrates and 

fruit on the foliage 

and branches on trees 

killed by the wildfire. 

(Photo by Daniel G. 

Neary.)
20 USDA Forest Service RMRS-RP-85. 2011.

Impacts of Fire Severity

It was anticipated that the Rodeo-Chediski Wildfire 

might impact the species and numbers of birds tallied on Watershed A differently than on Watershed 

B. However, occurrences and summaries of bird species numbers on the two watersheds indicated that the 

wildfire effects were mostly insignificant or generally 

inconclusive, with a few exceptions (Sibley 2000). 

Fewer birds were sighted in the fall of 2002, shortly 

after cessation of the wildfire and during the following year, on Watershed A. The presumed cause was the 

devastating direct and indirect impacts of the wildfire. 

Following this initial shock produced by the wildfire, 

the differences in the birds tallied on the two watersheds were inconsistent with little meaningful trend.

Species and Numbers of Birds Tallied

Of the 25 species tallied on the two watersheds 

(combined) in the fall observations, 12 of the species 

were sighted only once or twice in the study, compared 

to 10 of the 26 species observed in the spring that were 

tallied only once or twice. A few other bird species 

were observed in comparatively large numbers only 

once on either one or the other of the watersheds. The 

eight pine siskin (Carduelis pinus) individuals sighted 

in the fall of 2005 on Watershed A were the only observations of this species. The sole observation of a 

pygmy nuthatch (Sitta pygmaea) occurred in the fall 

of 2005 on Watershed B, when 18 birds were sighted. 

The 28 juniper titmouse (Baeolophus ridgwayi) sighted in the spring of 2007 on Watershed B were the only 

observations of this species throughout the study.

A few bird species were tallied in comparatively 

large numbers in only one of the observation periods, with fewer numbers sighted at least once on the 

watersheds at other times. A large number of hairy 

woodpecker (Picoides villosus) individuals was tallied in the spring of 2007 on Watershed A despite 

the high severity fire, while fewer were tallied on either watershed at any time either before or after the 

wildfire. Most of the large numbers of gray-headed 

junco (Junco hyemalis) observed in the study were 

tallied in the spring of 2005 on Watershed B. The grayheaded juncos were observed later in the fall of 2005 

on Watershed A. Bushtit (Psaltriparus minimus) was 

observed in the fall of 2002 on both of the Stermer 

Ridge watersheds following the wildfire and the following spring. The 20 bushtit sightings on Watershed 

B represented the largest tally of the species in one 

observation period. However, this species was not tallied on either of the watersheds for the remainder of 

the study period.

Seasonal Patterns

Comparisons of the seasonal patterns of species and 

numbers of birds were possible only in 2003, 2004, and 

2005, when tallies of birds were obtained in both the 

spring and fall. A greater number of species and birds 

were tallied in the fall than in the spring in each of 

those years, which possibly reflects the more abundant 

and diversified food supplies for birds in the summer 

months (as indicated by the fall tallies) than in the winter (signified by the spring sightings). Some species 

were tallied at least once in both the fall and spring, 

although there were a few exceptions when a species 

was sighted in only one of the two seasons. Pigmy 

nuthatch and yellow-rumped warbler (Dendroica coronata) were tallied in the fall but not the spring on 

both of the watersheds. Included in spring tallies but 

not the fall sightings were Grace’s warbler (Dendroica 

graciae), juniper titmouse, and violet-green swallow 

(Tachycineta thalassina). Increasing numbers of species and numbers of birds were sighted in both of the 

seasons as the Stermer Ridge watersheds began to recover from the impacts of the wildfire.

Species Richness, Diversity, and Evenness

Species richness of the birds that were sighted on 

the Stermer Ridge watersheds was similar in both the 

spring and fall observations, especially in the latter 

stages of the study. However, the number of bird species sighted ranged from a low of 3 to a high of 11 for 

the observation periods in the study, which was fewer 

than the 12 to 20 species reported by Szaro and Balda 

(1979) in their study of bird communities in unburned 

southwestern ponderosa pine forests. Species diversities were generally lower on Watershed A than on 

Watershed B, with the diversities tending to be lower 

in the fall than in the spring on both of the watersheds. 

The species diversities of birds on the Stermer Ridge 

watersheds were consistently less than the numbers 

found by Szaro and Balda (1979). Evenness of the 

bird species observed on the watersheds was variable 

throughout the study period.

More detailed information on the birds observed on 

the Stermer Ridge watersheds following the RodeoChediski Wildfire may be found in Ffolliott and others 

(2009). In that document are complete listings of the 

bird species observed in this study and their numbers 

tallied by species in the fall and spring observations on 

both of the watersheds. Comprehensive summaries of 

the post-fire species richness, diversities, and evenness 

of birds are also presented.

Other Studies on Impacts of Wildfire on Birds

Less is known about the impacts of wildfire on birds 

in southwestern ponderosa pine forests than about 

the effects of wildfire on avifauna in general (Smith 

2000), according to a literature review by Finch and 

others (1997) on the effects of fire, logging, and grazing on bird populations in the Southwestern Region. 

Interpretations of the results from the few studies 

cited by Finch and others on the impacts of wildfire 

on birds in southwestern ponderosa pine forests, including those by Aulenbach and O’Shea-Stone (1983), 

Blake (1982), Johnson and Wauer (1996), and Lowe 

and others (1978), were limited, however, because of 

methodological problems with the studies. Such limitations also occurred in this study of the Rodeo-Chediski 

Wildfire. For example, species and numbers of birds 

on the Stermer Ridge watersheds before the wildfire 
USDA Forest Service RMRS-RP-85. 2011. 21

were unknown, which limited a more comprehensive 

evaluation of the impacts of the burn on the species 

and numbers of birds tallied. Another limiting factor was that neither replication of the two watersheds 

studied nor unburned control sites for comparison purposes were available. Furthermore, because the two 

Stermer Ridge watersheds were relatively small in 

area, it was likely that some of the birds tallied in this 

study flew onto one or both of the watersheds from 

nearby burned sites of differing fire severities or from 

unburned areas. Therefore, the results presented in this 

paper should be interpreted within the context of such 

limitations.

Impacts on Hydrologic 

Functioning

Water-Repellent Soils

Impacts of Fire Severity

Water-repellent soils can occur at the soil surface as well as in the deeper layers of the soil 

mantle (DeBano and others 1998; Neary and others 2005). However, the water repellency found on 

the Stermer Ridge watersheds following the RodeoChediski Wildfire was confined mostly to the soil 

surface (Stropki and others 2005). More specifically, 

nearly two-thirds of the soils on Watershed A exhibited strong water repellency at the surface immediately 

after the fire, while moderate water repellency was 

found on one-third of the soils (fig. 16A). At the same 

time, strong water repellency was measured at the soil 

surface on approximately one-third of Watershed B, 

with 15 percent of the soils having moderate water repellency and almost one-half of the plots with slight or 

no water repellency (fig. 16B). The post-fire formation 

of water-repellent soils on both of the watersheds contributed to the record high peak stormflows generated 

[A] 

0

10

20

30

40

50

60

70

80

90

100

Area (percent)

Slight Moderate Strong None

[B] 

0

10

20

30

40

50

60

70

80

90

100

Area (percent)

Fall 2002 Spring 2003 Fall 2003 Spring 2004 Fall 2004 Spring 2005 Fall 2005 Spring 2006

Fall 2002 Spring 2003 Fall 2003 Spring 2004 Fall 2004 Spring 2005 Fall 2005 Spring 2006

Slight Moderate Strong None

Figure 16—Seasonal occurrences of the water-repellent soils on the Stermer Ridge watersheds 

that were burned by (A) a high severity fire and (B) a low severity fire. Levels of water repellency 

shown in this figure are based on criteria of the National Wildfire Coordinating Group (Clark 

2001).
22 USDA Forest Service RMRS-RP-85. 2011.

by summer rainstorms following the Rodeo-Chediski 

Wildfire (see the Peak Stormflows section).

Most of the water-repellent layers in soils had broken down on both of the Stermer Ridge watersheds 

within three years of the wildfire (fig. 16). Water repellency was observed three years post-fire on less than 

25 percent of Watershed A and only on 10 percent of 

Watershed B. The decline in the occurrence of waterrepellent soils on the two watersheds was attributed 

largely to the continuing downward erosion of the 

hydrophobic layer until it had eroded away. Repeated 

exposures of the soils to a cycle of wetting and drying 

events also led to a decrease in the degree of water 

repellency in the soils. Differences in the occurrences 

of water repellency on the two watersheds, the respective levels of the water repellency, and the patterns of 

decline in the water-repellent soils between the spring 

and fall seasons were inconsequential.

Other Studies on Impacts of Wildfire on WaterRepellent Soils

Campbell and others (1977) found that water-repellent soils on a severely burned watershed persisted 

for three years following a wildfire in a southwestern 

ponderosa pine forest, while occurrences of water repellency in the soils on a watershed that was burned 

by a fire of moderate severity was significantly less in 

this period. Elsewhere in the western United States, 

Huffman and others (2001) observed water- repellent 

soils for two years following a wildfire in a ponderosa 

pine forest on the Front Range of the Rocky Mountains 

of central Colorado. Dyrness (1976) reported a longer 

occurrence of water-repellent soils in the soils beneath 

a lodgepole pine (Pinus contorta) forest in the Cascade 

Mountains of Oregon, where post-fire hydrophobicity 

persisted for six years. While other researchers have 

also reported the occurrences of water-repellent soils 

after a wildfire (DeBano 2000; Neary and others 2005; 

Erickson and White 2008; National Research Council 

2008), only a few have indicated explicitly the duration of post-fire water repellency.

Transpiration and Infiltration

Impacts of Fire Severity

Instantaneous transpiration rates were obtained 

shortly after the fire on three severely damaged and 

three undamaged ponderosa pine trees, 18 to 24 inches in dbh, on each of the watersheds. While sap flow 

was detected in all of the trees, the few repeated measurements (two measurements for each tree sampled) 

were insufficient to differentiate with confidence the 

fire-related transpiration losses on the two watersheds. 

Nevertheless, it was concluded that the loss of water by 

the transpiration processes was reduced (to unknown 

levels) on both of the watersheds, with comparatively 

higher losses on Watershed A because of the greater 

mortality of trees.

