The primary objective of this study is to examine the control that substrate quality and climate have on patterns of long-term decomposition and nitrogen accumulation in above- and below-ground fine litter. Of particular interest will be to examine the degree these two factors control the formation of stable organic matter and nitrogen after extensive decay.
Transition zones between biomes consist of a mosaic of patch types dominated or co-dominated by species from the adjacent biomes. Most studies of biome transition zones have focused on the dominant life forms or characteristic species, and patterns in subordinate species composition are not well documented and understood, yet it is these species that contribute to biodiversity.
Our objective was to evaluate the effects of kangaroo rat mounds on species diversity and composition at a semiarid-arid grassland ecotone. We expected that source populations of plants occurring on kangaroo rat mounds have important influences on species composition of vegetation at the landscape scale, and that these influences differ by grassland type.