This project will examine nematode community differences across varying vegetation states associated with desertification. There are over 18,000 recognized species of nematodes known to exist. Because of the highly specialized feeding behavior and physiology of nematode stylus/mouthparts, the study plans to use nematodes as indicators into differences in soil biotic communities. Specific nematode genera have been identified to feed/prey upon all three of the root, fungal, and bacterial energy channels with plant roots belowground. Utilizing the specificity in feeding behaviors, this study asserts that food web theory plays an integral role in regulating productivity, stability, and structure through the mechanisms of soil biofeedbacks. More specifically, the study will address changes in soil biota within the loss of the semi-arid black grama grasslands of the Chihuahuan desert to a more desertified, shrub dominated state, by examining the associated changes in nematode community structure associated with the differing vegetation states. The community structure of nematodes associated with each vegetation state will then provide insight into differences in specific functional soil biotic groups (i.e. saprophytic fungi, actinomycetes, cyanobacteria, etc.) that may play mechanistic roles into how grasses are lost and how shrubs become established. The motivation for this expanded study is based on a pilot study’s results, where large shifts in the nematode communities were observed within a Bouteloua eripoda dominated grassland compared to an established mesquite duneland, which coupled with current research, indicates a large loss of a fungal ”loop” associated with soil-biotic crusts as desertification increases. This study intends to take a more in-depth look at the differences in these two end-member vegetation states of desertification and the ecotone between the two ecosystems. Once nematode community structure is established within each vegetation type and the transition zone between them, examination and quantification of the differences in soil biotic communities along a desertification gradient can be explored and their potential effects on vegetation community structure examined.