攀枝花干热河谷四种人工植被类型土壤水源涵养特征分析

本文从土壤非毛管孔隙、入渗、最大可蓄水量和有效水贮量等方面评价了攀枝花干热河谷4种人工植被土壤的水源涵养功能。4个类型土壤蓄水能力均较低,70 cm土层最大可蓄水量变动范围在225 mm~285.5mm,有效水贮量在110 mm~169 mm之间。其中以香樟混交林水源涵养功能最强,其次分别是桉树林,新银合欢林,最差为番麻地。以变质花岗岩石发育的土壤母质层仍有较强的蓄水能力,最大可蓄水量(体积)含量达30%左右,有效蓄水量达20%。但土壤的入渗状况极差,稳渗率(K10)仅为0.2 mm.min-1。改善母质层的入渗状况是增加土壤旱季水分贮量的关键措施。人工造林可加速土壤层的形成进程,提高土壤的入渗率,如香樟-羊蹄甲基混交林,土壤层稳渗率为4.72 mm.min-1,而母质层仅为0.16 mm.min-1。

An Analysis of Water-holding Features of Four Artificial Vegetation Types in the Dry and Hot Valleys in Pazhihua

The soil water-holding features of four artificial vegetation types in the Panzhiha dry and hot valleys were evaluated by means of four indexes of non-capillary pore,infiltration,maximum water-holding capacity and available field capacity of soil.The soil water-holding capacities of four vegetation types were lower.In the soil layer of 70 cm deep,the maximum water-holding storage ranged from 225 mm to 285.5 mm,and available water storage from 110 mm to 169 mm.The mixed Cinnamum glanduliferum forest soil had the largest water-holding capacity.The water-holding capacity in the Eucalypt forest soil was in the second place,that in the Leucaena forest soil was in the third,and that in the Agave soil was the minimun.Parent maternal layer had a larger water-holding capacity,but its stable infiltration rate is lower.Improving infiltration of parent maternal layer was a key measure to add up the soil water storage in the dry season.Vegetation restoration could speed up the process of soil formation and raise the infiltration rate of soil.