For thousands of years, the ecosystems 

of the Middle Rio Grande Basin (which 

includes the river environment and the 

associated upland watersheds) evolved 

under the infl uence of natural factors such 

as shifting landforms, fl oods, drought, 

wildfi re, and climate fl uctuations. More 

recently — since 1540, when the fi rst 

Spanish settlers arrived — human activities 

have had an enormous impact on the area’s 

environment. Factors such as urbanization, 

drought, grazing, timber harvesting, water 

demands, fl ood control measures, fi re 

suppression, hunting, and the introduction 

and spread of exotic (non-native) species 

have all contributed to many ecosystems 

that are altered at best and severely 

degraded at worst. 

Clearly, the Middle Rio Grande Basin no 

longer looks like it did back in the 1500s. 

Evidence of environmental degradation 

can be found throughout the area today: 

in the river itself, in the riverside bosque 

(cottonwood) ecosystems, and in the 

nearby upland ecosystems of grasslands, 

shrublands, and forests. For example: 

• Many fi sh and wildlife habitats have 

been signifi cantly altered in structure 

and composition and reduced in size 

and quality.

• Two species, the Rio Grande silvery 

minnow (Hybognathus amarus) and 

the southwestern willow fl ycatcher 

(Empidonax traillii extimus), have been 

placed on the federal endangered 

species list; others, such as the gray wolf 

(Canis lupus), have not been seen in the 

area for decades.

• At least half of the fi sh species once 

found in the middle Rio Grande 

drainage are no longer found there.

• Exotic tree species such as Russian olive 

(Elaeagnus angustifolia) and saltcedar 

(Tamarix ramosissima) have invaded 

MIDDLE RIO GRANDE BASIN — RESEARCH REPORT 2008 www.fs.fed.us/rmrs 1

U.S. Forest Service Research: 

Understanding, Conserving, and 

Restoring Southwestern Ecosystems

An ecosystem is rarely static. A natural system composed of plants, animals, and 

microorganisms interacting with an area’s physical factors, an ecosystem is always 

fl uctuating and evolving. But sometimes, often at the hands of humans, ecosystems 

change too much. Such is the case with many of the ecosystems of the Middle Rio 

Grande Basin of New Mexico.

Middle Rio Grande Basin

Research Report 2008

A progress report from the Middle Rio Grande Ecosystem Management 

Research Unit, U.S. Forest Service Rocky Mountain Research Station

CONTINUED ON PAGE 2

Inside

Restoring the 

Rio Grande...4

Drought in the 

Southwest...7

Grazing and 

Fire at Valles 

Caldera National 

Preserve...10

Climate

Change...13

Profi le: Hira Walker, 

Ph.D....15

Rio Grande Silvery 

Minnow Diet...17

More Than a 

Scenic Mountain 

Landscape...18

The Middle Rio Grande. 

Photo: David M. Merritt
river habitats, taking over where native species such as cottonwoods (Rio Grande 

cottonwood [Populus deltoides subsp. wislizeni] and Freemont cottonwood [Populus 

fremontii]) used to fl ourish, reducing water supplies, increasing fuel loads and fi re risk, 

and impeding wildlife and human travel.

• The native riverside ecosystems — the marshes, willows, and cottonwoods found 

adjacent to the river — have been greatly reduced in size, distribution, and health.

• Shrubs and small tree species have moved into areas that were once grasslands.

• Upland forests and woodlands have become increasingly subject to wildfi res and bark 

beetle infestations. 

• The Rio Grande itself has changed from a braided river that moved across the 

fl oodplain and regularly fl ooded its banks, and was associated with abundant wildlife 

populations, to one that is now largely constrained and not meandering, and has 

reduced fl ows. 

Conservation Efforts

Efforts to conserve and protect the natural resources of the Southwest date back to the 

1800s, when the U.S. Department of the Interior and the U.S. Bureau of Forestry were 

created, and some local forest reserves were set aside. Those early efforts were followed 

by more federal laws in the 1960s and 1970s, such as the Clean Water Act and the 

Endangered Species Act.

More recently, local conservation efforts have focused on restoring and maintaining the 

health and diversity of Middle Rio Grande Basin ecosystems — the forests, grasslands, 

and shrublands, and the species that inhabit them.

Many organizations, including federal, state, municipal, tribal, and private entities, have 

contributed to these efforts, with some success. For example, the Middle Rio Grande 

Endangered Species Act Collaborative Program and the Middle Rio Grande Bosque 

Initiative have been very successful in generating public interest and support for river 

and bosque restoration and recovering endangered species. 

Too often, however, proposed solutions for restoring Basin ecosystems are based on 

incomplete knowledge of the conditions that led to the problems. Solutions are put 

together without a thorough understanding of how factors such as drought, grazing, 

and fi re interact with each other and can affect restoration efforts. 

The Forest Service’s Research Program

To support and contribute to the ongoing conservation efforts, and to build a sound 

scientifi c basis for future efforts, the Middle Rio Grande Ecosystem Management Research 

Unit, a local unit of the U.S. Forest Service’s Rocky Mountain Research Station, embarked 

on an ambitious long-term research program in 1994.

“To restore and maintain the health of the ecosystems in the area, we fi rst need a better 

understanding of what is here,” explains Deborah Finch, Ph.D., the program’s Team 

MIDDLE RIO GRANDE BASIN — RESEARCH REPORT 2008 www.fs.fed.us/rmrs 2

“ To restore and maintain the 

health of the ecosystem in the 

area, we fi rst need a better 

understanding of what is here.”

 - DEBORAH FINCH, PH.D.

Middle Rio Grande Basin 

Research Report 2008 

is published by:

USDA Forest Service

Rocky Mountain Research 

 Station

2150 Centre Avenue

Fort Collins, CO 80526

www.fs.fed.us/rmrs

Deborah Finch, Ph.D.

Managing Editor

Team Leader

Middle Rio Grande Ecosystem 

Management Research Unit

USDA Forest Service

Rocky Mountain Research 

 Station

333 Broadway SE, Suite 115

Albuquerque, NM 87102

dfi nch@fs.fed.us

voice: 505-724-3671

cell: 505-401-0580

Science Writer/Editor

Catherine Dold

Boulder, CO

Report Design

Linda Parks

Boulder, CO 

The U.S. Department of Agriculture (USDA) 

prohibits discrimination in all its programs 

and activities on the basis of race, color, 

national origin, sex, religion, age, disability, 

political beliefs, sexual orientation, or 

marital or family status. (Not all prohibited 

bases apply to all programs.) Persons with 

disabilities who require alternate means 

for communication of program information 

(Braille, large print, audiotape, etc.) should 

contact USDA’s TARGET Center at 202-720- 

2600 (voice and TDD). To fi le a complaint 

of discrimination, write USDA Director, 

Offi ce of Civil Rights, Room 326-W, Whitten 

Building, 1400 Independence Avenue, SW, 

Washington, DC 20250-9410 or call 202-

720-5964 (voice and TDD). USDA is an equal 

opportunity employer. CONTINUED ON PAGE 3

A bobcat (Lynx rufus) at Valles 

Caldera National Preserve.

Photo: Marc Chipault
The Middle Rio Grande Basin includes the Rio Grande (in blue) from Bandelier National Monument 

in the north to the upper end of Elephant Butte Reservoir in the south, as well as the area 

surrounding the seven major tributaries that contribute to the river: Santa Fe River, Galisteo 

Creek, Jemez River, Las Huertas Creek, Rio Puerco, Rio San Jose, and Rio Salado.

Valles Caldera

National Preserve Bandelier 

National 

Monument

Leader. “We need to understand 

the structural components of the 

ecosystems and how they function and 

interact, particularly in response to 

factors such as population growth and 

extreme climate variability.

“We also need to know more about 

the effectiveness of various restoration 

methods, as well as how to best 

balance restoration plans with human 

needs and priorities.”

The research program is built around 

three broad areas: 1) understanding 

how perturbations such as drought 

and fi re affect ecosystems; 2) 

understanding how management 

practices affect ecosystems; and 3) 

ensuring that scientifi c information 

about the area is available to the 

people — from many backgrounds — 

who will be making decisions about 

how the Middle Rio Grande Basin is 

managed in the future. 

The individual research studies 

affi liated with the program are not 

all done by Forest Service research 

scientists. An annual funding program 

sponsors studies conducted by many 

outside researchers, such as university 

faculty and graduate students, and 

each research proposal is closely 

evaluated for how it fi ts into the 

larger research program. Each study 

alone might seem like it covers just 

a tiny piece of the puzzle. But taken 

together, over several years, these 

studies are uncovering the big picture 

of what we need to do to take care of 

the Middle Rio Grande Basin. 

Research Area 1: Effects of 

Drought and Other Perturbations

It’s no surprise to anyone that 

water availability is one of the most 

important factors infl uencing the 

environment of the Southwest. Water 

— or the lack of it during a drought 

— affects where people live, where 

species live, the makeup of plant 

and animal communities, agricultural 

operations, how people make their 

living and recreate, and much more. 

Long-term drought can also infl uence 

chain reactions of disturbances, 

such as insect outbreaks, extinction 

of native species, fl ourishing exotic 

species, catastrophic wildfi res, and 

changes in human social, cultural, and 

economic stability. 

In addition to water supply, other 

important perturbations are overgrazing, fi re exclusion, climate change, 

and plant and insect invasions. 

“For land managers to be good 

stewards, they need to understand 

how the Middle Rio Grande 

Basin ecosystems react to these 

disturbances, both currently and 

historically, as well as how all of these 

factors interact with each other and 

with humans,” says Finch.“Knowing 

how this all infl uences the dynamics, 

stability, productivity, biological 

diversity, and sustainability of local 

ecosystems forms the scientifi c basis 

for adaptively managing habitats, 

conserving species, and providing 

ecosystem services to humans.

“This knowledge will help us to 

develop the best restoration methods, 

avoiding quick fi x solutions that might 

not work long term.” 

Research in this area includes studies 

on: 1) the relationship between 

drought, bark beetle outbreaks, and 

pinyon pine (Pinus edulis) mortality; 

2) the interactive effects of drought, 

tree thinning, grazing, fuel removal, 

and prescribed fi re in various 

ecosystems; 3) decision-support tools 

for managing the consequences 

of biological invasions; and 4) 

understanding how humans respond 

socially, culturally, and economically 

to these and other issues.

MIDDLE RIO GRANDE BASIN — RESEARCH REPORT 2008 www.fs.fed.us/rmrs 3

CONTINUED ON PAGE 4
“ Maintaining the 

remnants of the 

ribbon of green 

that the Rio Grande 

forms through the 

Southwest is key to 

the ecological and 

social health of this 

region.”

 - DAVID M. MERRITT, PH.D.