Infiltration of water into the soil was not directly 

measured in the study. Formation of water-repellent 

soils in the early years of the study inhibited the infiltration rates on the watersheds, with much of the 

precipitation that reached the soil surface contributing to increased overland flows. This phenomenon 

was more pronounced on Watershed A because of the 

more extensive formation of strong water repellency. 

Water-repellent soils persisted for three years on the 

watersheds, after which it was presumed that infiltration rates increased as surface runoff declined.

Other Studies on Impacts of Wildfire on 

Transpiration and Infiltration

Watershed management studies throughout the 

world have demonstrated that streamflow can increase

following vegetative changes that reduce evapotranspiration losses (Bosch and Hewlett 1982; 

Troendle and King 1985; Hornbeck and others 

1993; Whitehead and Robinson 1993; Zhang and 

others 2001). Following a wildfire like the RodeoChediski Wildfire, less precipitation is converted 

into vapor through the transpiration process, and as a 

consequence, more water is available for streamflow. 

Vegetation-modifying or vegetation-replacing fire, 

therefore, can change evapotranspiration (Bond and 

van Wilgen 1996; Pyne and others 1996; DeBano and 

others 1998). Fire that modifies the composition and 

structure of the vegetation by removing foliar volume 

will result in reduced evapotranspiration losses from a 

watershed. This is also particularly true for the second 

fire effect on vegetation case where fire causes a replacement of deep-rooted, high profile trees or shrubs 

by shallow-rooted, low profile grasses and forbs. 

This vegetation replacement process leads to reduced 

transpiration losses because of changes in vegetation 

characteristics like rooting depth and density. In either 

instance, reduced evapotranspiration losses following 

a wildfire usually translate into increased streamflow.

Megahan (1983) reported on increased unsaturated 

soil water after a wildfire in Idaho. Soil water contents 

at the end of the first growing season after a wildfire 

were 44 to 72 percent higher than control areas with 

intact forest stands due to reduced transpiration of soil 

water and evaporation from soil surfaces. Shi and others (2009) studied the effects of eucalyptus plantation 

disturbances on evapotranspiration in China. Wildfire 

increased water yield mainly due to reductions in transpiration. Some water yield increases were the result of 

decreased utilization of shallow and deep groundwater 

by eucalyptus roots. Liu and others (2004) reported 

on the effects of Australian bushfires on hydrologic 

processes, including reductions in transpiration at a 

catchment scale.

Soil Movement

Soil erosion and soil deposition occurred in varying magnitudes at variable times on the hillslopes of 

the Stermer Ridge watersheds following the RodeoChediski Wildfire (Garcia-Chevesich and others 2004). 

Erosive forces were intensified on sites where the wildfire destroyed the vegetation that protected a site from 

the impacts of raindrops and splash, consumed the 
USDA Forest Service RMRS-RP-85. 2011. 23

protective litter accumulations and other organic matter 

on the soil surface, and caused the formation of water-repellent soils. In particular, elevated post-fire soil erosion 

is more often found on hydrophobic soils than on nonhydrophobic soils (DeBano and others 1998; Neary and 

others 2005). The resulting increased soil erosion gradually declined as a partial cover of protective vegetation 

was re-established and the water repellency of the soils 

had declined. The cycle of increasing and then decreasing soil erosion on the Stermer Ridge watersheds after 

the Rodeo-Chediski Wildfire is similar to results found 

following other wildfires (Brooks and others 2003; 

DeBano and others 1998; Neary and others 2005).

Patterns of soil deposition following the wildfire 

were less predictable. Post-fire depositions of soil were 

generally dependent on the cumulative effects of the 

severity of the fire; the magnitudes of post-fire soil erosion; the hillslope topography and obstructions to the 

movement of soil particles; and the magnitudes, intensities, and timing of precipitation events after the fire 

and consequent overland flows of water. While some of 

these contributing factors were measurable in this study, 

others were not, therefore, resulting in the unpredictability of where soil depositions occurred.

Measurements of soil erosion and deposition are 

summarized by bar graphs that illustrate the magnitudes 

of the two processes for the sampling periods (figs. 17 

and 18). Inferences relating to differences in and among 

the magnitudes of the two soil movement processes 

illustrated in the bar graphs are not necessarily valid, 

however, because frequency distributions of the data 

sets used in developing the bar graphs were mostly nonnormal. Occurrences of significant differences in the 

measurements of soil erosion and deposition were determined through interpretations of the non-parametric 

tests selected for this purpose.

Soil Erosion

The largest magnitudes of post-fire soil erosion 

were measured on both of the Stermer Ridge watersheds in the first years following the Rodeo-Chediski 

Wildfire. The erosion rates then declined to the end of 

the study. No measurable soil erosion was observed 

on either of the watersheds in the fall of 2005 or in 

the following spring (fig. 17). It was possible that 

compensating amounts of soil erosion and deposition 

occurred on a watershed basis at those times. It was 

less likely that neither of the two processes occurred.

Soil erosion in the fall of 2002, as indicated by the 

measurements of soil pedestals shortly after the wildfire, was larger on Watershed A than on Watershed B 

(fig. 17). Similar differences in soil erosion on the two 

watersheds, as determined by the subsequent measurements of the capped erosion pins, continued through 

the spring of 2004. The differences in soil erosion on 

the two watersheds in the early years following the 

wildfire were attributed largely to the combined effects of the greater loss of vegetative cover, the more 

extensive formation of water-repellent soils, and the 

higher amounts of overland flow of storm runoff on 

Watershed A. Soil erosion on the two watersheds was 

similar from the fall of 2004 to the end of the study.

Comparisons of soil erosion measurements in the 

spring with those in the fall were made only in 2003 

and 2004, when measurable soil erosion occurred 

in both of the seasons on both of the watersheds. 

While the seasonal measurements of soil erosion on 

Watershed A were similar in 2003, the measurements 

of soil erosion in the spring of 2004 were greater than 

those in the fall of that year. There were no differences in the seasonal measurements of soil erosion on 

Watershed B in either of these two years.

Measurements of soil erosion in the spring on 

Watershed A differed throughout the study period. 

However, the differences were inconsistent and not 

Figure 17—Soil erosion rates (tons/acre) on the Stermer Ridge watersheds following 

the Rodeo-Chediski Wildfire. Soil erosion in the fall of 2002 was estimated from 

measurements of soil pedestals. Otherwise, a sample of 12 or more plots was the 

minimum number of measurements necessary in analyzing these data sets.

0

15

20

25

30

35

Soil erosion (tons/acre)

High severity fire

Low severity fire

Fall

2002

Fall

2003

Spring

2004

Fall

2004

Spring

2005

Fall

2005

Spring

2006

Fall

2006

Spring

2007

5

10

Spring

2003
24 USDA Forest Service RMRS-RP-85. 2011.

related to the time since the wildfire occurred or the 

amount of seasonal precipitation prior to the measurements of soil erosion. Soil erosion measured in 

the fall on this watershed was not different. The measurements of soil erosion in the spring and in the fall 

were not significantly different on Watershed B.

Individual plots with measurable soil erosion were 

variable in number and spatial distribution throughout the study period. Comparatively, however, higher 

magnitudes of soil erosion tended to be found on 

sites located on steeper hillslopes with minimal postfire vegetation than elsewhere on the watersheds.

Soil Deposition

There were no significant differences in the 

amounts of soil deposition on the two watersheds 

throughout most of the study period. It should be 

noted, however, that measurable soil depositions 

were not recorded on either of the watersheds in the 

spring of 2003, Watershed A in the spring of 2006, 

or Watershed B in either of the seasons in 2005 and 

the spring of 2006 (fig. 18). That depositions of soil 

were not measured on a watershed basis at these 

times could have been because equal magnitudes of 

soil erosion and soil deposition occurred. It was less 

likely that neither soil erosion nor soil deposition 

occurred on the hillslopes of the watersheds in the 

measurement intervals.

Comparisons of soil deposition measurements in 

the spring with those in the fall were made in 2004 

and 2005 on Watershed A—the only times in the 

study that measurable soil deposition were recorded 

on the watershed in the two seasons. In both of those 

years, however, there were no significant differences 

in the magnitudes of soil deposition (fig. 18). The 

number of plots was too small to adequately compare 

the depositions of soil on Watershed B in the two seasons in 2004 and 2005.

Differences in the amounts of soil depositions 

measured in the spring and in the fall were insignificant on the two watersheds throughout the study 

period. Neither time since the wildfire nor the amount 

of seasonal precipitation that occurred prior to the 

measurements of soil deposition were correlated with 

depositions of soil on the watersheds.

Actual plot locations where soil deposition was 

measured in either the spring or the fall were scattered on both watersheds, with little relationship to 

hillslope position or where slope gradients tended 

to decrease near to the stream channels of the watersheds. Neither the amounts nor the locations of 

soil deposition were related to the amounts or locations of where soil erosion was measured in the same 

time interval and vice versa. That is, soil deposition 

was less than soil erosion in some instances, while 

soil deposition was greater than soil erosion at other times. Therefore, it was not possible to trace the 

movement of eroded soil particles from one plot to 

its deposition on another plot or into a stream channel. The sampling procedures in this study were not 

designed for this purpose.

Other Studies on Impacts of Wildfire on Soil 

Movement

Earlier studies have also reported increases in soil 

erosion rates of varying magnitudes following a wildfire (Brooks and others 2003; DeBano and others 1998; 

Neary and others 2005; and others). In most cases, the 

increases in soil erosion were greatest on fires that 

were characterized by large percentages of high severity fire and where high-intensity, short-duration rains 

fell on mineral soil surfaces exposed by the wildfire. 

Most studies have often found that the post-fire rates 

of soil erosion started to decline toward pre-fire rates 

0

8

10

12

14

16

Soil deposition (tons/acre)

High severity fire

Low severity fire

Spring

2003

Fall

2003

Spring

2004

Fall

2004

Spring

2005

Fall

2005

Spring

2006

Fall

2006

Spring

2007

2

4

6

Figure 18—Soil deposition (tons/acre) on the Stermer Ridge watersheds following the 

Rodeo-Chediski Wildfire. A sample of four or more plots was the minimum number of 

measurements necessary in analyzing these data sets.
USDA Forest Service RMRS-RP-85. 2011. 25

as a protective vegetative cover was re-established on 

the burned sites, and, as a consequence, the sites begin to recover from the impacts of the burn. A variety 

of fire-effects models are available to simulate these 

cycles of increasing and then decreasing post-fire soil 

erosion rates (Ryan and Elliot 2005).

