Effectiveness of Grazing Systems - A Snythesis of Evidence

TitleEffectiveness of Grazing Systems - A Snythesis of Evidence
Publication TypeConference Paper
Year of Publication2006
AuthorsHavstad K
Conference NameSociety for Range Management 59th Annual Meeting and Trade Show
Date PublishedFebruary 12-17,
Conference LocationVancouver, British Columbia, Canada
ARIS Log Number196147
Keywordsgrazing systems, health, sustained production
AbstractThe general body of evidence in support of the use of grazing systems for sustained production from and health of rangelands is underwhelming, at best. This is despite decades of scientific investigations, conservation programs, and textbook promotion of grazing systems as logical components of rangeland management. In early 20th Century North America, control over grazing was initially touted to regulate seasonal initiation and distribution of grazing. In this sense, grazing systems were delayed turn-out dates, salting and water placements, and herding practices. These systems morphed into more infrastructure and intensive practices built across landscapes to control periods of animal access and more evenly distribute grazing pressure. However, research and observation have shown that access to increasingly large areas of land ameliorates quality of available forages, and at any point in time foraging behaviors are consistently species-specific, as 4-6 plant species will comprise the bulk of an animal's diet. The papers in this symposium will illustrate that 1) minimal documentation exists that confirms pasture level controls over this specificity for plant species will actually affect the status of the land or of the grazing animal, and 2) the confounding influence of the extensive heterogeneity inherent within native rangelands constrains the effectiveness of traditional, short-term reductionist experimentation. Unsubstantiated rationales for adoption of these practices by practitioners further contribute to a restrained regard for grazing systems. Management of grazing is less about structural pasture-level controls over tiller and individual plant defoliation by livestock, and more about implementation of a suite of strategies that diversify tillers, species, and patches available for defoliation.