@inbook {KNZ00565,
	title = {Global grassland ecosystem modelling: development and test of ecosystem models for grassland systems},
	booktitle = {Global Change: Effects on Coniferous Forests and Grasslands},
	year = {1996},
	pages = {229 -270},
	publisher = {Wiley and Sons},
	organization = {Wiley and Sons},
	address = {Chichester},
	keywords = {LTER-KNZ},
	author = {Parton, W.J. and Coughenour, M.B. and Scurlock, J.M.O. and Ojima, D.S. and Gilmanov, T.G. and Scholes, R.J. and Schimel, D.S. and Kirchner, T.B. and Menaut, J.C. and Seastedt, T.R. and Moya, E.G. and Kamnalrut, A. and Kinyamario, J.I. and Hall, D.O.},
	editor = {Breymeyer, A.I. and Hall, D.O. and Melillo, J.M. and Agren, G.I.}
}
@inbook {KNZ00563,
	title = {Impact of climate and atmospheric carbon dioxide changes on grasslands of the world},
	booktitle = {Global Change: Effects on Coniferous Forests and Grasslands},
	year = {1996},
	pages = {271 -312},
	publisher = {Wiley and Sons},
	organization = {Wiley and Sons},
	address = {Chichester},
	keywords = {LTER-KNZ},
	author = {Ojima, D.S. and Parton, W.J. and Coughenour, M.B. and Scurlock, J.M.O. and Kirchener, T.B. and Kittel, T.G.F. and Hall, D.O. and Schimel, D.S. and Moya, E.G. and Gilmanov, T.G. and Seastedt, T.R. and Kamnalrut, A. and Kinyamario, J.I. and Long, S.P. and Menaut, J.C. and Sala, O.E. and Scholes, R.J. and van Veen, J.A.},
	editor = {Breymeyer, A.I. and Hall, D.O. and Melillo, J.M. and Agren, G.I.}
}
@proceedings {KNZ00576,
	title = {New technologies for remote sensing of ecosystem change in rangelands},
	journal = {Rangelands in A Sustainable Biosphere},
	year = {1996},
	pages = {139 -142},
	abstract = {The collective area of rangelands, 40-50\% of the global land surface, presents significant logistical challenges for obtaining ecological data for large, heterogeneous areas quickly, cheaply and with a significant level of accuracy. The use of remote sensing for rangeland monitoring and scaling up from plot to region is reviewed. A major challenge in remote sensing applications lies with assessing ecosystem function from spectral measurements of ecosystem structure. New methods which may assist in the identification and tracking of rangeland response to management practices at the regional scale and provide information on vegetation structure at the continental scale are described. On-going attempts to develop a coupled remote sensing rangeland ecosystem modelling approach for monitoring structure and quantifying energy flow and nutrient cycling are described and examples using Konza Prairie, Kansas, USA data are given},
	keywords = {LTER-KNZ},
	author = {Wessman, C.A. and Schimel, D.S. and S.R. Archer and Bateson, C.A. and Braswell, B.H. and Ojima, D.S. and Parton, W.J. and West, N.E.}
}
@article {KNZ00464,
	title = {Long and short-term effects of fire on nitrogen cycling in tallgrass prairie},
	journal = {Biogeochemistry},
	volume = {24},
	year = {1994},
	pages = {67 -84},
	abstract = {Fires in the tallgrass prairie are frequent and significantly alter nutrient cycling processes. We evaluated the short-term changes in plant production and microbial activity due to fire and the long-term consequences of annual burning on soil organic matter (SOM), plant production, and nutrient cycling using a combination of field, laboratory, and modeling studies. In the short-term, fire in the tallgrass prairie enhances microbial activity, increases both above-and belowground plant production, and increases nitrogen use efficiency (NUE). However, repeated annual burning results in greater inputs of lower quality plant residues causing a significant reduction in soil organic N, lower microbial biomass, lower N availability, and higher C:N ratios in SOM. Changes in amount and quality of below-ground inputs increased N immobilization and resulted in no net increases in N availability with burning. This response occurred rapidly (e.g., within two years) and persisted during 50 years of annual burning. Plant production at a long-term burned site was not adversely affected due to shifts in plant NUE and carbon allocation. Modeling results indicate that the tallgrass ecosystem responds to the combined changes in plant resource allocation and NUE. No single factor dominates the impact of fire on tallgrass plant production.},
	keywords = {LTER-KNZ, carbon, fire, immobilization, Mineralization, Nitrogen use efficiency, soil organic matter, tallgrass prairie},
	doi = {10.1007/BF02390180},
	author = {Ojima, D.S. and Schimel, D.S. and Parton, W.J. and Owensby, C.E.}
}
@article {KNZ00413,
	title = {Landscape patterns in soil-water relations and primary production in tallgrass prairie},
	journal = {Ecology},
	volume = {74},
	year = {1993},
	pages = {549 -560},