Rich (1962) reported that depositions of soil following a wildfire were found mostly on sites where 

slope gradients decreased near stream channels, resulting in decreased velocities of overland flows of 

water. However, the measurements of soil deposition 

in that study were obtained on a watershed with steeper slopes and greater annual precipitation amounts 

than the Stermer Ridge watersheds. Erosive forces on 

the watershed studied by Rich (1962) were likely more 

intensive as a consequence.

Peak Stormflows

The cumulative effects of losses of vegetative 

covers, decreases in litter and duff layers, formation 

of water-repellent soils, and other disruptions in the 

hydrologic functioning of the Stermer Ridge watersheds following the Rodeo-Chediski Wildfire were 

reflected to a large extent by the high peak stormflows 

that originated on the watersheds following the fire. 

Before precise stormflow measurements could be obtained following re-instrumentation of the watersheds 

with water-level recorders, historically high peak 

stormflows were estimated from high-water marks 

observed within, and occasionally above, the control 

sections. A peak of a stormflow event on Watershed 

A shortly after cessation of the burn was about 9.3 ft3/

sec or nearly 900 times what was measured before the 

wildfire (Ffolliott and Neary 2003; Neary and others 

2005). The peak stormflow estimated on Watershed B 

at the same time was about 50 percent less, but it was 

still far in excess of pre-fire measurements.

A subsequent and significantly higher peak stormflow that originated on Watershed A within a week of 

the earlier stormflow was estimated to be 232 ft3/sec 

or about 2230 times what measured before the burn 

(fig. 19). Though high peak flows are often observed 

following wildfire on smaller watersheds at the headwaters of larger river basins such as the Stermer Ridge 

watersheds, this latter estimate represented the highest 

known post-fire increase in peak stormflows in southwestern ponderosa pine forests (Ice and others 2004; 

Neary and others 2005). However, this estimated peak 

streamflow discharge was at the lower end of the 

ranges of streamflow discharges in the western United 

States, reported by Biggio and Cannon (2001) as cited 

by Neary and others (2005).

Comparatively high peak stormflows of varying magnitudes continued throughout the following 

summers of the study. However, the peaks gradually 

declined toward the pre-fire levels as hydrologic functioning of the two watersheds began to recover from 

the burn. This decline was particularly evident and 

more rapid on Watershed B, where the hydrologic 

functioning had not been severely disrupted by the 

burn.

Patterns of initially high and then declining peak 

stormflows following a wildfire have been reported 

elsewhere in southwestern ponderosa pine forests 

(Campbell and others 1977; DeBano and others 1998; 

Neary and Gottfried 2002; Neary and others 2005; 

and others). These extreme events accompanied by 

the transport of increased sediment have often led to 

significant changes in hydrologic functioning of the 

impacted stream systems. For the most part, peak 

stormflows are greatest the first year following fire 

and then decline thereafter and as watersheds recover. 

However, there is always the risk of higher peakflows 

in the second and subsequent years if unusual rainfall 

occurs. Steep terrain can also aggrevate this general 

statement about peak stormflow occurrence.

Post-fire stormflows with excessively high peaks 

are often associated with downstream flooding 

(Brooks and others 2003; Chang 2006; Neary 2002). 

Such a possibility was a concern to the people living 

downstream of the area burned by the Rodeo-Chediski 

Wildfire. In this regard, a high-intensity storm on the 

PRE‐FIRE 

POST‐F

Figure 19—The peak 

stormflow shortly after 

the wildfire, estimated on 

Stermer Ridge Watershed 

A, was nearly 2230 times 

that measured on the 

watershed before the fire. 

The 3-ft H-flume provides 

an approximate scale of the 

respective depths of the 

pre-fire and post-fire flows. 

(Photo by Daniel G. Neary.)
26 USDA Forest Service RMRS-RP-85. 2011.

White Mountains-Fort Apache Reservation dropped 

over 1.5 inches of rain onto a severely burned 

landscape on August 5, 2002—enough rainfall for meteorologists to call the storm a “10-year event.” The 

increase in streamflow as a result of this storm registered a peak discharge of nearly 1200 ft3

/sec at a stream 

gauge on the Reservation maintained by the U.S. 

Geological Survey. This put the peak stormflow in the 

category of a “100-year event” at the site, which was 

one order of magnitude larger than expected (Ffolliott 

and Neary 2003). Fortunately, excessive downstream 

flooding did not occur as a result of this or other postfire stormflow events originating on the burned area. 

However, this is a major problem for flood forecasters 

and emergency managers. In this case, a 10-year rainfall produced a 100-year streamflow. Data from other 

fires (Neary and others 2005) and the Rodeo-Chediski 

Wildfire have shown that post-fire flows can be 7, 50, 

100, and, in this instance, 2230 times pre-fire flows for 

a given rainfall. Floods from post-fire rainfall events 

are likely to be way outside the natural range of variability and to produce serious post-fire effects. This 

situation can be aggravated if steep terrain is involved 

in the wildfire.

Water Quality Characteristics

Analysis of the sediment-laden water running 

off the larger areas burned by the Rodeo-Chediski 

Wildfire that was sampled downstream of the Stermer 

Ridge watersheds showed that the stormflows generated by the initial summer rainstorms following 

the burn contained large concentrations of organic 

debris, dissolved nutrients (including nitrogen, phosphorus, and carbon), and other chemical constituents 

that were released by the burning event (Ffolliott and 

Neary 2003). The elevated concentrations of nitrogen 

and phosphorus were attributed largely to the decomposition of the fire retardants that were dropped 

from the air to slow the advancement of the wildfire during the fire-suppression activities. Some of 

the increases in nutrients might have also originated 

from the ash and other plant residues that resulted 

from the wildfire.

Some investigators have reported little impact of 

fire in southwestern ponderosa pine forests on water quality constituents (DeBano and others 1998; 

Gottfried and DeBano 1990), while other researchers have found higher post-fire concentrations of 

chemical constituents such as calcium, magnesium, 

potassium, and combined organic-inorganic nitrogen 

in stormflow events shortly after a wildfire (Campbell 

and others 1977). However, the elevated post-fire 

concentrations often returned to pre-fire levels after 

the initial stormflow events. Such was observed in 

stormflows following the Rodeo-Chediski Wildfire.

The seemingly poor quality of water flows entering the downstream Roosevelt Reservoir shortly 

after cessation of the Rodeo-Chediski Wildfire was 

another possible concern (Neary and others 2005). 

The reservoir is the primary source of water for 

Phoenix, the largest city in Arizona, and the surrounding metropolitan communities. What made 

this concern more serious than might otherwise be 

expected was the fact that the body of water in the 

Reservoir at the time of the wildfire was less than 15 

percent of its storage capacity. It was thought, therefore, that the elevated concentrations of sediments, 

organic debris, and nutrients in the water entering 

the Reservoir might threaten the aquatic life, leaving 

the reservoir water “lifeless” for months (Ffolliott 

and Neary 2003). However, that dire situation failed 

to materialize. Some fish died upstream and a few 

carcasses showed up at the diversion dam above the 

Reservoir, but the water in the Reservoir suffered 

little long-term environmental damage. Moreover, 

the anticipated formation of algae blooms that were 

predicted to consume much of the oxygen in the water did not occur. The debris in the flows of water 

that followed the wildfire was never a health risk for 

people as most of the pollutants were chemicals that 

were easily removed in downstream water-treatment 

facilities.

Impacts on 

Flammable Fuels

Pre-Fire Fuel Loadings

Standing trees were the largest fraction of the prefire flammable fuels on both of the Stermer Ridge 

watersheds (fig. 20). The comparatively smaller loading of standing trees on Watershed A was due to the 

smaller pre-fire volume of overstory trees (Ffolliott and 

others 2008). The estimated volume of pre-fire trees 

on this watershed was 1414 ft3/acre in comparison to 

a volume of 1950 ft3/acre on Watershed B. However, 

the estimated loadings of standing trees on both of the 

watersheds must be interpreted within the context of 

the volume table that was used to estimate the cubicfoot volumes of trees. This volume table (Ffolliott and 

others 1971) excluded the fuels contained in tree-tops, 

branches, and twigs and, therefore, underestimated the 

total fuel loading of the trees.

Post-Fire Fuel Loadings

One Year after Wildfire

Loadings of the flammable fuels one year after the 

burn on Watershed A provide an estimate of the initial 

impacts of the Rodeo-Chediski Wildfire on these fuels. Consumption of 40 percent of the pre-fire fuels on 

Watershed A was estimated to have occurred, mainly 

in the fraction of standing trees (fig. 20A). Almost 40 

percent of the standing trees on this watershed died 

in the first post-fire year (Ffolliott and others 2008), 

lowering the estimated loading of this fraction to an 

unknown level. Charred (burned) wood that was contained in the trees reduced the volume of fuel that might 

otherwise have been classified as flammable. The estimated loading of this fraction, therefore, was probably 

overestimated. The extent that the overestimates and 
USDA Forest Service RMRS-RP-85. 2011. 27

underestimates of the standing trees fraction attributed 

to the volume table used in the study were compensating is unknown. Nevertheless, the large loss of fuels in 

this fraction was expected because most of the pre-fire 

trees in the reconstructed overstory on this watershed 

had been either killed by the fire or suffered severe 

damage to their crowns (Ffolliott and others 2008).

About 20 percent of the pre-fire loadings of the fuels on Watershed B was lost and, therefore, these fuels 

were presumed to have been consumed in the wildfire, 

according to estimates made one year following the 

burn (fig. 20B). This result was also expected, as the 

portions of Watershed B that burned were impacted 

mostly by surface fire. As a consequence, less than 

5 percent of the pre-fire trees on this watershed were 

killed by the wildfire (Ffolliott and others 2008).

One year after the burn, loading of downed 

woody materials was greater on Watershed A than 

on Watershed B (fig. 20). This result was attributed 

largely to the fact that trees that were killed or severely damaged on Watershed A started to fall to the 

ground and, therefore, were included in the estimate 

of this fuel fraction. Otherwise, the accumulations of 

stem sections, branches, and twigs on the forest floor 

were largely the same on both of the Stermer Ridge 

watersheds.

Loading of litter and duff on Watershed B was 

almost 3.5 times greater than the loading of this fraction on the other high severity fire watershed (fig. 

