胡杨林的衰退原因与林地恢复策略

胡杨广布于地中海沿岸并呈带状东延至中国和蒙古人民共和国。目前,胡杨林已普遍呈不同程度退化,以塔里木盆地为例,垦伐等人为因素使林地总面积迅速减少。现场观测发现,一些林区缺乏胸径20cm以下的立木,而该地从1972年以来断绝洪水来源,显示洪水对幼苗补给可能存在相关,该地断绝洪水多年后,2002年重新出现洪泛过程,洪水退后出现大量的幼苗生长,从而证实洪水过程是胡杨幼林发生的必要条件。本文就此现象提出恢复部分林地的对策。

The Reasons of Populus euphratica Forest''''s Declination and The Woodland Renewing Countermeasure

Populus euphratica is distributed in the Mediterranean Seacoast far and wide and stretches to China and Mongolia presenting a shape of strip, and now Populus euphratica forest have decayed in different degrees. In the case of the Tarim Basin, the area of Populus euphratica forests has shrunk quickly duo to the artificial factors such as reclamation and cutover forest and etc.The observations on the sample are that some forest lacked the tree whose bosom diameter is below 20cm in the areas that have been no floods since 1972.Therefore, floods are possibly relevant to the young forests' replenishment, and the sample we observed developed a great deal of young trees when the floods receded in 2002. Prove that the floods are the necessary condition of the young forests' origination. The phenomenon will be further explained and the strategies and measures of restoration will be brought forward in this paper.