PS 23-103 - Linking microbial community and function across time in restored and remnant tallgrass prairie

Wednesday, August 10, 2016
ESA Exhibit Hall, Ft Lauderdale Convention Center
Elizabeth M. Bach and Andrew N. Miller, Illinois Natural History Survey, University of Illinois, Champaign, IL

Temporal fluctuations in soil microbial communities and their activities play an important role in carbon and nutrient cycling in both natural and managed ecosystems.  The extent to which ecological factors such as plant growth stages, soil texture, and weather patterns influence temporal shifts in microbial communities and activities is not well understood.  We explicitly tested the role of plant phenology and soil texture in temporal patterns of fungal community structure and activity.  We sampled soil at key plant growth stages including emergence, bolting, and senescence, in restored and remnant tallgrass prairie on clayey and sandy soils in Illinois.  We sampled directly under Schizacrium scoparium, a C4 grass, and Elymus canadensis, a C3 grass, at all sites and all sampling times to contrast the role of plant phenology on microbial parameters.  Soil fungal communities were evaluated using targeted amplicon sequencing of ITS1 rDNA.  Sequences were processed using the QIIME pipeline and community differences analyzed using non-parametric multivariate analysis of variance.  Microbial activity was measured using fluorometric extracellular enzyme activity assays for phosphatase, N-acetyl glucosaminidase, β-glucosidase, cellobiohydrolase, and β-xylosidase.  Enzyme activity data was contrasted between soil type and plant type using mixed models and correlated with microbial communities using vector-fitting analysis.


Fungal community richness and Shannon’s diversity was greater (P<0.0001) and enzyme activity lower (P<0.0001) in sandy soil compared with clayey soil.  This supports the paradigm that fungi are more competitive in sandy environments, but lower organic matter resources and moisture limit activity.  Temporal patterns in fungal communities and phosphorus and nitrogen enzyme activity were consistent on both soil types (P>0.1 for all), indicating soil texture does not influence temporal patterns in nutrient cycling.  However, carbon-cycling enzyme activities did exhibit different temporal patterns in sandy soil and clayey soil (P<0.01), which may reflect differences in organic matter availability.  Contrasts of remnant and restored prairie sites on both soil textures showed activity of all enzymes exhibited similar temporal patterns in restorations and remnants (P>0.1 for all).  Fungal communities differences between restorations and remnants interacted with soil type (P=0.0001), but temporal patterns were consistent in both site types (P=0.05).  Similar temporal patterns in fungal community shifts and enzyme activity indicate these patterns are not influenced by soil texture, and temporal patterns in nutrient cycling can be easily and effectively restored.  Fungal communities in restored prairies may differ from remnants, but functionally they perform similarly.