Desertification occurs in cropland (both irrigated and nor irrigated), pasture, and woodlands. Loss of soil, deterioration of soil, and loss of natural vegetation lead to desertification. Drought, a period of unusually dry weather, can cause loss of vegetation, which in turn leads to desertification. Poor land management and increasing population are factors that promote increased irrigation, improper cultivation or over cultivation, and increased numbers of livestock. These events alter the land and the soil, diminish the resources, and increase the chances of desertification.Desertification has sometimes been mistakenly described as the expansion of deserts into nondesert areas. Pictures of sand dunes engulfing agricultural lands encourage this misconception, but this type of desertification is rare. Arid and semiarid lands can be degraded even if there is no adjacent desert. Drought has also mistakenly been called the primary cause of desertification. Desertification can occur without drought, and drought can occur without resulting in desertification. Droughts are short-term and cyclical. By themselves, they do not degrade the land. However, they intensify the pressures that lead to mismanagement of land, plant, and water resources.While dry land rainfall is low on average, it is extremely variable from year to year and from place to place. Native plants and animals have adapted to this variability. For example, the seeds of many desert plants can remain dormant through several years of drought, waiting for a good rain to sprout. In order to survive in this harsh environment, humans must adapt their activities as well. However, many factors, including population growth, poverty, politics, disrupted social institution and the pursuit of short-term economic opportunity, may work together to promote unsustainable practices.
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