AP BIOLOGY

Detailed explanation-1: -Overgrazing by cattle reduces plant cover, eliminating the most desirable forage species first. This opens up the land to undesirable weeds, brush, and trees and leads to increasing soil erosion and lower soil fertility.

Detailed explanation-2: -Overgrazing reduces the usefulness, productivity and biodiversity of the land and is one cause of desertification and erosion. Overgrazing is also seen as a cause of the spread of invasive species of non-native plants and of weeds.

Detailed explanation-3: -Sheep can graze very close to the ground and like other livestock will overgraze, if they are allowed to. Overgrazing can lead to loss of vegetation and soil erosion.

Detailed explanation-4: -Overgrazing is grazing by livestock or wildlife to the point where the grass cover is depleted, leaving bare, unprotected patches of soil. As a result, water and wind cause erosion, especially on clay soils, and the growth of poisonous plants and thorny shrubs may increase.