@article {KNZ001042,
	title = {The use of pasture reflectance characteristics and arbuscular mycorrhizal root colonization to predict pasture characteristics of tallgrass prairie grazed by cattle and bison},
	journal = {Grass and Forage Science},
	volume = {61},
	year = {2006},
	pages = {32 -41},
	abstract = {An experiment was conducted to evaluate the potential for using arbuscular mycorrhizal fungal (AMF) root colonization and pasture reflectance characteristics as indicators of changes in tallgrass prairie vegetation resulting from differences in grazing history. The experiment was conducted within the context of a separate long-term experiment in which eight 4{\textperiodcentered}9-ha pastures were grazed by either bison or cattle for nine consecutive years. Two separate ungrazed pastures were selected for comparison with grazed areas on the basis of similarity in burning regime, vegetation, soil and topographic characteristics. Four 45 m-long transects were located in the upland sites within each pasture, and four plots were clipped to ground level along each transect. Reflectance readings were taken with a hand-held radiometer at each sampling location and a soil core was collected within each plot for analysis of AMF root colonization. Reflectance readings at sixteen different wavelengths were used directly as inputs during multiple regression development or were transformed into each of three vegetation indices (normalized difference vegetation index, soil-adjusted vegetation index and wide-dynamic-range vegetation index) and used in simple linear regressions. Ungrazed pastures were characterized by higher (P < 0{\textperiodcentered}01) grass biomass, total biomass and canopy height than grazed pastures, but had a lower proportional abundance of forbs (P < 0{\textperiodcentered}01) and amounts of forb biomass (P = 0{\textperiodcentered}04). Species of herbivore did not significantly influence above-ground characteristics that were measured. In general, AMF root colonization was relatively small and was not significantly affected by treatment and, accordingly, the variation was insufficient to test its potential as an indicator of grazing effects on vegetation or its potential relationship with pasture reflectance. Multiple regression equations based on individual wavelength reflectance values explained significantly more of the variation in above-ground vegetation characteristics than did simple regressions using vegetation indices as predictor variables (r2 values from 0{\textperiodcentered}36 to 0{\textperiodcentered}46 vs. 0{\textperiodcentered}11 to 0{\textperiodcentered}27) and have the potential to predict above-ground vegetation characteristics in heterogeneous rangelands.},
	keywords = {LTER-KNZ, Arbuscular mycorrhizal fungi, bison, Cattle, pasture characteristics, reflectance methods, tallgrass prairie},
	doi = {10.1111/j.1365-2494.2006.00505.x},
	author = {Villarreal, M. and Cochran, R.C. and Johnson, D.E. and Towne, E.G. and G.T. Wilson and D.C. Hartnett and Goodin, D.G.}
}
@article {KNZ00975,
	title = {Vegetationtrends in tallgrass prairie from bison and cattle grazing},
	journal = {Ecological Applications},
	volume = {15},
	year = {2005},
	pages = {1550 -1559},
	abstract = {Comparisons between how bison and cattle grazing affect the plant community are understood poorly because of confounding differences in how the herbivores are typically managed. This 10-year study compared vegetation changes in Kansas (USA) tallgrass prairie that was burned and grazed season-long at a moderate stocking rate by either bison or cattle. We held management practices constant between the herbivores and equalized grazing pressure by matching animals so that the total body mass in all pastures was similar each year. Trends in species cover and diversity indices in the bison and cattle pastures were compared with ungrazed prairie that also was burned annually. We found that little bluestem (Schizachyrium scoparium) cover decreased over time in bison pastures, and big bluestem (Andropogon gerardii) cover increased over time in cattle pastures. Grazing by either herbivore increased the canopy cover of annual forbs, perennial forbs, and cool-season graminoids, but both annual and perennial forb cover increased at a greater rate in bison pastures than in cattle pastures. Missouri goldenrod (Solidago missouriensis) and heath aster (Symphyotrichum ericoides) were primarily responsible for the increased forb cover in grazed pastures. Species richness at both small (10 m2) and large (200 m2) spatial scales increased at a greater rate in bison pastures than in cattle pastures, but richness did not change through time in ungrazed prairie. The number of annual forb species was significantly higher in bison pastures than in pastures grazed by cattle. Residual graminoid biomass at the end of the grazing season was lower in bison pastures than in cattle pastures, whereas forb residuum increased over time at a greater rate in pastures grazed by bison than in pastures grazed by cattle. Although bison and cattle differentially altered some vegetation components, the plant communities in bison and cattle pastures were 85\% similar after 10 years of grazing. We conclude that most measurable differences between bison-grazed and cattle-grazed pastures in tallgrass prairie are relatively minor, and differences in how the herbivores are typically managed may play a larger role in their impact on prairie vegetation than differences between the species.},
