Vanderweide, Benjamin , Hartnett, David .
Legacy effects of grazing: above- & below-ground plant community recovery dynamics.
The dynamics of tallgrass prairie plant communities have historically been driven by the interacting effects of grazing by large ungulate herbivores, frequent fire, and a variable mid-continental climate. The effects of grazing on tallgrass prairie are well known, and include decreased C4 grass abundance, increased forb abundance, increased species diversity, and increased spatial heterogeneity. However, the short- and long-term legacy effects that persist after grazing is removed are not well known. These legacy effects may have important implications for land managers, biodiversity conservation, and understanding of ecological processes. In this study we examine the above- and below-ground response of the plant community following release from persistent grazing. We monitored above-ground productivity, above-ground stem density, below-ground bud bank density, and cover of plant species on ungrazed, currently grazed, and recovering areas of upland tallgrass prairie (last grazed in 2007). Following grazer exclusion, above-ground plant productivity is consistently greater in recovering areas than long-term ungrazed areas. C4 grass cover and stem density in recovery areas are not different from ungrazed areas,but densities of C4 grass buds remain low compared to ungrazed areas.Overall bud bank densities of grazed areas are consistently lower than bud bank densities in ungrazed areas, while bud bank densities of recovering areas either are not different from densities of grazed areas or are intermediate between grazed and ungrazed densities. Species richness of the above-ground plant community in recovering areas is intermediate between species richness of ungrazed and grazed areas, but below-ground both recovery and grazed areas have greater species richness than ungrazed areas. These results suggest that after release from grazing, the plant communities of tallgrass prairie do not quickly return to the state of long-term ungrazed prairie. Furthermore, responses of the plant community differ above- and below-ground.
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1 - Kansas State University, Division Of Biology, 116 Ackert Hall, Manhattan, KS, 66506, USA
belowground bud bank
Presentation Type: Oral Paper:Papers for Sections
Location: Franklin B/Hyatt
Date: Wednesday, July 11th, 2012
Time: 11:15 AM