晋西黄土丘陵区不同人工林枯落物持水特性研究

为了定量评价森林枯落物的水文功能,通过野外观测和浸水法实验,调查了晋西黄土丘陵区不同人工林枯落物的蓄积量,分析了枯落物的持水能力与过程,并对枯落物持水量、吸水速率与浸泡时间的相互关系进行了研究。结果表明,枯落物蓄积量为6.81~56.64t/hm²,由大到小表现为:落叶松×白桦>落叶松>侧柏>油松×刺槐>油松>白桦>柠条>刺槐不同森林类型的枯落物最大持水量为10.08~100.78t/hm²,最大持水率变化范围为146.54%~203.74%,最大拦蓄量为9.41~88.65t/hm²,有效拦蓄量为7.90~73.53t/hm²枯落物浸水实验结果表明,枯落物持水量与浸水时间存在对数曲线关系,而枯落物吸水速率与浸泡时间呈反函数关系,在浸泡最初的0.5h持水量迅速增加,随后增幅减小,在12h以后枯落物吸水基本达到了最大值,持水量趋于动态平衡。表明落叶松×白桦混交林林下枯落物是8种林地中持水性最优的,刺槐纯林枯落物持水特性最差。

Water Holding Capacity Characteristics Under Litters of Different Kinds of Planted Forests in Loess Hilly Region of Western Shanxi Province

Hydrological functions of main planted forest litters were assessed by measuring and analyzing the litter amount,the water holding capacity,and the processes with methods of field survey and soaking extra tion experiment in the loess hilly region of Western Shanxi Province.The relationship between water-holding capacity of litter,water absorption rate and soaking time was established.The results showed that the litter amount ranged from 6.81 to 56.64 t/hm²,with a decrease order of Larix gmelini Rupr. X Betula platyphylla Suk.forest,followed by Larix gmelinii Rupr.forest,Platycladus orientalis(I,inn.)Franco forest,Pinus tabulaeformis Carr.X black locust forest,Pinus tabulaeformis Carr. forest,Betula platyphylla Suk.forest,Caragana korshinskii Kom.forest,black locust forest.The maximum water-holding volume of different forests litters ranged from 10.08 to 100.78 t/hm²,the maximum water holding rate ranged from 146.54%to 203.74%,and the mixed interception amount and the effective interception amount showed similar trends with values from 9.41 to 88.65 t/hm²,and 7.90 to 73.53 t/hm².Soaking experiments showed that the water-holding volume increased logarithmically with soaking time,while the water-absorption rate showed an inverse function with soaking time.And the water-holding volume increased sharply during the first 0.5 h,then slowly increased,when soaking 12 h,basically reached the maximum water holding volume,and water holding capacity tends dynamic equilibrium.Comprehensively speaking,the litter water holding characteristics of Larix gmelinii Rupr. X Betula platphylla eight kinds of plantation forest,and black locust forest platyphylla Suk. mixed forest was the host one of was the worst one.