"Spatial and temporal variation in energy flow through food webs contributes to ecosystem stability. In stable food webs, energy is channelled through resource compartments, in which energy passes independently of other compartments. Higher-order consumers can derive energy from multiple compartments; even though energy flow through individual compartments varies, populations of higher-order consumers are relatively stable since resources in multiple compartments are more likely to be continuously available. Therefore, food webs that contain functionally-diverse consumer communities are likely better equipped to withstand environmental variation that impacts the rates, timing, and quality of resources entering food webs. I propose to use soil food webs to test the hypotheses that diet plasticity and functional diversity in consumers promotes ecosystem stability. I also propose to better resolve trophic interactions and resource compartmentation in soil food webs using molecular techniques, characterize functional diversity of consumers in soil food webs from these more fully resolved interactions, and evaluate the consequences of consumer functional diversity on ecosystem functioning (soil aggregation and carbon sequestration)."