02723nas a2200193   4500008004100000245010400041210006900145300001300214490000800227520201700235653001402252653002702266653003502293653002302328653002502351100001702376700001602393856012002409       1997                        eng d00aContingent effects of plant species on soils along a regional moisture gradient in the Great Plains0 aContingent effects of plant species on soils along a regional mo  a393 -4020 v1103 aThe central grassland region of the United States encompasses major gradients in temperature and precipitation that determine the distribution of plant life forms, which in turn may influence key ecosystem processes such as nutrient cycling and soil organic matter dynamics. One such gradient is the threefold increase in precipitation from the eastern Colorado shortgrass-steppe, in the rain shadow of the Rocky Mountains, to the tallgrass prairie in eastern Kansas. We investigated the relative roles of plant species and plant cover in influencing soil C and N cycling in three sites along this gradient. Plant cover (i.e., the presence or absence of an individual plant) was relatively more important than plant species in explaining variability in soil properties at the dry site, the Central Plains Experimental Range in␣northeastern Colorado. However, plant species explained relatively more of the variability in soil properties than did plant cover at the two wetter sites, Hays and Konza, in central and eastern Kansas. The wetter sites had more continuous plant cover, resulting in less plant-cover-induced variation in soil C and N, than did the dry site, which had distinct patches of bare ground. Plant species at the wetter sites had higher and more variable levels of tissue C:N than plant species at the dry site, due to both within species changes and changes in species composition. Aboveground tissue C:N was better correlated with net nitrogen mineralization rates at the wet sites than the dry site. Thus, tissue chemistry appears to exert more control on nitrogen dynamics at the wet than the dry sites. The results suggest that plant species traits that are relevant to nutrient cycling (e.g., tissue C:N ratios, spatial patterns, productivity) reflect environmental limitations as well as species' physiological potentials. Furthermore, a dominant environmental driver such as precipitation may ameliorate or exaggerate the importance of individual species traits for nutrient cycling.10agrassland10a    Litter quality10a   Plant-soil interactions10a   Soil carbon10a   Soil nitrogen1 aVinton, M.A.1 aBurke, I.C.  uhttp://knz.lternet.edu/content/contingent-effects-plant-species-soils-along-regional-moisture-gradient-great-plains01366nas a2200157   4500008004100000245009500041210006900136260003000205300001000235520077300245100001701018700002401035700001601059700001701075856011601092       1997                        eng d00aLandscape gradients and habitat structure in native grasslands of the central great plains0 aLandscape gradients and habitat structure in native grasslands o  aNew YorkbSpringer-Verlag  a3 -193 aHabitat variables have a powerful influence on the distribution and abundance of organisms, and many organisms directly affect the physical structure of their local environment. These interactions produce a complex feedback system that drives community dynamics. This scenario is particularly true in grasslands where the effects of “keystone engineers,” such as the North American bison (Bison bison), have a tremendous influence on ecosystem structure and function (Collins and Benning 1996). This interplay between organisms and habitat structure in grasslands occurs within a climatic regime that varies dramatically from one year to the next. In addition, the relative influence of different habitat variables changes at different spatial and temporal scales.1 aVinton, M.A.1 aCollins, Scott., L.1 aKnopf, F.L.1 aSamson, F.B.  uhttp://knz.lternet.edu/content/landscape-gradients-and-habitat-structure-native-grasslands-central-great-plains01982nas a2200169   4500008004100000245011800041210006900159300001100228490000800239520134400247653002201591100001701613700001901630700001601649700001901665856012801684       1993                        eng d00aThe interactive effects of fire, bison (Bison bison) grazing and plant community composition in tallgrass prairie0 ainteractive effects of fire bison Bison bison grazing and plant   a10 -180 v1293 aFire and native large herbivore grazing were two important influences on the structure and function of North American grasslands. In 1988 and 1989 the influence of fire regime on grazing patterns of North American bison (Bison bison) was studied on the Konza Prairie in northeastern Kansas. Bison grazing was spatially and temporally nonrandom and was influenced by fire regime and local plant community composition. During the growing season, bison were observed up to 3 x more frequently than expected on watersheds burned in the spring. Summer grazing was concentrated in large watershed areas (79-119 ha) dominated by warm-season, perennial, C4 grasses. During the autumn and winter, bison grazed both burned and unburned watersheds more uniformly but grazed most intensively in areas with large stands of cool-season, C3 grasses. On a smaller spatial scale (5-10 m2), bison selected patches during the growing season with low forb cover dominated by the perennial C4 grass, Andropogon gerardii. Grazed patches were larger on frequently burned than on infrequently burned watersheds. The importance of fire history in determining patterns of bison grazing over the landscape indicates that interactions between bison grazing and fire regime may be important to the composition and spatial heterogeneity of tallgrass prairie vegetation.10atallgrass prairie1 aVinton, M.A.1 aHartnett, D.C.1 aFinck, E.J.1 aBriggs, J., M.  uhttp://knz.lternet.edu/content/interactive-effects-fire-bison-bison-bison-grazing-and-plant-community-composition-tallgrass02202nas a2200145   4500008004100000245011400041210006900155300001300224490000700237520162600244653002201870100001701892700001901909856012801928       1992                        eng d00aEffects of bison grazing on Andropogon gerardii and Panicum virgatum in burned and unburned tallgrass prairie0 aEffects of bison grazing on Andropogon gerardii and Panicum virg  a374 -3820 v903 a<p>Responses to clipping and bison grazing in different environmental contexts were examined in two perennial grass species, Andropogon gerardii and Panicum virgatum, on the Konza Prairie in northeastern Kansas. Grazed tillers had lower relative growth rates (RGR) than clipped tillers following defoliation but this difference was transient and final biomass was not affected by mode of defoliation. Grazed tillers of both species had higher RGR throughout the season than ungrazed tillers, resulting in exact compensation for tissue lost to defoliation. However, A. gerardii tillers which had been grazed repeatedly the previous year (1988) had reduced relative growth rates, tiller biomass and tiller survival in 1989. This suggests that the short-term increase in aboveground relative growth rates after defoliation had cost to future growth plant growth and tiller survival. In general, two species had similar responses to defoliation but their responses were altered differentially by fire. The increase in RGR following defoliation of A. gerardii was relatively greater on unburned than burned prairie, and was relatively greater on unburned than burned prairie, and was influenced by topographic position. P. virgatum responses to defoliation were similar in burned and unburned prairie. Thus grazing, fire, and topographical position all intreract to influence tiller growth dynamics and these two species respond differently to the fire and grazing pattern to influence a plants&#39; grazing history and thus its long tern performance. Key words: grazing, bison, fire, Andropogon gerardii, Panicum virgatum</p>10atallgrass prairie1 aVinton, M.A.1 aHartnett, D.C.  uhttp://knz.lternet.edu/content/effects-bison-grazing-andropogon-gerardii-and-panicum-virgatum-burned-and-unburned-tallgrass00528nas a2200133   4500008004100000245007500041210006900116260004300185300001000228490001400238653002200252100001700274856010300291       1990                        eng d00aBison grazing patterns and plant responses on Kansas tallgrass prairie0 aBison grazing patterns and plant responses on Kansas tallgrass p  aManhattan, KSbKansas State University  a1 -570 vMS Thesis10atallgrass prairie1 aVinton, M.A.  uhttp://knz.lternet.edu/content/bison-grazing-patterns-and-plant-responses-kansas-tallgrass-prairie