Effects of Livestock Grazing and Cultural Treatments on Regeneration of Green Ash Woodlands on the Northern Great Plains: An Update
Many green ash woodlands (Fraxinus pennsylvanica ) have become decadent with broken stems and limited regeneration of both trees and shrubs on the northern Great Plains. The purpose of this study was to determine the response of woodland regeneration of shrubs, trees and planting woody species over 25 post-treatment years (1) to livestock grazing with thinning low vigor trees, (40% reduction) in woodlands with transplanting woody plants, (2) livestock grazing with un-thinned woodlands-no transplanting of woody plants, (3) no livestock grazing with thinning low vigor trees, (40% reduction) in woodlands with transplanting woody plants, and (4) no livestock grazing with un-thinned woodlands-no transplanting of woody plants. Initial treatment response for trees and shrubs occurred during the first 6 years of post-treatment. After 25 years of post-treatment, trees and shrubs were not different between livestock grazing and no grazing treatments. American elm (Ulmus americana ) decreased in stem density and may have been influenced by disease. Stem density of snowberry (Symphoricarpos occidentalis ) decreased in the unthinned treatment. Common chokecherry (Prunus virginiana ) stem densities remained relatively constant over 25 years of post-treatments. Planted shrub and tree species had greater than 50% survival in ungrazed versus grazed treatments. Survival of bur oak (Quercus macrocarpa ), Rocky Mountain juniper (Juniperus scopulorum ) and American plum (Prunus americana ) was greater when livestock grazing was excluded. Herbaceous standing crop of the grasses, forbs, and total was variable throughout all years among treatments.