@article {KNZ00533, title = {Nitrogen transport from tallgrass prairie watersheds}, journal = {Journal of Environmental Quality}, volume = {25}, year = {1996}, pages = {973 -981}, abstract = {Discharge and N content of surface water flowing from four Karst watersheds on Konza Prairie Research Natural Area, Kansas, managed with different burn frequencies, were monitored from 1986 to 1992. The goal was to establish the influence of natural processes (climate, fire, and bison grazing) on N transport and concentration in streams. Streams were characterized by variable flow, under conditions that included an extreme flood and a drought during which all channels were dry for over a year. The estimated groundwater/stream water discharge ratio varied between 0.15 to 6.41. Annual N transport by streams, averaged across all watersheds and years, was 0.16 kg N ha-1 yr-1. Annual N transport per unit area also increased as the watershed area increased and as precipitation increased. Total annual transport of N from the prairie via streams ranged from 0.01 to 6.0\% of the N input from precipitation. Nitrate and total N concentrations in surface water decreased (P < 0.001, r values ranged from 0.14{\textendash}0.26) as length of time since last fire increased. Increased watershed area was correlated negatively (P < 0.0001) to stream water concentrations of NO-3N and total N (r values = -0.43 and -0.20, respectively). Low N concentration is typical of these streams, with NH+4-N concentrations below 1.0 {\textmu}g L-1, NO-3-N ranging from below 1.4 to 392 {\textmu}g L-1, and total N from 3.0 to 714 {\textmu}g L-1. These data provide an important baseline for evaluating N transport and stream water quality from unfertilized grasslands.}, keywords = {LTER-KNZ, tallgrass prairie}, doi = {10.2134/jeq1996.00472425002500050007x}, author = {W. K. Dodds and John M. Blair and Henebry, G.M. and Koelliker, J.K. and Ramundo, R.A. and Tate, C.M.} } @article {KNZ00428, title = {Methane consumption and carbon dioxide emission in tallgrass prairie: effects of biomass burning and conversion to agriculture}, journal = {Global Biogeochemical Cycles}, volume = {7}, year = {1993}, pages = {735 -784}, abstract = {Consumption of atmospheric methane and emission of carbon dioxide by soils were measured on unburned and annually burned tallgrass prairie and on adjacent wheat and sorghum agricultural plots in Kansas. Profiles of CH4 and CO2 concentration with soil depth were also measured. Overall patterns of CH4 consumption by soils varied temporally, with soil depth and land use. Mean CH4 consumption for the 200-day sampling period was -1.02 mg CH4 m-2 d-1 (SE=0.13, n=41) for burned prairie, -0.63 (SE=0.09, n=45) for unburned prairie, -0.85 (SE=0.20, n=36) for wheat, and -0.45 (SE=0.08, n=40) for sorghum. Less than 20 \% of the variance in CH4 consumption was explained by soil temperature and/or moisture content. Overall patterns of CO2 emission from prairie and agricultural soils varied temporally, but not among land use. Mean CO2 emission for the 200-day sampling period was 15.7 g CO2 m-2 d-1 (SE=1.8, n=41) for burned prairie, 14.5 (SE=1.3, n=45) for unburned prairie, 13.9 (SE=2.1, n=36) for wheat, and 10.3 (SE=2.1, n=40) for sorghum. More than 70\% of the variance in prairie CO2 emission rate was explained by soil temperature and moisture. Crop management practices influenced the timing of CO2 emission from agricultural plots but not the net annual rate of emission. Methane concentrations generally decreased and CO2 concentrations increased with soil depth, and the magnitude of CH4 and CO2 flux generally increased with increased magnitude of the soil gas concentration gradient. Fertilization of agricultural fields had no measured effect on CH4 or CO2 flux or on soil gas concentrations.}, keywords = {LTER-KNZ, tallgrass prairie}, doi = {10.1029/93GB02560}, author = {Tate, C.M. and Strigel, R.G.} } @article {KNZ00395, title = {Microbial decomposition of elm and oak leaves in a karst aquifer}, journal = {Applied Environmental Microbiology}, volume = {59}, year = {1993}, pages = {3592 -3596}, abstract = {Dry Chinquapin oak (Quercus macrocarpa) and American elm (Ulmus americana) leaves were placed in four microcosms fed by groundwater springs to monitor changes in dry mass, ash-free dry mass, and microbial activity over a 35-day period. Oxygen microelectrodes were used to measure microbial activity and to estimate millimeter-scale heterogeneity in that activity. Oak leaves lost mass more slowly than elm leaves. Generally, there was a decrease in total dry weight over the first 14 days, after which total dry weight began to increase. However, there were consistent decreases in ash-free dry mass over the entire incubation period, suggesting that the material remaining after initial leaf decomposition trapped inorganic particles. Microbial activity was higher on elm leaves than on oak leaves, with peak activity occurring at 6 and 27 days, respectively. The level of oxygen saturation on the bottom surface of an elm leaf ranged between 0 and 75\% within a 30-mm2 area. This spatial heterogeneity in O2 saturation disappeared when the water velocity increased from 0 to 6 cm s-1. Our results suggest that as leaves enter the groundwater, they decompose and provide substrate for microorganisms. The rate of decomposition depends on leaf type, small-scale variations in microbial activity, water velocity, and the length of submersion time. During the initial stages of decomposition, anoxic microzones are formed that could potentially be important to the biogeochemistry of the otherwise oxic aquifer.}, keywords = {LTER-KNZ}, url = {http://aem.asm.org/content/59/11/3592.short}, author = {Eichem, A. and W. K. Dodds and Tate, C.M. and Edler, C.} } @proceedings {KNZ00375, title = {Effects of tallgrass prairie vegetation on the concentration and seasonality of nitrate\-nitrogen in soil water and streams}, year = {1992}, pages = {9 -12}, publisher = {University of Northern Iowa}, abstract = {

