哈尼梯田景观水源林区土壤水分垂直变化与持水性能

Vertical Changes of Soil Moisture and Water Holding Capacity of Hani Terraces Landscape in Water Conservation Forest Region

采用ThetaProbeML2x土壤水分测定仪和环刀取样法对哈尼梯田景观水源林区主要植被类型(林地和草地)下0—300cm土层的土壤水分特征及其持水性能进行了研究。研究结果表明:(1)各样地〔样地Ⅰ(林地),样地Ⅱ(林地),样地Ⅲ(草地)〕土壤水分垂直分布为"双峰"波动型,样地Ⅰ和Ⅲ波动弱,样地Ⅱ波动剧烈,拐点出现在60,140和230cm土层附近,土壤水分运动趋势在拐点处受邻层土壤含水量影响大;(2)粉沙性质地土壤(样地Ⅱ)水分变异系数高于黏性质地土壤(样地Ⅰ,Ⅲ);林地土壤水分变异系数大于草地土壤;(3)样地Ⅰ土壤和草地Ⅲ土壤蓄水量均较样地Ⅱ高,且其值相近,黏性壤土的蓄水能力优于粉沙性土壤;(4)水源林区0—160cm土层最大持水量和毛管持水量由大到小均表现为:样地Ⅰ>样地Ⅲ>样地Ⅱ;非毛管持水量由大到小表现为:样地Ⅱ>样地Ⅰ>样地Ⅲ,样地Ⅰ和样地Ⅲ的土壤水源涵蓄能力较强,样地Ⅱ土壤调节水分能力较强。

Using soil moisture monitor （ThetaProbeML2x） and soil ring sampler methods, we analyzed the soil moisture and water capacity of the main landscape（forest, grassland）soil with a 300 cm depth in the wa- ter conservation forest region in the Hani terraces landscape in Yuanyang County, Yunnan Province. The re- sults indicated that. （1） The distribution features of the three soil profile sample plot Ⅰ （forest）, sample plot Ⅱ （forest）, sample plotⅢ （grass） were ＂double-peak fluctuation＂ type with turning points at nearby the 60, 140 and 230 cm. （2） The coefficient of variation of sandy soil moisture was higher than clay soil （sample plot Ⅰ ,Ⅲ ）, and the coefficient of variation of forest was higher than grass while both soil samples were clay. （3） The water storage capacity of both sample plot Ⅰ （forest） and on of sample plot Ⅲ （grass） were higher than sample plotⅡ （forest）, and values were similar, the water storage ability of clay loam was better than that of silty sand soil. （4） Both the max water holding capacity and capillary moisture capacity at the 0--160 cm depth were ordered as： sample plot Ⅱ （forest） higher than sample plot Ⅱ （grass） and higher than sample plot Ⅱ （forest）, this indicated the water retention function of sample plot I （forest） and sample plot Ⅱ （grass） were higher, however, soil water regulation function of sample plot Ⅱ （forest） was higher.