20). While relatively small in terms of the loadings 

of all of the fuels, this difference was a consequence 

of the increase in litter fall from the standing trees 

on Watershed B that had survived the burn but with 

slightly scorched crowns. Because most of the trees 

on Watershed A were killed outright by the wildfire 

or died within two years (Ffolliott and others 2008), 

post-fire litter fall was inconsequential. A similar result was reported by Davis and others (1968), who 

compared the litter fall from the trees with crowns 

that were “slightly damaged” by a fire in a southwestern ponderosa pine forest to that from trees on 

unburned sites.

Loadings of fuels that consisted of herbaceous 

plants and shrubs were less than 0.1 tons/acre on the 

two watersheds in the first post-fire year. Differences 

between the two watersheds had little significance.

Three Years after Wildfire

Changes in the loadings of flammable fuels on the 

Stermer Ridge watersheds three years following the 

wildfire in relation to the loadings of the fuels one 

year after the burn were comparatively small, with 

the exception of the standing trees (fig. 20). Nearly 

75 percent of the fire-damaged trees on Watershed A 

had died by the third post-fire year. This increase in 

Standing trees (dead)

Total

Standing trees (alive)

Downed woody materials

Litter and duff

[A] 

0

10

15

20

25

30

35

40

45

50

Flammable fuels (tons/acre)

Pre-Fire 2003 2005

5

[B] 

0

10

15

20

25

30

35

40

45

50

Flammable fuels (tons/acre)

Pre-Fire 2003 2005

5

Standing trees (dead)

Total

Standing trees (alive)

Downed woody materials

Litter and duff

Figure 20—Average 

loadings of 

flammable fuel 

fractions before and 

after the RodeoChediski Wildfire on 

the Stermer Ridge 

watersheds that were 

burned by (A) a high 

severity fire and (B) 

a low severity fire. 

Fine fuels consisting 

of herbaceous plants 

and shrubs are 

not plotted in this 

figure because the 

average loadings of 

this portion of the 

fraction were less 

than 0.1 tons/acre. 

Confidence intervals 

are not presented in 

this figure because 

of the variable 

procedures applied in 

obtaining the source 

data.
28 USDA Forest Service RMRS-RP-85. 2011.

mortality translated into an increase of 15 percent in 

the loading of standing dead trees over that observed 

one year after the wildfire. Dead trees on the ground 

were included in the estimate of downed woody materials when occurred on the measurement plots.

The continuous falling of dead and dying trees 

and needles from crown-scorched trees to the ground 

was the main factor that contributed to the small increases in downed woody materials and litter and 

duff layers (fig. 20). The increase in the fine fuels 

represented by the herbaceous plants and shrubs was 

inconsequential.

Following Salvage Cutting and Fuel 

Reduction Treatments

The salvage cutting and fuel reduction treatments 

on Watershed A also impacted the post-fire loadings 

of fuels in that the fraction that consisted of standing 

trees had been largely removed from this watershed. 

However, the loading of stem sections, branches, 

and twigs on the forest floor increased significantly 

(fig. 21). This fraction was about 2.5 times (or about 

7.4 tons/acre) greater following completion of the 

salvage cutting and fuel reduction treatments than 

was estimated three years following the wildfire. 

Almost 90 percent of the increase in this fraction was 

contained in materials 1 inch and larger in dbh that 

were mostly the residue of the treatments. Therefore, 

while the likelihood of a crown fire occurring on this 

watershed in the foreseeable future has been eliminated, the possibility of surface fire remains.

Other Studies on Impacts of Wildfire on 

Flammable Fuels

This analysis of the Rodeo-Chediski Fire’s impacts on the loadings of flammable fuels on the 

Stermer Ridge watersheds should be interpreted only 

as a case study of the impacts on the fractions studied. The extent to which these findings might apply 

elsewhere in the Southwestern Region is unknown. 

However, the impacts of wildfire on the loadings of 

flammable fuels in southwestern ponderosa pine forests and how combustion of these fuels has shaped 

the post-fire structure of the forests have been considered in a general framework in other studies (Arno 

2000; Cooper 1961; Daubenmire 1943; Martin and 

others 1979; Weaver 1951). Zimmerman (2003) presented a comprehensive overview of this topic in a 

paper on fuels and fire behavior in southwestern ponderosa pine forests.

Summary

Impacts on Ecosystem 

Resources

The Rodeo-Chediski Wildfire altered the pre-fire stand structures of tree overstories on the Stermer 

Ridge watersheds, with the impacts more drastic on 

Watershed A due to the high severity fire than on 

Watershed B that was burned by a low severity fire. 

The pole class of trees suffered higher mortality than 

trees in the sawtimber classes. Most of the trees that 

survived the wildfire but were severely damaged by 

the burn died within two years of the burn and had 

started falling to the ground. Salvage cutting and fuel 

reduction treatments on Watershed A eliminated most 

of the remaining standing trees. Stocking of ponderosa pine seedlings after the wildfire was insufficient 

on either of the watersheds to sustain a ponderosa 

pine forest.

Production of herbaceous plants and grass and forb 

components of the herbaceous plants were generally 

greater throughout the study on Watershed A. Larger 

reductions of the tree overstory and more complete 

removal of the litter and duff layers on the watershed 

contributed to this finding. Mullein represented almost one-half of the production of the forbs on the 

severely burned watershed at its peak occurrence, but 

this early-seral species contributed less to the lower 

Figure 21—Accumulations of stem 

sections, branches, and twigs on the 

forest floor following salvage cutting 

and fuel reduction treatments on 

Stermer Ridge Watershed B that was 

burned by a high severity fire. The 

remaining standing trees are mostly 

crown-killed Gambel oak (Quercus 

gambelii) with little merchantable value. 

The piles of logs and larger trees in the 

background were converted into chips 

to generate electricity for local towns. 

(Photo by Peter F. Ffolliott.)
USDA Forest Service RMRS-RP-85. 2011. 29

level of forb production on the watershed that was 

burned by a low severity fire. Mullein declined in 

occurrence after dominating the forb component of 

herbage on both of the watersheds in the early and 

middle years after the wildfire.

Impacts of the wildfire on the indigenous ungulates 

and small mammals on the Stermer Ridge watersheds 

differed in both magnitude and duration following the 

burn. Increased presence of elk in the third year after 

the burn on Watershed A was attributed to the increase 

in preferred forage plants. The availability of protective cover was a secondary factor of importance. The 

smaller quantities of browse preferred by mule deer 

resulted in lower occurrences of this ungulate relative 

to that of elk on both of the watersheds. The limited 

presence of cottontail on both of the watersheds was 

probably the result of the more limited availability 

of preferred forage plants. The apparent departure of 

Abert’s squirrel from Watershed A was caused largely 

by the loss of preferred feed trees in the high severity 

fire. However, the squirrel’s feeding activities by were 

observed two years after the wildfire on Watershed B, 

indicating their return to this watershed. This finding 

was attributed to the fact that most of the squirrel’s 

preferred feeding trees survived the fire.

Not knowing the structure of bird communities 

on the Stermer Ridge watersheds before the wildfire 

precluded comparisons of pre- and post-fire species 

and numbers. Nevertheless, the numbers of birds in 

some guilds declined, while birds in other guilds were 

affected less by the wildfire. Because of varying responses of birds to the Rodeo-Chediski Wildfire, a 

mosaic of habitat conditions on a scale larger than that 

on the Stermer Ridge watersheds seems necessary to 

sustain a full suite of bird species following the burn.

Impacts on Hydrologic 

Functioning

Nearly two-thirds of the soils on Watershed A exhibited strong water repellency at the surface immediately 

after the fire, while moderate water repellency was 

found on one-third of the soils. Strong water repellency was measured at the soil surface on approximately 

one-third of Watershed B, with 15 percent of the soils 

having moderate water repellency and almost 50 percent of the plots with slight or no water repellency 

(fig. 16B).

Most of the water-repellent layers in soils dissipated 

on both of the Stermer Ridge watersheds within three 

years of the wildfire. The decline in the occurrence of 

water-repellent soils on the two watersheds was attributed to several processes. Downward erosion of the soil 

into and through the hydrophobic layer and repeated 

exposures of the soils to cycles of wetting-drying and 

freezing-thawing events also led to a decrease in the 

degree of water repellency in the soils. Differences in 

the occurrences of water repellency on the two watersheds, the respective levels of the water repellency, and 

the patterns of decline in the water-repellent soils between the spring and fall seasons were inconsequential.

One impact of the wildfire on the hydrologic 

functioning of the Stermer Ridge watersheds was a 

decrease in the interception of precipitation due to the 

loss of tree overstories and consumption of litter and 

duff layers by the burn. Re-establishment of trees on 

the high severity fire areas is unlikely to occur without 

artificial regeneration. Litter and then duff layers will 

not re-form in the absence of trees.

Transpiration was another component of the water 

budget that was altered by the Rodeo-Chediski Fire. 

While sap flow was detected in all of the limited measurement trees, the few repeated measurements (two 

measurement for each tree sampled) were insufficient 

to differentiate with confidence the transpiration losses 

on the two watersheds. Nevertheless, it was concluded 

that the loss of water by the transpiration processes was 

reduced on both of the watersheds, with comparatively 

higher losses on Watershed A because of the greater 

mortality of trees.

Infiltration of water into the soil was not measured 

in the study. It was assumed, however, that formation of water-repellent soils in the early years of the 

study inhibited the infiltration rates on the watersheds, 

causing much of the precipitation that reached the 

soil surface to increase in surface runoff flows. This 

phenomenon was more pronounced on Watershed 

A because of the more extensive formation of strong 

water repellency associated with high severity fire. 

Water-repellent soils, and hence reduced infiltration 

rates, persisted up to three years on the watersheds, after which infiltration rates probably increased as water 

repellency declined.

Destruction of the vegetative covers and litter and 

duff layers coupled with formation of the water- repellent soils on the Stermer Ridge watersheds resulted in 

peak stormflows of historical magnitudes following 

the wildfire. The highest of the peak stormflows were 

observed following the high-intensity, short-duration 

rainfall events that occurred shortly after cessation of 

the wildfire. While post-fire stormflows of exceedingly 

high peaks are often characteristic of flooding regimes, 

downstream flooding following the Rodeo-Chediski 

Wildfire did not occur. Quality characteristics of the 

water flowing from the Stermer Ridge watersheds 

were not measured in this study. However, it was ultimately determined that the concentrations of sediment, 

nutrients, and other debris in the water flowing from 

the area that was burned by the wildfire presented few 

environmental problems.

