Data set ID:
**The objective of the present research was to determine whether there have been changes in the structure and function of the surface (0-20cm) soil system, the zone most affected by litter decompos
ition, which is associated with the rapid movement of mesquite from historical habitats (arroyo and playa fringe) into recent habitats (grassland and dunes). We hypothesized that the soil biotic communities would be poorly developed in the recent mesquite habitats because of lower soil C and nutrient concentrations. Data set contains microarthropod code, order, family, total number of mites, and trophic group for microarthropods sampled at two depth ranges in the top 20 cm of soil.
Field and electronic data sheets
**The soils were sampled in October 1986 at the end of the hot, dry summer season when surface soil biota in the Chihuahuan Desert reach their maximum densities. At each habitat type location (playa, arroyo, grassland and dune) soil samples were collected from the midcanopy beneath six mesquite plants at two depths (0-10 cm and 10-20 cm), using a bucket auger soil corer (7.5 cm diameter, 10 cm depth). The samples were placed in plastic bags, stored in a portable cooler, and then transported to the laboratories. These samples were later divided into subsamples for nematode extractions. Microarthropods and Collembola were extracted in modified Tullgren funnels into water (Santos et al. 1981), counted and identified to species, and place in functional groups based on information from Christiansen (1964), Krantz (1978), and Walter (1987). The functional gruops were (1) grazers (fungal and algal feeders), which include most of the Cryptostigmata, some Prostigmata, and Collembolans; (2) omnivores, which include some Prostigmata and some Collembola; and (3) predators, which include all Mesostigmata and some Prostigmata.
*Four mesquite ecosystems were stuided: playa, coppice dune, arroyo, and grassland. The arroyo, grassland, and a playa site were loacated on the NSF Jornada Long Term Ecological Research (LTER) site situated 40 km north of Las Cruces, NM, in the northern Chihuahuan desert. A coppice mesquite dune site was located on the adjacent USDA Jornada Experimental Range about 15 km from the above sites.