Land degradation
From Wikipedia, the free encyclopedia
Land degradation is a human induced or natural process which negatively affects the capacity of land to function effectively within an ecosystem by accepting, storing and recycling water, energy, and nutrients.
Desertification is land degradation occurring in arid, semiarid and dry subhumid areas of the world. These susceptible drylands cover 40 percent of the earth's surface and puts at risk more than 1 billion people who are dependent on these lands for survival.
Land degradation causes losses to agricultural productivity in many parts of the world.
The causes of land degradation are mainly anthropogenic and mainly agriculture related. The major causes include:
- Land clearing and deforestation
- Agricultural depletion of soil nutrients
- Urban conversion
- Irrigation
- Pollution
The major stresses on vulnerable land include:
- Accelerated soil erosion by wind and water
- Soil acidification or alkalinisation
- Salination
- Destruction of soil structure including loss of organic matter
Severe land degradation affects a significant portion of the earth's arable lands, decreasing the wealth and economic development of nations. Land degradation cancels out gains advanced by improved crop yields and reduced population growth. As the land resource base becomes less productive, food security is compromised and competition for dwindling resources increases, the seeds of potential conflict are sown.
Thus a downward eco-social spiral is created when marginal lands are nutrient depleted by unsustainable land management practices resulting in lost soil stability leading to permanent damage.
We often assume that land degradation only affects soil productivity. However, the effects of land degradation often have more significant impacts on receiving water courses (rivers, wetlands and lakes) since soil, along with nutrients and contaminants associated with soil, are delivered in large quantities to environments that respond detrimentally to their input. Land degradation therefore has potentially disastrous impacts on lakes and reservoirs that are designed to alleviate flooding, provide irrigation, and generate Hydro-Power.
[edit] See also
[edit] References
- Human Induced Land Degradation is Preventable. United States Department of Agriculture - Natural Resources Conservation Service. Retrieved on 2006-06-20.
This article incorporates text in the public domain produced by the USDA Natural Resources Conservation Service
[edit] Further reading
- Eswaran, H.; R. Lal and P.F. Reich. (2001). "Land degradation: an overview". Responses to Land Degradation. Proc. 2nd. International Conference on Land Degradation and Desertification, New Delhi, India: Oxford Press. Retrieved on 2006-06-20.
