What is desertification?

Desertification refers to the process by which land in arid or semiarid areas becomes increasingly desert-like, often as a result of various environmental factors including climate change, prolonged drought, deforestation, and unsustainable agricultural practices. This phenomenon leads to a decline in land productivity, making it difficult or impossible to sustain vegetation and agriculture, which in turn can contribute to food insecurity and displacement of populations.

The other options do not accurately describe desertification. The conservation of wetlands, for example, is related to the protection and restoration of wetland ecosystems, which is essentially the opposite of desertification. Improvement of land productivity generally implies increasing the ability of land to support vegetation and crops, thus contrasting with the degradation associated with desertification. Increased biodiversity in an ecosystem signifies a healthy, thriving environment, which would not occur in areas undergoing desertification. Therefore, the correct response highlights the critical issue of land degradation and its impact on both ecosystems and human livelihoods.