Desertification

Desertification, progressive desertification, or Sahel Syndrome refers to the degradation of land in relatively dry ( arid, semi-arid and dry sub-humid ) areas, which is brought about by various factors, including climate change and human activities. This degradation causes the formation or spread of deserts or desert-like conditions. The most upstream development stage of the steppe formation is called desertification. Every year, the earth loses currently approximately 12 million additional hectares of fertile land (roughly the arable land in Germany ), with an upward trend.

The term comes from the Latin facere desertum, which translates to " make desolate " or " devastate " means. The term usually is in German for desertification anthropogenic as opposed to natural desertification. This requires human intervention in the ecosystem.

Causes

Desertification can progress through deflation (wind gusts), denudation (water), salinity and skeletonization. The main causes of desertification due to human activities, desertification is therefore anthropogenic. However, one also natural variations in rainfall play a role by a Desertifikationsprozess can be triggered or exacerbated by drought.

As a result of the drought - and connected to the famine in the African Sahel - won the early 1970s, the problem of desertification is increasingly important. In 1977, in Nairobi, Kenya for the first time held "United Nations Convention to Combat Desertification ( UNCCD), " you came to the agreement that human degradation of the biological basis of the following anthropogenic interventions in nature happens:

• Overgrazing
• Overuse
• Deforestation
• Improper irrigation methods

Overgrazing and " undergrazing "

The most common human intervention in the natural environment of drylands is done by overgrazing, which means that the livestock per area is too large under the given climatic conditions. By grazing the vegetation becomes more sparse and the soil is loosened by increased livestock kick. The increased retention of goats is often the result, as these animals are still less demanding than other breeds. However, goats damage the turf again stronger. The result is an increasing erosion.

However, the regenerative capacity of the vegetation must not be underestimated! It is well established that initially recovered as irreversible desertifiziert classified areas according to the reduction of livestock numbers quickly and naturally. Therefore, rather of (temporary ) land degradation should be spoken here, instead of ( permanent ) desertification.

Recent research also show that the population and the wanderings of large herds an essential role in maintaining ( and fertilization ) of the soil could play and that rather the task of the mobile livestock and the lack of wildlife populations could be a major cause of desertification.

Overuse

In second place is a maladjusted agricultural use to call. Shortened fallow periods, incorrect irrigation, erosion conducive plowing on sloping surfaces in slope and unsuitable plants are causes of soil changes that lead to reduced growth and thus greater erosion. By chemical substances such as fertilizers or pesticides and mechanical compacting the soil life is impaired, which can lead to extinction of many soil-dwelling species (eg, earthworms ). On such surfaces, a desertification is much more likely than on pasture.

Deforestation

Finally, the deforestation in arid regions should be mentioned as an important cause of desertification. The recovery of arable land and the need for firewood and timber have in many arid regions of the earth the trees dramatically reduced, particularly in many densely populated regions of Africa, where wood still constitutes the main source of energy today. The lack of protection through the treetops and in particular the root system divulge the soil to erosion. The natural regeneration of tropical dry forests is not often given so that only targeted planting and care (such as in the Sahel ) which can stop desertification.

Complexes cause entanglement

The fight against desertification is a complex procedure. Overexploitation and climate variations can have identical impacts and be connected in feedbacks, which makes it very difficult to identify the causes of an advance of the desert, and to take appropriate countermeasures. Here the study of the past ( historical desertification ) plays a special role, since it allows a better distinction between natural and anthropogenic factors. Recent research results to the historic desertification in Jordan leave it at that appear questionable whether the current measures for the protection of vegetation and soils under increasing climate change can lead to success, and whether the influence of humans has not been significantly overestimated. Continued warming could lead, for example reforested forests to die.

Follow

According to estimates of the Millennium Ecosystem Assessment, the United Nations are well over a billion people and about a third of the arable land of the earth by soil degradation and thus potentially affected by desertification. This is especially true for large parts of North Africa in the Sahel, for South Africa, Central and South Asia, Australia, parts of North and South America and Southern Europe.

The consequences of desertification are profound from an environmental and economic point of view, while almost entirely negative. In summary: The agricultural and forestry productivity in particular, biodiversity and also the number of individuals decrease significantly, which may have serious consequences, especially in poorer countries because of there high dependence on natural resources and their usually low reserves and alternatives. Desertification reduces the availability of basic ecosystem services and endanger human safety. Also has by desertification, the number and intensity of sandstorms in recent years multiplied. It therefore constitutes a major obstacle to development, which is why the United Nations has proclaimed 2006 as the International Year of Deserts and Desertification.

