Impacts on the Physical Desert
- Once desertification starts, a pattern follows in a downward spiral, that not only affects the physical but also the human aspect
- Soil degradation → soil erosion → reduced agricultural output → malnutrition, famine → migration → conflict → soil degradation etc.
Impacts on ecosystems
- Ecosystems are affected by desertification in a number of ways:
- Loss of topsoil through exposure to wind and rain
- Over-exploitation of biodiversity through agricultural practices
- Vegetation is destroyed, leading to the migration of animals (and people)
- Water sources are depleted through over-abstraction and/or lack of precipitation, and biodiversity is lost
- Increased levels of soil salinity through poor irrigation practices
Flow chart showing links between climate change, biodiversity loss and desertification
- Desertification changes the landscape:
- Reduced sand dune formation as less vegetation to trap loose material
- Landslides on destabilised slopes where vegetation is removed
- Vegetation slows wind speeds - as vegetation reduces, wind speeds increase leading to more frequent sandstorms
- Soil moisture evaporation increases - soil dries quickly
- Plant root mat is lost - soil becomes unstable
- Increased erosion eventually exposes bedrock
- A combination of higher wind speeds and mobile sediment, transports sand, etc. into other areas, burying vegetation and soil
- Soil and sand encroachment impacts the ecosystem:
- Land becomes less fertile, impacting flora and fauna as less organic matter is returned to the soil, further reducing growth and biodiversity decreases
- Distribution of species has/is changing - flora and fauna populations that were present before desertification, have either died out or migrated to less degraded areas
- Species adaptation is slow and native species are outcompeted by inward, already-adapted species
- Desertification destroys soil and vegetation carbon sinks, releasing it back into the atmosphere, enhancing global warming and further changes in climate conditions