The Rio Grande has changed dramatically since 

the 1500s, when European and Spanish settlers 

fi rst arrived in the area. Back then, the river 

regularly fl ooded its banks, creating temporary 

pools and channels, washing away dead plant 

debris, and dispersing the seeds of native plants. 

The river meandered across the landscape, 

changing all the time, yet always forming a 

north-south migratory corridor of habitat for 

birds and a refuge for other animals from the 

surrounding desert. Native cottonwood forests, 

called bosques, and other habitats, such as 

marshes, wet meadows, and willow bars, were 

found along the river in many areas, providing 

habitat for birds, bats, lizards, insects, and other 

species. It was a healthy, thriving ecosystem. 

Over time, however, humans changed the river 

so they could more easily access and use its 

resources. They built dams and levees to control 

the fl oods. They built channels to divert the 

river’s water, delivering it for agricultural uses. 

They planted exotic tree species to secure the 

banks and control erosion. They grazed animals, 

logged the forests, and built roads in the larger 

Middle Rio Grande Basin, activities that all raised 

the sediment load in the river. 

Their intentions were good, but their efforts led to many problems. The plant 

species that relied on fl oods to regenerate, such as cottonwoods and willows, 

declined. The exotic trees, such as saltcedar (Tamarix ramosissima) and Russian 

olive (Elaeagnus angustifolia), thrived and became dominant in the bosque, 

forming dense dry thickets that could easily burn. Fish that were once abundant 

disappeared; two species are believed extinct, while another, the Rio Grande 

silvery minnow (Hybognathus amarus), is on the federal endangered species 

list. Woody debris and other plant litter, no longer washed away by fl oods, 

accumulated in the bosque, changing the landscape and the habitats, and setting 

the stage for potentially catastrophic fi res. Such fi res could cause even further 

damage; they could destroy the remaining native cottonwoods, clearing the way 

for even more exotic plants. Indeed, fi re could completely eliminate the largest 

remaining bosque in the Southwest. 

After so much change, and with so many demands on the river’s water, restoring 

the entire river to its original state is not possible. But researchers and land 

managers are looking at ways to return large portions of it to a more natural, 

ecologically healthy state. For the last seven years, Deborah Finch, Ph.D., Team 

Leader, and others have been exploring various methods for rehabilitating the 

bosque ecosystem.

Research Area 2: Effects of 

Management Practices

The second area of research 

looks at what happens when we 

try to manage or “fi x” various 

ecosystems. Many methods can 

be used, for example, to control 

fi re risk, remove exotic plants, or 

restore some aspect of a complex 

ecosystem. Some work better than 

others. Some can have unintended, 

negative outcomes. 

“We need to understand how the 

many components of the Middle 

Rio Grande Basin ecosystems — 

the water quality, soil quality, plant 

growth rates, fi sh habitat, nesting 

birds, and many other components 

— respond to various management 

practices,” says Finch.

For example, the bosque 

ecosystem, which long fl ourished 

along the Rio Grande, has been 

massively altered in the past 

century. Much of the bosque was 

converted into agricultural or urban 

areas. And many of the natural 

processes that the bosque needs for 

survival, such as spring fl oods that 

remove woody debris and disperse 

seeds, were disrupted after the river 

was channelized. Consequently, 

exotic plants, including saltcedar 

and Russian olive, have invaded 

the bosque, and woody debris has 

increased substantially. Various 

agencies have been using a 

number of tools, such as herbicides 

and chainsaws, to try to remove 

the exotic plants and restore the 

bosque. But the long-term impacts 

and effectiveness of these activities 

are largely unknown. 

Similarly, disturbances such as 

drought, habitat fragmentation, 

and invasive species can cause 

ecosystems to deteriorate, resulting 

in higher fi re risk, loss of species, 

and other ill effects. 

When land managers try to manage 

or restore these disturbed areas, 

MIDDLE RIO GRANDE BASIN — RESEARCH REPORT 2008 www.fs.fed.us/rmrs 4

CONTINUED ON PAGE 14 CONTINUED ON PAGE 5

Restoring the Rio Grande: 

Finding the Best Methods

The Middle Rio Grande in fall.

Photo: MarbleStreetStudio.com
Finch and her colleagues began by 

selecting 12 experimental sites along 

the river, stretching from Albuquerque 

south to Bosque del Apache National 

Wildlife Refuge, some 90 miles down 

the river. Each site was about 50 

acres in size, and was characterized 

by a cottonwood overstory (including 

Rio Grande cottonwood [Populus 

deltoides subs. wislizeni] and Fremont 

cottonwood [Populus fremontii]), an 

understory of native and exotic woody 

plants, and a high fuel load (lots of 

fl ammable debris). Three different 

restoration methods were chosen: 

1) mechanical removal of dead, 

downed, and exotic woody plants 

(using chainsaws, wood chippers, 

and hauling), plus treatment with an 

herbicide; 2) mechanical removal and 

herbicides, plus a prescribed fi re; and 

3) mechanical removal and herbicides, 

plus revegetation with native plants 

(mostly shrubs). Each treatment plan 

would be applied to three of the sites; 

three others would act as controls and 

receive no treatment.

During the fi rst three years of the 

study, no treatments were applied to 

the sites. The researchers established 

the sites, tested their monitoring 

methods, and collected data on 

the current conditions and resident 

species. At each site, they developed 

a detailed picture of what was there, 

measuring and plotting rainfall, 

air temperature, soil salinity and 

nutrients, groundwater levels, plant 

species and density, bird counts and 

nesting sites, bat activity, and the 

abundance of moths, beetles, reptiles, 

and amphibians. They collected 

thousands of points of data.

That baseline monitoring was 

followed by two years of active 

treatment: removal of plants, 

herbicide treatment, prescribed fi res, 

and replanting. After the treatments 

were done, monitoring was done 

to track the ecological responses. 

The researchers again measured the 

numbers and species of trees, birds, 

bats, and other bosque denizens. 

What did they fi nd? All of the 

treatments were successful in 

signifi cantly altering the sites. Overall, 

the treated areas have a more open 

understory, with fewer exotic trees, 

fewer branches on the ground, and 

less litter. 

“The sites changed from having 

dense thickets of exotic plants and 

piles of debris to a more open, or 

park-like understory,” says Heather 

Bateman, Ph.D. Bateman, who is now 

a U.S. Forest Service wildlife biologist, 

led the portion of the study that 

focused on reptiles and amphibians 

while she was a graduate student at 

the University of New Mexico, working 

with her supervisor, Alice ChungMacCoubrey, Ph.D.

Effects on Vegetation

Early analysis shows that the 

treatments were successful in getting 

rid of the exotic plants and decreasing 

fuel loads. Mortality rates of the exotic 

species overall was 84 percent. Their 

re-sprouting rates were acceptably 

low: about 16 percent overall (Russian 

olive was the lowest, at 3 percent, 

while Siberian elm [Ulmus pumila] 

was highest, at 50 percent, indicating 

it needs more intense treatment). 

Moreover, the native species that 

were planted as part of the treatments 

— such as pale wolfberry (Lycium 

pallidum), skunkbrush (Rhus trilobata), 

and screwbean mesquite (Prosopis 

pubescens) — survived well. Across 

the various species, 60 to 100 percent 

of them survived. 

So far, however, the diversity of the 

native plant species has not increased, 

and the cottonwoods, overall, have 

not shown higher growth rates (as 

measured by their annual growth 

rings). Nor have the cottonwoods 

increased the amount of canopy they 

provide. It was expected that the 

cottonwoods would be reinvigorated 

once they were no longer competing 

with the exotic trees (an event known 

as “competitive release”). It could be, 

however, that both native and exotic 

trees had adequate water before the 

treatments, and so the cottonwoods 

were already growing at normal rates. 

MIDDLE RIO GRANDE BASIN — RESEARCH REPORT 2008 www.fs.fed.us/rmrs 5

CONTINUED ON PAGE 6

A variety of methods were 

used to restore the bosque 

ecosystem, including 

mechanical removal of 

dead and exotic plants, 

herbicides, and prescribed 

fi res (far left). The restored 

areas (left) have a more 

open understory. 

Photos: David M. Merritt (far left); 

Heather L. Bateman (left)
A prairie lizard (Sceloporus consobrinus) in the 

middle Rio Grande bosque.

Photo: Heather L. Bateman

David Merritt, Ph.D., a riparian plant 

ecologist with the Forest Service who 

led the plant studies, notes that the 

positive effects of exotic tree removal 

might not be detectable in the fi rst 

years after treatment. “Ecosystem, 

community, and population responses 

may be realized only after several 

years of ‘recovery,’” he says. “Many 

native plant species that provide 

food, nectar, nest materials, and 

habitat are present at most of 

the cleared sites, and are likely to 

become more abundant with time.” 

Moreover, he notes, the study period 

included a severe drought, which may 

have hampered the recovery. Analysis 

of the vegetation data is continuing.

Effects on Animals

The treatments also changed the 

habitats available for many animal 

species. Finch studied the bird 

species found in the sites, focusing 

on the six most common species. 

Species that nest in tree cavities 

were mostly unaffected or showed 

a tendency to increase, probably 

because the exotic trees never 

suited them to begin with (most 

were multi-stemmed, with each 

stem being too narrow for nesting 

cavities). The treatments seemed 

to have little effect on the species 

that nest in the canopy, as well. 

Species that depend on the lower 

two-thirds of tree habitats, however, 

did show a signifi cant response. 

They declined in numbers after the 

treatments, particularly those species 

that had adapted to the presence of 

exotic plants by nesting in or under 

them. Black-chinned hummingbird 

(Archilochus alexandri), the most 

abundant nesting bird species, 

moved its nest sites from exotic 

plants to the remaining native trees, 

such as tall cottonwoods. However, 

those higher nests suffered greater 

predation than did nests built in 

shorter, multi-stemmed exotic trees. 

Lizards, meanwhile, were found in 

greater abundance in the treated 

areas, says Bateman. Four of the 

six most common lizard species 

increased in numbers, probably 

because there were fewer trees and 

less downed wood in the restored 

areas. Amphibians saw signifi cant 

increases as well, but that was due 

to a small fl ood event, rather than 

removal of the exotic plants, says 

Bateman. (For example, in 2005, the 

researchers found 45 times more 

toads as seen earlier, probably due 

to fl oods that created habitat where 

toads could lay eggs and tadpoles 

could develop.) Bats increased in 

activity, too; they were detected more 

often in areas that had less plant 

clutter than before, suggesting that 

exotic plant removal made it easier 

for bats to fl y in the bosque. 

Recommendations for 

Future Restorations

Several of the researchers are 

continuing their data analyses. They 

expect to learn more about the 

implications of bosque restoration 

in the near future, as species adapt 

to the restored conditions. In the 

meantime, however, they can 

recommend that land managers 

proceed with restoration efforts in 

areas where fuel loads are high, with 

some specifi c advice: 

• Removing exotic woody plants will 

help to avoid or reduce fi re risk 

 and intensity and so preserve the 

native trees.

