Soil Physical and Biological Diversity of Lawns in Dane County, Wisconsin.

Increasing urbanization is leading to the persistent conversion of farmland and native ecosystems to managed turfgrass ecosystems. The full implications of this type of land use change are unknown. Most turfgrass research has investigated the influence of management practices on microbial populations of sand-based systems. One important question that remains to be addressed is how native soil physiochemical properties influence microbial community structure. Microorganisms play important roles in biogeochemical cycling, organic matter decomposition, and influencing soil physical and chemical properties. During the summer of 2005, soil samples were taken from 43 lawns in Dane County, WI. Study participants were homeowners and caretakers who were recruited by emails, flyers, and word of mouth. The soils at the participating sites were analyzed for physical, chemical and biological properties. The lawns varied in greatly in soil physiochemical properties such as organic matter content (2 Ð 14%), bulk density (0.7 Ð 1.4 g cm-3), sand content (8 Ð 75%), clay content (6 - 29%), and pH (5.5 Ð 7.5). Soil microbial community composition was analyzed using a hybrid technique of phospholipid fatty acid (PLFA) and fatty acid methyl ester (FAME) analysis. Principal component analysis followed by one-way ANOVA was used to assess the differences among lawns by site. The lawns were dominated by bacterial biomass rather than fungal biomass. Our results indicate that a diversity of microbial communities of Dane County lawns exists. However, no clear trends between soil physiochemical properties and microbiological community composition could be identified. These results indicate that the microbial diversity may not be controlled by commonly analyzed soil properties.