Landscape variables affecting livestock impacts on water quality in the humid temperate zone

Abstract

The potential for impact by grazing livestock on unprotected watercourses may vary with climate, with landscape level factors including the landform within which the pasture is located, with the biophysical characteristics of the watercourse itself, and with pasture and grazing management practices. Policies seeking to implement cost-effective measures to protect downstream water quality need to acknowledge large-scale as well as small-scale processes which can moderate or exacerbate potential sources of pollution. Applied and scholarly evidence suggest that unrestricted livestock access accounts for a relatively modest share of watercourse pollution in humid temperate regions, as compared with such watershed-specific factors as leaking septic tanks and confinement feeding systems. A wide variety of evidence suggests that the degree of compatibility of grazing livestock with a healthy riparian ecosystem should be viewed as a hypothesis that is testable on a site-specific basis. Greater understanding of the factors causal to livestock behavior in, and impact on, watercourses may help to better focus preventative and remediation efforts by both producers and policymakers. Key words: Riparian ecosystem; beef cattle; pasture fertility; soil and water conservation