02476nas a2200157   4500008004100000245009400041210006900135300001300204490000700217520190200224653002202126100001902148700001802167700001902185856011402204       1996                        eng d00aEffects of bison grazing, fire and topography on floristic diversity in tallgrass prairie0 aEffects of bison grazing fire and topography on floristic divers  a413 -4200 v493 aGrazed and ungrazed sites subjected to different fire frequencies were sampled on the Konza Prairie Research Natural Area in northeast Kansas after 4 years of bison grazing (1987-1991). The objective was to study effects of bison grazing on plant species composition and diversity components (plant species richness, equitability, and spatial heterogeneity) in sites of contrasting fire frequency. Cover and frequency of cool-season graminoids (e.g. Poa pratensis L., Agropyron smithii Rydb., Carex spp.) and some forbs (e.g. Aster ericoides [A. Gray] Howell, and Oxalis stricta L.) were consistently higher in sites grazed by bison than in ungrazed exclosures, whereas the dominant warm-season grasses (Andropogon gerardii Vitman, Sorghastrum nutans [L.] Nash, Panicum virgatum L., Schizachyrium scoparium [Michx.] Nash) and other forbs (e.g. Solidago missouriensis Nutt.) decreased in response to bison. Plant species diversity (H′) and spatial heterogeneity in all areas sampled were significantly increased by bison. Increased heterogeneity and mean species richness in grazed prairie (40 species per sample site) compared to ungrazed prairie (29 species per site) were likely a result of greater microsite diversity generated by bison, whereas preferential grazing of the dominant grasses and concomitant increases in subordinate species resulted in an increase in equitability of species abundances. Species/area relationships indicated greater effects of bison on plant species richness with increasing sample area. Increases in plant diversity components associated with bison grazing were generally greater in annually burned than in 4-year burned sites. Effects of ungulate grazers on floristic diversity have important implications given recent evidence that plant species diversity and the compositional and production stability of grassland plant communities are positively related.10atallgrass prairie1 aHartnett, D.C.1 aHickman, K.R.1 aWalter, L.E.F.  uhttp://129.130.186.12/content/effects-bison-grazing-fire-and-topography-floristic-diversity-tallgrass-prairie00537nas a2200145   4500008004100000245007700041210006900118300001300187653002200200100001900222700001800241700001900259700001500278856009800293       1996                        eng d00aEffects of bison grazing on plant species diversity in tallgrass prairie0 aEffects of bison grazing on plant species diversity in tallgrass  a215 -21610atallgrass prairie1 aHartnett, D.C.1 aHickman, K.R.1 aWalter, L.E.F.1 aWest, N.E.  uhttp://129.130.186.12/content/effects-bison-grazing-plant-species-diversity-tallgrass-prairie02108nas a2200193   4500008004100000245007500041210006900116300001300185490000700198520154100205653001601746653001501762653002201777100001901799700001901818700002001837700001701857856004001874       1996                        eng d00aInterspecific nutrient transfer in a tallgrass prairie plant community0 aInterspecific nutrient transfer in a tallgrass prairie plant com  a180 -1840 v833 aInterplant nutrient transfer may be an important ecological process in grasslands, and may significantly influence plant neighborhood interactions. We investigated the potential for phosphorus transfer between the dominant grass Andropogon gerardii and several neighboring plant species in tallgrass prairie via a field 32PO4 labelling experiment. The mean amount of 32P received from donor shoots differed significantly among neighboring species and decreased with increasing distance from the donor. In general, forbs and cool-season C3 grasses received more labelled 32P than warm-season C4 grasses. Phosphorus transfer occurred over distances up to 0.5 m. The effects of species and distance on movement of phosphorus changed with increasing time after labelling. The relative mass of receiver and donor shoots did not affect amounts of 32P transfer. A benomyl fungicide treatment, applied to suppress mycorrhizal activity, likely did not affect existing vegetative hyphae and did not affect the amount of 32P transferred. These studies demonstrate that: (1) phosphorus is transferred among neighboring species in tallgrass prairie plant communities, (2) phosphorus may be transferred over significantly greater distances than reported in other grasslands, and (3) there is differential transfer among co-occurring species. Hypothesized mechanisms accounting for these patterns in tallgrass prairie include mycorrhizal hyphal interconnections and/or extensive and differential root and rhizosphere overlap among neighboring species.10amycorrhizae10aPhosphorus10atallgrass prairie1 aWalter, L.E.F.1 aHartnett, D.C.1 aHetrick, B.A.D.1 aSchwab, A.P.  uhttp://www.jstor.org/stable/244593600503nas a2200133   4500008004100000245007400041210006900115300001300184653002200197100001900219700001800238700001900256856009400275       1995                        eng d00aEffects of bison grazing, on floristic diversity in tallgrass prairie0 aEffects of bison grazing on floristic diversity in tallgrass pra  a215 -21610atallgrass prairie1 aHartnett, D.C.1 aHickman, K.R.1 aWalter, L.E.F.  uhttp://129.130.186.12/content/effects-bison-grazing-floristic-diversity-tallgrass-prairie