贡嘎山冷杉纯林地被物及土壤持水特性

Water holding capacity characteristic of ground cover and soil under pure Abies fabri forest on the Gongga Mountain.

为了研究贡嘎山冷杉 (Abiesfabri)纯林林下地被物及林地土壤在水土保持、水源涵养方面的作用 ,该文通过对贡嘎山 4种林龄的冷杉纯林 (幼龄林、中龄林、成熟林和过熟林 )林下地被物持水特性及林地土壤物理实验 ,得到不同林龄林下地被物最大持水量、吸水速度等水文特征参数及林地土壤总孔隙度、毛管孔隙度等物理特性参数 .结果表明 ,成熟林林下苔藓层持水量最大 ,为其风干重的 343 5 % ,过熟林林下的为 2 84 5 % ,中龄林林下的为 2 82 5 % ,幼龄林林下的为2 5 0 % 成熟林林下枯落物最大持水量为其风干重的 30 1 8% ,过熟林林下的为 2 2 6 4 % ,中龄林林下的为 2 0 9 4 % ,幼龄林林下的为 2 0 5 4 % .经分析拟合 ,得到林下苔藓层、林下枯落物吸水速度与浸泡时间之间关系式S =ktn.贡嘎山冷杉纯林林地土壤容重为 0 85 1～ 1 136g cm3,土壤饱和含水量为 5 5 2 9%～ 83 96 % ,毛管持水量为 4 4 4 8%～ 75 4 1% ,田间持水量为 39 5 0 %～ 6 5 86 % .

In order to study the effect of ground cover and forest soil under Abies fabri forest on the Gongga Mountain(29°20′～30°20′N,101°30′～102°15′E)on soil and water conservation and water source conservation, the authors got hydrological characteristic parameters such as the maximum water holding capacity, water absorption speed of ground cover and physical characteristic parameters such as the total porosity, the capillary porosity of the forest soil through the water holding characteristic experiment of the ground cover and the forest soil experiment under four types of Abies fabri forest (the young stand, the mid\|age stand, the mature stand and the overmature stand). The result shows that the maximum water holding capacity of the moss under the mature stand is the maximal, which is 343 5% of its dry weight, that of the moss under the overmature stand is 284 5%, that of the moss under the mid\|age stand is 282 5%, that of the moss under the young stand is 250%. The maximum water holding capacity of the litter under the mature stand is 301 8% of its dry weight, that of the litter under the overmature stand is 226 4%, that of the litter under the mid\|age stand is 209 4%, that of the litter under the young stand is 205 4%. The equation between the water absorption speed of the ground cover and the immersing time is S=kt n. The density of the forest soil on the Gongga Mountain is 0 851～1 136 g/cm\+3, the saturated capacity is 55 29%～83 96%, the capillary holding capacity is 44 48%～75 41%. The field holding capacity is 39 50%～65 86%.