	abstract = {Landscape variation in soil water relations, leaf xylem pressure potential ({\textdegree}) and leaf{\textemdash}level net photosynthesis (A) in Andropogon gerardii, and net primary production (NPP) were evaluated during the 1989 and 1990 growing seasons in a northeast Kansas (USA) tallgrass prairie. Landscape patterns were assessed along transects that spanned upland and lowland topographic positions in an annually burned and a long{\textemdash}term unburned watershed. Landscape variability in volumetric soil water content ({\textdegree}) was significantly greater in the unburned watershed (coefficient of variation [CV] = 0.425 and 0.479 for 0{\textemdash}15 and 0{\textemdash}30 cm soil depths in unburned prairie vs. 0.285 and 0.330 for similar depths in the burned watershed). In both watersheds, significantly higher {\textdegree} and total soil water content (0{\textemdash}30 cm) were measured in lowlands compared to uplands. Topographic anomalies, such as a lowland ridge, resulted in local, small{\textemdash}scale variation in soil moisture that equaled watershed variation. Variation across landscapes in predawn {\textdegree}, which was expected to reflect soil water content, was similar in both watersheds (CV = 0.312). Variation in midday @j was significantly greater across the burned than the unburned watershed in 1990 (maximum range in @j from uplands to lowlands was 0.708 MPa at predawn and 0.662 MPa at midday in the burned watershed). In both watersheds, variation in midday @j was much lower relative to {\textdegree}. Landscape patterns in leaf{\textemdash}level A in A. gerardii, the dominant species in this tallgrass prairie, were inconsistent when upland and lowland sites were compared. During an extended period of drought, A was significantly higher in plants in the unburned watershed. In both watersheds, NPP was strongly correlated with {\textdegree}. However, variability in NPP across topographic gradients in the unburned watershed was much less pronounced (CV = 0.224{\textemdash}0.245) than in the annually burned watershed (CV = 0.364{\textemdash}0.430). Moreover, the slope of the relationship between NPP and {\textdegree} was significantly greater in the annually burned watershed. We propose that relatively uniform energy limitations across topographic gradients in unburned tallgass prairie, caused by detrital accumulation that absorbs/reflects sunlight, reduced topographic variability in NPP in unburned watersheds. This pattern occurred in unburned watersheds despite greater landscape variation in {\textdegree} relative to burned watersheds. Analysis of long{\textemdash}term records of NPP from several watersheds supported the hypothesis that variability in NPP associated with topographic position is lower in unburned vs. burned watersheds. Variability in @j across watersheds and between years was muted by negative feedback of canopy leaf area (transpiring surface) on plant{\textemdash}soil water relations. We concluded that patterns in landscape variability in A and @j which may vary significantly over short time intervals, were not good predictors of seasonal carbon dioxide exchange or productivity in this tallgrass prairie. Nonetheless, interactions between A and @j, when combined with nitrogen and energy limitations to A. provide the mechanisms for integrated responses measured across these landscapes.},
	keywords = {LTER-KNZ, tallgrass prairie},
	doi = {10.2307/1939315},
	author = {Alan K. Knapp and Fahnestock, J.T. and Hamburg, S.P. and Statland, L.J. and Seastedt, T.R. and Schimel, D.S.}
}
@article {KNZ00418,
	title = {Observations and modeling of biomass and soil organic matter dynamics for the grassland biome worldwide},
	journal = {Global Biogeochemical Cycles},
	volume = {7},
	year = {1993},
	pages = {785 -809},
	abstract = {Century is a model of terrestrial biogeochemistry based on relationships between climate, human management (fire, grazing), soil properties, plant productivity, and decomposition. The grassland version of the Century model was tested using observed data from 11 temperate and tropical grasslands around the world. The results show that soil C and N levels can be simulated to within {\textpm}25\% of the observed values (100 and 75\% of the time, respectively) for a diverse set of soils. Peak live biomass and plant production can be simulated within {\textpm} 25\% of the observed values (57 and 60\% of the time, respectively) for burned, fertilized, and irrigated grassland sites where precipitation ranged from 22 to over 150 cm. Live biomass can be generally predicted to within {\textpm}50\% of the observed values (57\% of the time). The model underestimated the live biomass in extremely high plant production years at two of the Russian sites. A comparison of Century model results with statistical models showed that the Century model had slightly higher r2 values than the statistical models. Data and calibrated model results from this study are useful for analysis and description of grassland carbon dynamics, and as a reference point for testing more physiologically based models prediction{\textquoteright}s of net primary production and biomass. Results indicate that prediction of plant and soil organic matter (C and N) dynamics requires knowledge of climate, soil texture, and N inputs.},
	keywords = {LTER-KNZ},
	doi = {10.1029/93GB02042},