	keywords = {LTER-KNZ},
	doi = {10.1890/04-1958},
	author = {Towne, E.G. and D.C. Hartnett and Cochran, R.C.}
}
@article {KNZ00879,
	title = {Grazing management effects on plant species diversity in tallgrass prairie},
	journal = {Journal of Range Management},
	volume = {57},
	year = {2004},
	pages = {58 -65},
	abstract = {A 6-year study was conducted in tallgrass prairie to assess the effects of grazing management (cattle stocking densities and grazing systems) on plant community composition and diversity. Treatments included sites grazed season-long (May to October) at 3 stocking densities (3.8, 2.8, and 1.8 hectares per animal unit), ungrazed control sites, and sites under a late-season rest rotation grazing system at this same range of stocking densities. Plant communities were sampled twice each season using a nearest-point procedure. Native plant species diversity, species richness, and growth form diversity were significantly higher in grazed compared to ungrazed prairie, and diversity was greatest at the highest stocking density. This enhancement of plant species diversity under grazing was not a result of increased frequency of weedy/exotic species. There were no significant effects of grazing system on plant diversity, nor any significant stocking density {\texttimes} grazing system interactions, indicating that animal density is a key management variable influencing plant species diversity and composition in tallgrass prairie and that effects of animal density override effects of grazing systems. Increasing cattle stocking densities decreased the abundance of the dominant perennial tall grasses, and increased abundance of the C4 perennial mid-grasses. The frequency of perennial forbs was relatively stable across grazing treatments. Abundance of annual forbs varied among years and grazing treatments. In half of the years sampled, annual forbs showed the highest frequency under intermediate stocking density. Patterns of responses among plant groups suggest that some species may respond principally to direct effects of grazers and others may respond to indirect effects of grazers on competitive relationships or on the spatial patterns of fuel loads and fires. Thus, this study suggests that large grazer densities, fire, and annual climatic variability interact to influence patterns of plant community composition and diversity in tallgrass prairie. Effects of varying management such as stocking densities and grazing systems on plant species diversity and the relative abundances of different plant growth forms or functional groups may have important consequences for grassland community stability and ecosystem function.},
	keywords = {LTER-KNZ, Biodiversity, cattle grazing, Flint Hills, grazing systems, plant ecology, range management, stocking rates},
	doi = {10.2111/1551-5028(2004)057[0058:GMEOPS]2.0.CO;2},
	author = {Hickman, K.R. and D.C. Hartnett and Cochran, R.C. and Owensby, C.E.}
}
@proceedings {KNZ00551,
	title = {Effects of grazing systems and stocking rates on plant species diversity in Kansas tallgrass prairie},
	year = {1996},
	pages = {228 -229},
	keywords = {LTER-KNZ, tallgrass prairie},
	author = {Hickman, K.R. and D.C. Hartnett and Cochran, R.C.},
	editor = {West, N.E.}
}
@article {KNZ00571,
	title = {Elucidation of factors associated with the maturity related decline in degradability of big bluestem cell wall},
	journal = {Journal of Animal Science},
	volume = {74},
	year = {1996},
	pages = {648 -657},
	abstract = {Big bluestem (Andropogon gerardii) forage samples were collected from three ungrazed, annually burned pastures at 38, 58, and 97 d after burning. Cell wall material received five treatments: chlorite delignification, chlorite delignification plus alkali extraction, NaOH, NaOCH3 in methanol, or NaBH4. Untreated and treated cell walls were analyzed for carbohydrate composition (glucose, xylose, arabinose, galactose, and uronic acids), acetyl bromide lignin, acid detergent lignin, alkali-labile phenolics (p-coumaric and ferulic acids), acetyl groups, and 24- and 72-h in vitro degradabilities of neutral monosaccharides. A number of compositional features, notably concentrations of xylose, core lignin as measured by acetyl bromide lignin, alkali-labile phenolics, and acetyl groups, were well related to the decline in cell wall degradability that occurred with increasing maturity of big bluestem. p-Coumaric acid increased with increasing maturity to a greater extent than did ferulic acid. Acid detergent lignin was not well related to degradability of the cell wall for either the untreated or chemically treated cell walls. Chemical treatments failed to identify any particular cell wall component as being most inhibitory. However, all treatments improved in vitro degradability of the carbohydrate fraction, indicating that components contributing to the undegradability of big bluestem cell wall are sensitive to chemical alteration. Treatments involving alkali were most effective for improving degradability of big bluestem cell walls.},
	keywords = {LTER-KNZ},
	url = {https://dl.sciencesocieties.org/publications/jas/abstracts/74/3/648},
	author = {Titgemeyer, E.C. and Cochran, R.C. and Towne, E.G. and Armendariz, C.K. and K.C. Olson}
}