Impacts on Flammable Fuels

Estimates made one year post-fire indicated that 

40 percent of the pre-fire fuels on Watershed A had 

been eliminated, mostly in the standing trees fraction 

of the total watershed fuels. Almost 40 percent of the 

remaining standing trees were dead by that time, reducing the loading of the fraction. Nearly 75 percent 

of the pre-fire trees had died by 2005, three years after 

the wildfire, with this increase in mortality translating 

into an additional increase of 15 percent in loadings 

of standing dead trees in relation to that one year after 

the fire.
30 USDA Forest Service RMRS-RP-85. 2011.

Estimates made one year after the wildfire indicated that about 20 percent of the pre-fire loadings of 

flammable fuels on Watershed B had been consumed 

by the wildfire. Less than five percent of the pre-fire 

trees had been killed. This finding was not surprising, 

however, as much of the watershed was impacted only 

by low severity surface fire. The greater loading of 

litter and duff on the watershed at this time was attributed to the litter fall from standing trees that survived 

the burn with slightly scorched crowns. Post-fire litter 

fall on Watershed A was minimal because most of the 

trees were killed or severely damaged by the wildfire 

and died within two years.

Salvage cutting and fuel reduction treatments 

implemented on Watershed A impacted the post-fire 

loadings of flammable fuels. The fraction consisting of 

standing trees was essentially eliminated on this watershed. However, loadings of stem sections, branches, 

and twigs on the forest floor increased significantly as 

a result of the treatments. Therefore, while the probability of future crown fire has been reduced, the 

possibility of surface fire on the watershed remains.

Management Implications

Recovery of the Stermer Ridge watersheds from the Rodeo-Chediski Wildfire has been related to 

the respective fire severities that the two watersheds 

experienced. Watershed A that was burned by a high 

severity fire underwent a conversion from a southwestern ponderosa pine forest ecosystem to a landscape of 

grasses, forbs, and a few shrubs. This post-fire cover 

of herbaceous plants and shrubs is likely to persist in 

varying forms into the future in the absence of artificial regeneration of the tree species. Recovery of the 

hydrologic functioning on this watershed has begun 

on a limited scale with the elimination of fire-induced 

water-repellent soils and the resulting decrease in the 

magnitudes of overland flows of water; the reduction 

in hillslope soil erosion and deposition and, therefore, 

sediment production; and the gradual but continuous 

return of peak stormflows to pre-fire levels. It is anticipated, however, that the overall hydrologic functioning 

of this watershed will not approach pre-fire conditions 

for many years. Flammable fuels represented by standing trees have been eliminated on the watershed, but 

there has been an increase in stem sections, branches, 

and twigs on the forest floor. Therefore, while the 

possibility of a future crown fire has declined, the potential for surface fire remains.

Much of Watershed B was either burned at a low 

severity or unburned. The sites that were burned are 

slowly recovering from the impacts of the wildfire, a 

progression that is likely to continue into the future 

in the absence of wildfire or other major disturbances. 

Relatively small areas of Watershed B were burned 

at higher fire severities, but those sites were isolated 

and scattered throughout the landscape. Much of the 

hydrologic functioning of this watershed is returning 

slowly to its pre-fire level. The post-fire loadings of 

flammable fuels were largely unchanged from their 

pre-fire estimates. Consequently, this watershed remains vulnerable to future wildfire events.

References

Alig, R. J.; Brink, G. E.; Goforth, M. H.; LaBau V. J.; 

Mills, T. J. 1982. TRAS-1980: user’s manual for an 

expanded version of the TRAS projection system. 

Fort Collins, CO: U.S. Department of Agriculture, 

Forest Service, Rocky Mountain Forest and Range 

Experiment Station. 63 p.

Arno, S. F. 2000. Fire in western forest ecosystems. 

In: Brown, J. K.; Smith, J. K., eds. Wildland fire in 

ecosystems: effects of fire on flora. Gen. Tech. Rep. 

RMRS-GTR-42-Volume 2. Fort Collins, CO: U.S. 

Department of Agriculture, Forest Service, Rocky 

Mountain Research Station: 97-120.

Aulenbach, S.; O’Shea-Stone, M. 1983. Bird 

utilization of a ponderosa pine forest after a fire. 

Colorado Field Ornithology. 17(1): 14-19.

Avery, T. E.; Burkhart, H. E. 2002. Forest 

measurements. New York, NY: McGraw-Hill Book 

Company. 456 p.

Baker, M. B., Jr. 1990. Hydrologic and water quality 

effects of fire. In: Krammes, J. S., tech. coord. 

Effects of fire management of southwestern 

natural resources. Gen. Tech. Rep. RM-191. Fort 

Collins, CO: U.S. Department of Agriculture, 

Forest Service, Rocky Mountain Forest and Range 

Experiment Station: 31-42.

Baker, M. B., Jr. 1999. History of watershed research 

in the Central Arizona Highlands. Gen. Tech. 

Rep. RMRS-GTR-29. Fort Collins, CO: U.S. 

Department of Agriculture, Forest Service, Rocky 

Mountain Research Station. 56 p.

Barger, R. L.; Ffolliott, P. F. 1964. Specific gravity 

of Arizona Gambel oak. Res. Note RM-19. Fort 

Collins, CO: U.S. Department of Agriculture, 

Forest Service, Rocky Mountain Forest and Range 

Experiment Station. 2 p.

Barger, R. L.; Ffolliott, P. F. 1965. Specific gravity 

of alligator juniper in Arizona. Res. Note RM-40. 

Fort Collins, CO: U.S. Department of Agriculture, 

Forest Service, Rocky Mountain Forest and Range 

Experiment Station. 2 p.

Barger, R. L.; Ffolliott, P. F. 1971. Effects of extractives 

on specific gravity of southwestern ponderosa 

pine. Res. Note RM-205. Fort Collins, CO: U.S. 

Department of Agriculture, Forest Service, Rocky 

Mountain Forest and Range Experiment Station. 

4 p.

Biggio, E. R.; Cannon, S. H. 2001. Compilation of 

post-fire wildfire runoff data from the Western 

United States. U.S. Geological Survey, Open-File 

Report 2001-474. 24 p.

Blake, J. G. 1982. Influence of fire and logging on 

nonbreeding bird communities of ponderosa pine 

forests. Journal of Wildlife Management. 46: 

404-415.
USDA Forest Service RMRS-RP-85. 2011. 31

Bojorquez-Tapia, L. A.; Ffolliott, P. F.; Guertin, D. 

P. 1990. Herbage production-forest overstory 

relationships in two ponderosa pine forests. Journal 

of Range Management. 43: 25-28.

Bond, W. J.; van Wilgen, B. W. 1996. Fire and plants. 

London, UK: Chapman and Hall. 263 p.

Bosch, J. M.; Hewlett, J. D. 1982. A review of catchment 

experiments to determine the effect of vegetation 

changes on water yield and evapotranspiration. 

Journal of Hydrology. 55: 3-23.

Bowden, D. C.; Anderson, A. E.; Medin, D. E. 1969. 

Frequency distributions of deer and elk pellet 

groups. Journal of Wildlife Management. 44: 29-36.

Braun, C. E., ed. 2005. Techniques for wildlife 

investigations and management. Bethesda, MD: 

The Wildlife Society. 974 p.

Brawn, J. D.; Boecklen, W. J.; Balda, R. P. 1987. 

Investigations of density interactions among 

breeding birds in ponderosa pine forests: 

correlative and experimental evidence. Oecologia. 

72: 348-357.

Brooks, K. N.; Ffolliott, P. F.; Gregersen, H. M.; 

DeBano, L. F. 2003. Hydrology and the management 

of watersheds. Ames, IA: Iowa State Press. 574 p.

Brown, D. E. 1984. Arizona’s tree squirrels. Phoenix, 

AZ: Arizona Game and Fish Department. 114 p.

Brown, J. K. 1974. Handbook for inventorying 

downed woody materials. Gen. Tech. Rep. INT16. Ogden, UT: U.S. Department of Agriculture, 

Forest Service, Intermountain Forest and Range 

Experiment Station. 24 p.

Brown, J. K.; Oberheu, R. D.; Johnson, C. M. 1982. 

Handbook for inventorying surface fuels and 

biomass in the Interior West. Gen. Tech. Rep. INT129. Ogden, UT: U.S. Department of Agriculture, 

Forest Service, Intermountain Forest and Range 

Experiment Station. 48 p.

Campbell, R. E.; Baker, M. B., Jr; Ffolliott, P. F.; 

Larson, F. R.; Avery, C. C. 1977. Wildfire effects 

on a ponderosa pine ecosystem: an Arizona case 

study. Res. Pap. RM-191. Fort Collins, CO: U.S. 

Department of Agriculture, Forest Service, Rocky 

Mountain Forest and Range Experiment Station. 

12 p.

Chang, M. 2006. Forest hydrology: an introduction 

to water and forests. Boca Raton, FL: CRC Press. 

488 p.

Clark, B. 2001. Soil, water, and watersheds. In: Fire 

Use Working Team, National Wildfire Coordinating 

Group, eds. Fire effects guide. Boise, ID: National 

Wildfire Coordinating Group, National Interagency 

Fire Center: 93-109.

Clary, W. P. 1975. Range management and its 

ecological basis in the ponderosa pine type of 

Arizona: the status of our knowledge. Res. Pap. 

RM-158. Fort Collins, CO: U.S. Department of 

Agriculture, Forest Service, Rocky Mountain 

Forest and Range Experiment Station. 35 p.

Clary, W. P.; Larson, F. R. 1971. Elk and deer use 

are related to food sources in Arizona ponderosa 

pine. Res. Note RM-330. Fort Collins, CO: U.S. 

Department of Agriculture, Forest Service, Rocky 

Mountain Forest and Range Experiment Station. 

4 p.

Clary, W. P.; Ffolliott, P. F.; Jameson, D. A. 1968. 

Relationship of different forest floor layers to 

herbage production. Res. Note RM-123. Fort 

Collins, CO: U.S. Department of Agriculture, 

Forest Service, Rocky Mountain Forest and Range 

Experiment Station. 3 p.

Cochran, G. A.; Stains, H. J. 1961. Deposition and 

decomposition of fecal pellets by cottontails. 

Journal of Wildlife Management. 25: 432-435.

Collins, W. B.; Urness P. J. 1979. Elk pellet-group 

distributions and rates of deposition in aspen 

and lodgepole pine habitats. In: Boyle, M. S.; 

Hayden-Wing, L. D., eds. North American elk 

ecology, behavior, and management. Laramie, WY: 

University of Wyoming: 140-144.

