Plant Interspaces Resulting From Contrasting Grazing Management in Northern Mixed-Grass Prairie: Implications for Ecosystem Function |
| |
| Authors: | Justin D Derner Ashley J Whitman |
| |
| Institution: | 1. Rangeland Scientist, US Department of Agriculture–Agricultural Research Service (USDA–ARS), High Plains Grasslands Research Station, 8408 Hildreth Road, Cheyenne, WY 82009, USA;2. Graduate Student, Department of Renewable Resources, University of Wyoming, Laramie, WY 82071, USA;1. Research Scientist, Consejo Nacional de Investigaciones Científicas y Técnicas, Dept of Botany, Museo Argentino de Ciencias Naturales, Ángel Gallardo 470, 1405DJR, Ciudad Autónoma de Buenos Aires, Argentina;2. PhD Student, Consejo Nacional de Investigaciones Científicas y Técnicas, Dept of Botany, Museo Argentino de Ciencias Naturales, Ángel Gallardo 470, 1405DJR, Ciudad Autónoma de Buenos Aires, Argentina;3. Postdoctoral Researcher, Consejo Nacional de Investigaciones Científicas y Técnicas, Dept of Botany, Museo Argentino de Ciencias Naturales, Ángel Gallardo 470, 1405DJR, Ciudad Autónoma de Buenos Aires, Argentina;4. Research Scientist, Instituto Multidisciplinario de Biología Vegetal, Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Exactas Físicas y Naturales, Universidad Nacional de Córdoba, Vélez Sársfield 299, CC495, 5000, Córdoba, Argentina.;5. Rangeland Scientist, Consejo Nacional de Investigaciones Científicas y Técnicas, Dept of Botany, Museo Argentino de Ciencias Naturales, Ángel Gallardo 470, 1405DJR, Ciudad Autónoma de Buenos Aires, Argentina;1. PhD student, Rangeland Ecology, University of Limpopo, Sovenga, South Africa;2. Senior Research Scholar, Okavango Research Institute, University of Botswana, Maun, Botswana;3. National Director, South African Science Service for Climate Change and Adaptive Land Management (SASSCAL) Botswana National Node, Gaborone, Botswana;1. PhD candidate, Department of Animal and Range Sciences, New Mexico State University, Las Cruces, NM 88003, USA;2. Associate Professor, Department of Animal and Range Sciences, New Mexico State University, Las Cruces, NM 88003, USA;5. Professor, Department of Animal and Range Sciences, New Mexico State University, Las Cruces, NM 88003, USA;3. PhD student, Department of Computer Science, New Mexico State University, Las Cruces, NM 88003, USA;4. Assistant Professor, Department of Computer Science, New Mexico State University, Las Cruces, NM 88003, USA;1. Jilin Provincial Laboratory of Grassland Farming, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China;2. Institute of Grassland Science, Northeast Normal University, Changchun 130024, China;3. Department of Biology, University of Kentucky, Lexington, KY 40506, USA;4. Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY 40546, USA;5. State Key Laboratory of Forest and Soil Ecology, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110164, China |
| |
| Abstract: | We assessed plant interspaces in July 2007 using continuous line intercepts in twice-replicated pastures of northern mixed-grass prairie with contrasting grazing treatments: 1) long-term (25 yr) heavily grazed, dominated by the bunchgrass blue grama (Bouteloua gracilis), and 2) ungrazed, dominated by the rhizomatous grass western wheatgrass (Pascopyrum smithii). The number of plant interspaces was 26% higher in pastures heavily grazed, but the amount of soil surface occupied by plant interspaces was 27% greater without grazing. Plant interspaces were larger without grazing (14.8 ± cm, mean ± 1 SE) than heavily grazed (8.9 ± cm). Plant interspaces represented 87% and 68% of the total soil surface in the ungrazed and heavily grazed communities, respectively. The percentage of soil surface covered by plant interspaces < 20 cm was higher for the heavily grazed (94%) compared to the ungrazed (79%). Litter cover in the plant interspaces was higher without grazing (80 ± 1%) compared to the heavily grazed (57 ± 3%). Grazing-induced structural changes from a rhizomatous- to a bunchgrass-dominated vegetation community were manifest in the size and distribution of plant interspaces. Ecological consequences for erosion from raindrop impacts in larger plant interspaces in the ungrazed community are likely offset by greater litter cover in these communities; conversely, lower litter cover in heavily grazed pastures may increase erosion potential despite occurrence of smaller plant interspaces and less proportion of the soil surface covered by interspaces. Management practices that increase the cover of litter in plant interspaces should reduce the potential of erosion from water and wind in this semiarid rangeland. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
