西双版纳不同植被类型土壤物理性质差异分析

Study on Differences of Soil Physical Properties under the Different Vegetation Types in Xishuangbanna

以云南省西双版纳勐腊县的茶树林、次生季雨林和不同林龄橡胶林为研究对象,比较土壤物理性质之间的差异,热带雨林转变成人工林后土壤水源涵养能力的变化。结果表明:次生季雨林和不同林龄橡胶林的土壤密度较接近,且远远大于茶树林;次生季雨林的土壤非毛管孔隙度最大,为14.23%,是茶树林的1.94倍。不同林龄橡胶林的土壤非毛管孔隙度处于中间值,变化范围为10.86%—13.96%,且土壤非毛管孔隙度随着橡胶林林龄的增大而递增,相应不同覆被下的土壤最大持水量也呈相同的变化趋势。在0—70cm土层深度上,茶树林、次生季雨林和不同林龄橡胶林土壤密度、土壤总孔隙度和土壤最大持水量变化情况均随着土层加厚表现出一致性,各树种的土壤有效持水量随着土层深度加深表现出起伏不定的变化趋势,但这种趋势有一定规律,相对较稳定,可一定程度上反映其水源涵养能力。

The tea trees, secondary monsoon rain forests and rubber plantation with different ages were studied in Xishuangbanna. The soil physi- cal properties under the different types of vegetation were compared, reflecting the changes of the soil water conservation capacities in the tropical rain forest into plantation. The results showed that, the soil bulk density of the secondary monsoon rain forests and the rubber plantation with different ages were relatively closed but far outweigh from tea woods. The non- capillary porosity of the soil under the secondary monsoon forests was largest, which was 14.23%, and it was 1.94 times outweigh of tea trees. The soil non- capillary porosity of the rubber plantation with different ages was in the middle value and the range was from 10.86% to 13.96% ,and it was increased with the age increasing of the rubber plantation. The corresponding soil water holding capacity under the land cover change also showed the same trend. In the soil depth 0 - 70cm, the variation of the soil bulk density, total soil porosity and maximum soil water holding capacity was under the tea trees, secondary forests and rubber plantation with different ages showed the same trend with the soil depth. Each tree species valid at the time as the water - holding capacity of soil depth deeper, though showed fluctuating trend, but this trend indicated the regularity and relatively stable, which reflected its ability of water conservation.