...From the pages of Agricultural Research magazine
A River Runs Through It: The Jornada
Technician Dara Parker and
John Anderson, manager of
the Long-Term Ecological
Research (LTER) Network site,
reset weather recording
equipment used in Jornada
Range studies that focus
on global climate change,
desert ecology, rangeland
management, and the worldwide
threat of desertification.
The third longest river in North America, the Rio Grande, runs through
the middle of North America's largest desert. Located mostly in Mexico,
the Chihuahuan Desert intrudes quite a bit into New Mexico, and somewhat
into Arizona and Texas as well. The river brings waterlargely
from snow melted in the mountains of Coloradoto farmers and urban
desert dwellers through much of the Southwest.
The Rio Grande also runs right through Las Cruces, New Mexico, where the ARS Jornada Experimental Range has a 29,000-square-foot laboratory-and-office facility, barely 2 years old, on the campus of New Mexico State University (NMSU).
The Jornada Experimental Range comprises 193,000 acres in the middle of New Mexico's share of the desert. It is surrounded by national forests, like the Gila, nature preserves, and other public lands and federal complexes, including the White Sands Missile Range. Livestock graze parts of the range, but they are outnumbered by wildlife, such as coyotes, mountain lions, javelinas, antelope, desert bighorn sheep, kangaroo rats, black-tailed jackrabbits, and desert cottontails.
characteristic of the northern
Chihuahuan Desert on the
The Jornada is an important site for research on the health of rangeland
in this desertand of other desert rangelands in the western United
States. With about a century of data under its belt, the research center
has become one of the premier rangeland institutions in the world. Its
scientistsworking cooperatively with many other institutions,
agencies, and universities, including counterparts in Mexicohave
helped to improve application of ecological concepts to range management
and develop new technologies for conserving deserts in many parts of
the world. This year, they will publish research results in a book that
will make a significant contribution to developing standards for monitoring
rangeland health here and abroad.
The new facility at NMSU houses most of Jornada's 80-plus staff members, including 11 permanent scientists and a total federal staff of 37. The U.S. Department of Agriculture (USDA) provides base funding of about $4 million a year. Additional funding through grants and contracts of over $1 million a year supports 45 more full-time and part-time staff, mainly through a cooperative agreement with NMSU.
Postdoctoral research associate
Enrique Gomez-Landesa (background)
and hydrologist Al Rango evaluate
output from their predictive
models of water runoff into the
Upper Rio Grande Basin.
A Laboratory for the World
The Jornada Experimental Range lies in a broad valley filled with alluvial
materials, between mountain ranges of the Basin and Range Province.
This topography extends westward through Arizona's Sonoran Desert and
into the Mohave Desert of southern Nevada and California. USDA acquired
the Jornada in 1912, but there is some experimental data on the area
dating back to 1858. ARS began operating the site in 1954, soon after
the agency was formed.
The Jornada is home to the 960-acre, topographically and biologically diverse Chihuahuan Desert Nature Park. The National Science Foundation (NSF) helps fund the nonprofit organization that runs the park and works with Jornada staff to bring science education to 12,000 students and 700 teachers each year.
At the Jornada Range,
technicians Justin Van
Zee and Elaine Kneller
evaluate plant responses
to experimental treatments.
The Jornada is also one of 24 sites22 in North America and 2
in Antarcticathat are part of the NSF Long-Term Ecological Research
(LTER) Network, which supplies a portion of the extra $1 million a year
in funding. This network is a collaborative effort involving more than
1,100 scientists and students investigating a diverse array of ecosystems.
At the Jornada, the network includes scientists from USDA's Natural
Resources Conservation Service (NRCS) as well as from NMSU and universities
across the United States and Great Britain. The LTER Network offers
the broader environmental biology research community, including students
and foreign scientists, the opportunity to cooperatively use these sites
and long-term data. At the Jornada, the focus is on global climate change,
desert ecology, rangeland management, and the worldwide threat of desertification.
"Our ARS national program in rangeland melds well with LTER goals. Our collaborative studies in this program can be used to infer causes and consequences of desertification worldwide," says Kris Havstad, research leader at the Jornada. "Desertification is a major threat to dry areas around the world and is characterized by accelerated loss of the soil's protective vegetative cover," Havstad says. "When vegetation degrades, the resulting erosion by wind and water removes both soil and nutrients in soil that sustain life. There are many causes."
