北京九龙山自然保护区典型林分枯落物水文效应研究

Hydrological Effects of Typical Forest Litters in Beijing Jiulongshan Nature Reserve

在北京九龙山自然保护区内选取有代表性的4种林分类型,测定各林分枯落物的蓄积量,采用室内浸泡法对其水文效应进行研究,旨在为该区森林植被枯落物生态水文功能评价提供一定的参考。结果表明:(1)4种林分枯落物层蓄积量大小依次为:黄栌油松混交林(29.65t/hm2)>黄栌纯林(22.78t/hm2)>黄栌侧柏混交林(16.87t/hm2)>侧柏纯林(12.17t/hm2);(2)同一浸水时间下黄栌油松混交林的枯落物持水量最大,黄栌纯林、黄栌侧柏混交林次之,侧柏纯林最小,枯落物层的持水量与浸泡时间为对数函数关系,持水量历时过程呈现出迅速吸水、缓慢吸水、逐渐饱和、饱和4个阶段;(3)4种林分枯落物层的吸水速率与浸水时间为幂函数关系,其过程可分为迅速下降、缓慢下降、趋于稳定的3个阶段。

Four types of representative forests at the Jiulongshan Nature Reserve were selected to investigate the forest stock volume and water-holding capacity of litter layers, to provide reference for forest litter＇s eco- hydrological function evaluation in this area. The results showed： （1） the order of the total storage capacity of four stand litters showed mixed forest of Continus coggygria and Pinus tabulaeforrnis （29.65 t/hm2） 〉 Continus coggygria forests（22.78 t/hm2） ：〉mixed forest of Continus coggygria and Platycladus orientalis （16.87 t/hm2 ） ：〉 artificial Platycladus orientalis forests （12. 17 t/hm2 ） ; （2） under the same soaking time, mixed forest of Continus coggygria and Pinus tabulaeformis r water holdings capacity of litters is the largest, followed by Continus coggygria forests, mixed forest of Continus coggygria and Platycladus orientalis, ar- tificial Platycladus orientalis forests, the relationship between water holding capacity and soaking time is de- scribed by the equation of Q=aln（t）＋b, the lasting process of water holding capacity showed four stages as rapid water absorption, slow absorption, gradual saturation, saturated;（3） the relationship between absorp- tion rate and immersion time can be described by the equation of V=kt^n , the process can be divided into rapid decline, slow decline, tends to be stable three stages.