关于黄土丘陵典型地区植被建设中有关问题的研究Ⅲ、乡土树种在造林中的意义

根据调查资料 ,论述了外来种和乡土树种在土壤水分 ,林下自然条件下更新等方面的有利和不利因素 ,探讨了经济效益 ,乡土树种的不可替代作用等问题 ,最后提出了“延安试验研究区造林应以乡土树种为主体 ,辅以外来树种”的思路 ,针对这一思路提出了对策

According to investigation information,we discussed advantage and disadvantage of foreign and native trees in soil water and natural seeding reforestation,discussed problems of economic benefits and native trees non fungible,suggested that native trees is chief and supplementary foreign trees in Yan an area plantation.