The change of vegetation coverage indicates the changes of global and regional entironment. 植被覆盖及其变化是全球和区域生态环境变化的重要指示。
In north-west arid areas in China, regional eco-environment and economic construction are controlled and limited by the rationality of land use structure. 摘要在西北干早地区，土地利用结构的合理与否对区域生态环境和经济建设具有直接制约作用。
