论文部分内容阅读
通过对毛乌素沙地不同类型地农田防护林结构配置与防护效益关系的调查测定与分析，结果表明：毛乌素沙地农田防护林类型可分为林带林网状、小片林、四块状林、复合型林等４种，最佳的农田防护林结构配置应该是林带走向同道路、渠系相结合，主带结构采用稀疏型或低度疏透型，副带结构采用低度疏透型或低度通风型，带间距在不同类型地风沙危害程度树木生长及农业要求上的差异而不同。
The results showed that the types of farmland shelterbelts in Mu Us sandy land can be divided into four types: the forest belt forest net, the small patch forest, the four massive forest, the compound forest Etc. The best configuration of farmland shelterbelts should be the combination of forest belts with the same road and canal system, the main belt structure should be of sparse or low permeability type, the sub belt structure of low permeability or low ventilation , With different spacing between the different types of wind and sand hazard levels of tree growth and agricultural differences in the difference.