广东南部地理景观中土壤重金属垂直分异及其地球化学分层性

本文研究热带亚热带土壤中重金属分布的垂直分异及其分层性特征.土壤剖面中,水溶态、可交换态和有机结合态的重金属浓度自上层向底层降低.水溶态和有机结合态重金属的分布与有机质一致,而与pH值相反.Fe-Mn氧化物结合态的重金属分布与粘粒一致.残渣态分布的差异极小.

VERTICAL DIFFERENCE AND GEOCHEMICAL LAYER CHARACTERISTICS OF HEAVY METALS DISTRIBUTION IN THE SOIL OF GEOGRAPHICAL LANDSCAPES OF SOUTH GUANGDONG

The vertical difference of the distribution of heavy metals and their geo-chemical layer characteristics including Fe, Mn, Co, Ni, Zn and Pb in the soils of the Tropics and the Subtropics have been studied in this pape.The difference is reflected by the distribution in five forms including water-dis-soved, exchangeable, organic-bound, Fe-Mn oxide-bound and residual.There is a layered Characteristic of the form distribution of heavy metals in the soil.The concentrations of water-dissolved, exchangeable and organic-bound heavy metals descend from the upper layer to the lower layer in the soil profiles.The distribution of water-dissolved and organic-bound metals is consistent with the organic matter, and is contrary to the pH valve.The distribution of Fe-Mn oxide-bound metals is consistent with the clay particle. The distribution difference of the residual metal in every profile is very little.The order of potential mobility of heavy metals in the soila of geographical landscapes of the Tropics and the Subtropics is as follows.Fe>Mn>Pb>Cu>Zn>Co.