Jornada-Long Term Ecological Research Network (LTER)

The Jornada Long Term Ecological Research (LTER) project focuses on
changes in the distribution of soil resources as an index of the
impact of vegetation change--desertification--on semiarid
lands. Specifically, we hypothesize that a relatively homogeneous
pattern of soil nutrients is found in areas of grassland. Various
factors leading to vegetation change alter the distribution of soil
resources, leading to the invasion and persistence of shrubs and the
development of a patchy distribution of soil nutrients. Nutrient-rich
areas that develop under shrub canopies are known as "islands of
fertility," while soil resources are lost from the adjacent
inter-shrub spaces by wind and water erosion. These changes in soil
resources have importance consequences for ecosystem function, linking
the ecosystem processes in deserts to changes in the global
environment (Schlesinger et al. l990).

Similar changes in vegetation and soils have occurred over large areas
of the Chihuahuan desert and in other areas of the world, where
semiarid grasslands have been replaced by shrubland vegetation. The
Jornada Experimental Range is a designated Man and the Biosphere (MAB)
Reserve, which allows comparative studies at other MAB Reserves in the
Chihuahuan Desert at Big Bend National Park (Texas) and the Mapimi
Biosphere Reserve in Mexico. In addition, we believe that studies at
the Jornada LTER program can be used to infer the causes and
consequences of desertification worldwide.

Field research at the Jornada LTER is conducted in various habitat
types found within New Mexico State University's Chihuahuan Desert
Rangeland Research Center (25,900 ha) and the adjacent lands of the
USDA Jornada Experimental Range (78,266 ha). These lands, which form
the Jornada del Muerto Basin in southern New Mexico, are found at the
northern end of the Chihuahuan desert (MAP- 60Kb), which extends from
southcentral New Mexico, USA to the state of Zacatecas, Mexico,
comprising 36% of North American Desert land (MacMahon and Wagner
l985).

This information was obtained in part from the Jornada LTER home page at
"http://jornada-www.nmsu.edu/".

Jornada is part of the Long Term Ecological Research Network, which is funded
by the National Science Foundation, and accessible at
www.lternet.edu. Data are one of the most valuable products of the
LTER program. The goal of the Network is to provide fast, effective,
and open access to LTER data. Over 2000 ecological datasets are part
of a network-wide information system designed to facilitate data
exchange and integration to meet the needs of ecological scientists.