树木年轮及其根部土壤元素含量的对数线性相关模型的验证及应用

Nine Platanus acerifolia(Ait),Willd.trees growing in the Nanjing Children Teacher‘s School,Nanjing,China ,were selected to determine the contents of 13 chemical elements both in the 1994‘s growth rings,C(Z,t),and in the soils near the roots,C′(Z,t),of the trees ,The results showed that the relationship be-tween C(Z,t) and C′(Z,t) followed the logarithmic liner correlation moedl.lgC′(Z,t),=a(Z) b(Z)lgC(Z,t),Based on this model the chrono-sequences of chemical element contents in the soils were reproduced fromt those ih the tree rings;i.e., the dynamic variations in the chemical element contents of the soils at the sites were trced.In this study the chrono-sequences of the chemical elements including Cd,Pb,Mn,Co and Zn in the soils near the roots of a Platanus acerifolia tree from 1957 to 1994 were established ,and the background values of Cd,Pb,Mn,Co and Zn in the soil were calcuated by taking the lowest values of the chrono-sequences of the element conents as upper limits of the background values.

Application and verification of logarithmic linear correlation model of element contents between tree rings and soils near the tree roots

Potassium chloride, Na-pyrophosphate, CuCl2, NH4-oxalate, dithionite-citrate-bicarbonate (DCB) and Na-citrate solutions were employed to extract Al and Fe sequentially and separately from 15 acidic soils from the Mangshan Mountains, Hunan Province, China. Results showed that separate pyrophosphate extracted mainly KCl-extractable Al, organo-Al complexes and some inorganic Al compounds, whereas separate CuCl2 extracted KCl-extractable Al and some organo-Al complexes. CuCl2 extracted much less amounts of Al than pyrophosphate did from the soils. Separate oxalate did not extract all KCl-pyrophosphate-CuCl2-oxalate sequentially extractable Al and Fe. Separate DCB did not extract all KCl-pyrophosphate-CuCl2-oxalate-DCB sequentially extractable Al. The forms of Al extracted by oxalate and DCB from the soils were mostly noncrystalline. The interlayered materials of 1.4-nm intergrade minerals of the soils were attributed mainly to hydroxy Al polymers.