• Replanting with native woody 

plants will improve plant species 

diversity and will help reduce 

the effects of restoration on 

animal species sensitive to loss 

of exotic plants.

• Species that prefer a less-cluttered, 

more open habitat will benefi t 

from treatment.

• Where removal of invasive plants 

is necessary, it’s best to stagger 

the treatments over time, to allow 

animals to adapt to changes in 

their habitats.

• It is critical for scientists to have 

both experimental sites and notreatment control sites, as well as 

opportunities for pre-treatment 

monitoring, in order to evaluate 

the effects of plant removal both 

spatially and temporally. 

“The middle Rio Grande will no 

doubt be the focus of ongoing efforts 

to restore the riparian forest habitat,” 

says Bateman. “This research will 

help to identify species sensitivities to 

habitat changes and the abundances 

of those species currently inhabiting 

this semi-disturbed area.”

“Maintaining the remnants of the 

ribbon of green that the Rio Grande 

forms through the Southwest is key 

to the ecological and social health of 

this region,” adds Merritt. “But it’s a 

formidable challenge given the everincreasing human demands for water 

and the warmer, dryer climate that is 

predicted for the coming years.” ∫

PUBLICATIONS

Bateman, Heather L.; Chung-MacCoubrey, Alice; Finch, 

Deborah M.; Hawksworth, David. 2006. Effects of exotic 

plant removal and fuels reduction on vertebrates along 

the Middle Rio Grande, New Mexico. 2006 Tamarisk 

Research Conference: Current Status and Future 

Directions; 2006 Oct. 3-4; Fort Collins, CO.

Bateman, Heather L.; Chung-MacCoubrey, Alice; Snell, 

Howard L. 2008. Impact of Non-Native Plant Removal 

on Lizards in Riparian Habitats in the Southwestern 

United States. Restoration Ecology. 16: 180-190.

Bateman, Heather L.; Harner, M. J.; Chung-MacCoubrey, 

Alice. 2008. Abundance and reproduction of toads 

(Bufo) along a regulated river in the southwestern 

United States: importance of fl ooding in riparian 

ecosystems. Journal of Arid Environments. 72(9): 

1613-1619.

MIDDLE RIO GRANDE BASIN — RESEARCH REPORT 2008 www.fs.fed.us/rmrs 6

CONTINUED ON PAGE 7
Chung-MacCoubrey, Alice L.; Bateman, Heather 

L. 2006. Herpetological Communities of the Middle 

Rio Grande Bosque: What Do We Know, What Should 

We Know, and Why? In: Aguirre-Bravo, C.; Pellicane, 

Patrick J.; Burns, Denver P.; Draggan, Sidney, eds. 

Monitoring Science and Technology Symposium: 

Unifying Knowledge for Sustainability in the Western 

Hemisphere; 2004 September 20-24; Denver, CO. 

Proceedings RMRS-P-42CD. Fort Collins, CO: U.S. 

Department of Agriculture, Forest Service, Rocky 

Mountain Research Station: 57-66.

Chung-MacCoubrey, A. L.; Bogan, Michael A. 2004. 

Bats of the Piñon-Juniper woodlands of southwestern 

Colorado. In: M.L. Floyd, ed. Ancient Piñon-Juniper 

woodlands: a natural history of Mesa Verde Country. 

Boulder, CO: University Press of Colorado: 131-149.

Finch, Deborah M.; [and others]. 2004. Annual report 

for middle Rio Grande fuels reduction study 2003. 

Albuquerque, NM: U. S. Department of Agriculture, 

Forest Service, Rocky Mountain Research Station. 

200 p.

Finch, Deborah M.; Chung-MacCoubrey, Alice L.; 

Kelly, J. F.; Jemison, R. 2000. A project to evaluate 

fuels-reduction effects on vertebrates, vegetation, 

and water resources along the Middle Rio Grande. In: 

Taylor, John P., ed. Proceedings from the Conference 

on Fire in Riparian Areas, Middle Rio Grande Bosque 

Initiative; Albuquerque, NM. U.S. Fish & Wildlife 

Service: 69-89.

Finch, Deborah M.; Galloway, June; Hawksworth, 

David. 2006. Monitoring Bird Populations in Relation to 

Fuel Loads and Fuel Treatments in Riparian Woodlands 

with Tamarisk and Russian Olive Understories. In: 

Aguirre-Bravo, C.; Pellicane, Patrick J.; Burns, Denver 

P.; Draggan, Sidney, eds. Monitoring Science and 

Technology Symposium: Unifying Knowledge for 

Sustainability in the Western Hemisphere; 2004 

September 20-24; Denver, CO. Proceedings RMRSP-42CD. Fort Collins, CO: U.S. Department of 

Agriculture, Forest Service, Rocky Mountain Research 

Station: 113-120.

Jemison, R. 2004. Relationships between hydrology, 

exotic plants, and fuel loads in the Middle Rio Grande. 

In: Hydrology and Water Resources in Arizona and 

the Southwest. Proceedings of the 2003 meetings of 

the hydrology section Arizona-Nevada Academy of 

Science; 2003 April 12; Flagstaff, AZ: Northern Arizona 

University. 33. 8 p.

Najmi, Y. 2006. Monitoring riparian restoration: A 

management perspective. Proceedings RMRS-P-42CD. 

U.S. Department of Agriculture, Forest Service, Rocky 

Mountain Research Station: 177-180.

Joint Fire Science Program. 2008. Pentimento: Fuels 

Reduction and Restoration in the Bosque of the Middle 

Rio Grande. Fire Science Brief. Issue 7. Boise, ID. 9 p.

Smith, D. M.; Kelly, J. F.; Finch, Deborah M. 2006. 

Cicada emergence in southwestern riparian forest: 

Infl uences of wildfi re and vegetation composition.

Ecological Application. 16(4): 1608-1618.

Smith, D. M.; Kelly, J. F.; Finch, Deborah M. 

2006. Infl uences of disturbance and vegetation 

on abundance of native and exotic detritivores 

in a southwestern riparian forest. Environmental 

Entomology. 35: 1525-1531.

Smith, D. M.; Kelly, J. F.; Finch, Deborah M. 2007. 

Avian nest box selection and nest success in burned 

and unburned southwestern riparian forest. Journal of 

Wildlife Management. 71(2): 411-421.

Stropki, C. L. 2003. Restoration treatments in the 

middle Rio Grande bosque: Effects on soil compaction. 

Albuquerque, NM: University of New Mexico. Thesis. 

Stropki, Cody, L.; Jemison, R. 2004. Restoration 

treatments in the Middle Rio Grande Bosque: Effects 

on soil compaction. In: Hydrology and Water Resources 

in Arizona and the Southwest. Proceedings of the 2003 

meetings of the hydrology section Arizona-Nevada 

Academy of Science; 2003 April 12; Flagstaff, AZ: 

Northern Arizona University. 33. 7 p.

MIDDLE RIO GRANDE BASIN — RESEARCH REPORT 2008 www.fs.fed.us/rmrs 7

The southwestern United States 

is currently experiencing a severe 

drought, the likes of which has not 

been seen since the 1950s. 

A drought is more than just a couple 

of hot, dry summers. It is an unusually 

long period of dry weather, and it can 

have substantial effects on ecosystems 

— dying trees, insect invasions, and 

heightened fi re risks — that can last 

for years. Already, an estimated 10 

to 20 percent of pinyon pines in the 

Four Corners states have died, with 

mortality up to 95 percent in some 

stands. And to make matters worse, 

scientists now believe that climate 

change will lead to even more frequent 

and severe droughts in the future.

Several studies funded by the Middle 

Rio Grande Ecosystem Management 

Research Unit are looking at droughtrelated issues, to help scientists better 

understand what is happening in 

various ecosystems as a result of the 

current drought, what might occur in 

the future, and what land managers 

might do on the ground to protect 

ecosystems and lessen future damage. 

Two groups of researchers are focusing 

on the pinyon-juniper (Pinus edulisJuniperus monosperma) woodlands, 

an ecosystem found in the Middle Rio 

Grande Basin uplands. In particular, 

they want to learn more about how 

drought and invasions of bark beetles 

(such as Ips confusus) may have 

contributed to the vast die-offs of trees 

that have occurred in the uplands in 

recent years. 

The generally accepted theory is that 

drought leaves trees weakened and 

vulnerable, and insects such as bark 

beetles then take advantage of that 

state, infesting the trees and killing 

them. But what exactly happens in a 

tree during that cascade of events? 

What is killing the trees that show no 

sign of insects? And how are these 

changes affecting the larger pinyonjuniper ecosystem?

Drought’s Effect on 

Water Transport

One research team, led by Nate G. 

McDowell, Ph.D., a staff member at 

Los Alamos National Laboratory, is 

studying the internal mechanisms that 

seem to leave the trees so weakened 

during a drought. They want to know 

more about the system by which plants 

normally transport water from the soil 

to their tissues above. Does this water 

transport system simply fail when water 

is scarce? Or does the risk of water 

transport failure in times of drought 

trigger other problems in the tree? 

For example, could the gas-exchange 

openings on leaves (the stomata) be 

shutting down to avoid dehydration, 

leading to a low uptake of carbon 

dioxide during photosynthesis and 

Gutters are used to simulate rainfall 

scenarios at a study plot.

Photo: Jennifer Plaut 

Drought in the Southwest: 

How it Affects Ecosystems

CONTINUED ON PAGE 8
thus lowered carbon reserves to use in 

growth and insect defense?

McDowell and others are exploring 

these questions by manipulating rainfall 

at several pinyon-juniper study plots. 

Located at the Sevilleta Long Term 

Ecological Research site in central New 

Mexico, each study plot contains at 

least fi ve mature and fi ve young pinyon 

trees. The researchers installed a system 

of rain gutters and sprinklers over the 

plots, which they use to simulate rainfall 

scenarios. One site gets 50 percent less 

rain than occurs naturally, one gets 50 

percent more rain, and the rest are used 

as controls. The researchers are now 

collecting data on what is happening 

in the soil and in the plants (such as 

transpiration and growth rates), which 

will allow them to better understand the 

water transport system and assess how 

the trees react to the simulated climates. 

The project is primarily funded by the 

U.S. Department of Energy Program 

for Ecosystem Research. The Middle 

Rio Grande Ecosystem Management 

Research Unit is funding the portion that 

looks at the ecosystem carbon cycle 

consequences of climate change. By 

attaching chambers to the soils or to the 

stems of the plants, the researchers will 

measure the carbon dioxide fl ux from 

those tissues, using an infra-red gas 

analyzer. This allows them to determine 

what happens to the carbon cycle during 

drought. Do these ecosystems lose more 

carbon during a drought? Or are they 

carbon emitters? 

