Submitted to: Journal of Soil Biology and Biochemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/30/2011
Publication Date: 10/1/2011
Citation: Jangid, K., Williams, M.A., Franzluebbers, A.J., Schmidt, T.M., Coleman, D.C., Whitman, W.B. 2011. Land-use history has a stronger impact on soil microbial community composition than aboveground vegetation and soil properties. Journal of Soil Biology and Biochemistry. 43: 2184-2193. 2011. Interpretive Summary: Diversity of microorganisms in soil is enormous. Little is known about how land-use change might affect the composition and genetic diversity of bacteria and fungi in soil. A collaborative research effort among scientists at the University of Georgia, Mississippi State University, Michigan State University, and USDA-Agricultural Research Service in Watkinsville Georgia was developed to understand the role of successional land-use change from agriculture to grassland or forest on soil microbial diversity in soils from the Kellogg Biological Station in Hickory Corners MI. Contents of soil organic carbon and nitrogen increased with increasing years of grassland or forest succession. With succession, abundance and composition of soil bacteria increased. Although microbial communities were relatively similar in native deciduous forest and long-term mowed grassland, history of land use was a stronger determinant of microbial composition than vegetation and soil properties. These results have important implications for scientists in their quest to preserve global genetic diversity and for society to understand the impact of agriculture on the environment.
Technical Abstract: The response of soil microbial communities following soil disturbances is poorly understood. The development of soil microbial communities in two restoration gradients was studied to investigate the impact of land-management regime at the W. K. Kellogg Biological Station, Michigan. The first restoration gradient comprised a conventionally tilled cropland (CT), mid-succession forest (SF) abandoned from cultivation prior to 1951, and native deciduous forest (DF). The second gradient comprised the CT cropland, early-succession grassland (ES) restored in 1989, and long-term mowed grassland (MG). In addition, the impacts of tillage, vegetation and land-use history in shaping the underlying soil microbial communities were investigated. Upon restoration to either DF or MG, the total microbial phospholipid fatty acids (PLFA) and soil microbial biomass C consistently increased. While the bacterial rRNA gene diversity remained unchanged, the abundance and composition of many phyla changed significantly. The DF and MG soil communities were very similar despite major differences in soil properties and vegetation. After >50 years of restoration, microbial communities in SF were more similar to those in DF than in CT. In contrast, even after 17 years post-restoration, microbial communities in ES were more similar to CT than MG. Tillage did not have a major effect on soil microbial communities in CT than never-tilled soils. In contrast, the conifer forest (CF) soils had significantly different community composition, lower pH, C and N content, soil microbial biomass, PLFAs, and 16S rRNA gene diversity than DF soils. In conclusion, with the exception of the conversion of deciduous to conifer forests, history of disturbance was a stronger determinant of the composition of microbial communities than vegetation and the chemical and physical properties of soil.