南极半岛海洋气候区的土壤Ⅲ.冻-融作用与水分状况

自由水活动在南极海洋性气候区土壤形成与演化过程中发挥极为重要的作用。本文对土壤自由水的来源、冻-融作用、永冻层和活动层动态以及自由水参与下的物质迁移过程等几个方面进行了论述,讨论了上述不同过程的影响因素以及土壤发生学意义,指出以土壤水形态转化和自由水活动为基础的土壤过程具有显著的微域性特点,是决定本区土壤发生类型与分布模式的重要因素之一。

SOILS IN THE MARITIME ANTARCTIC Ⅲ.FREEZE-THAW PROCESS AND MOISTURE DYNAMICS

Availability of free water plays a most important role in soil-forming and developing processes in the maritime Antarctic. Source and generation of free water, freeze-thaw process, permafrost and active-layer dynamics, and material translocation induced by leaching are expatiated in the article. Meanwhile, various factors driving and limiting the above-mentioned processes are analyzed. And pedogenetic significance of these water-based processes within soils is discussed. It is pointed out that within soils activities induced by moisture availability could vary greatly due to site difference in a small distance, thus, to some extent, determining genesis and development of individual soils and distribution pattern of soils in this region.