长白山区暗棕壤成土作用地球化学特征

以代表性暗棕壤垂直剖面土壤地球化学数据为依据,研究了长白山区特定的森林景观条件下成土过程中元素的分异与富集特征。研究结果表明,在岩石风化过程中主要以CaO、Na2O、Sr淋溶为主,有机酸淋溶过程中SiO2、Al2O3、K2O部分被淋溶,部分游离铁下渗到土体中下部氧化成铁锰胶膜;微量元素在风化过程中被次生黏土矿物吸附,不同程度地富集,在腐殖质积累过程中Cd、Zn、Pb、Mo、Hg、Co、Mn、Cr等亲生物元素进一步富集于表层土壤,Ce、Ni、Sb、Ti、V、Y、Zr在表生环境中地球化学性质稳定,残留富集于土壤表层。母质层继承和保留了基岩元素地球化学分布的基本特征。

Geochemistry of pedogenesis of dark brown soil in Changbai Mountain area

The authors studied the differentiation and enrichment of elements in pedogenesis process in the special forest landscape of Changbai Mountain area based on the representative soil geochemical data in vertical pro- file of dark brown soil． The results show that CaO，Na 2 O and Sr predominated in eluviating during rock- weathering process． In the leaching process of organic acid，SiO 2 ，Al 2 O 3 and K 2 O were partially eluviated，some free irons infiltrated into the lower soil and oxidized to Fe- Mn coatings． The trace elements were absorbed by secondary clay minerals and enriched inordinately in weathering process． In humus- accumulating process，the biophile elements like Cd，Zn，Pb，Mo，Hg，Co，Mn and Cr further enriched in the surface soil． In supergene environment，the elements such as Ce，Ni，Sb，Ti，V，Y and Zr were stable so that they remained and enriched in the surface soil． The C- horizon inherits and retains the basic characteristics of element geochemical distribution of bedrocks．