Disruption of arid zone ecosystems
- Endangered dryland ecosystems
- Threatened ecology of scrublands
Nature
Dryland habitat degradation results primarily from overgrazing by wild or domestic animals, excessive burning to clear land for agricultural purposes, or misguided provision of waterpoints. The introduction of domestic animals leads to overstocking; this overstocking, particularly in areas which are often burned, inevitably leads to progressively less perennial grass surviving to the end of the dry season, and an increase in shrubs and trees.
Semi-arid and arid areas (drylands) are increasingly susceptible to chemical and physical deterioration, such as salinization and crusting of topsoil, as well as soil displacement from water and wind erosion. Drylands are characterized by desert conditions, namely nutrient deficient soils, low moisture content and high salinity concentrations, and extremely vulnerable to degradation due to slow recoveries from disturbances. Due to these qualities, many dryland areas are more susceptible to desertification, rendering the soil infertile and nutrient and water deficient. Human activities, such as intensification of agriculture, fuel wood collection, and high intensity pastoralism, can accelerate physical processes (i.e, water and wind erosion) and exacerbate desertification.