Desertification is defined as degradation of land, especially in semiarid areas, caused primarily by what?

Desertification is defined as degradation of land, especially in semiarid areas, caused primarily by what?

• A. Volcanic activity
• B. Human actions such as excessive cropping, grazing, and tree cutting
• C. Plate tectonics
• D. Oceanic erosion

Answer: (B)

Desertification happens when land in dry regions loses its ability to support vegetation and soils under ongoing stress, especially from human use. In semiarid areas, rainfall is already limited, so the land relies on vegetation to hold soil in place and protect organic matter. When people practice excessive cropping, overgraze with livestock, or cut down forests, the protective plant cover is removed. Without roots to hold the soil and with reduced soil structure, erosion increases and soil fertility declines. Over time, the land becomes increasingly degraded and desert-like, even if rainfall patterns don’t change much. Other processes like volcanic activity, plate tectonics, or erosion from the ocean operate on different scales and mechanisms and don’t explain the rapid, vegetation-driven degradation seen in drylands. Drought can intensify the problem, but the primary driver described here is unsustainable land-use practices that remove vegetation and degrade soil.

Desertification happens when land in dry regions loses its ability to support vegetation and soils under ongoing stress, especially from human use. In semiarid areas, rainfall is already limited, so the land relies on vegetation to hold soil in place and protect organic matter. When people practice excessive cropping, overgraze with livestock, or cut down forests, the protective plant cover is removed. Without roots to hold the soil and with reduced soil structure, erosion increases and soil fertility declines. Over time, the land becomes increasingly degraded and desert-like, even if rainfall patterns don’t change much.

Other processes like volcanic activity, plate tectonics, or erosion from the ocean operate on different scales and mechanisms and don’t explain the rapid, vegetation-driven degradation seen in drylands. Drought can intensify the problem, but the primary driver described here is unsustainable land-use practices that remove vegetation and degrade soil.