03157nas a2200169   4500008004100000245011300041210006900154300001100223490000700234520253800241100001502779700001402794700001602808700002002824700002402844856011902868       2020                        eng d00aSoil heterogeneity increases plant diversity after twenty years of manipulation during grassland restoration0 aSoil heterogeneity increases plant diversity after twenty years   ae020140 v303 a<p>The &ldquo;environmental heterogeneity hypothesis&rdquo; predicts that variability in resources promotes species coexistence, but few experiments support this hypothesis in plant communities. A previous 15‐yr test of this hypothesis in a prairie restoration experiment demonstrated a weak effect of manipulated soil resource heterogeneity on plant diversity. This response was attributed to a transient increase in richness following a post‐restoration supplemental propagule addition, occasionally higher diversity under nutrient enrichment, and reduced cover of a dominant species in a subset of soil treatments. Here, we report community dynamics under continuous propagule addition in the same experiment, corresponding to 16&ndash;20 yr of restoration, in response to altered availability and heterogeneity of soil resources. We also quantified traits of newly added species to determine if heterogeneity increases the amount and variety of niches available for new species to exploit. The heterogeneous treatment contained a factorial combination of altered nutrient availability and soil depth; control plots had no manipulations. Total diversity and richness were higher in the heterogeneous treatment during this 5‐yr study due to higher cover, diversity, and richness of previously established forbs, particularly in the N‐enriched subplots. All new species added to the experiment exhibited unique trait spaces, but there was no evidence that heterogeneous plots contained a greater variety of new species representing a wider range of trait spaces relative to the control treatment. The richness and cover of new species was higher in N‐enriched soil, but the magnitude of this response was small. Communities assembling under long‐term N addition were dominated by different species among subplots receiving added N, leading to greater dispersion of communities among the heterogeneous relative to control plots. Contrary to the deterministic mechanism by which heterogeneity was expected to increase diversity (greater variability in resources for new species to exploit), higher diversity in the heterogeneous plots resulted from destabilization of formerly grass‐dominated communities in N‐enriched subplots. While we do not advocate increasing available soil N at large scales, we conclude that the positive effect of environmental heterogeneity on diversity can take decades to materialize and depend on development of stochastic processes in communities with strong establishment limitation.</p>1 aBaer, S.G.1 aAdams, T.1 aScott, D.A.1 aBlair, John, M.1 aCollins, Scott., L.  uhttp://knz.lternet.edu/content/soil-heterogeneity-increases-plant-diversity-after-twenty-years-manipulation-during00535nas a2200121   4500008004100000245016500041210006900206260004900275490001400324100001400338700001500352856004600367       2017                        eng d00aThe role of soil heterogeneity in the recruitment of new species and interactions with grasshoppers (Acrididae) and Katydids (Tettigoniidae) in restored prairie0 arole of soil heterogeneity in the recruitment of new species and  aCarbondale, ILbSouthern Illinois University0 vMS Thesis1 aAdams, T.1 aBaer, S.G.  uhttps://opensiuc.lib.siu.edu/theses/2080/