@inbook {KNZ00661, title = {Belowground biology and processes}, booktitle = {Grassland Dynamics: Long-Term Ecological Research in Tallgrass Prairie}, year = {1998}, pages = {244 -264}, publisher = {Oxford University Press}, organization = {Oxford University Press}, address = {New York}, keywords = {LTER-KNZ, tallgrass prairie}, author = {C. W. Rice and Todd, T.C. and John M. Blair and Seastedt, T.R. and Ramundo, R.A. and G.T. Wilson}, editor = {Alan K. Knapp and J. M. Briggs and D.C. Hartnett and Scott. L. Collins} } @inbook {KNZ00620, title = {Terrestrial nutrient cycling in tallgrass prairie}, booktitle = {Grassland Dynamics: Long-term Ecological Research}, year = {1998}, pages = {222 -243}, publisher = {Oxford University Press}, organization = {Oxford University Press}, address = {New York}, keywords = {LTER-KNZ, tallgrass prairie}, author = {John M. Blair and Seastedt, T.R. and C. W. Rice and Ramundo, R.A.}, editor = {Alan K. Knapp and J. M. Briggs and D.C. Hartnett and Scott. L. Collins} } @article {KNZ00561, title = {Fire and topographic effects on decomposition rates and nitrogen dynamics of buried wood in tallgrass prairie}, journal = {Soil Biology \& Biochemistry}, volume = {28}, year = {1996}, pages = {323 -329}, abstract = {Decay rates and N dynamics of wood in soils of annually burned and unburned tallgrass prairie were measured over a 3-y period. Wooden dowels were placed at upland, mid-slope and lowland sites in two annually burned and two unburned watersheds. After 3 y, an average of only 15\% of initial wood mass remained in burned watersheds, while 34\% remained in unburned watersheds. Topographic position also significantly affected decay rates, with dowels decaying faster in the shallow-soil, upland sites and slope sites than in the deep-soil, lowland sites. This pattern is opposite of that generally observed for plant productivity (i.e. greater at lowland sites compared to uplands), and suggests that the controls of belowground decomposition and plant productivity are dissimilar. Dowels in both burned and unburned watersheds showed significant increases in N concentration over 3 y. Topographic position did not affect N concentration in the residual dowel material. Burn treatment, however, did affect N concentration, with dowels decomposing in burned watersheds having a higher average N concentration (0.5\% after 3 y exposure) than dowels in unburned watersheds (0.43\%). Relatively rapid decay rates resulted in net release of N, despite increased N concentration in the residual material. Faster net N release on the annually burned watershed was due to faster mass loss, since there were no differences in the rate of increase in N concentration per unit mass lost. Surface soil temperatures on burned prairie following spring fire usually exceed those on unburned prairie. However, average monthly summer soil temperatures (May{\textendash}August) at a 10 cm depth in burned and unburned plots during the study were not statistically different and could not explain decay rate differences. Additionally, one of our unburned watersheds was accidentally burned during the first year of the study. Surprisingly, there were no significant differences in rates of wood decay between that watershed and the other unburned watershed. This suggests that indirect effects of annual fire (i.e. changes in the composition of soil flora and fauna) may override the short-term effects of fire (i.e. changes in soil temperature and moisture) on belowground decomposition in tallgrass prairie.}, keywords = {LTER-KNZ, tallgrass prairie}, doi = {10.1016/0038-0717(95)00138-7}, author = {O{\textquoteright}Lear, H.A. and Seastedt, T.R. and J. M. Briggs and John M. Blair and Ramundo, R.A.} } @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.} } @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 {KNZ00295, title = {The influence of fire on belowground processes of tallgrass prairies}, booktitle = {Fire in North American Tallgrass Prairie}, year = {1990}, pages = {99 -117}, publisher = {University of Oklahoma Press}, organization = {University of Oklahoma Press}, address = {Norman, OK}, keywords = {LTER-KNZ, tallgrass prairie}, author = {Seastedt, T.R. and Ramundo, R.A.}, editor = {Scott. L. Collins and Wallace, L.L.} } @article {KNZ00293, title = {Site-specific underestimation of wetfall NH+4 using NADP data}, journal = {Atmospheric Environment}, volume = {24A}, year = {1990}, pages = {3093 -3095}, abstract = {

Estimates of NH4+ in weekly composited wetfall samples were measured by two laboratories, one at Kansas State University and that operated by the National Atmospheric Deposition Program (NADP) in Illinois. NH4+ samples were lower in the NADP estimates and exhibited a strong seasonal difference in concentrations. Losses were likely not due to volatilization; microbial immobilization of NH4+ likely occurred during transport of samples. Differences in estimates of annual ammonium ion deposition were larger than those observed for average weekly concentrations because of seasonal rainfall patterns. NADP values will require site-specific corrections for models describing or predicting regional or national patterns of nitrogen inputs in wetfall. Key words: Ammonium, NADP, nitrate, wetfall

