Plant Species Diversity and Management of Temperate Forage and Grazing Land Ecosystems
- M. A. Sanderson *a,
- R. H. Skinnera,
- D. J. Barkerb,
- G. R. Edwardsc,
- B. F. Tracyd and
- D. A. Wedine
- a USDA-ARS Pasture Systems and Watershed Management Research Unit, Building 3702 Curtin Road, University Park, PA 16802
b Department of Horticulture and Crop Science, The Ohio State University, 202 Kottman Hall, 2021 Coffey Road, Columbus OH 43210
c Animal Sciences Section, Department of Agricultural Science, Imperial College London, Wye Campus, Kent, U.K. TN25 5AH
d Department of Crop Science, University of Illinois, 1102 S. Goodwin Avenue, Urbana, IL 61801
e School of Natural Resources, University of Nebraska, Lincoln, NE 68583-0814
More than a century since Charles Darwin stated that diverse grasslands produce more herbage than monocultures, scientists still debate the relationship between species diversity and ecosystem function. Postulated benefits of diversity in experimental grasslands include greater and more stable primary production along with more efficient nutrient use. These benefits have been extrapolated to forage and grazing land systems with little supporting objective data. Most information on the potential benefits of increased plant diversity comes from studies of synthesized grasslands that have not included domestic grazing animals. We explore this debate relative to the management of temperate forage and grazing lands. Plant species diversity refers to the number of species (richness) and their relative abundance (evenness) within a defined area. Plant relations influence biodiversity responses through positive (e.g., facilitation, N2 fixation, hydraulic lift) and negative interactions (e.g., competitive exclusion, allelopathy). Early 20th century research on complex mixtures of forage species (limited to grasses and legumes) for pasture indicated equivocal results regarding benefits of species-rich mixtures and typically recommended using the best adapted species in simple grass–legume mixtures. Recent research indicates potential herbage yield benefits from species-rich mixtures for pastures. Limited animal productivity research on species-rich mixtures indicates variable responses and much more research is needed. Grazing land productivity is a primary focus for biodiversity benefits because of the direct economic relevance to producers. However, taking a broader view of the multifunctionality of grazing lands to include environmental and aesthetic benefits to humans reveals a great scope for using biodiversity in grazing land management.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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