北京九龙山8种林分的枯落物及土壤水源涵养功能

Water conservation function of litters and soil of eight kinds of forest stands in Jiulong Mountain in Beijing City

为了阐明森林植被的水源涵养功能,对北京九龙山油松纯林、华北落叶松纯林、侧柏纯林、樟子松纯林、栓皮栎纯林、五角枫纯林、油松日本落叶松混交林、油松华北落叶松混交林等8种林分类型的枯落物和土壤持水性能进行研究.结果表明：各林分枯落物总储量变化范围为8.87 ～47.87 t/hm^2,其中未分解层储量大于半分解层储量;综合枯落物未分解层和半分解层最大持水量和有效拦蓄量的变化规律来看,油松纯林最大持水量最大（36.46t/hm^2）,其次为华北落叶松纯林（36.06 t/hm^2）,侧柏纯林最小（11.83 t/hm^2）;油松日本落叶松混交林的有效拦蓄量最大（23.51 t/hm^2）,其次为樟子松纯林（19.85 t/hm^2）,侧柏纯林最小（9.53t/hm^2）;综合考虑不同林分枯落物与土壤涵养水源能力发现,华北落叶松纯林和油松华北落叶松混交林具有良好的水源涵养功能;不同层次枯落物持水量、吸水速率与浸水时间均存在较好的函数关系;8种林分土壤容重均值在0.89～ 1.41 g/cm3之间变动,总孔隙度在39.43％ ～54.23％之间变动;林地土壤的入渗速率与人渗时间通过回归分析得出,二者呈幂函数关系,且R2值均在0.90以上.

In order to clarify the water resource conservation function of forest vegetation,using Pinus tabuliformis pure forest,Larix principis-rupprechtii pure forest,Platycladus orientalis pure forest,Pinus sylvestris var.mongolica pure forest,Quercus variabilis pure forest,Acer mono pure forest,the mixed forest of Pinus tabuliformis and Larix kaempferi,the mixed forest of Pinus tabuliformis and Larix principisrupprechtii as the research objects in Jiulong Mountain in Beijing City,we investigated forest litters and soil water-holding capacity of eight kinds of forest stands.The results showed that the total litter storage capacity of the eight kinds of forest stands ranged from 8.87 to 47.87 t/hm^2,and the storage capacity of undecomposed litter was higher than that of semi-decomposed litter.By analyzing the change rules of maximum water-holding capacity and the effective interception amount of undecomposed litter and semidecomposed litter,we found that water-holding capacity of pure Pinus tabulaeformis forest was the highest as 36.46 t/hm^2,followed by the pure Larix principis-rupprechtii forest （36.06 t/hm^2）,while that of pure Platycladus orientalis forest was the lowest,11.83 t/hm^2.For the effective interception amount,the mixed forest of Pinus tabulaeformis and L.kaempferi had the maximum amount,23.51 t/hm^2,followed by the pure P.sylvestris var.mongolica forest,19.85 t/hm^2,and Platycladus orientalis pure forest had the minimum amount,9.53 t/hm^2.In terms of the forest litters and soil water conversion function of eight kinds of forest stands,we found that L.pure principis-rupprechtii forest and the mixed forest of Pinus tabulaeformis and L.principis-rupprechtii are much better than other forest stands.The water-holding capacity and immersion time of different litter layers are well correlated,and so are the water absorption rate of litter layers and immersion time.The average of soil bulk density of eight stands ranged from 0.89 to 1.41 g/cm3,and the total soil porosity varied from 39.43% to 54.23%.By analyzing soil infiltration rate and infiltration time,we found that there is a power function relation between them with all values of R2 greater than 0.90.