If grassland systems respond to rainfall without significant lags, but shrub systems do not, then consumer species should reflect these differences. In addition, shifts from grassland to shrubland results in greater structural heterogeneity of the habitats. We have hypothesized that consumer populations, diversity, and densities of some consumers will be higher in grasslands than in shrublands. Data will be collected for the duration of the LTER program in order to provide data to test these hypotheses. Data for arthropods captured in pitfall traps on LTER III consumer plots at 2 month intervals.
Data includes order, family, genus, species, and number.
To minimize rodent damage to the pitfalls, chicken wire fences with lids were installed around each trap. Unfortunately, rodents or lizards smaller than the holes in the chicken wire continued to cause significant damage to the traps after the exclosures were added, so in June 1996, hardware cloth collars were also added to the pitfalls. Additional holes were cut for any grass clumps surrounding the pitfalls to minimize disturbance to the vegetation. They are buried under a thin layer of soil. The traps are continuously open, and the arthropods in them collected every 2 months.