Exposed and rearranged topsoil can be blown away by wind or washed away by rain. The physical structure and biochemical composition of the soil may deteriorate thereby. Gullies and cracks can occur and essential plant nutrients by wind or water are carried away. If the water table rises due to inadequate drainage and poor irrigation practices, the soil can get bogged down or too salty. If the soil is also trampled by cattle and compacted, this can have the consequence that no more plants grow and the precipitates can not penetrate into the ground, but run off the surface. The loss of vegetation cover is both a consequence and a cause of land degradation. In loose soil, plants can buried by shifting sands or their roots are exposed. If pasture is overused by too many animals or non-adapted species, traditional food plants may disappear due to excessive corrosion.

Some of the above consequences can also affect people outside the directly affected areas. Desolate country can lead to floods, to reduced water quality, increased deposits of sediments in rivers and lakes, and silting of reservoirs and navigation channels. The caused multiplied number and intensity of sandstorms and often leads to damage of machinery or to mental or physical stress (eg infections of the eyes, respiratory diseases and allergies).

Another aspect is that the production of food is adversely affected. If desertification is not stopped and reversed, the income to food in many affected areas will decrease. Malnutrition, hunger and famine in the end would be the result ( especially given the growing world population). However, food production depends not only on the progress of land degradation. However, one can say with certainty that desertification contributes to the emergence of famine. Desertification is a huge drain on economic resources represents an unpublished study by the World Bank suggests that the decline of natural resources in a Sahelian country, 20 percent of gross domestic product ( GDP) of that State. Worldwide, it is estimated that the revenue to which every year must be omitted in the directly affected by desertification areas, to about 42 billion U.S. dollar amount. The indirect economic and social costs suffered outside the affected areas - about the influx of " environmental refugees " and losses in food production for the domestic market - can be much higher.

Drought and land degradation also contribute (eg due to the violation of borders in search of food ) to trigger crises that are tightened in sequence by the fact that food products are distributed insufficient and the population does not have access to them. Because of war, drought and land degradation in drylands, many people have been displaced or forced within their own country in Africa to migrate to other countries. The environmental resources in towns and camps where these people settle down, as well as the surrounding areas are under considerable strain (eg by deforestation of the remaining vegetation). Difficult living conditions and the loss of cultural identity undermined the stability of social structures.

Countermeasures

The Convention to Combat Desertification is implemented through National Action Programmes ( NAPs). Of the signatories to the convention is expected to deal with their role in supporting these programs and target a holistic, integrated and participatory approach to the management of natural resources in the ecosystems of drylands. That is, if the States have developed along with helping States a national action program and there are projects in this donor directly (eg financial) can be supported. By March 2008 102 National Action Programmes ( NAPs) were elaborated and adopted. They are reference points or less to see a control mechanism for the Convention if their efforts bear fruit for ongoing planning processes for poverty reduction and sustainable development in drylands.

Efforts to combat desertification should be also integrated into other development framework programs (such as land degradation and poverty alleviation ). These two objectives include improved food supply, education and training for the people who strengthen capacity at local level and the mobilization of non-governmental organizations. In the national action programs attempting long-term strategies to implement with the participation of the local population. Only if the people can help shape the political process, they will identify with the resulting strategies. Targeted priorities are preventive measures and the promotion of commitment to sustainable activities of the people who work the land and are dependent on him. From the National Action Programmes (NAPs ) is expected to mobilize substantial funds from external sources. NAPs also describe concrete steps and measures as well as the obligations of governments to create an " enabling environment ".

Overall, it is therefore possible an effective counter- strategy against desertification usually only be achieved through such a package of measures with both climatic and forest and agricultural as well as social and political aspects. This means that can be implemented together with the construction of forest protection strips only permanently at the local level, for example, reforestation projects, when in the local population on the one hand awareness of the problem and on the other hand, an alternative to firewood exists. It also issues of local population growth, poverty and urbanization are crucial as they can make such alternatives often impossible.

As a measure spot against desertification stone or Lehmwälle are often built to impound the low volume of rainfall. It is sufficient to set up 30 to 40 cm high plants. At the same time must be made in the rule-making activity in the population with regard to the maintenance of the dams so that damages repaired by water, cattle and other factors kick annually before the rainy season. On the resulting fields can be planted in the sequence forage crops, such as millet. Another option is to plant hedges and plantings Rain.

Another strategy against the spread of the desert could be the use of economical stoves and solar cookers. Since they require significantly less or no firewood, also decreases the fuelwood extraction. Due to the lightweight design of this advanced equipment is designed to allow the residents to build such a furnace itself. This method strengthens its economy and reduce deforestation. Another approach, in Central Asia, is the better insulation of houses, so there is less firewood is needed for heating.

One in development cooperation are often discussed and promising approach are agro forestry measures. It will be planted on farmland trees. These brakes on the one hand, the erosion effect of the wind and reduce the other hand, the evaporation losses due to the shadow effect; so they control against the drying of soils. Furthermore, it is necessary to solve the economic and political problems in the countries concerned in order to achieve an effective and long-term fight against desertification.