Postdoctoral research associate
Mary Lucero and animal scientist
Rick Estell evaluate plant-extract
data from cattle diets.
LTER research concentrates on the Jornada's five major habitat types of the northern Chihuahuan Desert: black grama grassland, creosotebrush shrub, mesquite dunes, tarbrush shrublands, and playas, low-lying, grassy, infrequently flooded areas. The climate is characterized by abundant sunshine, wide daily temperature ranges, low humidity, and rainfall averaging only 9 inches a year. Snow is rare, but it's effective in wetting the soil because less evaporation occurs in the cold months.
Looking Back To Predict Future Changes
ARS ecologist Debra Peters came to the Jornada in 1998 and is the lead investigator for the Jornada Basin LTER team. She developed the ECOTONE computer model, which enables Jornada researchers to use many years of collected data to predict future changes on these landscapes.
Chihuahuan Desert Nature
Park director Stephanie
Bestelmeyer and Jornada
Eddie Garcia work with
elementary school children
on a field trip at the
"One major threat to rangeland here is brush overtaking the black
grama grassland, so we're very interested in knowing what conditions
cause it," says Peters. "We named the model ECOTONE because
that's the technical term for the transition area where two different
life forms meet, such as grasses and shrubs. This model can predict
where a grass area is likely to be overtaken by brush."
So far, brush is winning, here and on many other continents, and it
wins by leaps and bounds after years of drought, such as the one the
area has undergone the past 5 years.
ARS hydrologist Al Rango, an expert in remote sensing, spotted this trend by examining the Jornada's long history of data, including USDA aerial photography that began in the 1930s. He computed the speed of brush invasion and found that it picked up after severe droughtsespecially the intense one in the 1950s. He sees the same thing todaya result of the current drought. Shrubs seem to outcompete grass in dry times.
Animal scientist Alfredo
Gonzalez moves cattle as
part of studies examining
livestock grazing behaviors
in desert landscapes.
Rango's main task these days is predicting how much water the Rio
Grande will deliver to the desert, particularly to farmers who use the
river to irrigate. Farmers around the Jornada grow mainly chili peppers,
cotton, and pecans. Farther north, farmers use older, smaller irrigation
systems to grow tomatoes and other high-value crops.
Rango works with NRCS and the Bureau of Reclamation to research ways
to predict the Rio Grande's streamflow. He has been predicting daily
flow of the river at Del Norte, Colorado, for the past 3 years. He usually
does forecasts for April through September, to cover the growing season.
He checks the predictions with actual streamflow measured daily at Del
Rango does these predictions using the Snowmelt Runoff Model (SRM),
which he developed in the 1970s. Ironically, Rango first tested the
SRM on the Rio Grande in the late 1970s while stationed at ARS's Beltsville
(Maryland) Agricultural Research Center. The runoff model is used together
with sensors positioned throughout the West to measure snowpack.
Once streamflow predictions become operational, farmers will use them
to decide which and how many crops to plant each year. They will also
be used by NRCS, the U.S. Army Corps of Engineers, state engineers'
offices, and others in managing these water resources.
In 2001, when the National Aeronautics and Space Administration launched
the Terra satellite with the new MODIS (Moderate Resolution Imaging
Spectroradiometer) sensor, Rango and colleagues began using this imagery
of snow-covered parts of the Chihuahuan Desert and mountain snowpacks
in Colorado and New Mexico. Later, NASA launched a complementary satellite,
Aqua, which also supplies data to Rango. The MODIS sensors give a higher
resolution than satellite imagery he had been using.
Rango also contributes his remote-sensing expertise to other areas of Jornada research, including the monitoring of rangeland health and controlling of livestock grazing.
Monitoring Rangeland Now
ARS soil scientist Jeff Herrick and colleagues led the effort to develop
an improved rangeland-monitoring manual for field use. It contains instructions
for various soil and vegetation measurements and forms for ranchers
and land managers to record data. "It provides a way to gather
data needed to support rangeland assessments done with the guidelines
that were first issued in 1999," Herrick says.
