Friday, March 13, 2020

Land Degradation essays

Land Degradation essays Land degradation is a decline in the quality of land. There are several major types of land degradation in Australia. Some of which are listed below: Soil erosion occurs when large numbers of trees are removed from a small area. Normally, soil is held together by tree roots. However, when these trees are removed, there is nothing to hold the soil together, so when the wind blows the rich, fertile topsoil is easily blown away. Once this has occurred, crops planted on this land are of lesser quality and quantity, as there are less nutrients present in the soil. Sometimes this problem is so severe that crops can not be planted at all. This is a big problem to farmers, as their profits are greatly reduced. The only solution is to plant trees with strong roots in an effort to hold the soil together, to prevent further damage, and, years later, to try to replant crops. The only way that we can resolve soil erosion is by leaving trees in a small area as is, and cutting down trees in big areas where trees arent really needed. If we can do this, Soil erosion will hopefully be kept to a minimum and farmers would be able to make more profit and provide us with food. Soil salinity is another problem related to the removal of trees. Underneath the soil is a layer of water called the water table. Normally, the level of this stays constant, as any rain is absorbed by the trees. However, when these trees are removed, rainfall causes the water table to rise, bringing with it dissolved salts from rocks deep under the earth. The water then becomes salty. As salty water cannot be absorbed by plants, the plant runs out of water, so its leaves fall off. Without these leaves, photosynthesis can not occur, so the plants die. This is called dieback. This can only be helped by planting one of a very few salt-tolerant trees, which help by: 1. Absorbing rainfall, preventing the water table from rising further. 2. Removing salt from the water, thi...