The study, which is ongoing, is expected 

to lead to a deeper understanding of 

the cascade of events that occur during 

drought and beetle invasion. Having 

such information could greatly help 

scientists to determine ideal tree stand 

densities (trees per acre), predict stand 

growth and carbon uptake, and also 

predict how future disturbances such 

as drought might affect the growth and 

survival of the pinyon-juniper woodlands. 

Collaborating with McDowell are Michael 

G. Ryan, Ph.D., Rocky Mountain Research 

Station; William T. Pockman, Ph.D., 

MIDDLE RIO GRANDE BASIN — RESEARCH REPORT 2008 www.fs.fed.us/rmrs 8

Bark beetles are a natural 

component of ponderosa 

pine (Pinus ponderosa) and 

pinyon-juniper (Pinus edulisJuniperus monosperma) 

forests. Adult beetles (there 

are several species) infest 

trees by chewing through the 

bark and laying their eggs 

inside. When the larvae hatch, 

they feed on the inner bark 

of the tree, cutting off the 

fl ow of sap. The beetles also 

produce a characteristic “blue 

stain” fungus, which blocks 

the transport of water and 

nutrients through the tree. 

Eventually, the tree dies. 

Under normal conditions, 

healthy trees defend 

themselves from a bark 

beetle infestation by pushing 

the insects out with sap. 

The beetles thus are usually 

limited to attacking only a 

few diseased or weakened 

trees. Under drought 

conditions, however, trees 

are unable to produce 

those defensive resins, 

leaving many more of them 

vulnerable to attack. 

The current bark beetle 

infestation began in 2002, in 

association with worsening 

drought conditions. Tens of 

millions of pinyon pines have 

already been killed in New 

Mexico, making this the worst 

infestation since an outbreak 

that occurred during a 

drought in the 1950s. (Juniper 

trees are not affected by the 

insects, and ponderosa pine 

deaths have been limited.) 

Those millions of dead trees 

may be setting the stage for 

potentially catastrophic fi res. 

What Is a 

Bark Beetle?

Once a tree has been attacked by bark beetles it cannot be 

saved. For tips on protecting trees and disposing of dead trees, 

see the U.S. Forest Service Southwestern Region bark beetle site, 

www.fs.fed.us/r3/resources/health/beetle/index.shtml.

Several species of bark beetle are involved in the 

current outbreak, including the pinyon bark beetle 

(Ips confusus), right.

Photos: James Holland (pinyon pine); Darren 

Blackford, USFS, Bugwood.org (pinyon bark beetle)

CONTINUED ON PAGE 9
An estimated 10 to 

20 percent of pinyon 

pines in the Four 

Corners states have 

died, with mortality 

up to 95 percent in 

some stands.

Photo: William M. Ciesla, Forest 

Health Management International, 

Bugwood.org

MIDDLE RIO GRANDE BASIN — RESEARCH REPORT 2008 www.fs.fed.us/rmrs 9

University of New Mexico; Richard 

H. Waring, Ph.D., Oregon State 

University; Nicholas C. Coops, Ph.D., 

University of British Columbia; Sue 

A. White, University of New Mexico; 

and Robbie A. Hember, University of 

British Columbia.

Drought’s Effect 

on Tree Stands

The second team of researchers, led 

by Neil S. Cobb, Ph.D., is focusing 

on how drought — in combination 

with bark beetle outbreaks — affects 

the larger pinyon-juniper ecosystem. 

Cobb is director of the Northern 

Arizona University Merriam-Powell 

Center for Environmental Research 

and also curator at the Colorado 

Plateau Museum of Arthropod 

Biodiversity. He and his collaborators 

have been funded by the Middle 

Rio Grande Ecosystem Management 

Research Unit since 2005.

Cobb and his colleagues are working 

on several different studies that 

will 1) help to clarify how upland 

ecosystems at the plot level respond 

to the disturbances of drought and 

bark beetles; 2) assess the changes 

in tree stands and fuel loads in 

areas that have already seen large 

tree die-offs; and 3) determine how 

these disturbances have affected 

the overall Middle Rio Grande Basin 

tree stand structure. Working with 

Cobb are Paulette Ford, Ph.D., 

Rocky Mountain Research Station; 

Robert J. Delph, Colorado Museum 

of Arthropod Biodiversity; Michael 

Clifford, Merriam-Powell Center 

for Environmental Research; and 

Monique Rocca, Ph.D., Colorado 

State University. 

The researchers set up a large 

number of study plots throughout the 

Basin, in areas where many trees had 

died (high-mortality areas) and also 

where they had not (low-mortality 

areas), and carefully measured 

what was found in each plot. They 

recorded data such as basal trunk 

diameter, foliage density, canopy 

height and depth, litter depth, 

percentages of shrubs, grasses and 

forbs, the amount of dead and down 

woody debris, and the abundance 

of more than 300 species of insects, 

spiders, and other arthropods. 

Among the questions they have 

asked: What has changed in the 

pinyon-juniper ecosystem because 

of the drought and bark beetle 

disturbances? Have invasive plant 

species moved in? Have dead trees 

provided habitats that will support 

more arthropods? Have decaying 

trees changed the soils with a 

fl ush of added nutrients? Are 

downed trees raising the risk of 

fi re? What has happened to stand 

structures regionally?

By comparing the data from the 

various sites, the researchers have so 

far found some signifi cant changes in 

the upland ecosystem: 

• Understory vegetation was 

changed, with increases in a more 

drought-tolerant grass species in 

high-mortality areas. 

• A loss of canopy cover reduced 

litter depth in high-mortality 

areas, but soil composition did 

not change. 

• Some classes of fuel loads (the 

amount of woody debris of a 

certain diameter) increased in 

quantity, but others did not, and 

while fi re dynamics were altered, 

the probability of a catastrophic 

fi re due to high levels of dead 

trees is low. 

• Somewhat surprisingly, the overall 

abundance of arthropods was not 

found to be signifi cantly different 

between high- and low-mortality 

areas. This could be because most 

of the dead trees have not fallen 

to the ground yet, and so have not 

increased habitat complexity for 

these species. 

• Arthropod community 

composition was different 

between high- and low-mortality 

areas, with 25 percent indicating 

preferences for either high- or lowmortality habitats. This indicates 

that ground-dwelling arthropod 

communities are changing as a 

result of drought.

• Perhaps the most interesting 

fi nding was that the density of 

trees in a stand did not affect tree 

mortality levels. This contradicts 

the popular theory that trees in 

dense stands are more stressed 

and so tree thinning will reduce 

susceptibility to drought-bark 

beetle outbreaks. 

While the changes to the pinyonCONTINUED ON PAGE 10
Grazing elk are common in Valles 

Caldera National Preserve. 

Photo: Marc Chipault 

MIDDLE RIO GRANDE BASIN — RESEARCH REPORT 2008 www.fs.fed.us/rmrs 10

Disturbances to natural ecosystems, such as 

fi re and grazing, have long been a fact of 

life in the Southwest. 

Sometimes these disturbances are due to 

human activities, sometimes not. Humans 

have been using the resources of the 

Middle Rio Grande Basin for some 10,000 

years, and intense livestock grazing has 

been common for centuries. Elk (Cervus 

canadensis) have long grazed in the area 

as well, recently reaching historically large 

populations. And fi res occurred naturally for 

at least 9,000 years, until they were largely 

suppressed in the late 1800s. 

Although such disturbances are common, scientists do not have a complete 

understanding of how they can affect the landscape. What long-term impacts 

might livestock and elk have on grasslands, forests, rivers, and riparian areas? 

How might they affect fi sh populations, aquatic invertebrates, or water quality? 

How do ecosystems respond when a fi re burns through an entire valley? 

With the creation of the Valles Caldera National Preserve in 2000, there is a great 

need for such information. The preserve’s land managers are now focusing on 

restoration of ecosystems, reduction of forest and grassland fuels to prevent 

catastrophic fi res, and sustainable use of the forests, wildlife, and livestock. 

In addition, some streams in the preserve are considered possible sites for 

reintroduction of the Rio Grande cutthroat trout, (Oncorhynchus clarki virginalis), 

a native species and New Mexico’s state fi sh. Two ongoing U.S. Forest Servicefunded research projects in the preserve may help those managers to make 

decisions on these and other issues in the future.

The Effects of Grazing on Stream Systems

One collaborative, multi-agency study has focused on how grazing by livestock 

and elk might affect stream systems: the fi sh populations, aquatic invertebrate 

communities, water quality, terrestrial insects, vegetation, and stream bank 

morphology. It is being led by Robert R. Parmenter, Ph.D., chief scientist at the 

preserve, Colleen Caldwell, Ph.D., Assistant Leader, Cooperative Fish and Wildlife 

Research Unit, jointly of the U.S. Geological Survey (USGS) and New Mexico State 

University, and Robert DuBey, Ph.D., of New Mexico State University.

The researchers selected 18 multi-acre study sites along three different reaches 

of river in the preserve: the East Fork of the Jemez River, Jaramillo Creek, and the 

San Antonio River. Using fences of varying heights, they built three different types 

of study sites: “open treatments,” where cattle and elk could graze freely; “cattle 

treatments,” where elk could graze but cattle were excluded; and “elk and cattle 

treatments,” where no grazing was allowed. 

Grazing and Fire: Studies in Valles 

Caldera National Preserve

CONTINUED ON PAGE 11

juniper ecosystem are not yet 

considered drastic, the forests will 

continue to change over the coming 

years, as more of the dead trees fall 

down. Indeed, the full extent and 

impacts of the current drought are 

not likely to be known for decades or 

even centuries, and several aspects 

of these studies will be continuing 

in the future. But the changes noted 

so far are a clear indication that land 

managers must be prepared to deal 

with severe events like drought — 

not just average climate conditions 

— in the future. 

“The future management of these 

woodlands needs to take into 

consideration predicted extreme 

climatic events,” says collaborator 

Michael Clifford. “Southwestern 

ecosystems, especially the semi-arid 

woodlands, are susceptible to these 

extreme events and may act as a 

barometer for climatic change.” ∫

PUBLICATIONS

Clifford, Michael; Cobb, Neil S.; Delph, R.; Ford, 

P. L. 2006. Stand Characteristics of Pinyon-Juniper 

Woodlands After a Major Drought Event. 33rd Annual 

Natural Areas Conference; 2006 September 20-23; 

Flagstaff, AZ. 

Clifford, M. J.; Rocca, M. E.; Delph, R.; Ford, P. L.; 

Cobb, N. S. 2008. Drought Induced Tree Mortality 

and Bark Beetle Outbreaks in Southwestern PinyonJuniper Woodlands. In: Gottfried, G. J.; Shaw, J. D.; 

Ford, P. L., eds. Ecology, management, and restoration 

of pinyon-juniper and ponderosa pine ecosystems: 

combined proceedings of the 2005 St. George, Utah, 

and 2006 Albuquerque, New Mexico workshops. 

