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"The increase in human population to a present day level of over six billion is having an impact on the biosphere that is greater than ever before". The vast amount of impact is greatly due to three major activities including agriculture, industrialization, and urbanisation. Agriculture being one of the major activities contributing to the impact on the biosphere, is the clearing of natural habitat, which most of our ancestors did when they settled in Australia, and consequently without the knowledge of the side effects of clearing forests, cultivating the soil, repeatedly harvesting crops, as well as today's humans who still continue, can lead to dryland salinity and soil erosion, which both accordingly lead to land degradation. Although the seriousness of the agriculture is getting worse, it can be combated. Humans have been obliterating forests all over the world for reasons like, timber, firewood, settlement and agricultural purposes. The benefit for agriculture is almost pointless because the soil in tropical rainforests is of poor nutrients, although the land often becomes productive after a couple of years after the clearing but when there is a limited supply of nutrients in the soil, which is rapidly used up, the crop just declines. ...read more.
One thing that decreases the amount of dryland salinity is planting native saltbush which can be grown because of its tolerance of salt. It lowers the water level and provides food for native animals and also protects the soil against soil erosion which is also a crisis through out Australia. Since European settlement in Australia, the state of the soil has been significantly altered due to agriculture purposes such as vegetation clearance, grazing, cultivation, the introduction of introduced soil flora and fauna and the use of fertilisers, herbicides and pesticides. These practices accounts for soil erosion. Soil erosion is one of the most significant problems that have resulted from agricultural purposes. Soil erosion permanently reduces the productivity of agricultural lands. Soil erosion occurs after forests are cleared and accordingly the top soil either washes away or blows away with the wind because there is no plant roots to hold it in place. "There are about 10.2 million hectares of agricultural land in South Australia and approximately 2.43 million hectares (23.8%) ...read more.
The best thing possible that us as Australians can do to reduce the fact that we have one of the worst land degradation problems on Earth is "to plant billions of trees over the next 20 years", because 40% of Australia's degraded land is in need of revegetation. Regreening programs across Australia and possibly overseas have under gone revegetation practices to help this problem. Not only will this reduce soil erosion and dryland salinity problems but also because of the large amount of planting taking place, it also increases the efficiency on farms, by supplying shelter and food for livestock and in addition increases the bird populations, which feed on insect pests. "The activities of each individual person may appear to be insignificant, but added up they are contributing to a global impact of a great magnitude". Every individual has to take some concern towards the environment, otherwise the severe problems that are already at a point where some things are permanently damaged, will affect us more greatly in the future if action doesn't take place now. ...read more.
This student written piece of work is one of many that can be found in our GCSE Living Things in their Environment section.
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