Dissolved aluminum and organic carbon in soil solution under six tree stands in Lushan forest ecosystems.

WANG Lianfeng, PAN Genxing, SHI Shengli, ZHANG Lehua, HUANG Mingxing ( Institute of Resource, Ecosystem and Environment for Agriuclture, Nanjing Agricultural University, Nanjing 210095, China; Lushan Botany Garden, Chinese Academy of Sciences, Jiangxi 332900, China). Chin . J . Appl . Ecol., 2003,14(10): 1602-1606.

Soil solution chemistry, Dissolved aluminum, Dissolved organic carbon. Forest stand, Eco-chem-istry.

Different depths of soils under 6 tree stands in Lushan Botany Garden were sampled and water-digested at room temperature. The dissolved aluminum and organic carbon were then determined by colorimetry, using 8-hydrox-ylquilin and TOC Analyzer, respectively. The results indicated that even derived from a naturally identical soil type, the test soils exhibited a diverse solution chemistry, regarding with the A1 speciation. The soil solutions under Japanese cedar, giant arborvitae and tea had lower pH values and higher contents of soluble aluminum than those under Giant dogwood, azalea and bamboo. Under giant arborvitae, the lowest pH and the highest content of total soluble aluminum and monomeric aluminum were found in soil solution. There was a significant correlation between soluble aluminum and DOC, which tended to depress the accumulation of toxic monomeric aluminum. The 6 tree stands could be grouped into 2 categories of solution chemistry, according to aluminum mobilization.