论文部分内容阅读
蓊蓊郁郁的森林,茂密丛生的植被在人类尚未出现以前,就作为地球上最原始的“居民”为人类的生存提供了条件。这是人类赖以生存的绿色屏障。然而,由于各种自然因素和人为因素的影响,我国的森林资源日趋减少,绿色植被遭到了极大破坏,风沙侵袭,水土流失越来越严重。据统计资料表明,我国水土流失总面积已达367万平方公里,土壤流失总量每年为50亿吨左右,相当于在全国的耕地上每年刮去厚达1厘米的肥沃土壤,水土流失带走的有机质含量相当于4000多万吨化肥,价值71.6亿元;湖泊减少了
In the gloomy forests, densely covered vegetation provided the conditions for the survival of mankind as the most primitive “inhabitant” on earth before mankind appeared. This is the green barrier on which mankind depends. However, due to various natural and anthropogenic factors, the forest resources in our country have been decreasing day by day, the green vegetation has been greatly damaged, and the sandstorms have hit and soil erosion has become more and more serious. Statistics show that the total area of soil and water loss in our country has reached 3.67 million square kilometers and the total amount of soil loss is about 5 billion tons per year, equivalent to scraping up to 1 cm of fertile soil every year on cultivated land all over the country, taking soil and water loss away The organic content of the equivalent of more than 40 million tons of fertilizers, worth 7.16 billion yuan; reduce the lake