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Monitoring Standing Herbage Of Mid-Grass Prairie On The Fort Pierre National Grassland, South Dakota, Daniel W. Uresk
Monitoring Standing Herbage Of Mid-Grass Prairie On The Fort Pierre National Grassland, South Dakota, Daniel W. Uresk
The Prairie Naturalist
Monitoring vegetation with a modified Robel pole on the Fort Pierre National Grassland was evaluated for combined shallow clay and loamy overflow ecological sites (dominated by warm-season grasses), and for clayey ecological sites (dominated by cool-season grasses). My objectives were to 1) develop a relationship between visual obstruction readings (VOR) and standing herbage, 2) provide guidelines for vegetation monitoring, and 3) evaluate vegetation monitoring during the growing season for clayey ecological sites. The relationship between visual obstruction readings and standing herbage was linear and regression coefficients were highly significant (P < 0.001) for both ecological types. Cluster analyses for shallow clay and loamy overflow ecological sites grouped the VOR and standing herbage (kg•ha-1) into 4 resource categories. Monitoring with 4 transects will provide adequate information to estimate standing herbage within 259 ha (1 section). Three resource categories (VOR + herbage) for clayey ecological sites were defined by cluster analyses. Monitoring with 4 transects was determined to provide reliable estimates of standing herbage. July validation of vegetation with the developed clayey ecological site model will provide reliable monitoring of standing herbage from July through November for this ecological site.
Cattle Grazing Reduces Survival And Reproduction Of The Western Prairie Fringed Orchid, Bonnie Warner Alexander, Donald Kirby, Mario Biondini, Edward Dekeyser
Cattle Grazing Reduces Survival And Reproduction Of The Western Prairie Fringed Orchid, Bonnie Warner Alexander, Donald Kirby, Mario Biondini, Edward Dekeyser
The Prairie Naturalist
QuantifYing impacts of livestock grazing and prairie management strategies on the threatened western prairie' fringed orchid (Platanthera praeclara) is difficult due to the erratic appearance of the orchid above-ground. We monitored above-ground survival of orchids from flowering to mature seed capsule production, comparing plant height, flower numbers, and seed capsule numbers from 2002-2004 in rotationally grazed pastures and non-grazed sites. Orchid survival differed significantly between grazed and non-grazed pastures, with the proportion of plants surviving from flower to capsule production consistently lower in grazed pastures. Mean orchid survival in grazed and non-grazed areas was 40% and 87%, respectively. …