中国西南喀斯特土壤水分特征研究进展

喀斯特土壤水分是岩溶植被的生命线、岩溶作用的驱动力和土壤流失的重要影响因子,关系岩溶区生态地质环境安全和社会经济发展。现有研究表明:中国西南喀斯特土壤水分含量差异大,土壤水分含量森林>灌丛>草地,阔叶林>针叶林,天然林>人工林;土壤水分含量空间分布呈斑块状,具有变异性和相关性,坡面分布复杂;含水量随土壤深度增加而增加,随季节演替呈低—升—高—降变化,干湿季差异大,日变化表现为从早到晚先降后升;土石相间分布、土下裂隙发育的小生境差异是喀斯特土壤水分空间差异大、坡位变化异常的重要原因。今后的研究重点是:喀斯特土壤水分的理化性质,土壤储水库的动态特征、适度水分、干季保水补水工程技术和湿季土壤无流失排水工程技术,对全球变化的响应,滇东高原喀斯特区土壤水分的相关研究等。

Progress of Study on Karst Soil Moisture Characteristics of Southwest China

Soil moisture is the lifeblood of karst vegetation,the driving force of karstification and important factors of soil erosion.It not only affect ecological and geological security of karst region,but also concern the social and economic development.The existing research shows that: a) the difference of karst soil moisture in southwest China is great,the sequence of soil moisture content is as follows,forest > shrub > grass,broadleaf forests > coniferous forests,and natural forests > plantations;b) the spatial distribution of soil moisture content is in the form of patchy,having variability and relativity and complicated distribution on slope;c) the moisture content increases along with the increase of soil depth,changing as low-up-high-down with seasonal succession.The moisture content is difference between wet and dry season and the daily change is down in the morning and up at night and;d) the difference of sub-environment of soil alternates with rock and the fracture extension under soil are the important reasons for great spatial differences of karst soil moisture and abnormal changes of slope.The main research in the future is on the studies of the physical and chemical properties of karst soil moisture,dynamic characteristic of soil water storage reservoir,moderate moisture,engineering techniques of replenishment water in dry season and drainage in wet season with no soil loss,respond to global climate change and soil moisture of karst area in eastern of Yunnan plateau.