Shrub Density Effects on the Structure and Composition of a Desert Animal Community

Positive interactions between shrubs and animals are frequent in desert ecosystems. Shrub canopies can provide refuge to some animal species from predators and shelter from stressful environmental conditions by ameliorating high temperatures. Consequently, there have been many contrasts of shrub versus open effects, however, I extend this approach further by testing these effects on a gradient of shrub densities in a region of the Carrizo National Monument, California. I tested the hypothesis that shrub density is a landscape-level predictor of vertebrate community composition and structure. I used camera traps, transects, and focal observations to estimate animal density and composition, and temperature sensors were also deployed. Plots were established within shrub patches ranging from 0 to 12 shrubs per 20m area. Plots with relatively higher shrub densities had increased abundance and richness of vertebrates. Temperature and residual dry matter were important mediators of animal density and richness.