Soil microbial ecosystem dynamics of semi-arid wetlands under differing land-use

Authors: RILEY, M - Texas Tech University; Acosta-Martinez, Veronica; COLDREN, C - Texas Tech University; RAINWATER, K - Texas Tech University; SLAUGHTER, L - Texas Tech University

Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 8/21/2019
Publication Date: 11/12/2019
Citation: Riley, M., Acosta Martinez, V., Coldren, C., Rainwater, K., Slaughter, L.C. 2019. Soil microbial ecosystem dynamics of semi-arid wetlands under differing land-use. ASA-CSSA-SSSA Annual Meeting Abstracts. 1.

Interpretive Summary:

Technical Abstract: Playas are ephemeral wetlands that are a significant landscape feature in the semi-arid Southern High Plains (SHP) of West Texas. These wetlands form some of the only remaining native habitat in the region and are a source of recharge to the Ogallala Aquifer. With ~20,000 playas present in the SHP alone, expanding urban areas have developed around these wetlands, incorporating them into a major component of their municipal stormwater management systems. Little is known about the soil microbes in the playa ecosystem. This is concerning because we do not know the impact these anthropogenic activities have on microbial communities and the effects on their biogeochemical processes. Our objective was to determine the spatial distribution and activities of soil microbes within and across playas under various stages and types of development. We sought to identify (i.) the general microbial community structure (ii.) their spatial distribution and (iii.) how the microbes respond to land use, which were classified according to the dominant surrounding land use: native rangeland, residential, and parking lot. Microbial biomass and community structure were assessed by measuring microbial carbon/nitrogen and by characterizing extracted ester-linked fatty acid profiles (EL-FAMEs). Non-metric multidimensional scaling (NMS) ordinations of selected lipid biomarkers were used to characterize microbial structure between and within playas. Extracellular activity was evaluated by conducting selected enzyme assays. Total microbial biomass did not differ across the three sites, but each playa exhibited a significantly distinct microbial community structure that was distributed differently across playa zones. This suggests playas are unique and dynamic habitats that are influenced by increasing anthropogenic activities. These findings are vital for understanding the impacts of urbanization on playa microbial communities which drive biogeochemical processes and will allow researchers, developers, and landowners to make informed management decisions for future development projects.