Cook, C. W.; Stubbendieck, J., eds. 1986. Range 

research: basic problems and techniques. Denver, 

CO: Society for Range Management. 317 p.

Cooper, C. F. 1961. Pattern in ponderosa pine forests. 

Ecology. 42: 493-499.

Costa, R.; Ffolliott, P. F.; Patton, D. R. 1976. 

Cottontail response to forest management in 

southwestern ponderosa pine. Res. Note RM-330. 

Fort Collins, CO: U.S. Department of Agriculture, 

Forest Service, Rocky Mountain Forest and Range 

Experiment Station. 4 p.

Daubenmire, R. 1943. Vegetational zonation in the 

Rocky Mountains. Botanical Review. 9: 325-393.

Davis, D. E., ed. 1982. Handbook of census methods 

for terrestrial vertebrates. Boca Raton, FL: CRC 

Press. 397 p.

Davis, J. R.; Ffolliott, P. F.; Clary, W. P. 1968. A 

fire prescription for consuming ponderosa pine 

duff. Res. Note RM-115. Fort Collins, CO: U.S. 

Department of Agriculture, Forest Service, Rocky 

Mountain Forest and Range Experiment Station. 

4 p.

DeBano, L. F. 1981. Water repellent soils: a state-ofthe-art. Gen. Tech. Rep. PSW-46. Berkeley, CA: 

U.S. Department of Agriculture, Forest Service, 

Pacific Southwest Forest and Range Experiment 

Station. 21 p.

DeBano, L. F. 2000. Water repellency in soils: a 

historical overview. Journal of Hydrology. 231-

232: 4-32.

DeBano, L. F. 2003. The role of fire and soil heating 

on water repellency. In: Ritsema, C. J.; Dekker, 

L. W., eds. Soil water repellency: occurrence, 

consequences, and amelioration. Amsterdam, The 

Netherlands: Elsevier Science, BV: 193-223.

DeBano, L. F.; Neary, D. G.; Ffolliott, P. F. 1998. 

Fire’s effects on ecosystems. New York, NY: John 

Wiley & Sons, Inc. 333 p.
32 USDA Forest Service RMRS-RP-85. 2011.

Dieterich, J. H. 1979. Recovery potential of firedamaged southwestern ponderosa pine. Res. Note 

RM-379. Fort Collins, CO: U.S. Department of 

Agriculture, Forest Service, Rocky Mountain 

Forest and Range Experiment Station. 8 p.

Doerr, S. H.; Shakesby, R. A.; Walsh, R. P. D. 2000. 

Soil water repellency: its characteristics, causes 

and hydrogeomorphological consequences. Earth 

Science Review. 51: 33-65.

Dyrness, C. T. 1976. Effects of fire on soil wettability 

in the high Cascades of Oregon. Res. Pap. PNW202. Portland, OR: U.S. Department of Agriculture, 

Forest Service, Pacific Northwest Forest and Range 

Experiment Station. 18 p.

Eberhardt, L. E.; White G. C. 1979. Movements of mule 

deer on the Los Alamos National Environmental 

Research Park. Los Alamos, NM: Los Alamos 

National Environmental Research Park Report LA7742. 29 p.

Ehrlich, P. R.; Dobkin, D. S.; Wheye, D. 1988. The 

birders handbook: a field guide to the natural 

history of American birds. New York, NY: Simon 

& Schuster, Inc. 785 p.

Epple, A. O. 1995. A field guide to the plants of 

Arizona. Guiford, CN: The Globe Pequot Press. 

347 p.

Erickson, H. E.; White, R. 2008. Soils under fire: soils 

research and the Joint Fire Science Program. Gen. 

Tech. Rep. PNW-GTR-750. Portland, OR: U.S. 

Department of Agriculture, Forest Service, Pacific 

Northwest Research Station. 17 p.

Ffolliott, P. F. 1983a. Implications of snag policies 

on management of southwestern ponderosa pine 

forest. Gen. Tech. Rep. RM-99: Fort Collins, CO: 

U.S. Department of Agriculture, Forest Service, 

Rocky Mountain Forest and Range Experiment 

Station: 28-32.

Ffolliott, P. F. 1983b. Overstory-understory 

relationships: southwestern ponderosa pine 

forests. In: Bartlett, E. T.; Betters, D. R., eds. 

Overstory-understory relationships in western 

forests. Fort Collins, CO: Western Regional 

Research Publication. 1: 3-18.

Ffolliott, P. F.; Baker, M. B., Jr. 1977. Characteristics 

of Arizona ponderosa pine stands on sandstone 

soils. Gen. Tech. Rep. RM-44: Fort Collins, CO: 

U.S. Department of Agriculture, Forest Service, 

Rocky Mountain Forest and Range Experiment 

Station. 7 p.

Ffolliott, P. F.; Gottfried, G. J. 2008. Plant communities 

and associations. In: Ffolliott, P. F.; Davis, O. K., 

eds. Natural ecosystems of Arizona: from deserts 

and mountains. Tucson, AZ: University of Arizona 

Press: 70-119.

Ffolliott, P. F.; Neary, D. G. 2003. Impacts of a 

historical wildfire on hydrologic processes: a 

case study in Arizona. In: Pfeffer, M. J.; Van Abs, 

D. J.; Brooks, K. N., eds. Water management for 

water supply systems: proceedings of the 2003 

International Congress. Middleburg, VA: American 

Water Resources. CD-ROM.

Ffolliott, P. F.; Patton, D. R. 1978. Abert squirrel use 

of ponderosa pine as feed trees. Res. Note RM-362. 

Fort Collins, CO: U.S. Department of Agriculture, 

Forest Service, Rocky Mountain Forest and Range 

Experiment Station. 4 p.

Ffolliott, P. F.; Clary, W. P.; Baker, M. B., Jr. 1976. 

Characteristics of the forest floor on sandstone and 

alluvial soils in Arizona ponderosa pine type. Res. 

Note. RM-308. Fort Collins, CO: U.S. Department 

of Agriculture, Forest Service, Rocky Mountain 

Forest and Range Experiment Station. 4 p.

Ffolliott, P. F.; Clary, W. P.; Larson, F. R. 1977. Effects 

of a prescribed fire in an Arizona ponderosa pine 

forest. Res. Note RM-336. Fort Collins, CO: U.S. 

Department of Agriculture, Forest Service, Rocky 

Mountain Forest and Range Experiment Station. 

4 p.

Ffolliott, P. F.; Larson, F. R.; Barger, R. L. 1971. 

Predicting scaled volume recoverable from cutover 

southwestern ponderosa pine stands. Res. Note 

RM-195. Fort Collins, CO: U.S. Department of 

Agriculture, Forest Service, Rocky Mountain 

Forest and Range Experiment Station. 8 p.

Ffolliott, P. F.; Rasmussen, W. O.; Guertin, D. P. 

1988. STAND: an interactive model to simulate the 

growth and yield of woodlands in the Southwest. 

In: Ek, A. R.; Shifley, S. R.; Burk, T. E. eds. Forest 

growth modelling and prediction: proceedings of 

the IUFRO conference. Gen. Tech. Rep. NC-120. 

St. Paul, MN: Fort Collins, CO: U.S. Department 

of Agriculture, Forest Service, North Central Forest 

and Range Experiment Station: 968-975.

Ffolliott, P. F.; Stropki, C. L.; Neary, D. G. 2008. 

Historical wildfire impacts on ponderosa pine 

tree overstories: an Arizona case study. Res. Pap. 

RMRS-RP-75. Fort Collins, CO: U.S. Department 

of Agriculture, Forest Service, Rocky Mountain 

Research Station. 24 p.

Ffolliott, P. F.; Stropki, C. L.; Chen, H.; Neary, D. G. 

2009. Observations of bird numbers and species 

following a historic wildfire in Arizona ponderosa 

pine forest. Journal of the Arizona-Nevada 

Academy of Science. 41(1): 18-23.

Finch, D. M.; Ganey, J. L.; Yong, W.; Kimball, R. T.; 

Sallabanks, R. 1997. Effects and interactions of 

fire, logging, and grazing. In: Block, W. M.; Finch, 

D. M., tech. eds. Songbird ecology in southwestern 

ponderosa pine forests: a literature review. Gen. 

Tech. Rep. RM-GTR-292. Fort Collins, CO: U.S. 

Department of Agriculture, Forest Service, Rocky 

Mountain Forest and Range Experiment Station: 

103-136.

Fowler, J. F.; Sieg, C. H. 2004. Postfire mortality 

of ponderosa pine and Douglas-fir: a review 

of methods to predict tree death. Gen. Tech. 

Rep. RMRS-GTR-132. Fort Collins, CO: U.S. 

Department of Agriculture, Forest Service, Rocky 

Mountain Research Station. 25 p
USDA Forest Service RMRS-RP-85. 2011. 33

Fox, K. M.; Ffolliott, P. F.; Baker, M. B., Jr.; DeBano, 

L. F. 2000. More water for Arizona: a history of 

the Arizona Watershed Program and the Arizona 

Water Resources Committee. Phoenix, AZ: Primer 

Publishers. 118 p.

Garcia-Chevesich, P. A.; Ffolliott, P. F.; Neary, D. G. 

2004. Soil losses following the Rodeo-Chediski 

Wildfire: an initial assessment. Hydrology and 

Water Resources in Arizona and the Southwest. 34: 

51-56.

Gottfried, G. J.; DeBano, L. F. 1990. Streamflow and 

water quality responses to preharvest prescribed 

burning in an undisturbed ponderosa pine 

watershed. In: Krammes, J. S., ed. Effects of fire 

management of southwestern natural resources. 

Gen. Tech. Rep. RM-191. Fort Collins CO: U.S. 

Department of Agriculture, Forest Service, Rocky 

Mountain Forest and Range Experiment Station: 

222-228.

Harrington, M. G. 1986. Comparison on forest floor 

depth to loading relationships from several Arizona 

ponderosa pine stands. Res. Note RM-463. Fort 

Collins, CO: U.S. Department of Agriculture, 

Forest Service, Rocky Mountain Forest and Range 

Experiment Station. 5 p.

Harrington, M. G. 1987. Ponderosa pine mortality 

from spring, summer, and fall crown scorching. 

Western Journal of Applied Forestry. 2: 14-16.

Hendricks, D. M. 1985. Arizona soils. Tucson, AZ: 

University of Arizona Press. 244 p.

