Microbial Nutrient Utilization of Anthropogenic Inputs across the Central Arizona-Phoenix Long Term Ecological Research Site (CAP-LTER)

Straus, Samantha H.; Hall, Sharon J.; and Huber, David P
School of Life Sciences, Arizona State University

Microorganisms as bacteria and fungi live in soils and control major processes in nutrient cycling. Nutrient cycling is the process by which molecules are transformed by one organism to the next and can be controlled by nutrients entering the soil. Inputs of nutrients to ecosystems occur as natural and anthropogenic atmospheric deposition, rainfall, and natural inputs from plants as litterfall. In the greater Phoenix area, anthropogenic inputs of organic carbon and nitrogen are deposited onto the soils by human activity and agricultural sources. In this study I wanted to know how these inputs are affecting microbial communities and nutrient cycling in and around the urban Phoenix area. I collected soils from upwind, core, and downwind regions from urban Phoenix areas. In the lab I added treatments of water, nitrogen, and carbon to the soils in factorial. I will measure soil respiration (CO2) to determine how readily the microorganisms are utilizing carbon and nitrogen compounds. These results will help us to better understand the effects of urban deposition on native soils of the Sonoran desert.