%0 Book Section %B Climate Variability and Ecosystem Response at Long-Term Ecological Research Sites %D 2003 %T Climate variability in tallgrass prairie at multiple timescales: Konza Prairie Biological Station %A Goodin, D.G. %A P. Fay %A McHugh, M.J. %E Greenland, D. %E Goodin, D.G. %E Smith, R.C. %B Climate Variability and Ecosystem Response at Long-Term Ecological Research Sites %I Oxford University Press %C New York %P 411 -424 %G eng %M KNZ00907 %0 Journal Article %J Ecological Applications %D 2003 %T The influence of disturbance from military training activities on terrestrial-aquatic linkages in a tallgrass prairie ecosystem %A Quist, M.C. %A P. Fay %A Guy, C.S. %A Alan K. Knapp %A Rubenstein, B.N. %K carbon cycling %K decomposition %K litter breakdown %K metabolism %K organic matter budgets %K organic matter dynamics %K streams %X The role of allochthonous organic matter in lotic ecosystems has been an important research topic among aquatic ecologists since the seminal work by Lindeman was published in 1942. Since 1986, studies on organic matter budgets, ecosystem metabolism, and decomposition published in J-NABS have made significant contributions to the overall understanding of organic matter dynamics in streams. In this review, we summarize the utility of organic matter budgets, cover the major advances in research on ecosystem metabolism, and describe the intrinsic and extrinsic factors influencing organic matter decomposition. We also discuss future directions and current applications of research and highlight the need for additional studies on the role of land use and climate change, as well as continued use of organic matter processing as a functional metric in biomonitoring studies. We emphasize the need for continued data synthesis into comprehensive organic matter budgets. Such comparative studies can elucidate important drivers of organic matter dynamics and can assist in the understanding of large continental/global changes that might be occurring now and in the near future. In general, continued emphasis on synthesizing information into a larger framework for streams and rivers will improve our overall understanding of the importance of organic matter in lotic ecosystems. %B Ecological Applications %V 13 %P 432 -442 %G eng %M KNZ00820 %R 10.1899/08-170.1 %0 Journal Article %J Environmental Entomology %D 2003 %T Insect diversity in two burned and grazed grasslands %A P. Fay %K fire %K Grazing %K insects %K sandhills prairie %K tallgrass prairie %X This study examined insect diversity in two native grassland ecosystems undergoing burning and grazing by bison and cattle, the Niobrara Valley Preserve (Nebraska) and the Tallgrass Prairie Preserve (Oklahoma). Sweep-sampling for insects was conducted during July 1994 and 1995 along transects in management units that were grazed by bison and partially burned, grazed by cattle and either burned (Tallgrass) or unburned (Niobrara), or ungrazed and unburned. At both sites, species richness (S) and diversity (log series ) were higher and similarity (Sorensen’s index) lower for bison than for cattle or ungrazed management units. High bison management unit diversity was associated with significantly higher S and  in burned (Tallgrass) and unburned (Niobrara) portions of bison units compared with their respective cattle units, suggesting that habitat heterogeneity in terms of plant productivity, composition, and structure were higher in bison versus cattle and ungrazed management units. Replicated factorial experiments and sampling of additional taxa and time points are needed to verify how fire and grazing management impacts insect diversity in these grasslands. %B Environmental Entomology %V 32 %P 1099 -1104 %G eng %M KNZ00877 %R 10.1603/0046-225X-32.5.1099 %0 Journal Article %J Oecologia %D 2003 %T Productivity responses to altered rainfall patterns in a C4-dominated grassland %A P. Fay %A Carlisle, J.D. %A Alan K. Knapp %A John M. Blair %A Scott. L. Collins %K Climate change %K Konza Prairie %K Net primary productivity %K Precipitation %K soil moisture %X Rainfall variability is a key driver of ecosystem structure and function in grasslands worldwide. Changes in rainfall patterns predicted by global climate models for the central United States are expected to cause lower and increasingly variable soil water availability, which may impact net primary production and plant species composition in native Great Plains grasslands. We experimentally altered the timing and quantity of growing season rainfall inputs by lengthening inter-rainfall dry intervals by 50%, reducing rainfall quantities by 30%, or both, compared to the ambient rainfall regime in a native tallgrass prairie ecosystem in northeastern Kansas. Over three growing seasons, increased rainfall variability caused by altered rainfall timing with no change in total rainfall quantity led to lower and more variable soil water content (0–30 cm depth), a ~10% reduction in aboveground net primary productivity (ANPP), increased root to shoot ratios, and greater canopy photon flux density at 30 cm above the soil surface. Lower total ANPP primarily resulted from reduced growth, biomass and flowering of subdominant warm-season C4 grasses while productivity of the dominant C4 grass Andropogon gerardii was relatively unresponsive. In general, vegetation responses to increased soil water content variability were at least equal to those caused by imposing a 30% reduction in rainfall quantity without altering the timing of rainfall inputs. Reduced ANPP most likely resulted from direct effects of soil moisture deficits on root activity, plant water status, and photosynthesis. Altered rainfall regimes are likely to be an important element of climate change scenarios in this grassland, and the nature of interactions with other climate change elements remains a significant challenge for predicting ecosystem responses to climate change. %B Oecologia %V 137 %P 245 -251 %G eng %M KNZ00863 %R 10.1007/s00442-003-1331-3 %0 Book Section %B Precipitation Regimes and Terrestrial Ecosystems. A North American Perspective %D 2003 %T Rainfall timing, soil moisture dynamics, and plant responses in a mesic tallgrass prairie ecosystem %A P. Fay %A Alan K. Knapp %A John M. Blair %A Carlisle, J.D. %A Danner, B.T. %A McCarron, J.K. %E Weltzin, J.F. %E McPherson, G.R. %K tallgrass prairie %B Precipitation Regimes and Terrestrial Ecosystems. A North American Perspective %I University of Arizona Press %C Tucson, AZ %P 147 -163 %G eng %M KNZ00847