榆林毛乌素沙地沙柳人工林生长状况调查研究

Investigation on Growth of Salix psammophila Plantation in Mu US Sandy Land

在榆林市榆阳区小纪汗对毛乌素沙地沙柳人工林生长状况进行了调查研究,结果为1 a内沙柳高生长在5-6月,之后枝条高生长逐渐缓慢,枝条地径生长量逐渐增加,9-10月生长逐渐停止;自然生长到一定年限后,其个体生长繁殖能力逐渐下降,自然生长15-20 a后,如不进行人工复壮更新,沙柳将面临死亡的威胁;丘间地、迎风坡、沙丘顶部等不同立地条件下,沙柳衰退速度依次逐渐加快,地下水位低于20 m以下时,沙柳衰退速度明显增加。

The growth status of Salix psammophila plantation in Mu Us sandy land was investigated.The results showed that the height of Salix psammophila grew fast from May to June in a year,then slowly.The diameter of branches increased and stopped both gradually from September to October.The individual growth and productivity of Salix declined gradually after growing for a certain number of years.If not rejuvenated,Salix trees grown naturally for 15 to 20 years would suffer from declining of growth to death.The growth recession followed an order like inter-sand site,windward slope and top of sand dunes.When underground water is lower than 20m,the growth declines would speed up.