title: [Distribution characteristics and environmental significance of heavy metals in soil particle size fractions from tropical forests in China].
abstract: Three tropical forest soils were collected from Haikou, Qionghai and Tunchang in Hainan Island. Soil particle size fractionations were conducted using the standard dry-sieving procedure. Distribution of heavy metals in bulk samples and particle size fractions was determined by ICP-MS. The distribution characteristics and the response to organic carbon and iron were discussed. The results showed that the distribution of heavy metals was highly associated with the particle size fractions and variable patterns were found, which decreased with the increasing size. The accumulation of Cr, Ni, Cu, Zn, Cd and Cd was predominantly contributed by the particles finer than < 53 microm in diameter, whereas As mainly accumulated in particle size of 53-1 000 microm. Generally, the microaggregate (< 250 microm) contributed 14.38%-65.04% of heavy metals to the contents in bulk soil and the silt-clay aggregates (< 53 microm) contributed 2.61% -32.01%. The content of heavy metals except for As and Cd and Pb in Haikou soil in these different size fractions were controlled by the organic carbon and iron contents, which increased with the decreasing particle size.
authors.affiliation: Key Laboratory of Nuclear Analytical Techniques, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Cang
authors.initials: C
authors.lastname: Gong
authors.forename: Dian-Dou
authors.initials: DD
authors.lastname: Xu
authors.forename: Hang-Xin
authors.initials: HX
authors.lastname: Cheng
authors.forename: Ya-Ge
authors.initials: YG
authors.lastname: Ren
authors.forename: Zhi-Ming
authors.initials: ZM
authors.lastname: Liu
authors.forename: Ying-Han
authors.initials: YH
authors.lastname: Liu
authors.forename: Fei
authors.initials: F
authors.lastname: Liu
authors.forename: Hai-Feng
authors.initials: HF
authors.lastname: Nie
authors.forename: Xiang
authors.initials: X
authors.lastname: Zheng
authors.forename: Ling-Ling
authors.initials: LL
authors.lastname: Ma
mesh_terms: D002681:China; D004784:Environmental Monitoring; D019216:Metals, Heavy / Q000032:analysis*; D010316:Particle Size; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis*; D014197:Trees / Q000254:growth & development*; D014329:Tropical Climate
chemical_list: D019216:Metals, Heavy; D012987:Soil; D012989:Soil Pollutants