Jornada LTER History

The Jornada Basin is located in the Southwestern United States where dynamic changes in ecosystems have occurred in response to extreme drought and livestock overgrazing. During the late nineteenth century, the native grasslands of the Chihuahuan Desert began a transition toward a woody plant-dominated landscape. These changes in ecosystems are often interpreted as “desertification”, the broad scale conversion of perennial grasslands to dominance by xerophytic woody plants and the associated loss of soils and biological resources, including biodiversity. Large numbers of domestic livestock in combination with extreme, multi-year drought were devastating to native grasses and allowed native, drought adapted, long-living shrubs to dominate large expanses throughout the region by the early 1900s. In response, two research sites were established in southern New Mexico: the US Department of Agriculture’s Jornada Experimental Range in 1912 and New Mexico State University’s College Ranch (currently Chihuahuan Desert Rangeland Research Center) in 1926. In 1982, the Jornada Basin LTER was funded by the National Science Foundation (NSF) to study the causes and consequences of desertification through long-term research. This funding led to a long-term collaboration with the USDA-ARS, NMSU, and scientists at other universities and federal agencies that continues to present day.

From 1982-2000, research at the Jornada Basin LTER focused on causes and consequences of desertification governed by processes at the plant-interspace scale. From 2000-2012, Jornada LTER researchers studied the role of redistribution of resources and organisms across multiple scales with a focus on patch structure and connectivity, and how pattern-process relationships can explain spatial variation in desertification dynamics. A conceptual framework for the role of cross-scale interactions in transitions from grassland to shrubland states was developed. From 2006-2012, LTER research tested and confirmed elements of this conceptual framework in the context of grassland to shrubland transitions, and was expanded to focus on the recovery of perennial grasses on desertified shrublands. In 2012, LTER research was expanded to examine additional types of transitions occurring in the region, including those: (a) between different types of shrublands, and (b) from grasslands or shrublands towards novel ecosystems involving invasive species. We focused on transitions in the five major ecosystem types in Chihuahuan Desert ecosystems: upland grasslands, playa grasslands, mesquite shrublands on the sand sheet, creosotebush shrublands on the upper bajada, and tarbush shrublands on the lower bajada.

From 2018 to present, we are exploring how landscape-level spatial heterogeneity evolves in response to the effects of disturbance triggers, connectivity-mediated feedbacks, and their interactions with the soil-geomorphic template. We are expanding our landscape linkages framework to contribute to emerging ecological theory on: (a) alternative states and resilience, (b) ecosystem sensitivity to global change, and (c) cross-scale interactions. Our recent observations indicate the need to conceptually and computationally integrate data and knowledge into a Data Science Integrated System (DSIS) of drylands that will allow Jornada results to be translated to other locations in the Chihuahuan Desert and to drylands globally. Our research is resulting in five major products: (1) new understanding of state changes, in particular in drylands, that lead to theory development, testable hypotheses, and new experiments; (2) accessible data, derived data products, and visualization tools applicable at multiple scales; (3) explanatory and predictive relationships among drivers, patterns, and processes that can be used to (4) predict dynamics of alternative states at new locations or future conditions with assessments of their impacts on ecosystem services; and (5) provide training, outreach and information transfer to broader audience locally, nationally and internationally.