Herrick co-authored those earlier assessment guidelines along with
representatives of the U.S. Geological Survey, NRCS, and the Bureau
of Land Management (BLM). These are now in use widely in the United
States, and the Mexican government has translated them into Spanish.
"This is one of the biggest impacts we have had," he says.
Herrick is working with ARS ecologist Brandon Bestelmeyer, who is doing
ecological descriptions of Southwestern rangelands based on research
at the Jornada. Together they are integrating monitoring and assessment
tools with the ecological models Bestelmeyer works with. They are collaborating
with the U.S. Department of Defense, NRCS, BLM, and the National Park
The models Bestelmeyer works on are called "state and transition"
models because they predict how broad areas of land might change under
various management practices. So far, he has created or contributed
to models that will work for much of New Mexico, Arizona, Utah, and
Texas. They can help everyone from ranchers to government personnel
in interpreting data on their land to make land-management decisions.
Bestelmeyer is working with Peters and ARS range ecologist Sandy Tartowksi
to describe how ecological drivers at different scales are changing
vegetation. Their data feed into both ECOTONE and the state and transition
Bestelmeyer says, "Historical data shows us that vegetation reaches a threshold point, a critical stage beyond which the change is irreversible. Here, that's usually grassland being replaced by shrubs. Different pressures, such as overgrazing or drought, can push land over the threshold. We want to predict when that threshold will be reached, so we can avoid it."
Virtual Cattle Herding
Animal scientist Dean M. Anderson has a vision of how to reduce grazing
pressure by fencing sheep, cows, and other animals with Directional
Virtual Fencing (DVF), an invisible electronic fence similar to
that sometimes used to control dogs. Anderson patented the concept in
collaboration with Craig S. Hale of Future Segue, a private electronics
firm in Las Cruces.
"This tool combines electronic technology with animal behavior
and knowledge of animal and plant biology to control livestock movement
in a humane way," Anderson says.
With it, cows would cross their large desert pastures, guided by Global
Positioning System technology, to locations where forage is available
and suitable for grazing. They would keep returning to a watering hole
where they would get "marching orders" from satellites. Computer
nodes at the watering hole would download the cows' meandering data
and send it back for analysis of grazing patterns.
DVF data is stored in an electronics package similar in size to a deck
of playing cards. The current version of the device is worn on a neck
collar that sends cues to ear tags to steer the cows to water or fresh
grass. When the cows are first learning their boundaries, they get an
audio cue or a mild electric shock similar to that used on dogs.
Anderson has proven the concept works by testing prototypes on three
cows and using them to move a small herd around. By the end of 2004,
he expects to have many more prototypes built to conduct larger-scale
tests."We're right on the verge of commercializing this device,"
Rango is helping Anderson find ways to eventually link with satellites that would locate desirable grazing areas for livestock.
The End of Range Wars
Tartowski, who is working to develop new remediation technologies,
has high hopes for Anderson's research. She knows from the ranchers
and land managers she works with how much they would like to do away
with traditional fences.
"It's a major cost to build and maintain fences," she says.
"And they're not always placed in the areas that make the most
sense in terms of rainfall patterns or animal management."
The main thing that impresses Tartowski about DVF technology is that
it changes the perception of livestock from being a land problem to
a land-improvement tool that can help shape the landscape in a desirable
way. Virtual fencinglike much of the Jornada researchcan
help slow desertification or even stop it in some cases, because it
promises an economical way to keep cattle properly distributed across
Research at the Jornada is all about judiciously nudging natural ecosystem
processes to improve land health while supporting sustainable human
use. More than a century's experience with a landscape that still bears
the scars of natural assaults on vegetation and misuse from the days
of the Old West provides an ideal laboratory for meeting these needs.
Furthermore, tools like the ECOTONE model allow scientists to make better
use of this historical data to forecast future dynamics.
The Jornada scientists are helping build a database for rangeland management
that has significance for the one-third of the Earth's land mass that
is desertan area that is increasing all the time.By Don
Comis, Agricultural Research Service Information Staff.
This research is part of Rangeland, Pasture, and Forages, an ARS
National Program (#205) described on the World Wide Web at www.nps.ars.usda.gov.
"A River Runs Through It: The Jornada Experimental Range Battles Desertification" was published in the July 2004 issue of Agricultural Research magazine.