Herman, F. R. 1954. A guide for marking fire-damaged 

ponderosa pine in the Southwest. Res. Note RM-13. 

Fort Collins, CO: U.S. Department of Agriculture, 

Forest Service, Rocky Mountain Forest and Range 

Experiment Station. 4 p.

Holechek, J. L.; Pieper, R. D.; Herbel, C. H. 2004. 

Range management: principles and practices. 

Upper Saddle River, NJ: Prentice Hall. 607 p.

Hornbeck, J. W.; Adams, M. B.; Corbett, E. S.; Verry, 

E. S.; Lynch, J. A. 1993. Long-term impacts of 

forest treatments on water yields: a summary for 

northeastern USA. Journal of Hydrology. 150: 

323-344.

Huffman, E. L.; MacDonald, L. H.; Stednick, J. D. 

2001. Strength and persistence of fire induced 

hydrophobicity under ponderosa pine and lodgepole 

pine, Colorado Front Range. Hydrological 

Processes. 15: 2877-2892.

Hungerford, R. D. 1996. Soils: fire in ecosystem 

management notes: Unit II-I. Boise, ID: U.S. 

Department of Agriculture, Forest Service, National 

Advanced Resources Technology Center.

Hurteau, S. B. G.; Sisk, T. D.; Block, W. M. 2008. 

Avian community response to forest thinning and 

prescribed surface fire alone and in combination. 

In: van Riper, C., III, C.; Sogge, M. K., eds. The 

Colorado Plateau: integrating research and resource 

management for effective conservation. Tucson, 

AZ: University of Arizona Press: 185-196.

Ice, G. G.; Neary, D. G.; Adams, P. W. 2004. Effects of 

wildfire on soils and watershed processes. Journal 

of Forestry. 102(6): 16-20.

Johnson, T. H.; Wauer, R. H. 1996. Avifauna response to 

the 1977 La Mesa fire. In: Allen, C. H., tech. ed. Fire 

effects in southwestern forests: proceedings of the 

second La Mesa fire symposium. Gen. Tech. Rep. 

GTR-RM-286. Fort Collins, CO: U.S. Department 

of Agriculture, Forest Service, Rocky Mountain 

Forest and Range Experiment Station: 70-94.

Keith, J. O. 1965. The Abert squirrel and its dependence 

on ponderosa pine. Ecology. 46: 150-163.

Klemmedson, J. O.; Meier, C. E.; Campbell, R. E. 

1985. Needle decomposition and nutrient release 

in ponderosa pine ecosystems. Forest Science. 31: 

647-660.

Kruse, W. H. 1972. Effects of wildfire on elk and deer 

use of a ponderosa pine forest. Res. Note RM-226. 

Fort Collins, CO: U.S. Department of Agriculture, 

Forest Service, Rocky Mountain Forest and Range 

Experiment Station. 4 p.

Kufeld, R. C. 1973. Food eaten by the Rocky Mountain 

elk. Journal of Range Management. 26: 106-113.

Kundaeli, J. N.; Reynolds, H. G. 1972. Desert 

cottontail use of natural and modified pinyonjuniper woodland. Journal of Range Management. 

25: 116-118.

Larson, F. R.; Ffolliott, P. F.; Clary, W. P. 1986. 

Managing wildlife habitat—in southwestern 

ponderosa pine, diverse treatments are the key. 

Journal of Forestry. 84(3): 40-41.

Larson, R. W.; Goforth, M. H. 1970. TRAS: a computer 

program for the projection of timber volume. Ag. 

Handb. 377. Washington, DC: U.S. Department of 

Agriculture, Forest Service. 24 p.

Letey, J.; Carrillo, M. L. K.; Pang, X. P. 2000. 

Approaches to characterize the degree of water 

repellency. Journal of Hydrology. 231: 61-65.

Liu, S.; Leslie, L. M.; Speer, M.; Bunker, R.; Mo, 

X. 2004. The effects of bushfires on hydrological 

processes using a paired-catchment analysis. 

Meteorology and Atmospheric Physics 86: 31-44.

Lowe, P. O.; Ffolliott, P. F.; Dieterich, J. H.; Patton, 

D. R. 1978. Determining potential wildlife benefits 

from wildfire in Arizona ponderosa pine forests. 

Gen. Tech. Rep. RM-52. Fort Collins, CO: U.S. 

Department of Agriculture, Forest Service, Rocky 

Mountain Forest and Range Experiment Station. 

12 p.

MacArthur, R. H.; MacArthur J. W. 1961. On bird 

species diversity. Ecology. 42: 594-598.

Martin, R. E.; Anderson, H. E.; Boyer, W. D.; Dieterich, 

J. H.; Hirsch, S. N.; Johnson, V. J.; McNab, W. H. 

1979. Effects of fire on fuels: a state-of-knowledge 

review. Gen. Tech. Rep. WO-13. U.S. Department 

of Agriculture, Forest Service. 64 p.

McConnell, B. R.; Smith, J. G. 1970. Frequency 

distributions of deer and elk pellet groups. Journal 

of Wildlife Management. 34: 29-36.
34 USDA Forest Service RMRS-RP-85. 2011.

McHugh, C. W.; Kolb T. E. 2003. Ponderosa pine 

mortality following fire in northern Arizona. 

International Journal of Wildland Fire. 12: 7-22.

McPherson, G. R. 1992. Ecology of oak woodlands 

in Arizona. In: Ffolliott, P. F.; Gottfried, G. J.; 

Bennett, D. A.; Hernandez C, V. M.; OrtegaRubio, A.; Hamre, R. H., tech. coords. Ecology 

and management of oak and associated woodlands. 

Gen. Tech. Rep. RM-218. Fort Collins, CO: U.S. 

Department of Agriculture, Forest Service, Rocky 

Mountain Forest and Range Experiment Station: 

24-33.

McPherson, G. R. 1997. Ecology and management of 

North American savannas. Tucson, AZ: University 

of Arizona Press. 208 p.

Megahan, W. F. 1983. Hydrologic effects of 

clearcutting and wildfire on steep granitic slopes in 

Idaho. Water Resources Research. 19: 811-819.

Morton, D. C.; Roessing, M. E.; Camp, A. E.; Tyrrell, 

M. L. 2003. Rodeo-Chediski. In: Morton, D. C.; 

Roessing, M. E.; Camp, A. E.; Tyrrell, M. L., eds. 

Assessing the environmental, social, and economic 

impacts of wildfire. New Haven, CT: Yale 

University Global Institute of Sustainable Forestry 

Research Paper. 1: 35-38.

Myers, C. A. 1963. Estimating volumes and diameters 

at breast height from stump diameter. Res. Note 

RM-9. Fort Collins, CO: U.S. Department of 

Agriculture, Forest Service, Rocky Mountain 

Forest and Range Experiment Station. 2 p.

National Interagency Fire Center. 2009. Fire 

information: wildland fire statistics. Available: 

http://www.nifc.gov [January 1, 2010].

National Research Council. 2008. Hydrologic effects 

of a changing forest landscape. Washington, DC: 

The National Academies Press. 168 p.

Neary, D. G. 2002. Post-fire flood generation processes. 

Hydrology and Water Resources in Arizona and the 

Southwest. 32: 71-76.

Neary, D. G.; Gottfried, G. J. 2002. Fires and floods: 

post-fire watershed responses. In: Viegas, D., 

ed. Forest fire research and wildland fire safety. 

Rotterdam, The Netherlands: Millpress: 1-7.

Neary, D. G.; Zieroth, E. J. 2007. Forest bioenergy 

system to reduce the hazard of wildfires: White 

Mountains, Arizona. Biomass & Energy. 31: 

638-645.

Neary, D. G.; Ryan, K. C.; DeBano, L. F., eds. 2005. 

Wildland fire in ecosystems: effects of fire on 

soil and water. Gen. Tech. Rep. RMRS-GTR-42-

Volume 4. Fort Collins, CO: U.S. Department of 

Agriculture, Forest Service, Rocky Mountain 

Research Station. 249 p.

Neff, D. J. 1968. The pellet-group techniques for biggame trend, census, and distribution: a review. 

Journal of Wildlife Management. 32: 597-614.

Neff, D. J. 1972. Responses of deer and elk to Beaver 

Creek watershed treatments. Arizona Watershed 

Symposium. 16: 18-24.

Neff, D. J. 1974. Forage preferences of trained deer 

on the Beaver Creek watersheds. Special Rep. 4. 

Phoenix, AZ: Arizona Game and Fish Department. 

61 p.

O’Brien, R. A. 2002. Arizona’s forest resources, 1999. 

Resour. Bull. RMRS-RB-2. Fort Collins, CO: U.S. 

Department of Agriculture, Forest Service, Rocky 

Mountain Research Station. 116 p.

Oswald, B. S.; Covington, W. W. 1983. Changes 

in understory production following a wildfire in 

southwestern ponderosa pine. Journal of Range 

Management. 36: 507-509.

Patton, D. R. 1975a. Abert squirrel cover requirements 

in southwestern ponderosa pine. Res. Pap. RM-145. 

Fort Collins, CO: U.S. Department of Agriculture, 

Forest Service, Rocky Mountain Forest and Range 

Experiment Station. 12 p.

Patton, D. R. 1975b. Nest use and home range of tree 

Abert squirrels as determined by radio tracking. Res. 

Note RM-281. Fort Collins, CO: U.S. Department 

of Agriculture, Forest Service, Rocky Mountain 

Forest and Range Experiment Station. 3 p.

Pearson, G. A. 1950. Management of ponderosa pine 

in the Southwest. Agric. Monog. 6. Washington, 

DC: U.S. Department of Agriculture. 218 p.

Pearson, H. A.; Davis J. R.; Schubert, G. H. 1972. 

Effects of wildfire on timber and forage production 

in Arizona. Journal of Range Management. 25: 

250-253.

Pechanec, J. F.; Pickford, G. D. 1937. A weight 

estimate method for determination of range or 

pasture production. Journal of the American 

Society of Agronomy. 29: 894-904.

Pyne, S. J.; Andrews, P. L.; Laven, R. D. 1996. 

Introduction to wildland fire. New York, NY: John 

Wiley & Sons Inc. 769 p.

Ralph, C. J.; Sauer, C. J.; Droege, S. 1995. Monitoring 

bird populations by point counts. Gen. Tech. Rep. 

