Data set ID:
Termites are important detritivores in Chihuahuan Desert ecosystems and appear to have key roles in plant litter decomposition and nutrient cycling and in altering soil structure and hydrologic processes. These data were collected in conjunction with a study using exclosures to test the effects of rodents on vegetation and abiotic factors, established at each of the Sevilleta, Jornada and Mapimi research locations. At the Jornada, the effects of cattle were also measured using an additional exclosure. Three replicate experimental blocks of plots are randomly located at each study site to measure vegetation responses to the exclusion of rodents, and lagomorphs, and cattle. Due to their role in processing of plant matter, data on grasshoppers and termites was also collected at the Jornada. Each study site is 1 km by 0.5 km in area. A grid of 36 sampling points are positioned at 5.8-meter intervals on a systematically located 6 by 6 point grid within each plot. A permanent one-meter by one-meter vegetation measurement quadrat is located at each of the 36 points. A tape measure was used to measure the length, diameter, and height, for each occurrence of a termite casing in units of one centimeter. This study is complete.
Field micro-cassette tape recorders
Look for termite mud casing on plant litter and dead standing plant material on the quadrat. There will usually be a number of separate occurrences of casing. Measure each one as a separate observation. Use your tape measure and measure the length, diameter, and height, for each occurrence of casing in units of one centimeter. The minimum measurement for each dimension is one centimeter. Most casing will be flat on the surface, covering leaf litter, stems, rabbit feces, etc. In some situations, the casing will cover something vertical such as standing dead plant stems. For the height measurement, measure the vertical height of the mud casing perpendicular to the length and width, not from the ground surface. In situations where there are many vertical mud case covered stems, for example a dead clump of grass, just measure the height, length, and width of the entire clump, not each stem. If there are lots of individual occurrences of mud casing on a single quadrat (say about 10 or more) then simply record a pooled visual estimate of all of the mud casing with one set of three dimension measures (e.g., length 20, diameter 20, height 5). Record a comment that you have made a pooled visual estimate. Old termite mud casing is difficult to detect and looks like regular soil. If you are uncertain whether or not mud was produced by termites, do not measure or record it.
SAS programs was used to analyze data
A creosotebush shrub study site and a black grama grassland study site have been established at each of the Sevilleta, Jornada and Mapimi research locations. Each study site is 1 km by 0.5 km in area. Three rodent trapping webs and four replicate experimental blocks of plots are randomly located at each study site to measure vegetation responses to the exclusion of small mammals. The blocks of study plots are all oriented on a site in a X/Y coordinate system, with the access road to each site forming the X axis. The compass orientation at the Jornada grassland site is to the north, and Jornada creosotebush site is oriented to the south. Treatments within each block include one unfenced control plot (Treatment: C; control), one plot fenced with hardware cloth and poultry wire to exclude rodents and rabbits (Treatment: R; rodent), and one plot fenced only with poultry wire to exclude rabbits (Treatment: L; lagomorph), and one plot fenced with barbed wire to exclude cattle (Treatment B; bovine). Note that there are cattle exclosure plots only at the Jornada grassland site where cattle are present, for a total of 4 measurement plots at each of the grassland site blocks. There are only 3 measurement plots at each of the creosotebush site blocks. The treatments were randomly assigned to each of the four possible plots in each block independently, and their arrangements differ from block to block. Each of the plots in a replicate block are separated by 20 meters. Each experimental measurement plot measures 36 meters by 36 meters (see Figure 4). A grid of 36 sampling points are positioned at 5.8-meter intervals on a systematically located 6 by 6 point grid within each plot.
Twice each year through 1995: April and October Once every 5 years after 1995: October. This study was completed in 2005.