| 亚热带高山森林土壤典型重金属的空间分布格局及其影响因素:以云南哀牢山为例 |
| 摘要点击 2208 全文点击 804 投稿时间：2020-12-04 修订日期：2020-12-29 |
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| 中文关键词 哀牢山 微量重金属 海拔分布 影响因素 来源分析 |
| 英文关键词 Ailao Mountain trace heavy metals altitude distribution influencing factors source analysis |
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| 中文摘要 |
| 为探究微量重金属元素的分布格局与局地气候、人类活动、植被分布和土壤发育差异等影响因素的关联作用，本文以云南哀牢山迎风坡（西坡）与背风坡（东坡）850~2650 m之间的9个海拔高度的森林样地为研究对象，重点探讨了迎风坡与背风坡森林表层土壤中典型重金属海拔分布格局差异及其主控因素.结果表明，土壤中Cd、Sb、As、Cr和Pb的含量及富集因子较高；东西坡土壤层中Cd、Sb和西坡Pb的含量具有较明显的海拔分布模式，其含量随海拔升高而增加；同一海拔西坡土壤层中Cd、Sb、As和Cr的含量显著高于东坡的相关含量.相关分析和主成分分析结果显示，Cd和Sb分布格局变化主要受控于大气输入沉降与土壤有机质的强结合作用，高海拔区域存在明显的"冷捕集"效应（cold-trapping），As和Cr的分布变化主要来源于土壤母质风化差异，而Pb的分布差异受基岩矿物风化控制.研究结果强调了大气沉降输入、降水与植被的综合效应（如"冷捕集"效应、促进冠层过滤、凋落物沉降与岩石风化等）对偏远高山土壤中微量重金属分布格局的影响作用. |
| 英文摘要 |
| In this study, we hypothesized that the distribution patterns of trace metal elements in montane regions would be controlled by the local climate, human activities, vegetation distribution and soil development. Hence, we selected nine forest sites among the elevation of 850 m to 2650 m on the windward (western slope) and leeward (eastern slope) slopes of Ailao Mountain in Yunnan Province of China to determine the typical heavy metal concentrations in forest surface soils, and their differences for distribution trends along with the increasing elevations, and the corresponding environmental factors. The results showed that surface soil Cd, Sb, As, Cr, and Pb had relatively higher concentrations and distinct enrichment factors both on eastern and western slopes. Specifically, the concentrations of Cd and Sb in surface soils of the eastern and western slopes and Pb on the western slope all had obvious altitude distribution trends, which showed their concentrations increased with the increasing elevation. In addition, we found the concentrations of Cd, Sb, As, and Cr in surface soils of the western slope were significantly higher than those of the eastern slope at the same altitude. The correlation analysis and principal component analysis further depicted that the elevation trends of Cd and Sb were mainly controlled by the strong combining effects from long-range atmospheric input and soil organic matter strong absorption, and there was an obvious "cold trapping" effect in high altitude areas. The distribution variations of As and Cr were mainly derived from the weathering difference of soil parent material, while the variations for Pb were controlled by the weathering of bedrock minerals. This study highlights the important role of combining effects from long-range atmospheric input, and from precipitation and vegetation (such as "cold trapping" effect, promoting canopy filtration, litterfall deposition and bedrock weathering) on the distribution trends of trace metals in remote alpine soils. |
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