What is desertification?Desertification is the
spreading of the world's
deserts and creation of new deserts in areas that were once
fertile, turning large
portions of
land barren each
year. This
environmental problem is a result of
human and
climatic processes.
What causes desertification?
Overgrazing: Because nowadays animals such as sheep and cattle are fenced into an area, they will feed on the vegetation available to them. If too many animals are feeding on a limited amount of plant life, they eventually strip away the vegetation cover, leaving the soil exposed. This soil then in turn is eroded by wind and water.
Overcultivation: Growing more crops than the land can handle will, after a few years, damage soil structure and reduce fertility levels. Many people overcultivate because they are desperate to increase crop productivity in the short term and fail to consider any long term effects.
Climate Change: This is a rather gradual process. Altered rainfall patterns and rising temperatures can take their toil on semi-arid regions, putting strain on the limited supply of water and soil.
Deforestation: Mass cutting down of trees for firewood or to clear land for farming means the soil loses the vegetation which binds it. Wind and water erodes the soil.
Salinisation: When vegetation is removed less water is used by plants. Any excess water is soaked into the ground, yet the salts which were dissolved in rainfall linger in the soil. The amount of salt gradually rises, leaving any plant life remaining unable to continue to grow in soil with such a great level of salinity.
Drought: In semi-arid regions, water is already a limited resource. Any prolonged lack of rainfall damages plants.
While each of the above can cause desertification, overgrazing and overcultivation pose the biggest threats. This is sad to see, seeing both are a result of the actions of humans.
How is desertification affecting our planet?
Recent estimates claim that around 60,000 square kilometres of previously fertile land is being turned into desert each year. This rate is so rapid that an area as large as Brazil has become desert over the past 5 years. On average, the edge of the Sahara desert extends 16 metres every day. Semi-arid regions are at most risk, however deforestation in such countries as Brazil has started to take its toll on the land.
The continents of Africa and Australia are most at risk. For Australia, a country with very little fertile land, desertification could have a dreadful effect on the farming industry.
How can we prevent desertification?
The process of desertification has actually been reversed in some places, for example the Negev desert in Isreal. There the desert is slowly being reclaimed for farmland. But how do we go about slowing down or even preventing desertification ever taking place?
By replanting trees and other vegetation in land where trees have previously been removed. Once the trees planted have started to grow, soil will bind together and be able hold water. The soil may need mulch to help it sustain plant growth.
On the downside, replanting trees and laying down mulch can be an expensive task. A cheaper alternative would be stopping overcultivation and overgrazing on semi-arid land. Educating people on how to care for their land may indeed be our best bet on combating desertification.