Inorganic nitrogen concentrations in tallgrass prairie soils and streams exhibit a sinusoidal seasonal pattern; nitrate levels are relatively high in winter and low in summer. The pattern is not observed in either rainfall or canopy drip (throughfall). Thus, the pattern is created by plant root-microbial interactions; when roots are not active, nitrates accumulate and can be leached from the soil. We used nitrogen fertilizer and herbicide in a factorial experiment to test the strength of root uptake activities on soil water nitrogen. Soil-water nitrate concentrations were 10 times higher when prairie roots were deactivated by application of a foliar herbicide. Ammonium nitrogen concentrations were unaffected. When fertilizer was added, nitrate levels of soil water beneath herbicide-treated vegetation were double that of untreated prairie. Mineralization of nitragen from herbicide-treated roots was not believed to be the source of the increased nitrate. These and previous studies at Konza Prairie emphasize the importance of plant cover in maintaining low nitrate concentrations of streams

}, keywords = {LTER-KNZ, tallgrass prairie}, author = {Ramundo, R.A. and Tate, C.M. and Seastedt, T.R.}, editor = {Smith, D.A. and Jacobs, C.A.} } @inbook {KNZ00340, title = {Improving use of existing data}, booktitle = {Comparative Analyses of Ecosystems: Patterns, Mechanisms and Theories}, year = {1991}, pages = {348 -350}, publisher = {SpringerVerlag}, organization = {SpringerVerlag}, keywords = {LTER-KNZ}, author = {Tate, C.M. and Jones, C.G.}, editor = {Cole, J.J. and Findlay, S.E.G. and Lovett, G.M.} } @article {KNZ00332, title = {Stochastic analysis of the dynamics of nitrogen concentration in a stream ecosystem}, journal = {Ecological Modeling}, volume = {56}, year = {1991}, pages = {33 -45}, keywords = {LTER-KNZ}, doi = {10.1016/0304-3800(91)90191-3}, author = {Nassar, R. and Stewart, R. and Tate, C.M.} } @article {KNZ00298, title = {Patterns and controls of nitrogen in tallgrass prairie streams}, journal = {Ecology}, volume = {71}, year = {1990}, pages = {2007 -2018}, abstract = {

A descriptive and experimental approach was used to study patterns of nitrogen concentrations in tallgrass prairie streams in Kansas. Nitrate concentrations varied depending on the year, season, time of day, stream flow conditions, source of water, and location where the sample was taken. Mean nitrate concentrations during the dormant season decreased from 1982 to 1984, corresponding to above normal precipitation during this same period. Nitrate concentrations decreased from third-order (grass/shrub riparian vegetation) to fourth-order channels (gallery forests). Nitrate, organic N, and total N were higher in a third-order intermittent stream than in a third-order perennial stream. Water from seeps and tributaries had higher nitrate concentrations than stream water; however, streams and tributaries had higher organic N than seeps. Maximum nitrate concentrations during storm flows were directly related to the magnitude of storms and inversely related to the frequency of storm events. The activity of terrestrial vegetation influenced nitrate concentrations within streams, seeps, and tributaries; nitrate concentrations were always higher during periods of vegetation dormancy. Aquatic biota influenced both spatial patterns (downstream decrease in nitrate concentrations and increase in organic N) and diel patterns of nitrate concentration (night greater than day). Uptake rates of nitrate by biota were greater during the day than during the night as determined by experimental addition of nitrate. Nitrogen (N) and/or phosphorus (P) limitations of algal growth were tested experimentally using nutrient- diffusing substrata (clay saucers filled with enriched agar) and enrichment of artificial channels. Addition of N and P in combination increased algal biomass (chlorophyll a and ash-free dry mass) over controls or single addition of N or P. Thus, algal biomass was N and P limited; however, individual taxa responded to specific N and/or P concentrations or atomic N:P ratio. Key words: flooding, intermittent stream, nitrate, nitrogen, nutrient limitation, organic nitrogen, periphyton, phosphorus, tallgrass prairie, stream