}, keywords = {LTER-KNZ}, doi = {10.1016/0960-1686(90)90489-A}, author = {Ramundo, R.A. and Seastedt, T.R.} } @proceedings {KNZ00250, title = {Effects of manipulation on foliage characteristics of Andropgon gerardii Vitman}, year = {1989}, pages = {143 -146}, publisher = {University of Nebraska Press}, address = {Lincoln, NE}, abstract = {

The effects of burning, mowing, and nitrogen fertilizer on the chlorophyll, nitrogen, and phosphorus content of big bluestem were measured using a factorial experimental design at Konza Prairie Research Natural Area. While spring burning usually increased foliage production, burning had no effect on mid-season chlorophyll or nitrogen concentrations. Chlorophyll concentrations were significantly increased by fertilizer and mowing treatments. Nitrogen concentrations of foliage were higher on fertilized and mowed plots. Mowing also increased phosphorous concentrations of foliage, but nitrogen fertilizer significantly reduced phosphorus concentrations. These results support other research indicating that 1) nitrogen use efficiency (grams biomass produced per gram of foliage nitrogen) is higher on burned prairie, 2) removal of foliage by mowing results in more nutrient-rich regrowth, and 3) the amount of phosphorus available to big bluestem foliage is limited. The dilution of phosphorus caused by added nitrogen was a consequence of increased productivity on these plots and suggessts phosphorus uptake in excess of requirements for maximum growth. The relationships between burning, mowing, and nitrogen on the spectral reflectance patterns of vegetation indicated that chlorophyll (or nitrogen) concentrations of foliage appeared to more strongly affect indices of greenness and plant vigor than did the amount of plant biomass. Key words: biomass, burning, mowing, big bluestem, Andropogon gerardii, chlorophyll, nitrogen, phosphorus, Kansas

}, keywords = {LTER-KNZ, burning}, author = {Ramundo, R.A. and Shapley, T.D. and Turner, C.L. and Dyer, M.I. and Seastedt, T.R.}, editor = {Bragg, T.B. and Stubbendieck, J.} } @proceedings {KNZ00252, title = {Silica, nitrogen and phosphorus dynamics of tallgrass prairie}, year = {1989}, pages = {205 -209}, publisher = {University of Nebraska Press}, address = {Lincoln, NE}, abstract = {

Experiments were conducted on big bluestem (Andropogon gerardii Vitman) in the greenhouse and on a tallgrass site on Konza Prairie to evaluate the effects of simulated grazing on the cycling of silica (SiO2), nitrogen, and phosphorus. Concentrations of all elements increased in vegetation that had been clipped or pruned. The absolute amount of nitrogen obtained by plants in the greenhouse experiment was increased by clipping foliage. Phosphorous exhibited only neutral or negative responses, while the absolute amount of silica declined in all but one experiment involving root pruning. In that experiment, the absolute amount of silica in roots was increased by 25\% by cutting a portion of the root system. These results suggest that the direct effects of clipping or pruning on the absolute amounts of elements cycled through vegetation are usually neutral or negative. Increased silicification or grazed foliage is suggested to be a consequence of delayed senescence and reduced leaf area. This interpretation provides a proximate reason why silicification is an \"inducible defense\" against herbivores. Key words: big bluestem, Andropogon gerardii, simulated grazing, nutrients, productivity, roots, Kansas

}, keywords = {LTER-KNZ, tallgrass prairie}, author = {Seastedt, T.R. and Ramundo, R.A. and Hayes, D.C.}, editor = {Bragg, T.B. and Stubbendieck, J.} } @article {KNZ00205, title = {Maximization of densities of soil animals by foliage herbivory: empirical evidence, graphical and conceptual models}, journal = {Oikos}, volume = {51}, year = {1988}, pages = {243 -248}, abstract = {

Feeding by consumers on one portion of a plant resource often results in benefits to consumer feeding on other portions of the same resource. Moderate grazing of foliage often increases densities and biomass of belowground herbivores and detritivores in spite of a neutral or reduced root growth response to foliage removal. Graphical and conceptual models are presented to describe these responses and suggest causal relationships. Empirical data and the models indicate that the positive numerical response of soil animals to foliage herbivory results from increased quality (nitrogen concentration) of roots and changes in consumer assimilation efficiencies. Root growth and senescence and acquisition of soil inorganic nitrogen by microbes colonizing senescent roots are hypothesized as additional causal agents for the soil animal response

}, keywords = {LTER-KNZ}, doi = {10.2307/3565649}, author = {Seastedt, T.R. and Ramundo, R.A. and Hayes, D.C.} }