Grazing - Ecological Effects

Ecological Effects

A number of ecological effects derive from grazing, and these may be either positive or negative. Negative effects of grazing (or more usually over-grazing) include increased soil erosion, adverse water quality impacts from increased runoff and loss of biodiversity. For example historical grazing, along with other land consversion, in Northern and Central California has reduced native chaparral and forest lands by approximately 70 percent. Ongoing grazing expansion {and land conversion} driven by human population growth in this region threatens the remaining integrity of California chaparral and woodlands habitat in this region.

In some habitats, appropriate levels of grazing may be effective in restoring or maintaining native grass and herb diversity in rangeland that has been disturbed by overgrazing, lack of grazing (such as by the removal of wild grazing animals), or by other human disturbance. Conservation grazing is the use of domestic livestock to manage such habitats, often to replicate the ecological effects of the wild relatives of livestock, or those of other species now absent or extinct. For example, heathland in Europe requires grazing by cattle, sheep or other grazers to maintain its structure and diversity.

Much grazing land has resulted from a process of clearance or drainage of other habitats such as woodland or wetland.