	author = {Parton, W.J. and Scurlock, J.M.O. and Ojima, D.S. and Gilmanov, T.G. and Scholes, R.J. and Schimel, D.S. and Kirchner, T. and Menaut, J.C. and Seastedt, T.R. and Moya, E.G. and Kamnalrut, A. and Kinyamario, J.I.}
}
@article {KNZ00383,
	title = {Effects of management and topography on the radiometric response of a tallgrass prairie},
	journal = {Journal of Geophysical Research},
	volume = {97},
	year = {1992},
	pages = {18855 -18666},
	keywords = {LTER-KNZ, tallgrass prairie},
	doi = {10.1029/92JD00654},
	author = {Turner, C.L. and Seastedt, T.R. and Dyer, M.I. and Kittel, T.G.F. and Schimel, D.S.}
}
@article {KNZ00335,
	title = {Physiological interactions along resource gradients in a tallgrass prairie},
	journal = {Ecology},
	volume = {72},
	year = {1991},
	pages = {672 -684},
	abstract = {<p>Spatial variability in availability of resources that limit photosynthesis (water and N) leads to variation in rates of atmosphere- biosphere exchange. N content and allocation are canopy properties that link ecosystem, physiological, and biophysical processes and that vary in space at scales relevant to atmosphere-biosphere interaction. We studied landscape-scale variation in these and related canopy properties in Kansas Tallgrass Prairie (USA). The tallgrass ecosystem was suited to this investigation because primary production in the prairie is constrained by N availability. This work was designed to aid in interpertation and spatial extrapolation of gas exchange measurements made using aerodynamic techniques as part of FIFE (First ISLSCP Field Experiment), a NASA- supported study. We collected data on spatial disrtibution of biomass, leaf area index (LAI), canopy N mass. N concentration ([N]), and gas exchange along topographic and management gradients. We also measured height distribution of N, light interception, and gas exchange within canopies as a function of position in the landscape. Substantial variation in biomass, LAI, N accumulation, and N allocation occurred over time, with topography, and as a result of previous burning. The verticle gradient of [N] and photosynthetic capacity within canopies were correlated, in space and time, with biomass and canopy light interception. The gradients were steper in high biomass sites than in low biomass sites. In addition, proportional N allocation to the upper layer increased with time (12\% in June, 32\% in August) as biomass increased. As nutrient uptake increased within the tallgrass landscape, biomass increased and light limitation in the lower canopy was induced. As this light limitation increased with increasing biomass, or with accumulation of dead vegetation, allocation of N to the upper canopy increased. Height distribution of photosyntheticd capicity paralleled within-canopy N allocation and light interception. As resource ratios (light, water and nitrogen) varied in the landscape, so did rates of gas exchange. This work suggests that in interactions between light extinction, N allocation, and photosynthesis that have been proposed for monospecific stands apply to the multispecies, but structurally simple, canopy of the tallgrass prairie. Models of plant performance based on evolutionary arguments may provide a powerful basis for spatial extarapolation of atmosphere-ecosystem exchange rates from sites to landscape and larger regions. Key words: atmosphere-ecosystem exchange, FIFE; Konza Prairie Long-Term Ecological Research site; leaf area index; light interception; nitrogen allocation; photosynthetic capacity; photosynthetically active radiation; remote sensing; toposequences</p>},
	keywords = {LTER-KNZ, tallgrass prairie},
	doi = {10.2307/2937207},
	author = {Schimel, D.S. and Kittel, T.G.F. and Alan K. Knapp and Seastedt, T.R. and Parton, W.J. and Brown, V.B.}
}
@article {KNZ00221,
	title = {Effects of available P and N:P ratios on non-symbiotic dinitrogen fixation in tallgrass prairie soils},
	journal = {Oecologia},
	volume = {79},
	year = {1989},
	pages = {471 -474},
	abstract = {<p>Prescribed burning is a major control over element cycles in Tallgrass prairie (Eastern Kansas, USA). In this paper we report potential effects on fire on non-symbiotic nitrogen fixation. Fire resulted in additions of available P in ash, which may stimulate nitrogen fixation by terrestrial cyanobacteria. Cyanobacterial nitrogenase activity and biomass responded positively to additions of ash or P in laboratory assays using soil. Further assays in soils showed that cyanobacteria responded to changes in available N: available P ratio (aN:P) across a range of concentrations. Nitrogen fixation rate could be related empirically to a N:P via a log-linear relationship. Extrapolation of laboratory results to the field yielded a maximal estimate of 21 kg N ha-1y-1. Results support arguments from the marine and terrestrial literature that P availability is central to regulation of ecosystem N budgets. Key words: Cyanobacteria, fire, acetyline reduction, ash</p>},
	keywords = {LTER-KNZ, tallgrass prairie},
	doi = {10.1007/BF00378663},
	author = {Eisele, K.A. and Schimel, D.S. and Kapustka, L.A. and Parton, W.J.}
}
