哈尼梯田生态系统森林土壤水源涵养功能分析

Water Conservation Function of Forest Soil in Honghe Hani Rice Terrace System

位于云南省哀牢山区红河南岸的红河哈尼稻作梯田系统是全球重要农业文化遗产之一,自上而下形成了垂直分布的"森林、村庄、梯田、河谷"四素同构的良性原始农业生态系统,使得该系统成功地抵御了多年的连续干旱。以哈尼梯田的核心区域撒马坝梯田上方的典型森林为对象,对其土壤水源涵养功能进行了系统分析和评价。结果表明,研究区平均土壤容重为1.09g/cm3,总孔隙度为65.1%,非毛管孔隙度为18.7%,平均土壤蓄水容量达2 589t/hm2,土壤滞留贮水量达739t/hm2,表层土壤平均初渗率达13.57mm/min,稳渗率达7.22mm/min,充分说明了该区域的土壤水热交换条件和土壤渗透性都十分良好。与我国其他区域森林相比,哈尼梯田森林具有很高的土壤水源涵养能力,是其适应极端干旱气候的重要保障,其模式可为我国适应极端气候变化减少农业经济损失提供重要的经验借鉴。

Honghe Hani Rice Terraces System, located in the Ailao Mountain area and the south of Honghe River in Yunnan Province, is one of the Globally Important Agricultural Heritage Systems （GIAHS） sites. The vertical distribution of the Forest-Village-Terrace River ecological landscape provides a well-functioning water conservation system, which makes it resist the continuous drought events successfully. The typical forest above the Samaba Terrace, core area of Honghe Hani Rice Terraces System, was taken as the study area. The soil water conservation functions of this area were analyzed and evaluated. The results show that the mean soil bulk density is 1.09 g/cm2 , the total porosity is 65.1%, the non-capillary porosity is 18.7%, the average soil water storage capacity is 2 589 t/hm2 , the retention storage capacity is 739 t/hm2 , the aver age initial infiltration rate at the top layer is 13.57 mm/min, and the stable infiltration rate is 7.22 mm/min, which means that the condition for water and heat exchange is good, so does the soil permeability. Compared with the forests in other regions of China, Honghe Hani Rice Terraces System has significant soil water conservation ability, which guarantees its resilience to extreme drought events. This system can provide impor tant experience to adapt to extreme climate change and reduce economic losses in agriculture.