AP BIOLOGY

Detailed explanation-1: -Grasslands are found where there is not enough regular rainfall to support the growth of a forest, but not so little that a desert forms.

Detailed explanation-2: -Because of the low annual precipitation, temperate grasslands have very few trees.

Detailed explanation-3: -Woody plants, shrubs or trees may occur on some grasslands-forming savannas, scrubby grassland or semi-wooded grassland, such as the African savannas or the Iberian deheza. As flowering plants and trees, grasses grow in great concentrations in climates where annual rainfall ranges between 500 and 900 mm (20 and 35 in).

Detailed explanation-4: -The trees do not replace grasses as they require more water than grasses and this would lead to water scarcity for other species. Also, trees are prone to catch fire and the fire spreads swiftly. Due to these reasons, trees do not replace the grasses as a part of ecological succession.

Detailed explanation-5: -Grassland degradation, also called vegetation or steppe degradation, is a biotic disturbance in which grass struggles to grow or can no longer exist on a piece of land due to causes such as overgrazing, burrowing of small mammals, and climate change.