秦岭南坡不同林分类型枯落物层和土壤层水文功能综合评价

Comprehensive Evaluation of Hydrological Function of Litter and Soil Layers in Different Stand Types in the South Slope of the Qinling Mountains

为探究秦岭地区典型林分下枯落物层和土壤层水文功能差异,采用室内浸水法、环刀法定量研究秦岭火地塘林区油松林、锐齿栎林和华北落叶松林下枯落物层和土壤层持水特征,并借助主成分分析法、熵权法综合评价其水文功能。结果表明:1)3个林分下枯落物层厚度和蓄积量分别为3.11~7.44 cm和5.58~10.02 t·hm^(-2),其中锐齿栎林枯落物厚度最大,而华北落叶松林蓄积量最高;2)枯落物层自然含水率、最大持水率、最大持水量和有效拦蓄量分别为12.54%~102.59%、185.93%~557.7%、14.41~17.8 t·hm^(-2)和7.66~14.34 t·hm^(-2),其中锐齿栎林的最大持水量和有效拦蓄量最大,华北落叶松林则在枯落物自然含水率及最大持水率上表现最佳;3)3个林分下土壤容重均随着土层深度的增加而增加,其值为0.89~1.21 g·cm^(-3),油松林的土壤储水量最低,华北落叶松林下的土壤总孔隙度和毛管孔隙度则最大,0~40 cm土层最大持水量依次为华北落叶松林(257 mm)>锐齿栎林(234 mm)>油松林(231 mm)。通过熵权法综合评价,锐齿栎林在枯落物拦蓄能力方面表现最佳,而华北落叶松林土壤层的持水功能最优,因此建议在今后的森林管理中合理优化树种配置,以更好地发挥其水源涵养功能。

In order to explore the differences in hydrological function of the litter and soil layers in typical forest stands occurring in the Qinling Mountains,the indoor re-soaking and the ring knife method were used to examine the water-holding characteristics of litter and soil layers in Pinus tabuliformis,Quercus aliena var.acuteserrata and Larix principis-rupprechtii forests in Huoditang of Qinling Mountains.Principal component analysis and entropy weight method were used to comprehensively evaluate the hydrological function of the three forest stands.The results showed that 1)the thickness and accumulation of litter layer in the three stands ranged 3.11-7.44 cm and 5.58-10.02 t·hm^(-2),respectively,and the Q.aliena var.acuteserrata forest had the thickest litter layer,and L.principis-rupprechtii forest accumulated the highest amount of litter.2)The natural water content,maximum water holding rate,maximum water holding capacity,and effective storage capacity of litter layer under three forest stands were 12.54%-102.59%,185.93%-557.7%,14.41-17.8 t·hm^(-2),and 7.66-14.34 t·hm^(-2),respectively.Among them,the Q.aliena var.acuteserrata forest had the highest maximum water-holding capacity and interception capacity,while the L.principis-rupprechtii forest performed the best in terms of natural water content and maximum water-holding rate.3)The soil bulk density in the three stands increased with soil depth,with values ranging from 0.89 to 1.21 g·cm^(-3).The soil water storage in the P.tabulaeformis forest was the lowest,while the L.principis-rupprechtii stand had the highest total porosity and capillary porosity of the soil.The maximum water capacity in the 0-40 cm soil of the three stands was in the order of L.principis-rupprechtii(257 mm)>P.tabuliformis(234 mm)>Q.aliena var.acuteserrata(231 mm).Based on the comprehensive evaluation of entropy weight method,the Q.aliena var.acuteserrata forest performed the best in the retention capacity of litter,while the L.principis-rupprechtii forest had the best water retention function in the soil layer.Therefore,it is recommended to reasonably optimize the tree species allocation in future forest management to better utilize its water conservation capacity in this area.