PARENT SESSION
Poster Session # 10: Soil Ecology.
Tuesday, August 5 Presentation from 5:00 PM to 6:30 PM. SITCC Exhibit Hall B.
Characterization of environmental and edaphic factors affecting soil microbial communities using a tallgrass prairie restoration chronosequence.
Allison, Victoria*,1, Miller, Mike1, Jastrow, Julie1, Matamala, Roser1, 1 Argonne National Laboratory, Argonne, IL, USA
ABSTRACT- We examined environmental factors regulating soil microbial community structure, using a tallgrass prairie restoration chronosequence located at the Fermi National Accelerator Laboratory in Batavia, Illinois. This chronosequence allows us to examine microbial community structure over a wide range of soil and biotic conditions. Soil microbial community structure was determined using phospholipid fatty acid (PLFA) patterns, and summarized by correspondence analysis. We found a clear difference between agricultural and restored prairie plots. The prairie plots had considerably higher relative amounts of the fungal signature PLFA 18:2:omega:6, and the arbuscular mycorrhizal fungal signature 16:1:omega:5c. In contrast, agricultural plots had higher relative amounts of cy17:0 and cy19:0; markers for gram-negative bacteria. Further, the ratio of cyclopropyl fatty acids to their precursors was considerably lower in prairie than in agricultural plots indicating higher substrate availability in the restored prairie soils. Regression of ordination plots against environmental variables indicated that the chronosequence represents an aggrading soil system, with microbial composition related to a suite of environmental variables, most notably increased production of root biomass, surface litter accumulation, and a widening of plant tissue and soil C:N ratios. These changes in biotic and edaphic factors encountered along the chronosequence appear to be related to the termination of tillage and fertilizer inputs, and especially to the associated increases in plant biomass (both above and belowground), all associated with the cessation of agriculture.
Key words: PLFA, Microbial, aggrading, restoration