Notes: G6-Explain the impact of desertification on the environment.
Vocabulary:
1. Desertification – lowering soil quality to the point that nothing will grow in it
2. Environment – what is around a person
3. Savanna - the grassland in Africa
4. Steppe - a partly dry area next to a desert
5. Degradation - lowering the quality of something
6. Arid – dry
7. Semi-arid - partly dry
8. Drought – a long period of little or no rain
9. Over-farming - growing too many crops grown in the same area for too long
10.Over-grazing - too many animals eating too much grass in too small an area
11.Over-population - too many people living in too small an area
12.Globally - world-wide
Desertification is the degradation of land in arid and semi-arid regions. The
biggest causes of it are over-grazing, over-farming, and deforestation; with all of
these mostly being caused by over-population. The biggest impact of
desertification on the environment is the loss of rich soil.
It is a common misconception that droughts themselves cause desertification.
While drought is a contributing factor, the real causes are all related to man’s
overuse of the environment. Droughts are common in arid and semi-arid lands,
and well-managed lands can recover from drought when the rains return.
Continued land abuse during droughts, however, can cause desertification.
Some arid, and most semi-arid lands can support crops, but additional pressure
from greater populations can lead to the few plants that are there disappearing.
The soil then becomes exposed to the wind. The top layer becomes eroded. With
the removal of shade (in the form of plants), the moisture that is present
evaporates more quickly and draws salt to the surface, which in turn prevents
plant growth even more. The loss of plants causes less moisture to be retained in
the area, which may change the climate pattern and lead to even less rainfall.
Desertification does not happen in straight, easy to map patterns. Deserts
advance erratically, forming patches on their borders. Areas far from natural
deserts can degrade quickly to poor soil, rock, or sand because of bad land
management. The presence of a nearby desert has no direct relationship to
desertification.
What are the results of desertification regions? In the steppe, the once semi-arid
land is becoming desert. This causes people who lived there to move to the
savanna where the pattern just repeats itself. The people whose once-fertile land
has become desert must move somewhere. The result has been overcrowding in
the savanna and rainforest regions. There are even patches of desertified land
visible in rainforest regions, due mostly to overcrowding and deforestation.
Globally each year, desertification claims an area of once-productive land the size
of the state of Nebraska.
1. The main cause of desertification is over-population which leads to over-grazing,
over-farming, and deforestation.
2. The biggest impact of desertification on the environment is the loss of rich soil.
3. Desertification does not occur in straight, easy to map patterns.
4. Desertification is causing the semi-arid steppe to become desert.
5. People whose land has become arid must move somewhere this results in
overcrowding of the savanna and rainforests.