%0 Journal Article %J Grass and Forage Science %D 2006 %T The use of pasture reflectance characteristics and arbuscular mycorrhizal root colonization to predict pasture characteristics of tallgrass prairie grazed by cattle and bison %A Villarreal, M. %A Cochran, R.C. %A Johnson, D.E. %A Towne, E.G. %A G.T. Wilson %A D.C. Hartnett %A Goodin, D.G. %K Arbuscular mycorrhizal fungi %K bison %K Cattle %K pasture characteristics %K reflectance methods %K tallgrass prairie %X 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 4·9-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 < 0·01) grass biomass, total biomass and canopy height than grazed pastures, but had a lower proportional abundance of forbs (P < 0·01) and amounts of forb biomass (P = 0·04). 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 0·36 to 0·46 vs. 0·11 to 0·27) and have the potential to predict above-ground vegetation characteristics in heterogeneous rangelands. %B Grass and Forage Science %V 61 %P 32 -41 %G eng %M KNZ001042 %R 10.1111/j.1365-2494.2006.00505.x %0 Journal Article %J Journal of Wildlife Diseases %D 1991 %T Hematological and blood chemistry parameters of American bison grazing on Konza Prairie, Kansas %A Vestweber, J.G. %A Johnson, D.E. %A Merrill, G.L. %A Staats, J.J. %X

Normal hematological and blood chemistry were measured in 45 American bison (Bison bison) that were divided into three age groups for comparison. There was a statistically significant (P less than .05) increase with advancing age in mean corpuscular volume, mean corpuscular hemoglobin, absolute neutrophil and eosinophil counts, total protein, globulin, creatinine, and blood urea nitrogen. There was a statistically significant (P less than .05) decrease with advancing age in levels of sorbital dehydrogenase, alkaline phosphatase, glucose, sodium, calcium and phosphorus. Key words: Hematology, blood chemistry, American bison, Bison bison, age groups

%B Journal of Wildlife Diseases %V 27 %P 417 -420 %G eng %M KNZ00342 %0 Journal Article %J Remote Sensing of the Environment %D 1986 %T Distinguishing among tallgrass prairie cover types from measurements of multispectral reflectance %A Asrar, G.A. %A Weiser, R.L. %A Johnson, D.E. %A Kanemasu, E.T. %A Killeen, J.M. %K tallgrass prairie %X

The heterogeneity in surface cover caused by management practices or natural events complicates monitoring the conditions of grasslands and asseessing their productivity by remote sensing techniques. Statistical procedures were sought that would allow different grassland surface cover types (bare soil,senescent vegetation, and green vegetation) to be distinguished by using measurements of grassland multispectral reflectance. Two procedures, discriminant functions and canonical discriminant analysis, were found suitable for achieving this objective. Linear classification functions and canonical variables were derived, which distinguish between the three cover types. A comparison between two sensor systems, a Barnes multiband radiometer and an Exotech radiometer that simulates the Landsatthematic mapper (TM) and multispectral scanner (MSS) bands, respectively, showed that the separability among the three cover types was substantially improved by the additional and improved spectral features of the Barnes radiometer

%B Remote Sensing of the Environment %V 19 %P 159 -169 %G eng %M KNZ00110 %R 10.1016/0034-4257(86)90069-6