RMRS-P-51. Fort Collins, CO: U.S. Department of 

Agriculture, Forest Service, Rocky Mountain Research 

Station. 218 p.

Delph, R. J.; Clifford, M.; Cobb, N.; Ford, P. L. 

2006. Impact of Drought and Bark Beetle Outbreak 

on Ground-dwelling Arthropod Dynamics in the 

Pinyon-Juniper Woodlands in the Middle Rio Grande 

Basin. 33rd Annual Natural Areas Conference; 2006 

September 20-23; Flagstaff, AZ. 

Ford, P.; Cobb, N.; Rocca, M. 2006. Impact of a Megadrought & Bark Beetle Outbreak on Pinyon-Juniper 

Woodland Ecosystems in the Middle Rio Grande Basin. 

2006 Sevilleta LTER Research Symposium; 2006 March 

1; Albuquerque, NM.

McDowell, Nate; Pockman, William T.; Allen, Craig D., 

[and others]. 2008. Mechanisms of plant survival and 

mortality during drought: why do some plants survive 

while others succumb to drought? New Physiologist. 

178: 719-739.

McDowell, Nate; White, S. Andra; Pockman, William 

T. [submitted June 2008]. Transpiration and stomatal 

conductance across a steep gradient in the southern 

Rocky Mountains. Ecohydrology. 
MIDDLE RIO GRANDE BASIN — RESEARCH REPORT 2008 www.fs.fed.us/rmrs 11

Since 2002, each site has been 

assessed in the spring and fall. The 

researchers have been collecting 

data on the physical, chemical, and 

biological effects of each treatment. 

The Valles Caldera researchers 

have focused on measuring the 

riparian vegetation, terrestrial 

insect populations, and stream 

channel geomorphology, while the 

USGS researchers have focused on 

habitat characteristics (stream width, 

substrate, water velocity, runs vs. 

pools), water quality, fi sh abundance 

and body condition, and the aquatic 

invertebrate communities. 

The data collection is ongoing, but 

initial analyses have allowed the 

researchers to develop a better 

understanding of the watershed 

dynamics on the preserve. For 

example:

• There are large differences in the 

fi sh species present and in species’ 

abundances from one river to the 

next. 

• Vegetation data analysis has shown 

there were signifi cant increases in 

plant biomass and (in dry years) 

plant diversity in riparian areas 

where livestock and elk were 

excluded. 

• An initial analysis of the aquatic 

invertebrate community data has 

indicated improved stream-bottom 

conditions at the sites where 

grazing was excluded. 

• Restoration of grasses in the nongrazing sites seems to have had a 

benefi cial impact on the structure 

of the streams; they are becoming 

relatively deeper and narrower, 

which provides fi sh with better 

living conditions.

The data collection will continue 

through 2008. When the study is 

completed, it is expected to improve 

our understanding of the effects of 

grazing, as well as help the preserve’s 

land managers to develop livestock 

range models for managing riparian 

habitat and native fi sh communities in 

these watersheds. It will also provide 

data that may help to restore habitats 

that could aid in the recovery of the 

Rio Grande cutthroat trout.

The Effects of Fire 

Plus Grazing

The second study in the preserve 

is examining the effects of fi re and 

grazing on grasslands and forests. 

Parmenter and colleagues selected 

two adjacent watersheds for study: 

Valle Toledo, which would be 

subjected to a prescribed fi re, and 

Indios Creek, which would be a 

no-fi re control site. 

In 2005, the researchers established 

numerous study plots in the two 

watersheds and collected baseline 

data on many parameters, such as 

plant abundance and the species 

present. They also built fences to 

exclude cattle and elk from several 

of the study plots, so that plant 

responses to fi re with and without 

grazing could be assessed. In 

late 2005, fi re crews conducted a 

prescribed burn in Valle Toledo, 

burning about 1,800 acres of 

grassland and ponderosa pine 

(Pinus ponderosa) forest. 

For two years after the burn, the 

researchers returned periodically 

to take detailed measurements 

at the study plots. They assessed 

plant cover, soil nutrients, litter 

decomposition, soil erosion, 

and water quality, as well as the 

abundance and species of fi sh, 

terrestrial arthropods, and aquatic 

macroinvertebrates. To monitor how 

elk and cattle used the areas, they set 

up several cameras that automatically 

took pictures every 15 minutes. 

Data collection continued through 

2007, and analyses are now underway. 

But some interesting early results 

have been noted. In many of the 

areas studied, there were no major 

adverse effects seen due to the fi re. 

Macroinvertebrate communities 

were mostly unaltered, as were fi sh 

populations. Stream water quality was 

not signifi cantly changed. Soil erosion 

was non-existent. Plant communities 

were signifi cantly reduced in canopy 

size and leaf height after one year, 

indicating that they likely need two 

or more years to recover. In contrast, 

plant nutritional characteristics 

were enhanced. There was more 

protein and mineral content, which 

provides better forage for wildlife 

and livestock. Not surprisingly, the elk 

signifi cantly increased their use of the 

burned areas. 

A prescribed burn is set in Valle Toledo, Valles Caldera National Preserve.

Photo: Valles Caldera Trust Cultural Resources 

CONTINUED ON PAGE 12
It is expected that the fi nal results 

from this study, too, will help Valles 

Caldera National Preserve managers 

to implement more effective 

restoration and conservation plans 

in the future. In addition, the 

study results will allow the public 

to learn more about the positive 

effects of fi re, and will help to build 

public confi dence in management 

decisions on the use of prescribed 

and natural fi re. ∫

PUBLICATIONS

Anderson, Mike; Caldwell, Colleen. 2008. Effects of 

Riparian Grazing on Growth Rate and Movement of 

Brown Trout in the Valles Caldera National Preserve, 

New Mexico. In: Proceedings and Abstracts: The 

2008 Jemez Mountains Science Symposium; 2008 

March 28; Santa Fe, NM; Valles Caldera Trust. 

Abstract.

Anderson, Mike; Caldwell, Colleen; DuBey, Robert; 

Parmenter, Robert. 2008. Stream Fish Response 

and Water Quality Characteristics Following 

Prescribed Fire, Valles Caldera National Preserve, 

NM. In: Proceedings and Abstracts: The 2008 Jemez 

Mountains Science Symposium; 2008 March 28; Santa 

Fe, NM; Valles Caldera Trust. Abstract.

Barnes, Will; Parmenter, Bob; Padgett, Molly. 2008. 

Valle Toledo Fire Experiment: Plant responses to fi re 

and grazing. In: Proceedings and Abstracts: The 2008 

Jemez Mountains Science Symposium; 2008 March 

28; Santa Fe, NM; Valles Caldera Trust. Abstract.

Civitello, Jamie A. 2008. Valle Toledo Prescribed 

Fire: Obsidian Responses to Fire. In: Proceedings 

and Abstracts: The 2008 Jemez Mountains Science 

Symposium; 2008 March 28; Santa Fe, NM; Valles 

Caldera Trust. Abstract.

Dubey, R. 2005. Grazing Effects on Habitat, 

Macroinvertebrates, and Fishes in Streams on the 

Valles Caldera National Preserve. Las Cruces, NM: 

New Mexico Cooperative Fish and Wildlife Research 

Unit: 2, 3, 20.

Dubey, R. J.; Caldwell, C. A.; Gould, W. R. 2007. 

Relative susceptibility and effects on performance 

of Rio Grande cutthroat trout and rainbow trout 

challenged with Myxobolus cerebralis. Transactions 

of the American Fisheries Society. 136: 1406-1414.

Duran, Zoe Anna; Parmenter, Robert R. 2008. Valle 

Toledo Fire Experiment: Ground-dwelling arthropod 

responses to fi re and grazing. In: Proceedings and 

Abstracts: The 2008 Jemez Mountains Science 

Symposium; 2008 March 28; Santa Fe, NM; Valles 

Caldera Trust. Abstract.

Jacobi, Jerry. 2008. Valle Toledo Fire Experiment: Fish 

population responses. In: Proceedings and Abstracts: 

The 2008 Jemez Mountains Science Symposium; 2008 

March 28; Santa Fe, NM; Valles Caldera Trust.

Parmenter, Robert R. 2008. Valle Toledo Fire 

Experiment: Introduction and Overview. In: 

Proceedings and Abstracts: The 2008 Jemez 

Mountains Science Symposium; 2008 March 28; Santa 

Fe, NM; Valles Caldera Trust. Abstract.

White, Carlton S. 2008. Valle Toledo Prescribed 

Fire: Interactive effects of fi re with grazing and 

vegetation on soil nutrient dynamics. In: Proceedings 

and Abstracts: The 2008 Jemez Mountains Science 

Symposium; 2008 March 28; Santa Fe, NM; Valles 

Caldera Trust. Abstract.

MIDDLE RIO GRANDE BASIN — RESEARCH REPORT 2008 www.fs.fed.us/rmrs 12

How Do Birds 

React to Fire?

One long-accepted viewpoint in 

the Southwest is that decades of 

fi re suppression, combined with 

logging and grazing practices, 

have led to tree stands that 

are very dense and at risk of 

fi res that are unnaturally large 

and severe. With that in mind, 

many ecosystem restoration 

programs now aim to reduce 

tree stand densities, hoping that 

such changes will reduce the 

risk of severe fi res and allow for 

the return of more controlled 

understory fi res. 

However, some researchers 

think this scenario might be 

oversimplifi ed, noting that 

severe fi res are not unheard of 

in southwestern history. Indeed, 

severe fi res may be ecologically 

benefi cial.

Natasha B. Kotliar, Ph.D., 

an ecologist with the U.S. 

Geological Survey (USGS), in 

Fort Collins, CO, proposed 

to look at this question by 

examining how birds react to 

fi re conditions. 

After the severe Cerro Grande 

fi re of 2000, which burned 

42,000 acres near Los Alamos, 

Kotliar launched a multi-year 

study of the birds in the region. 

She marked off 49 study plots 

in the hills near the 2000 fi re, 

in burned as well as unburned 

areas. Each site was ranked in 

terms of how severely it was 

burned, and was then surveyed 

several times to see which bird 

species were found there. She 

also did surveys at nearby sites 

that had been surveyed by a 

colleague a few years before the 

fi re (1986-1990) and had also 

burned in 2000.

Statistical analysis was used to 

build a picture of the number of 

birds found in the various areas. 

Overall, the majority of species 

(71 percent) showed either a 

positive or neutral response 

to fi re, as measured by their 

density in burned areas. And 

many showed positive responses 

even to the most severely 

burned areas. Western woodpewee (Contopus sordidulus) 

and western bluebird (Sialia 

Mexicana), for example, were 

found almost exclusively in 

severely burned areas. Other 

species were found in areas 

of all burn severity, but were 

most often found in severely 

burned areas: hairy woodpecker 

(Picoides villosus), house wren 

(Troglodytes aedon), and broadtailed hummingbird (Selasphorus 

platycercus).

