西宁南北山主要人工林林型枯落物的持水特性

Water-Holding Characteristics of the Litters under Main Plantation Stands in Xining South and North Mountainous Areas

为了解西宁南北山不同人工林林型枯落物的水源涵养效果,以12种林型为研究对象,对各林型枯落物的蓄积量、持水量、持水速度和持水能力等进行分析。结果表明:1)各林型枯落物的厚度和蓄积量相差悬殊,且枯落物的总蓄积量大小与枯落物的厚度不完全一致。2)各林型枯落物的持水量与浸水时间的动态变化规律基本一致,呈正相关关系,且不同林型的持水量变幅与平均持水量存在一定差异。3)随着浸水时间的延长,各林型枯落物的平均持水速度逐渐降低,且各林型24h内的平均持水速度存在一定差异,其中,青杨×青海云杉×沙棘等5种林型的持水速度是柽柳纯林的1.75倍,是青杨纯林的1.4倍。4)枯落物的有效拦蓄量以青杨×青海云杉×沙棘最大,其次是青海云杉纯林,最小为柽柳纯林。

In order to understand the water conservation function of the litters under plantation in the South and North mountainous areas of Xining, 12 main plantation stands were studied. The system analysis was carried from the four aspects, which were litter accumulation, moisture content, water- holding rate and the water-holding capacity. The results showed that： 1） it was very different about the depth and accumulation of litter among the main plantation stands and it was inconsistent between the accumulation of litter and the depth of litter. 2） The dynamic changes of water-holding capacity and time of water immersion under different plantations were basically similar and had a positive correlation. The varied extent and the average value of water-holding capacity among different plantations were different. 3） With the extending of immersion time, the average value of water-holding rate of litter reduced and the average water-holding rate of litters were different in 24 hours among the plantation stands. Among them, the water-holding rate of litters under five plantation stands such as P. cathayana × P. crassifolia × H. rhamnoides subsp was 1.75 times than T. austromongolica trees and 1.4 times than P. cathayana trees. 4） Among these, the effective water conservation of P. cathayana × P. crassifolia × H. rhamnoides subsp were the largest, followed by P. crassifolia trees and the smallest was T. austromongolicatrees.