文献类型： 外文期刊

作者： Bu, Xiaoli ¹ ; Ruan, Honghua ² ; Wang, Limin ³ ; Ma, Wenbao ⁴ ; Ding, Jiumin ⁵ ; Yu, Xingna ⁶ ;

作者机构： 1.Nanjing Forestry Univ, Fac Sci, Nanjing 210037, Jiangsu, Peoples R China

2.Nanjing Forestry Univ, Fac Forest Resources & Environm Sci, Key Lab Ecol, Nanjing 210037, Jiangsu, Peoples R China

3.Fujian Acad Agr Sci, Dept Soil & Fertil, Fuzhou 350013, Peoples R China

4.Sichuan Acad Forestry, Chengdu 610081, Peoples R China

5.Lianyungang Tech Coll, Fac Business, Lianyungang 222006, Peoples R China

6.Nanjing Univ Informat Sci & Technol, Dept Atmospher Phys, Key Lab Atmospher Phys & Environment, Nanjing 210044, Peoples R China

关键词： Light fraction;Heavy fraction;Altitude gradation;Vegetation types;Dissolved organic carbon;Microbial biomass

期刊名称：APPLIED SOIL ECOLOGY （ 影响因子：4.046； 五年影响因子：4.884 ）

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收录情况： SCI

摘要： Density fractionation can be a useful means of separating soil organic matter (SOM) into light and heavy fractions. Our objective was to evaluate SOM storage in density fractions and the relative contribution of the light fraction to total SOM pool under four different vegetations, including evergreen broad-leaved forest (EBF), coniferous forest (CF), dwarf forest (DF) and alpine meadow (AM), along an altitude gradation in the Wuyi Mountains of southeastern China, and to investigate the factors controlling the pool size in density fractions. Here we separated light and heavy fractions using 1.7 g cm(-3) sodium iodide solution. The concentrations of C and N in light and heavy fractions were the highest in AM soils, while the C/N ratios in density fractions were the highest in CF soils across soil depths. The amounts of C and N in the heavy fractions increased with increasing silt plus clay content in the corresponding soil depth. Greater SOM storages in light and heavy fractions under AM suggested that the accumulation of SOM at higher altitude (lower soil temperature and higher soil moisture) mainly depends on slower decomposition rate despite lower organic matter inputs rate. The relatively larger contribution of the light fraction to total SOM under CF than that under the other three vegetation types is mainly attributed to its higher amount and quality of litterfall input and greater fine root biomass. Significant correlation existed between light fraction C and N, dissolved organic C. microbial biomass C and N, indicating considerable cycling of C and N between these pools. A stronger correlation between heavy fraction C and microbial biomass C suggested that the heavy fraction organic matter could be associated with most microbial biomass. (C) 2011 Elsevier B.V. All rights reserved.