These results, says Kotliar, 

demonstrate that severe fi res 

are important to the landscape. 

They create forest structures 

and elements, such as standing 

dead trees, that are not likely 

to be created by forest thinning 

and understory fi res, but that 

are preferred by some species. 

“Fire management that includes 

a range of variability, including 

severe fi res, is more likely to 

preserve a broad range of 

ecological functions,”she says. Photos top right: Valles Caldera Trust 

Cultural Resources (background fi re); 

Ashok Khosla, seeingbirds.com 

(western bluebird)
Is it getting warmer out there? After many years of debate, most scientists now 

agree that climate change is a reality, and the Earth is getting warmer. Last year, the 

Intergovernmental Panel on Climate Change (IPCC) reported that “warming of the 

climate system is unequivocal,” and that the warming was very likely due to human 

activities such as deforestation and the burning of fossil fuels.

Whether or not this warming is affecting environmental systems worldwide is no 

longer in question either. Scientists have observed signifi cant declines in glaciers 

and snow cover, rising sea levels, increased precipitation in some parts of the world, 

and longer and more intense droughts in other areas. Climate change has also 

been correlated with an increased frequency in forest fi res and insect outbreaks 

(including in the Southwest), earlier spring runoff peaks, and shifts in distribution and 

reproductive patterns of plants, fi sh, and wildlife. Moreover, these changes are very 

likely to accelerate in the future.

Still, there is much that is not known about climate change and its potential effects. 

Scientists and decisionmakers in the U.S. and elsewhere want to better understand 

how climate change could infl uence plants, animals, ecosystems, and disturbance 

patterns. They want to know more about how it could affect the products and 

services that ecosystems provide, such as timber, clean water, food supplies, 

biodiversity, fl ood protection, recreation, and aesthetic and spiritual benefi ts. And 

land managers are looking for information on how they can best manage their 

forests, grasslands, and other areas in the face of a changing climate. 

The U.S. Forest Service is well-positioned to help provide those answers, as the 

agency has been conducting research on climate change for 20 years. As forest 

Service Chief Gail Kimbell noted at a recent conference on science, policy, and 

the environment, “climate change cuts across virtually every major issue we face in 

forest management — fi re and fuels, invasive species, water resources, forest health, 

endangered species, outdoor recreation, and more.” 

“The Forest Service has a strong scientifi c basis for addressing climate change in all 

of these areas,” she added.

The Agency’s Research and Development branch, which includes the Rocky Mountain 

Research Station (RMRS), has been studying issues related to climate change for 

many years. The organization’s climate change research priorities include 1) providing 

national leaders on policies, issues, and discussions, and 2) conducting extensive 

research on the effects of climate change. Such research includes adaptation science, 

which addresses how ecosystems respond under different climate scenarios, and how 

land managers can prepare for uncertain future conditions; and mitigation science, 

which looks at how forests, woodlands, and grasslands can sequester carbon, as well 

as related issues.

In the fi rst area, providing national leadership on the issues, Forest Service 

scientists and consultants are taking part in a number of national and international 

assessments: they are analyzing the extensive scientifi c literature on climate change 

in order to apply existing knowledge toward improving conditions, identify gaps 

MIDDLE RIO GRANDE BASIN — RESEARCH REPORT 2008 www.fs.fed.us/rmrs 13

“ Climate change cuts 

across virtually every 

major issue we face in 

forest management 

— fi re and fuels, 

invasive species, water 

resources, forest health, 

endangered species, 

outdoor recreation, 

and more,” says Forest 

Service Chief Gail 

Kimbell.

 For further discussion

 on climate change,

 see “Climate Change and 

the Nation’s Forests: Challenges 

and Opportunities,” a paper that 

recently appeared in the Journal 

of Forestry. Dale Bosworth, chief 

emeritus of the Forest Service, 

and Linda Joyce, a quantitative 

ecologist with the Rocky Mountain 

Research Station, are co-authors of 

the paper. 

Bosworth, Dale; Birdsey, Richard; 

Joyce, Linda; Millar, Constance. 

2008. Climate Change and the 

Nation’s Forests: Challenges and 

Opportunities. Journal of Forestry. 

106(4): 214-221.

The U.S. Forest Service 

Takes on Climate Change

A great blue heron (Ardea herodias) 

at Bosque del Apache National 

Wildlife Refuge in New Mexico. 

Photo: Dick Thompson 

CONTINUED ON PAGE 14
MIDDLE RIO GRANDE BASIN — RESEARCH REPORT 2008 www.fs.fed.us/rmrs 14

in needed information, and make 

recommendations for future research. 

One of the most notable of these 

endeavors was the participation of 

several Forest Service researchers 

in writing the recent report from the 

IPCC, which was awarded the 2007 

Nobel Peace Prize, along with former 

U.S. vice president Albert Gore. 

In the second area, the research arena, 

RMRS scientists are now carrying out 

numerous scientifi c studies throughout 

the West, looking at issues such as 

the effect of temperature on trout 

habitat and the effect of snow cover 

on wolverine dens. In the Middle 

Rio Grande Basin area, scientists are 

focusing on issues of local concern, 

such as the effects of climate change 

in drought, outbreaks of insects such 

as bark beetles, non-native species 

distribution, and the risk of severe 

forest fi res. 

In addition, a strong emphasis on 

climate change issues in the RMRS’s 

most recent strategic framework 

ensures that these issues will continue 

to be a priority in years to come.

Among the questions researchers will 

try to answer in the future are:

• What is climate’s role in the major 

disturbances we are seeing now, 

specifi cally in aspen (Populus 

tremuloides) die-back and 

pinyon loss in pinyon-juniper 

ecosystems (Pinus edulis-Juniperus 

monosperma)?

• Can carbon sequestration rates 

be increased in forested lands? 

• What does climate change mean 

for ecosystems thought to be 

natural or undisturbed, such as 

wilderness areas?

• How will climate change directly 

infl uence species at risk, such as 

wolverine (Gulo gulo luscus), wolf 

(Canis lupus), spotted owl (Strix 

occidentalis caurina), and grizzly 

bear (Ursus arctos horribilis), as 

well as migratory birds and aquatic 

species?

• How will a changing climate 

alter fi re intensity, severity, and 

occurrence?

“We have made a start,” in addressing 

climate change, says Forest Service 

Chief Kimbell. “However, climate 

change will remain a challenge for 

generations to come.” ∫

“Climate Change 2007,” the IPCC report 

that won the Nobel Prize, is available at 

www.ipcc.ch/ipccreports/assessmentsreports.htm.

they need to fully understand the ecological consequences 

of their decisions. For example, if exotic plants are removed 

from the bosque, will they re-sprout? How quickly? How 

much grazing can be allowed in a grassland while still 

protecting biological diversity? Will removing fuels in an 

upland watershed, such as with a prescribed fi re or by 

thinning small-diameter trees, help to restore a productive 

environment?

And again, land managers also need more information 

on social concerns. How do these activities affect humans 

and their relationship with the environment? For example, 

misunderstandings can easily arise among residents, 

landowners, and recreationists if it appears that access to 

resources such as water or a forest may be limited. 

Research in this area includes studies on: 1) understanding 

the effects of disturbances on aquatic habitats and fi sh 

populations; 2) understanding the effects of removing 

bosque exotic species and fuels; and 3) developing 

information to aid in resolving social concerns. 

Research Area 3: Communicating Research Findings

The third area of research is intended to ensure that 

information developed on Middle Rio Grande Basin 

ecosystems is easily and quickly made available to all 

interested parties. Scientists and others are being funded to 

develop publications, databases, computer programs, fi eld 

trips, and conferences to help synthesize and make public 

their research fi ndings. 

A Long-Term Program

The questions raised by the Middle Rio Grande Ecosystem 

Management Research Unit won’t be answered overnight. 

Research takes time; in some cases, years. But much work 

has already been done. For example, a comprehensive 

environmental history of the area has been published, as 

well as a history of irrigation in the area and a synthetic 

review of Basin ecology and issues. Many fi eld researchers 

have been funded, and many of them have presented 

their fi ndings at symposia and professional meetings and 

published noteworthy articles in peer-reviewed journals. 

Newer studies continue with multi-year research. 

This report describes several of the research projects most 

recently funded by the Middle Rio Grande Ecosystem 

Management Research Unit. ∫

CONTINUED FROM PAGE 4

U.S. Forest Service Research: Understanding, Conserving, and Restoring Southwestern Ecosystems

A woman fi shes on the Middle Rio Grande. 

Climate change could possibly affect how 

people, such as this angler, experience the 

outdoors. 

Photo: Jeff Greenberg
MIDDLE RIO GRANDE BASIN — RESEARCH REPORT 2008 www.fs.fed.us/rmrs 15

Growing up in California, Hira 

Walker had always been interested 

in birds. She delighted in watching 

the hummingbirds and doves 

that frequented the trees outside 

her bedroom window. In college 

at the University of California at 

Santa Cruz, she pursued degrees in 

biology and environmental studies. 

But it wasn’t until a guest speaker — 

a professional ornithologist — spoke 

to her natural history class that she 

realized she could build an entire 

career around her love for birds. 

“It was the fi rst time I realized I could be an ornithologist,” Walker recalls. 

She hung around after class to talk with the guest speaker, and he offered her 

a volunteer position. Walker soon found herself working directly with birds, 

capturing them with mist nets and putting identifi cation bands on their legs. 

Her career as an ornithologist was underway.

A few years later, Walker was pursuing graduate studies in Missouri when 

contact with another professional ornithologist — Deborah Finch, Ph.D., of 

the U.S. Forest Service — led to another big career move. After talking with 

Finch, Walker transferred to the University of New Mexico, where Finch was 

a research associate professor. In Albuquerque, Walker studied under Finch 

and also began working for the Rocky Mountain Research Station under the 

authority of the Student Temporary Employment Program and alternatively 

as a contractor. Her fi rst job with the Station, in 1997, involved studying how 

neotropical migrant birds used different habitats at the Bosque del Apache 

National Wildlife Refuge. 

Walker continued to work with the agency for the next ten years, while she 

worked on her Ph.D., and afterward, as a postdoctoral researcher. With Finch 

as her mentor, she held numerous part-time and full-time jobs with the agency, 

gaining experience in many aspects of ornithology, including vegetation 

and bird surveys, nest searching and monitoring, data collection techniques, 

supervision and training of biological technicians, study design and analysis, 

and preparation of progress reports and articles for peer-reviewed publications. 

The “trust, support, and encouragement,” she got from Finch was invaluable, 

says Walker. “She gave me a lot of independence and the opportunity to 

develop my own projects.”

Hira Walker with a greater roadrunner 

(Geococcyx californianus). 

