title: [Characteristics of the wetland soil iron under different ages of reclamation].
abstract: The temporal-spatial trends of soil total iron concentration (Fet), free degree (Fed/Fet), activation degree (Feo/Fed) and complex degree (Fep/Fed) of soil iron oxides after reclamation were studied in Sanjiang Plain Wetlands. The result suggests that Fet in the upper tillage layers (0 - 20 cm) are influenced by reclamation more significantly than that in the lower ones (20 - 100 cm), and so does the early ages (0 - 1 years) than the late ages (1 - 25 years). Fet is negatively correlated with organic matter extremely significantly (R = - 0.62), while that with total phosphorus and pH are not significant. Fet of soil layer I (0 - 10 cm) increases obviously during the first 7 years after reclamation, and tends to become stable after 13 years, while those ages of soil layer II (10 - 20 cm) are 8 years and 15 years respectively. Soil layer I shows shorter responding time and better regularity than layer II. Fed/Fet increases rapidly after reclamation, decreases later and then increases again. Feo/Fed indicates exponential decrease with the reclamation ages as well as Fep/Fed. Feo/Fed of layer I decreases radically during the first 4 years after reclamation and tends to become stable after 13 years, while that of layer II decreases dramatically within the first year and keeps stable henceforth. The counterparts of Fep/Fed are 6 years, 14 years, and 2 years respectively. With the fitted experimental equations of Fet, Feo/Fed, and Fep/Fed, the ages of reclamation can be deduced reversely, which indicates the implication of iron on the shifts of soil environment.
authors.affiliation: Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agricultural Ecology, Chinese Academy of Sciences, Changchun 130012, China. zouyc@neigae.ac.cn
authors.forename: Yuan-Chun
authors.initials: YC
authors.lastname: Zou
authors.forename: Xian-Guo
authors.initials: XG
authors.lastname: Lü
authors.forename: Ming
authors.initials: M
authors.lastname: Jiang
mesh_terms: D002681:China; D016000:Cluster Analysis; D003247:Conservation of Natural Resources; D017753:Ecosystem; D007501:Iron / Q000032:analysis* / Q000737:chemistry; D012987:Soil / Q000032:analysis*; D013997:Time Factors; D053833:Wetlands
chemical_list: D012987:Soil; D007501:Iron