Jornada Experimental Range, NM (LTAR)

Location - The Jornada Experimental Range Long Term Agro-ecosystem Research (LTAR) Network site is located within the Jornada Basin in south-central New Mexico. The site lies in the northern Chihuahuan Desert and is bound to the west by the Rio Grande Valley and to the east by the San Andres Mountains. The Jornada Basin sits at an elevation of 1320 m above sea level, with adjacent peaks reaching 2747 m in the San Andres Mountains.

Climate - The Jornada Basin has an arid to semi-arid climate. The mean annual precipitation (1915-2014) for the Basin is 250 mm, with mean annual evaporation of 2204 mm. Precipitation has large inter-annual variability (coefficient of variation = 35%) and strong seasonality. Typically ~60% of the annual rainfall occurs in the summer months from June through September. The mean annual maximum and minimum temperatures range from 25°C to 5°C.

Vegetation and soil - Vegetation at the Jornada Network site is comprised of a mixed community of several native species of warm season (C4) grasses, perennial forbs and shrubs. Grasses such as dropseeds (Sporobolus R. Br.), tobosa grass (Pleuraphis mutica Buckley), black grama (Bouteloua eriopoda Torr.), and burrograss (Scleropogon brevifolius Phil.) are interspersed throughout the site, along with moderately-sized honey mesquite shrubs (Prosopis glandulosa Torr.) and scattered soaptree yucca (Yucca elata ((Engelm.) Engelm.).  Most honey mesquites have accumulated wind-blown soil (coppiced up to 30 cm) under their canopies.  Leatherweed (Croton pottsii (Klotzsch) Müll. Arg.) is the most common perennial forb that occurs throughout the site in intershrub spaces.  Several species of annual forbs grow on the site in the spring and summer months if sufficient soil moisture is present.  Surface soil textures are mostly sandy loam to fine sandy loam, with weak biological and physical crusting.  Slope is less than 0.5%.  Subsurface soil textures range from sandy loam to sandy clay loam, with high calcium carbonate content.  No restrictive horizon exists within a meter of the soil surface.

Management - Rangeland research station, grazed by cattle.

Site Contact - Nicholas Webb

Photos of the Jornada Experimental Range (LTAR) Network site showing meteorological tower (left) and close-up of the tower base, MWAC sediment samplers, rain gauge and Sensit (right).