四川盆地西缘山地土壤的坡向性分异研究——以二郎山、大相岭为例

Slope-directive Variation of Mountain Soils in the Western Borders of the Sichuan Basin——A Case Study of Mt.Erlang and Mt.Daxiangling

以四川盆地西缘二郎山和大相岭为例,探讨山地迎风坡与背风坡的土壤分异及其生产、生态意义。在山地迎风坡(WS),由于雨水充沛,植被繁茂,以土壤有机质和氮素为主要标志的生物积累旺盛,土壤盐基风化淋溶强烈,酸化明显。而在背风坡(LS),因雨水急剧减少,土壤生物积累和盐基淋溶及酸化作用明显减弱,基带土壤甚至出现有CaCO3聚积的钙化特征。山地土壤及其环境的这种坡向分异,导致了不同坡向土地资源利用和生态环境建设的差异:在迎风坡,耕地分布高度低,以水田为主,生态环境建设方式简单;背风坡则是耕地分布上限高,以旱地为主,生态环境建设方式相对复杂,难度也大。

Taking Mt. Erlang and Mt. Daxiangling in the western borders of the Sichuan basin for example, this paper discusses soil variation between windward slope （WS） and leeward slope （LS） in mountain and its significance on productivity and ecology. In WS, soil bio-accumulation which is marked by organic matter and nitrogen is bloom for rich rainwater and flourishing vegetation; Soil base leaching is intense, and soil acidification is obvious. However, in LS, soil bio-accumulation and base leaching are weak because rainwater sharply decreases; Soil even takes on calcification character in mountain base. The slope-direction variation of mountain soils and their environment lead to difference in land resource utilization and eco-environmental construction in different slope-directive. In WS, the upper altitude limit of cultivated land distribution is lower; paddy field is major in cultivated land, and mode of eco-environment construction is simpler. Whereas, in LS, the upper altitude limit of cultivated land distribution is higher; dry land is major difficult in eco-environment construction.