Photo: Susan Allerton 

Launching a Career 

with the U.S. Forest 

Service

In addition to Hira Walker (left), 

Heather Bateman (“Restoring the 

Rio Grande,” page 4) and Hugo 

Magaña (“What Do Rio Grande 

Silvery Minnows Prefer to Eat?,” 

page 17) also began their careers 

as students working for the 

U.S. Forest Service. Many other 

students around the country have 

also benefi tted professionally from 

their associations with the Agency. 

The Forest Service has several 

programs that can help students 

to launch a career in the natural 

resources. These programs 

may involve part-time positions 

during the school year, full-time 

jobs during vacation periods, 

internships, scholarships, and more. 

Students are often hired fi rst 

under the Student Temporary 

Employment Program (STEP). 

Students who show strong 

potential may be recruited for 

the Student Career Experience 

Program (SCEP), which often leads 

to permanent employment with the 

government. Students may 

also fi nd opportunities in the 

national Student Volunteer 

Program, the U.S. Department 

of Agriculture (USDA) National 

Scholars Program, the USDA 

Summer Intern Program, local 

work-study programs, and research 

joint ventures with universities. 

For information, see www.fs.fed.

us/fsjobs/index.html, or contact 

your local Forest Service offi ce.

“ There is a desire to simplify things as ‘non-native bad, native 

good.’ But it’s really much more complex. Is something bad 

just because it is exotic? ” 

 - HIRA WALKER, PH.D.

Profi le: Hira Walker, Ph.D.

From Student to Professional

CONTINUED ON PAGE 16
As her studies and work experience 

progressed, Walker developed her own 

area of expertise: assessing how human 

activities, such as habitat destruction 

and the introduction of exotic plants, 

can affect migrating, breeding, and 

wintering birds. Her work has included 

research on a very timely issue in 

New Mexico — the proliferation of 

a common exotic plant, saltcedar 

(Tamarix ramosissima).

“Saltcedar is the predominant plant 

in some areas of the Southwest,”

she says. Indeed, it is now the most 

common plant species in many local 

riparian ecosystems. By some 

estimates, saltcedar and other exotic 

plants could dominate southwestern 

riparian ecosystems within the next 50 

to 100 years. Many agencies are 

in the midst of aggressive programs 

to remove the exotics and replant with 

native vegetation. But given that the 

saltcedar is here, Walker says, we 

need to look at how it affects birds. 

“Can it be a functional replacement for 

the native vegetation?” she wants to 

know. “Which birds use it and which 

ones are avoiding it?” 

In her studies, Walker has found that 

some migrating bird species do make 

good use of saltcedar. “In certain 

circumstances, saltcedar vegetation 

can support higher numbers of bird 

species and individuals than native 

vegetation,” she says. “Not all 

saltcedar vegetation has equal value 

to birds, however. Their use of it 

depends on such factors as whether it 

is a young shrub or a mature tree, and 

whether it is intermixed with native 

plants.” Moreover, she reports, the 

“bad” exotic species might in fact be 

helping to stem declines in some bird 

populations, by providing a refugia 

in landscapes where other woody 

vegetation is absent.

“There is a desire to simplify things 

as ‘non-native bad, native good,’” 

she says. “But it’s really much more 

complex. Is something bad just 

because it is exotic?”

Walker is not opposed to efforts to 

eradicate exotic plants, but based 

on her research, she advises that 

land managers take precautions to 

protect bird species. “If you are going 

to remove saltcedar, you have to do 

it in stages,” she says. “Otherwise, 

what are the birds going to do in 

the meantime?” She suggests that 

eradication programs fi rst target 

habitats that are less diverse (and 

that support fewer species), and that 

replanting after exotics are removed 

is made a priority. Walker reports she 

is pleased to see that many programs 

are now taking such tactics, selectively 

removing exotics, and leaving some in 

place until native plants are restored. 

Walker recently started a new job, 

working as an endangered species 

ornithologist for the New Mexico 

Department of Game and Fish. Her 

work with the Forest Service was 

invaluable in helping to land that 

position, she says. “I had a Ph.D. and 

ten years of experience,” she notes. 

“It made a signifi cant difference.” 

Her advice for other aspiring 

ornithologists and biologists? “Align 

yourself with people who support and 

promote you, and push yourself to take 

on challenges whenever opportunities 

arise,” she says. ∫

PUBLICATION

Walker, Hira A. 2008. Floristics and Physiognomy 

Determine Migrant Landbird Response to Tamarisk 

(Tamarix Ramosissima) Invasion in Riparian Areas. 

The Auk. 125(3).

MIDDLE RIO GRANDE BASIN — RESEARCH REPORT 2008 www.fs.fed.us/rmrs 16

A New Field 

Guide to 

the Middle 

Rio Grande 

Bosque

a. What large insect lives underground 

for fi ve to ten years, emerging only 

as an adult? 

b. What local herb was often used in folk 

medicine, even though its sap is toxic, 

and was also used to make ropes? 

c. In what species do the males get 

together as a chorus to serenade 

females?

(See answers below)

A new fi eld guide to the plants and 

animals of the middle Rio Grande bosque 

and nearby areas will soon provide those 

answers, as well as details on 700 other 

local species.

A Field Guide to the Plants and Animals 

of the Middle Rio Grande Bosque

features information on how to identify 

each species, its taxonomy, where it lives, 

how common it is, and interesting details 

about its natural history. 

“Our goal is to help sensitize the next 

generation of New Mexicans to our 

natural heritage,” says co-author JeanLuc E. Cartron, a former postdoctoral 

employee with the Rocky Mountain 

Research Station (RMRS), Albuquerque 

Laboratory, and now with the Drylands 

Institute. 

Cartron’s co-authors are local natural 

history experts David C. Lightfoot, 

Jane E. Mygatt, Sandra L. Brantley, and 

Timothy K. Lowrey. The Field Guide is 

the result of a collaboration between the 

Drylands Institute and the University of 

New Mexico Museum of Southwestern 

Biology, with sponsorship by many 

organizations, including RMRS. All 

proceeds will be used to buy copies of 

the guide for classrooms and educational 

programs.

Answers: 

a. Giant cicada (Tibicen marginatus)

b. Indian-hemp (Apocynum cannibinum)

c. Several toad species, including the Woodhouse’s toad

 (Bufo woodhousii) 

Woodhouse’s toads are known to serenade 

female toads. Photo: Jean-Luc E. Cartron
The Rio Grande silvery minnow has 

been on the federal endangered 

species list since 1994. 

Photo: Joel Lusk, USFWS

MIDDLE RIO GRANDE BASIN — RESEARCH REPORT 2008 www.fs.fed.us/rmrs 17

Restoring or protecting an endangered or 

threatened species is a complex task. What 

sort of habitat does it need? What does it 

eat? What caused its demise in the fi rst place: 

habitat loss, pesticides, an invasive species 

that displaced it or preyed on it, or something 

else? Field managers often need the answers 

to these and other questions before they can 

take meaningful steps to help populations of a 

species recover.

Such is the case with the Rio Grande silvery 

minnow (Hybognathus amarus). This tiny fi sh 

species, once the most abundant fi sh in the Rio 

Grande Basin, is now found in only fi ve percent 

of its historic range. It was placed on the federal endangered species list in 1994, and 

resource managers are now working on a recovery plan. 

Many likely causes of the fi sh’s decline have been cited, including water quality 

problems, water impoundments along the river, and the effects of cattle grazing. 

But little research had been done on the species’ food preferences. Hugo A. 

Magaña, Ph.D., now a research fi sheries biologist with the Rocky Mountain Research 

Station in Albuquerque, decided to explore that question as part of his Ph.D. work 

at the University of New Mexico. Magaña’s salary was sponsored by the Scientist 

Recruitment Initiative of the U.S. Forest Service, and his research was sponsored by 

the Middle Rio Grande Ecosystem Management Research Unit, as well as by the U.S. 

Bureau of Reclamation and the U.S. Army Corps of Engineers.

Magaña set up a series of feeding trials to look at several questions, such as which 

diatom (algae) species the fi sh prefer, and whether they could learn to respond 

to offered food. He cultured samples of 15 different diatoms, placed some young 

hatchery-produced fi sh in a series of fi sh tanks, and systematically offered them food 

sources. To determine their food preferences, he documented on videotape how 

long it took the fi sh to fi nd the food, how often they returned to the food source, and 

how much time they spent sampling it. 

His results showed that Rio Grande silvery minnows do indeed have some dining 

preferences: they clearly preferred two diatoms, Nitzschia palea and Nitzschia 

paleacae, over other species. And they could be conditioned to eat; fi sh that had 

earlier been offered a food source were much quicker to feed upon it when it was 

offered a second time.

Magaña’s results suggest that it might be possible for hatchery-produced Rio Grande 

silvery minnows to be trained to forage for food, before they are released into the 

wild as part of reintroduction efforts. “Given that 95 percent of all hatchery fi sh 

die from predation or starvation within weeks of their release,” he says, “instilling 

such skills in Rio Grande silvery minnows before their release could greatly increase 

their ability to survive in the wild. It could help them come back from the brink of 

extinction.” ∫

The Middle Rio 

Grande Ecosystem 

Management 

Research Unit

The Middle Rio Grande Ecosystem 

Management Research Unit 

(Research Work Unit 4652), which 

provided funds for the research 

projects described in this report, is 

part of the Grassland, Shrubland, 

and Desert Ecosystems Research 

Program of the U.S. Forest Service’s 

Rocky Mountain Research Station 

(RMRS).

The RMRS, headquartered in Fort 

Collins, Colorado, administers and 

conducts research throughout a 

14-state area, covering the Great 

Basin, the Southwest, the Rocky 

Mountains, and part of the Great 

Plains. Its scientists investigate 

issues related to wildlife and fi sh, 

fi re and fuels, invasive species, 

forest and rangeland inventory, 

recreation, resource management 

and use, and water and air quality 

at numerous research stations and 

other locations. This vast research 

organization is comprised of 

seven programs and a wilderness 

institute, which produce and 

deliver scientifi c information to 

help land managers, planners, 

and other specialists make wise 

decisions about our nation’s forests, 

rangelands, and grasslands. RMRS 

is one of six research stations that 

are part of the U.S. Department of 

Agriculture Forest Service Research 

and Development organization, the 

largest natural resources research 

organization in the world. 

All research funded by the Middle 

Rio Grande Ecosystem Management 

Research Unit falls within the 

strategic framework focus areas 

established by RMRS: fi re, water, 

terrestrial ecosystems, climate 

change, and human connections. 

See www.fs.fed.us/rmrs/research/

programs for more information 

on these programs. 

What Do Rio Grande Silvery 

Minnows Prefer to Eat?
More Than a Scenic 

Mountain Landscape

is available free of 

charge from:

USDA Forest Service

Rocky Mountain Research

 Station

240 West Prospect Rd. 

Fort Collins, CO 80526-2098

rschneider@fs.fed.us

970-498-1392 

www.fs.fed.us/rm/pubs/rmrs_

gtr196.html

Also of interest:

State of the Preserve 2002-

2007, a report published by 

the Valles Caldera Trust, which 

identifi es collaborative studies 

with Rocky Mountain Research 

Station and others.

