Effects of acidic solutions on element dynamics in the monsoon evergreen broad-leaved forest at Dinghushan, China. Part 2: dynamics of Fe, Cu, Mn and Al.
BACKGROUND
Soil metal dynamics are affected by acid deposition. Little knowledge is available about the process in the lateritic soils under the monsoon forest in south China.


METHODS
Samplings of Acmera acuminatissima, Cryptocarya concinna and Schima superba were grown from October, 2000 to July, 2002 in pots with a natural acid lateritic forest soil from Dinghushan. Pots were watered weekly with an acid solution (pH 3.05, 3.52, 4.00 or 4.40) or with tap water. Fe, Mn, Cu and Al were measured in soils, leachates and sapling leaves.


RESULTS
Soil extractable Fe and leachate Al and Mn concentrations increased with a decreasing treatment pH. Soil reactive Al exhibited the opposite trend and decreased over time. The Ca/Al and Mg/ (Al+Mn) ratios did not decrease in the leaves of Schima superba, but decreased with a decreasing treatment pH for Cryptocaria concinna. Both ratios only decreased in the pH 3.05 treatment for Acmena


CONCLUSIONS
Cu will not be toxic for plants since soil extractable Cu was not high and Fe will not be toxic either given that its root uptake was inhibited by Mn. Acid rains will lead to increased Mn and Al mobility in soil. Cryptocaria concinna will be the most sensible species to these changes (nutrient deficiency and direct Mn toxicity), while Schima superba should retain a good growth.
Liu
Juxiu
J
Division of Restoration Ecology, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, PR China. ljxiu@scbg.ac.cn
Zhou
Guoyi
G
Zhang
Deqiang
D
D015258:Acid Rain / Q000633:toxicity*; D000535:Aluminum / Q000032:analysis / Q000378:metabolism; D002681:China; D003300:Copper / Q000032:analysis / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000032:analysis / Q000378:metabolism; D019770:Lauraceae / Q000187:drug effects / Q000378:metabolism; D008345:Manganese / Q000032:analysis / Q000378:metabolism; D008670:Metals / Q000032:analysis* / Q000378:metabolism; D027822:Myrtaceae / Q000187:drug effects / Q000378:metabolism; D012987:Soil; D012996:Solutions; D028242:Theaceae / Q000187:drug effects / Q000378:metabolism; D014197:Trees / Q000187:drug effects* / Q000378:metabolism
D015258:Acid Rain; D008670:Metals; D012987:Soil; D012996:Solutions; D008345:Manganese; D003300:Copper; D000535:Aluminum; D007501:Iron