}, keywords = {LTER-KNZ, tallgrass prairie}, doi = {http://www.jstor.org/stable/1937609}, author = {Tate, C.M.} } @article {KNZ00178, title = {Hydrologic influences on leaf decomposition in a channel and adjacent bank of a gallery forest stream}, journal = {The American Midland Naturalist}, volume = {120}, year = {1988}, pages = {11 -21}, abstract = {

Hydrologic extremes of flooding and drought typically occur each year in prairie streams. Two experiments were conducted in a fifth- order, gallery forest reach of King\&$\#$39;s Creek, Kansas, to assess the effect of hydrologic conditions on decomposition of leaves in the stream channel and on the adjacent floodplain. Temporal patterns of weight loss were examined in the first experiment. Leaves of bur oak and hackberry decomposed more rapidly in the channel than on the adjacent bank. A sharp drop in percent remaining for hackberry in the 2nd month (mid- December to mid-January) coincided with a period of high shredder densities on hackberry leaves. On the bank, decomposition of hackberry leaves was fastest during intervals that included one or more inundations of the leaf packs. Bur oak leaves decomposed more slowly than hackberry leaves and were influenced less by the hydrologic history. In the second experiment, spatial variation in decomposition rate of hackberry leaves was examined by placing 20 pairs of leaf packs in a transect extending from the center of the stream channel on the top of the upper bank. Position on the transect affected the frequency and duration of inundations on the floodplain, which ranged from one (minimum of 0.2 hr) to 17 times (272 cumulative hr under water), while three pairs of packs in the channel were always under water. The logarithm of percent remaining after 274 days was significantly correlated with number of hours inundated and number of times inundated, although other factors such as soil moisture or amount of flood-deposited silt may have influenced differences in decomposition rates along the transect. We concluded that flood frequency, during and timing affected both spatial and temporal patterns of decomposition, especially of a fast-decomposing species, in the riparian forest of an intermittent prairie stream

}, keywords = {LTER-KNZ, gallery forest}, doi = {10.2307/2425882}, author = {Gurtz, M.E. and Tate, C.M.} } @article {KNZ00129, title = {Comparison of mass loss, nutrients, and invertebrates associated with elm leaf litter decomposition in perennial and intermittent reaches of tallgrass prairie streams}, journal = {The Southwestern Naturalist}, volume = {31}, year = {1986}, pages = {511 -520}, abstract = {

Decay rates, nutrient content and invertebrates associated with American elm leaves were examined in an intermittent and a perennial stream draining adjacent tallgrass prairie watersheds (Konza Prairie, Kansas). Both streams were flowing in November 1981 when leaf packs were placed in the channel. Elm leaves decayed faster in the perennial stream than in either of two intermittent sites. Decay rates were not different between the two intermittent sites. There were no significant differences among sites in either nitrogen (N) or phosphorus (P) concentrations or carbon to nitrogen (C:N) ratios in elm leaves. N concentrations of the leaves increased during decomposition whereas P decreased in concentration for the first two months and then increased; C:N ratios in elm leaves decreased during decomposition. Initial leaching of leaves may provide a nutrient input into prairie streams; but decomposing leaf material may also act as a nutrient sink and compete with other ecosystem processes. Shredder insects were low in abundance or absent from leaf packs

}, keywords = {LTER-KNZ, tallgrass prairie}, doi = {10.2307/3671705}, author = {Tate, C.M. and Gurtz, M.E.} } @proceedings {KNZ0094, title = {The interaction of biological and hydrologic phenomena that mediate the quality of water draining native prairie on the Konza Prairie Research Natural Area}, journal = {Perspectives on Nonpoint Source Pollution}, year = {1985}, pages = {478 -482}, publisher = {U.S. Enviromental Protection Agency}, address = {Washington DC}, abstract = {

The quality of water from native landscapes in the baseline against which the impact of pollutants on surface water resources must be evaluated. The King\&$\#$39;s Creek watershed has been a U.S. Geological Survey benchmark watershed since 1979. It represents the landscape type tyat gave rise to much of the agricultural midwestern United States. Hydrologic, chemical, and biological measurements have been made by ecologists performing long-term ecological research (LTER) in tallgrass prairie. Streamwater chemistry varies seasonally with the amount and movement of groundwater and soil water, with changes in prairie vegetation, and in response to changes in surface water discharge. Concentrations of organic carbon, organ and inorganic nitrogen, and phosphorus increase during storm flows. The particulate fractions in transport and in storage in the stream bed and on the flood plain vary seasonally with recent hydrologic history and changes in vegetation

}, keywords = {LTER-KNZ, tallgrass prairie}, author = {McArthur, J.V. and Gurtz, M.E. and Tate, C.M. and Gilliam, F.S.} } @phdthesis {KNZ00100, title = {A study of temporal and spatial variations in nitrogen concentrations in a tallgrass prairie stream}, volume = {PhD Dissertation}, year = {1985}, pages = {1 -93}, school = {Kansas State University}, type = {Ph.D. Thesis}, address = {Manhattan, KS}, keywords = {LTER-KNZ, tallgrass prairie}, author = {Tate, C.M.} }