Interactions Between Ecosystem Dynamics On Belowground Microbial Community Capacity Under Semiarid And Arid Conditions

Ecosystem sustainability in semi-arid to arid landscapes depends on plant-microbe soil interactions. The belowground microbial communities of semi-arid and arid ecosystems are less robust than those of temperate climates and therefore more vulnerable to environmental stress and anthropogenic disturbance. Study of the ecosystem dynamics that accompany ecosystem degradation during the transition from semiarid to arid landscapes may provide critical insights applicable to the reclamation of semi-arid marginal lands, such as those compromised by mining activities. The specific goal of this project is to define the characteristics of semiarid and arid ecosystems and their relationship to the sustainability of associated vegetation and microbial communities. To supplement ecosystem characterization, the microbial biomass of soils from undisturbed Sonoran Desert areas will be compared to degraded substrate compromised by mining activities at Resolution Copper Mine. This comparison of semi-arid and arid microbial communities between undisturbed sustainable soil and disturbed substrate from variable levels of reclamation may determine the importance of microbial community composition on reclamation success. The research questions to be addressed by this thesis are what are the defining physical characteristics of sustainable semi-arid and arid zones and what are the crucial interactions between aridity driven water deficit and vegetation and microbial communities