摘要
研究了云南西双版纳热带不同海拔梯度山地雨林枯落物层及土壤层水文功能.结果表明:土壤容重随着海拔的增加而降低,土壤总孔隙度、非毛管孔隙度、毛管孔隙度、土壤最大持水率、最大持水量、有效持水量和土壤含水量随海拔的增加而增加,局部有所波动;雨季前期含水量、饱和含水量和有效调蓄水空间随海拔的增加而增加,其中,饱和含水量和土壤有效调蓄水空间在不同海拔区差异均显著(P<0.05).土壤渗透性能与总孔隙度和非毛管孔隙度均呈极显著正相关关系(P<0.01),其中,非毛管孔隙对土壤渗透性的影响更为显著.不同海拔枯落物未分解层厚度均占总厚度的一半以上,枯落物厚度均表现为未分解层>半分解层;枯落物总蓄积量和半分解层蓄积量占枯落物总蓄积量的比例均随海拔的增加而增加,说明低海拔枯落物分解速度较慢,高海拔枯落物分解速度较快.不同海拔枯落物半分解层和未分解层最大持水量、最大持水率、自然含水率、有效拦蓄率和有效拦蓄量均随海拔的增加而增加,并且各海拔未分解层均高于半分解层,而有效拦蓄量深度随海拔的增加而降低,局部有所波动.综合未分解层和半分解层的变化规律可知,高海拔拦蓄能力较强,低海拔较弱.不同海拔枯落物持水量随着浸泡时间增加而增加;枯落物吸水速率随着浸泡时间增加而降低,12 h后枯落物吸水速率逐渐趋于饱和.不同海拔枯落物持水量与浸水时间可用对数方程表示;吸水速率与浸泡时间可用冥函数方程表示.综合分析各项因子,低海拔热带山地雨林水源涵养能力普遍低于高海拔.
A study of the hydrological functions of litters and soil of the tropical montane rain forest in Xishuangbanna was carried out. The results showed that the soil bulk density decreased with the increase of altitude, while the soil total porosity, the noncapillary porosity, the capillary porosity, the maximum soil moisture rate, the maximum water holding capacity, the effective water holding capacity, the soil moisture increased with the increase of altitude with local fluctuation. In addition, the soil moisture in early stage of rainy season, the saturated water content and the effective reservoir space increased with the increasing altitude, and the saturated water content and the effective reservoir space had a significant difference at different altitudes （P〈0.05）. The soil permeability had a significantly positive correlation to the soil total porosity and non-capillary porosity （P 〈 0.01 ）, moreover, the soil non-capillary porosity had a more significant effect on the soil permeability. The thickness of under-composed layer at different altitudes was half more than that of the total litter thickness, which showed that the under-composed layer 〉 semi-decomposed layer. The total volume of litters and the ratio of the volume of semi-decomposed layer to the total volume of litters increased with the increasing altitude, which indicated that the decomposition speed of litters was slower at a low altitude and faster at a high altitude. The maximum capacity of soil moisture, the maximum rate of soil moisture, the natural moisture rate, the effective rate of interception and the effective capacity of interception increased with the increasing altitude in under-composed layer and semi-decomposed layer, and their values in under-composed layer were higher than those in semi-decomposed layer. However, the depth of effective capacity of interception decreased with the in-creasing altitude with local fluctuation. Comprehensive analysis demonstrated that the water eonser-vation ability was stronger at a high altitude and weaker at a low altitude. The water holding capacity of litters at different altitudes increased and the water absorption rate of litter decreased with the soa-king time, while after 12 hours, the water absorption rate of litters gradually became saturated. More-over, the water holding capacity of litters at different altitudes and soaking time had a logarithmic relationship, and the relationship between the water absorption rate of litters and soaking time was described by power function. In short, there was a stronger water conservation function at high alti-tude compared with low altitude of the tropical montane rain forest in Xishuangbanna.
出处
《应用生态学报》
CAS
CSCD
北大核心
2017年第1期55-63,共9页
Chinese Journal of Applied Ecology
基金
浙江省公益技术应用研究项目(2016C32G4010093)资助~~
关键词
西双版纳
热带山地雨林
枯落物
土壤
水文功能
Xishuangbanna
tropical montane rain forest
litter
soil
hydrological function.
