Jornada Experimental Range (JER)
Las Cruces, New Mexico
The JER is located in the northern Chihuahuan Desert, accessible from University of Texas at El Paso and New Mexico State University. The climate is characterized by high solar radiation, a wide range between day and night temperatures, low relative humidity, and seasonal monsoonal precipitation occurring in late summer. Annual precipitation is 247 mm and maximum temperatures average 13°C in January and 36°C in June. Within the JER, a piedmont land cover leads into a basin rich in playa wetlands. Through NSF and USDA research dating back four decades, JER has gathered rich datasets and knowledge on dryland critical zone processes. Here, the unique development of thick caliche layers in older geomorphic surfaces modifies critical zone structure and function, especially ecohydrology, biological processes and atmosphere-land exchange. The selected sites are piedmont, with an existing eddy covariance tower, and the Red Lake playa.
For more information about the Jornada, please visit their website.
The JER is located in the northern Chihuahuan Desert, accessible from University of Texas at El Paso and New Mexico State University. The climate is characterized by high solar radiation, a wide range between day and night temperatures, low relative humidity, and seasonal monsoonal precipitation occurring in late summer. Annual precipitation is 247 mm and maximum temperatures average 13°C in January and 36°C in June. Within the JER, a piedmont land cover leads into a basin rich in playa wetlands. Through NSF and USDA research dating back four decades, JER has gathered rich datasets and knowledge on dryland critical zone processes. Here, the unique development of thick caliche layers in older geomorphic surfaces modifies critical zone structure and function, especially ecohydrology, biological processes and atmosphere-land exchange. The selected sites are piedmont, with an existing eddy covariance tower, and the Red Lake playa.
For more information about the Jornada, please visit their website.
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Piedmont
In dryland piedmont, episodic precipitation drives critical zone processes including hydrologic fluxes, biogeochemical cycles, and soil development. Dryland soils are characterized by accumulation of pedogenic carbonate and other salts due to limited leaching in dry environments. Salt accumulation controls nutrient availability, reduces soil permeability and porosity, modifies water dynamics, and more importantly, plays a critical role in the carbon cycles.
Primary productivity and microbial decomposition are low in drylands due to water limitation. However, diverse organisms, including grasses, shrubs, and biological soil crusts (biocrusts) regulate carbon and nutrient cycles, particularly during precipitation pulses, and play important roles in dryland ecosystem functions and services. In dryland ecosystems, annual net ecosystem carbon balance varies substantially on multiple axes: within sites, between sites, and interannually. This variation is important to capture because recent studies demonstrate that interannual variation in the terrestrial carbon sink in drylands can impact global atmospheric carbon. Jornada Research Site
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Playa
Playas are ephemerally flooded depressional wetlands that are widely distributed in drylands. These areas are among the most productive and diverse desert environments, are hotspots of soil organic carbon and nutrient storage, and are known to be sources of dust. Playa ecosystems play a key, but rarely quantified, role in regional carbon cycles.
Playas fill during rain events but have no external drainage. Depending on the nature of the substrate, infiltration and recharge rates to the underlying aquifer are variable for a given playa, and so is the water loss through evaporation Based on water flux mass balance models, unusually high rates of potential groundwater recharge have been recognized via storage losses in playas and runoff losses in channels at the Jornada LTER. This finding challenges the paradigm that dryland aquifers generally receive limited or no modern recharge except as mountain block and mountain front recharge at higher elevation, and further work is warranted to improve understanding of this phenomenon. |
