Grazing effects on aboveground primary production and root biomass of early-seral, mid-seral, and undisturbed semiarid grassland

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• 作者：D.G. Milchunas^a ; ^{Daniel.Milchunas@Colostate.edu} ; M.W. Vandever^b
• 关键词：Conservation Reserve Program (CRP) ; Grassland recovery after cultivation ; Herbivory ; Restoration revegetation ; Secondary succession ; Shortgrass steppe
• 刊名：Journal of Arid Environments
• 出版年：2013
• 出版时间：May, 2013
• 年：2013
• 卷：92
• 期：Complete
• 页码：81-88
• 全文大小：551 K

文摘

Annual/perennial and tall/short plant species differentially dominate early to late successional shortgrass steppe communities. Plant species can have different ratios of above-/below-ground biomass distributions and this can be modified by precipitation and grazing. We compared grazing effects on aboveground production and root biomass in early- and mid-seral fields and undisturbed shortgrass steppe. Production averaged across four years and grazed and ungrazed treatments were 246, 134, and 102?g?m^?2?yr^?1 for the early-, mid-seral, and native sites, respectively, while root biomass averaged 358, 560, and 981?g?m^?2, respectively. Early- and mid-seral communities provided complimentary forage supplies but at the cost of root biomass. Grazing increased, decreased, or had no effect on aboveground production in early-, mid-seral, and native communities, and had no effect on roots in any. Grazing had some negative effects on early spring forage species, but not in the annual dominated early-seral community. Dominant species increased with grazing in native communities with a long evolutionary history of grazing by large herbivores, but had no effects on the same species in mid-seral communities. Effects of grazing in native communities in a region cannot necessarily be used to predict effects at other seral stages.