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. Click the image for more
information about it.
story for more information.
Desert Laboratory for the World
By Don Comis
July 1, 2004
The fifth year of drought on the
Agricultural Research Service's
193,000-acre Jornada Experimental Range
at Las Cruces, N.M., has sped up the loss of grazing land to brush invasions.
In 1912, the U.S. Department of Agriculture
acquired the Jornada, located in the vast Chihuahuan Desert.
Jornada scientists led by Kris Havstad, an ARS rangeland
scientist, analyzed USDA aerial photographs of the Jornada taken from the 1930s
on and noticed that shrubs seemed better able to outcompete grass in dry times.
The historical data showed that vegetation reaches a threshold beyond which a
change--such as from grass to brush--is irreversible.
The scientists are investigating what drives this vegetation
change. They are feeding historical and current data into computer models to
help them predict, and avoid, the threshold.
The desert rangeland scientists' main concern is protecting the
land's health while sustaining farming and ranching. They collaborate with
numerous organizations. The National Science
Foundation has a major presence at the Jornada, with its funding for the
educational Chihuahuan Desert Nature
Park and its inclusion of the Jornada in its
Long-Term Ecological Research
Network. The Jornada is one of 24 sites--including two in Antarctica--in
the network, at which more than 1,100 scientists and students investigate
The network's Jornada focus is on global warming, desert
ecology, rangeland management and the worldwide threat of desertification. The
ARS national program in rangeland management research melds well with this
focus. Collaborative studies help infer causes and consequences of
Jornada researchers have about a century of historical data to
rely on, in addition to new data being collected. They are finding ways to mine
the past for clues to help rangeland managers around the world shape the
landscape in desirable ways on the one-third of the Earth's land mass that is
information about this research can be found in the July 2004 issue of
ARS is USDA's chief scientific research agency.