PSW-GTR-149. Berkeley, CA: U.S. Department 

of Agriculture, Forest Service, Pacific Southwest 

Forest and Range Experiment Station: 161-168.

Rich, L. R. 1962. Erosion and sediment movement 

following a wildfire in a ponderosa pine forest of 

central Arizona. Res. Note RM-76. Fort Collins, 

CO: U.S. Department of Agriculture, Forest 

Service, Rocky Mountain Forest and Range 

Experiment Station. 12 p.

Rosenstock, S. S. 1996. Habitat relationships of 

breeding birds in northern Arizona ponderosa pine 

and pine-oak forests. Phoenix, AZ: Arizona Game 

and Fish Department Technical Report 23. 53 p.

Rowland, M. M.; White, G. C.; Karlen, E. M. 1984. 

Use of pellet-group counts to measure trends in 

deer and elk populations. Wildlife Society Bulletin. 

12: 147-155.

Ryan, E.; Elliot, W. J. 2005. Fire effects and soil 

erosion models. In: Neary, D. G.; Ryan, K. C.; 

DeBano, L. F., eds. Wildland fire in ecosystems: 

effects of fire on soil and water. Gen. Tech. Rep. 

RMRS-GTR-42-Volume 4. Fort Collins, CO: U.S. 
USDA Forest Service RMRS-RP-85. 2011. 35

Department of Agriculture, Forest Service, Rocky 

Mountain Research Station: 171-177.

Ryan, K. C.; Noste, N. V. 1985. Evaluating prescribed 

fires. In: Lotan, J. E.; Kilgore, B. M.; Fischer, W. C.; 

Mutch, R. W., eds. Proceedings—symposium and 

workshop on wilderness fire. Gen. Tech. Rep. INT182. Ogden, UT: U.S. Department of Agriculture, 

Forest Service, Intermountain Forest and Range 

Experiment Station: 230-238.

Sackett, S. S. 1979. Natural fuel loadings in ponderosa 

pine and mixed conifer forests of the Southwest. Res. 

Pap. RM-213. Fort Collins, CO: U.S. Department of 

Agriculture, Forest Service, Rocky Mountain Forest 

and Range Experiment Station. 10 p.

Sackett, S. S.; Haase, S. M. 1996. Fuel loading in 

southwestern ecosystems of the United States. 

In: Ffolliott, P. F.; DeBano, L. F.; Baker, M. B., 

Jr.; Gottfried, G. J.; Solis-Garza, G.; Edminster, 

C. B.; Neary, D. G.; Allen, L. S.; Hamre, R. H., 

tech. coords. Effects of fire on Madrean Province 

ecosystems: a symposium proceedings. Gen. 

Tech. Rep. RM-GTR-289. Fort Collins, CO: U.S. 

Department of Agriculture, Forest Service, Rocky 

Mountain Forest and Range Experiment Station: 

187-192.

Sackett, S.; Haase, S.; Harrington, M. G. 1994. 

Restoration of southwestern ponderosa pine 

ecosystems with fire. In: Covington, W. W.; 

DeBano, L. F., tech. coords. Sustainable ecological 

systems: implementing an ecological approach to 

land management. Gen. Tech. Rep. RM-247. Fort 

Collins, CO: U.S. Department of Agriculture, 

Forest Service, Rocky Mountain Forest and Range 

Experiment Station: 115-121.

Schmidt, W. C., compiler. 1988. Proceedings—future 

forests of the Mountain West: a stand culture 

symposium. Gen. Tech. Rep. INT-243. Ogden, UT: 

U.S. Department of Agriculture, Forest Service, 

Rocky Mountain Forest and Range Experiment 

Station. 402 p.

Schubert, G. A. 1974. Silviculture of southwestern 

ponderosa pine: the status of our knowledge. Res. 

Pap. RM-123. Fort Collins, CO: U.S. Department 

of Agriculture, Forest Service, Rocky Mountain 

Forest and Range Experiment Station. 71 p.

Severson, K. E. 1981. Food habitats and nutritional 

relationships of mule deer in the Southwestern 

United States. In: Ffolliott, P. F.; Gallina, S., 

eds. Deer biology, habitats requirements, and 

management in Western North America. Mexico, 

Distrito Federal: Instituto de Ecologia: 149-164.

Shannon, C. E.; Weaver, W. 1948. The mathematical 

theory of communication. Urbana, IL: University 

of Illinois Press. 117 p.

Shi, Z.; Xu, D.; Zhang, N.; Qiu, Z.; Hu, Z.; Guo, J. 

2009. Progress in researches on hydrological 

effects of Eucalyptus plantations. Scientia Silvae 

Sinicae. 45: 135-140.

Shiue, C. 1960. Systematic sampling with multiple 

random starts. Forest Science. 6: 42-50.

Shoop, M. C.; McIlvain, E. H. 1963. The microunit forage inventory method. Journal of Range 

Management. 16: 172-179.

Sibley, D. A. 2000. The Sibley guide to birds. New 

York, NY: Alfred A. Knopf. 544 p.

Sieg, C. H.; Phillips, B. G.; Moser, L. P. 2003. Exotic 

invasive plants. In: Friederici, P., ed. Ecological 

restoration of southwestern ponderosa pine forests. 

Washington, DC: Island Press: 251-267.

Smith, J. K., ed. 2000. Wildland fire in ecosystems: 

effects of fire on fauna. Gen. Tech. Rep. RMRS-GTR42-Volume 1. Fort Collins, CO: U.S. Department of 

Agriculture, Forest Service, Rocky Mountain Forest 

and Range Experiment Station. 83 p.

Smith, R. H. 1968. A comparison of several sizes 

of circular plots for estimating deer pellet-group 

density. Journal of Wildlife Management. 32: 

585-591.

Smith, W. B.; Miles, P. D.; Vissage, J. S.; Pugh, S. 

A. 2004. Forest resources of the United States, 

2002. Gen. Tech. Rep. NC-241. St. Paul, MN: U.S. 

Department of Agriculture, Forest Service, North 

Central Research Station. 137 p.

States, J. S.; Gaud, W. S.; Allred, W. S.; Austin, J. 

1988. Foraging patterns of tassel-eared squirrels 

in selected ponderosa pine stands. In: Szaro, R. 

C.; Severson, K. E.; Patton, D. R., tech. coords. 

Management of amphibians, reptiles, and small 

mammals in North America. Gen. Tech. Rep. 166. 

Fort Collins, CO: U.S. Department of Agriculture, 

Forest Service, Rocky Mountain Forest and Range 

Experiment Station: 425-431.

Stropki, C. L.; Ffolliott, P. F.; DeBano, L. F.; Neary, D. 

G. 2005. Water-repellent soils on the Stermer Ridge 

watersheds after the Rodeo-Chediski Wildfire: 

a preliminary assessment. Hydrology and Water 

Resources in Arizona and the Southwest. 35: 47-50.

Swanson, R. H. 1994. Significant historical 

development in thermal methods for measuring sap 

flow in trees. Agricultural and Forest Meteorology. 

72: 113-132.

Szaro, R. C.; Balda, R. P. 1979. Bird community 

dynamics in a ponderosa pine forest. Lawrence, 

KS: Cooper Ornithological Society Studies in 

Avian Biology No. 3. 66 p.

Tecle, A.; Hamre, R. H., tech. coords. 1989. 

Multiresource management of ponderosa pine 

forests. Gen. Tech. Rep. RM-185. Fort Collins, CO: 

U.S. Department of Agriculture, Forest Service, 

Rocky Mountain Forest and Range Experiment 

Station. 282 p.

Thill, R. E.; Ffolliott, P. F.; Patton, D. R. 1983. Deer 

and elk forage production in Arizona mixed conifer 

forests. Res. Pap. RM-248. Fort Collins, CO: U.S. 

Department of Agriculture, Forest Service, Rocky 

Mountain Forest and Range Experiment Station. 

13 p.
36 USDA Forest Service RMRS-RP-85. 2011.

 Troendle, C. A.; King, R. M. 1985. The effect of timber 

harvest on the Fool Creek watershed: 30 years later. 

Water Resources Research. 21: 1915-1922.

U.S. Forest Service. 2002. Rodeo-Chediski Wildfire: 

research coordination meeting. Summary Report. 

Flagstaff, AZ: U.S. Department of Agriculture, 

Forest Service.

U.S. Natural Resources Conservation Service. 1999. 

Eastern cottontail. Washington, DC: U.S. Natural 

Resources Conservation Service Fish and Wildlife 

Habitat Management Leaflet 4. 8 p.

Van Wagner, C. E. 1968. The line intersect method of 

forest fuel sampling. Forest Science. 14: 20-26.

Weaver, H. 1951. Fire as an ecological factor in the 

southwestern ponderosa pine forests. Journal of 

Forestry. 49: 93-98.

Wells, C. G.; Campbell, R. E.; DeBano, L. F.; 

Lewis, C. E.; Frederickson, R. L.; Franklin, E. C.; 

Froelich, R. C.; Dunn, P. H. 1979. Effects of fire on 

soil: a state-of-the-knowledge review. Gen. Tech. 

Rep. WO-7. Washington, DC: U.S. Department of 

Agriculture, Forest Service. 34 p.

Whelan, R. J. 1997. The ecology of fire. Cambridge, 

UK: Cambridge University Press. 346 p.

White, G. C.; Bennetts, R. E. 1996. Analysis of 

frequency count data using the negative binomial 

distribution. Ecology. 77: 2549-2557.

White, G. C.; Eberhardt, L. E. 1980. Statistical 

analysis of deer and elk pellet-group data. Journal 

of Wildlife Management. 44: 121-131.

Whitehead, P. G.; Robinson, M. 1993. Experimental 

watershed studies—an international and historical 

perspective for forest impacts. Journal of 

Hydrology. 145: 217-230.

Yazici, B.; Yolacan, S. 2007. A comparison of 

various tests of normality. Journal of Statistical 

Computation and Simulation. 77: 175-183.

Zar, J. H. 1999. Biostatistical analysis. Englewood 

Cliff, NJ: Prentice Hall. 663 p.

Zhang, L.; Dawes, W. R.; Walker, G. R. 2001. 

Response of mean annual evapotranspiration to 

vegetation changes at a catchment scale. Water 

Resources Research. 37:701-708.

Zimmerman, G. T. 2003. Fuels and fire behavior. 

In: Friederici, P., ed. Ecological restoration of 

southwestern ponderosa pine forests. Washington, 

DC: Island Press: 126-143.
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