三江平原大面积开荒对自然环境影响及对策探讨

INFLUENCE OF LARGE-SCALE RECLAMATION ON NATURAL ENVIRONMENT AND TREND ANALYSIS IN THE SANJIANG PLAIN

根据1996—1999年及多年来在三江平原调查研究积累的大量资料,对比开垦前后不同年代的数据,分析三江平原大面积开荒引起的区域环境变化,包括生态类型的变化、土地退化、水环境变化以及动植物资源的变化等,并在总结三江平原开荒过程中经验教训的基础上提出区域环境保护对策。

There was a sparse population in the Sanjiang Plain before the 19 th century. At the beginning of the liberation, the farmland area was nearly 78.6×106 hm2.So,the plain is famous for 'the great northern wildness' . With the rapid increase of population and government investment, the farmland area had been 457.24×104 hm2 up to 1994. with reclamation over 40 years, the area of mire had decreased over 300×104 hm2 , and the area of forest land decreased 307×104 hm2 by 1983,much more than in 1949.Reclaiming and destorying forest and grass land has led to a series of ecological problems, such as the worse of soil erosion, the increase of local desertification area and water erosion, the emphasis on reclamation rather than harness, the emphasis on use only rather than culture, the divorce between reclamation and construction, and result in the decrease at different level of cultivated soil fertility, and the intensification of pollution of farm chemicals, chemical fertilizer and surface water. In recent years, growing rice in large scale by well-irrigation has led to the falling of local ground water level. At the same time, it also has resulted in the destruction of biodiversity and the decrease of valuable and rare animals and plants. In order to restore and protect region eco-environment, it is imperative to stop reclaiming at once, take the way to reform middle and low yield cropland mainly, to strengthen effective management of mire nature reserves, to improve shelter-forest system, combine use with culture, culture soil, rational plan and use land. We should set up superior structure of agriculture forestry stock raising, improve regional eco-environment and reinforce sustainable use of regional resources.