苔鲜层是森林生态系统垂直结构上的主要功能层之一,其在保持水土,调节径流和改良土壤等方面扮演着重要的角色。为了探讨川西亚高山天然林下苔鲜层的水文功能,研究了川西亚高山云杉林(PP)、方枝柏林(SS)、冷杉+云杉混交林(AF+PP)和冷杉+桦木混交林(AF+BP)林下苔藓层蓄积量、最大持水量和吸水速率等水文特征参数。结果表明:AF+BP苔藓层的蓄积量最大(11.35t/hm^2),其次是AF+PP(9.85t/hm^2)和PP(7.58t/hm^2),SS(3.32t/hm^2)最小。苔藓层持水量呈现AF+BP〉AF+PP〉PP〉SS。AF+BP、AF+PP、PP和SS林下苔藓层最大持水率分别为739.3%、709.6%、588.9%和279.4%。林下苔藓层持水量随浸泡时间的增加而增加,其规律遵循对数方程(Q—k lnt+p)。4种林分中AF+BP、AF+PP和PP在各浸泡时间的吸水速率基本一致,而SS较小,各类林分下苔藓层的吸水速率随着浸泡时间增加按方程V—kt^b的趋势下降。
Bryophyte is one of main functional layers in vertical structure of forest ecosystem, which plays an important role in soil and water conservation, runoff regulation and soil improvement etc. In order to understood hydrological function of bryophyte layer under natural forests in sub-alpine region of western Sichuan, hydrological characteristic parameters, such as bryophyte amount, maximum water capacity and water absorption rate of bryophyte layer under Picea purpurea (PP), Sabina saltuaria (SS), Abies faxoniana & P icea purpurea (AF+PP) and Abies f azconiana & Betula P lat yph ylla (AF+BF) in the sub-alpine region of Western Sichuan were studied. The results showed that, the amount of bryophyte layer un der AF+BF(11.35 t/hm^2)was the largest among four stands, followed by AFTPP(9.8.5 t/hm^2), PPAF+PP〉PP〉SS. The proportional water holding capacity as a percentage of bryophyte layer under AF+ BP,AF+PP,PP and SS were 739.3%, 709.6%, 588.9% and 279.4% respectively. The water holding capacity of bryophyte layer increased logarithmically ( Q = klnt+p ) with time immersed in water. The water absorption rates of bryophyte layer under AF+BP,AF+PP and PP were similar, however lower under the SS. Water absorption rates of bryophyte layer under all stands decreased according to equation V=kt^b with time immersed in water.