Available from: 

Valles Caldera Trust

PO Box 359

Jemez Springs, NM 87025 

www.vallescaldera.gov/

about/trust/docs/trust_

SOPDecember2007ExecSum.

pdf

Valles Caldera National Preserve 

Photo: Marc Chipault

Valles Caldera National Preserve was 

established in 2000, when the U.S. 

Congress authorized the purchase of 

the historic Baca ranch located just 

west of Los Alamos, New Mexico. 

The 88,900-acre preserve is known 

for its scenic beauty; it features 

11,000-foot mountain peaks, 

coniferous forests, broad open 

meadows, geothermal hot springs, 

and wildlife ranging from prairie dogs 

(Cynomys gunnisoni) to black bears 

(Ursus americanus) and bald eagles 

(Haliaeetus leucocephalus). Many of 

today’s visitors to the preserve believe 

it to be pristine, untouched wilderness. 

But in fact, for more than 100 years the 

area supported intense sheep grazing, 

cattle ranching, timbering, and mineral 

and geothermal exploration by AngloAmericans, activities that deeply 

affected the area’s appearance. 

The area was used by earlier people, 

as well. Archaeological evidence shows 

that the earliest visitors to the area, 

some 11,000 years ago, were hunters 

who passed through while looking for 

mammoth (Mammuthus jeffersonii) 

and bison (Bison antiquus). The area 

was not home to those animals, but 

it offered the hunters obsidian, which 

they used to refurbish their hunting 

gear, as well as other resources they 

needed for their journeys. Following 

those early hunters, countless 

generations of Native Americans 

visited the area to hunt deer and elk, 

gather plants for food and other uses, 

and collect obsidian for tools. By the 

time the Spanish explorers arrived in 

New Mexico in the 16th century, the 

area was well-known and important 

to the region’s many and diverse 

indigenous people.

A new U.S. Forest Service report, 

More Than a Scenic Mountain 

Landscape: Valles Caldera National 

Preserve Land Use History, explores 

the nature and intensity of all the 

human impacts on the area. Focusing 

primarily on the past four centuries 

of Spanish, Mexican, and U.S. 

governance, the study details how the 

land was used, the social organizations 

of the times, and the communities and 

major actors involved. It traces how 

this remarkable landscape changed 

from an area that was shared by many 

to being the private property of a 

few individuals (who often competed 

fi ercely with each other to control 

the land), and was fi nally returned 

to public ownership. The study also 

includes an archaeological review of 

human use of the area before Spanish 

colonization, describing traditional 

Native American land-use practices 

and associations.

Overall, the report provides a 

thorough record of the economic, 

social, and ideational relationships that 

Native Americans (including Pueblo, 

Navajo, Apache, and Ute), Hispanics, 

and Anglo-Americans have had with 

the area. 

The report will be of interest to land 

managers and researchers as they 

assess the ecological history of the 

area and develop management plans 

for the future. It will also be of interest 

to history buffs who are intrigued 

by the area. It was written by Kurt 

F. Anschuetz, an archaeologist and 

anthropologist, and program director 

of the Rio Grande Foundation for 

Communities and Cultural Landscapes, 

and Thomas Merlan, a historian and 

historic preservation specialist. ∫

MIDDLE RIO GRANDE BASIN — RESEARCH REPORT 2008 www.fs.fed.us/rmrs 18

More Than a Scenic Landscape: 

A New Report on the History of 

Valles Caldera National Preserve
Backyard conservation tips

www.nrcs.usda.gov/feature/backyard

Bark beetle outbreaks

www.fs.fed.us/r3/resources/health/

beetle/index.shtml

Bird checklists: New Mexico

www.npwrc.usgs.gov/resource/birds/

chekbird/r2/35.htm 

Bosque del Apache National 

Wildlife Refuge

www.fws.gov/southwest/refuges/

newmex/bosque/index.html 

City of Albuquerque Open 

Space Division

www.cabq.gov/openspace 

Climate change and western 

ecosystems

www.fs.fed.us/rmrs/climate-change 

Climate research, Los Alamos 

National Laboratory

http://climateresearch.lanl.gov 

Drylands Institute

www.drylandsinstitute.org 

Endangered species

www.fws.gov/endangered 

Fire management in the West

www.fs.fed.us/fi re/index.html

The Friends of The Bosque del Apache 

National Wildlife Refuge

www.friendsofthebosque.org

Friends of the Rio Grande Nature 

Center State Park

www.rgnc.org

Joint Fire Science Program

www.fi rescience.gov 

Merriam-Powell Center for 

Environmental Research, 

Northern Arizona University

www.mpcer.nau.edu

Middle Rio Grande Bosque Initiative

www.fws.gov/southwest/mrgbi 

Middle Rio Grande Conservancy District

www.mrgcd.com 

Middle Rio Grande Endangered Species 

Act Collaborative Program

www.fws.gov/mrgesacp 

New Mexico Cooperative Fish & 

Wildlife Research Unit 

http://fws-nmcfwru.nmsu.edu

New Mexico Department of 

Game and Fish

www.wildlife.state.nm.us 

New Mexico Energy, Minerals and 

Natural Resources Department

www.emnrd.state.nm.us 

New Mexico Forest and Watershed 

Restoration Institute

www.nmhu.edu/nmfwri 

New Mexico State University

www.nmsu.edu 

Sevilleta Long Term Ecological Research

http://sev.lternet.edu

Sevilleta National Wildlife Refuge

www.fws.gov/southwest/refuges/

newmex/sevilleta 

The University of New Mexico

www.unm.edu 

U.S. Fish & Wildlife Service 

Southwest Region

www.fws.gov/southwest 

U.S. Forest Service jobs and student 

and volunteer opportunities

www.fs.fed.us/fsjobs/about.html 

U.S. Forest Service Rocky Mountain 

Research Station

www.fs.fed.us/rmrs 

U.S. Forest Service 

Southwestern Region

www.fs.fed.us/r3

Valles Caldera National Preserve

www.vallescaldera.gov 

Water Resources Program, 

University of New Mexico

www.unm.edu/~wrp 

Learn More About It

For more information on Middle Rio Grande research projects 

and Forest Service research partners, as well as 

local recreation areas, volunteer programs, species of 

concern, and more, see these websites.

MIDDLE RIO GRANDE BASIN — RESEARCH REPORT 2008 www.fs.fed.us/rmrs 19

To Our Partners:

Thank You!

Few research programs are done in 

isolation. Most are collaborative efforts 

that are funded by several organizations 

and carried out by many staff members, 

outside researchers, students, and 

volunteers. The organizations below 

have all contributed to the efforts to 

understand, protect, and restore the 

ecosystems of the Middle Rio Grande 

Basin. The Forest Service gratefully 

acknowledges all of their kind efforts. 

Armendaris Ranch

Bandelier National Monument

Bosque del Apache National Wildlife Refuge

Cibola National Forest 

City of Albuquerque Open Space Division

Drylands Institute 

Intel Corporation

Joint Fire Science Program

Middle Rio Grande Bosque Initiative

Middle Rio Grande Conservancy District

National Fish Hatcheries 

National Partnership-Whirling Disease 

Initiative

Natural Resources Conservation Service 

The Nature Conservancy

New Mexico Collaborative Forest 

Restoration Program

New Mexico Cooperative Fish and Wildlife 

Research Unit 

New Mexico Department of Game and Fish

New Mexico Environment Department

New Mexico Highlands University

New Mexico State Forestry Division

New Mexico State University

Northern Arizona University 

Pueblo de Cochiti

Rio Grande Foundation for Communities & 

Cultural Landscapes

Rio Grande Nature Center

Santa Fe National Forest

Save Our Bosque Task Force

Sevilleta Long Term Ecological Research

Sevilleta National Wildlife Refuge

Daniel B. Stephens & Associates

SWCA Environmental Consultants

Texas A&M University

Tree New Mexico

University of Arizona

University of New Mexico Department of 

Biology

University of New Mexico Museum of 

Southwestern Biology

University of New Mexico Water Resources 

Program

University of Oklahoma

U.S. Army Corps of Engineers, Albuquerque 

District

U.S. Bureau of Indian Affairs 

U.S. Bureau of Land Management

U.S. Bureau of Reclamation

U.S. Fish & Wildlife Service 

U.S. Forest Service Southwestern Region 

U.S. Geological Survey

Valles Caldera Trust
Scientist Hira Walker published an article in 

a recent issue of The Auk. She also painted 

the cover art, which depicts a Wilson’s 

warbler (Wilsonia pusilla) on tamarisk 

(Tamarix ramosissima) and MacGillivray’s 

warbler (Oporornis tolmiei) on coyote willow 

(Salix exigua).

Cover Art: Copyright 2008 Hira Walker, 

published in The Auk 125.3 by the University 

of California Press, on behalf of the American 

Ornithologists’ Union.

A cottonwood tree beside the Middle Rio Grande. Photo: Keith Coronel

MIDDLE RIO GRANDE BASIN — RESEARCH REPORT 2008 www.fs.fed.us/rmrs 20

PUBLICATIONS SUPPORTED 

BY THE MIDDLE RIO GRANDE 

ECOSYSTEM MANAGEMENT 

RESEARCH UNIT

The scientists funded by the Middle 

Rio Grande Ecosystem Management 

Research Unit share their fi ndings by 

publishing papers in scientifi c journals, 

making presentations at scientifi c 

meetings, and producing technical 

reports. In so doing, they are making 

a signifi cant contribution to the body 

of scientifi c knowledge about the 

Southwest. Many of these efforts are 

listed with the articles in this report. 

Other recent efforts are listed below. 

Calamusso, B.; Rinne, J. N. 2004. Distribution and 

abundance of Rio Grande cutthroat trout (Oncorhynchus 

clarki virginalis), relative to an introduced salmonid, in 

Northern New Mexico. In: Scrimgeour, G. J.; Eisler, G.; 

McCulloch, B.; Silins, U.; Monita, M. eds. Forest LandFish Conference II — Ecosystem Stewardship through 

Collaboration; 2004 April 26-28; Edmonton, Alberta. 

Canada. Proc. Forest-Land Fish Conf. II.: 31-37.

Calamusso, Bob; Rinne, John N.; Edwards, Robert J. 

2005. Historic Changes in Rio Grande Fish Fauna: Status, 

Threats, and Management of Native Species. American 

Fisheries Society Symposium. 45.

Dubey, Robert J. 2008. Genetic Differentiation of 

Lineages of Tubifex Tubifex from the San Juan River, New 

Mexico. The Southwestern Naturalist. 53(2): 268-272.

Dubey, Robert; Caldwell, Colleen. 2004. Distribution 

of Tubifex tubifex Lineages and Myxobolus cerebralis

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