重庆缙云山4种典型植被覆盖下汞的释放通量及影响因素 |
摘要点击 2557 全文点击 1188 投稿时间:2017-04-01 修订日期:2017-06-08 |
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中文关键词 植被覆盖 汞 缙云山 释放通量 环境因子 |
英文关键词 vegetation cover mercury Jinyun mountain released flux environmental factors |
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中文摘要 |
为了揭示不同植被覆盖下土壤/大气界面释汞通量及其交换特征,在缙云山国家级自然保护区内选择4种典型植被覆盖类型(常绿阔叶林、楠竹林、灌木林以及草地)为研究对象,连续同步监测不同植被覆盖下土/气界面汞释放通量,同时考察各环境因子对土壤释汞的影响.结果表明,缙云山在4种不同植被覆盖下土壤汞释放通量具有明显的差异,总体表现为楠竹林[17.77 ng·(m2·h)-1] >草地[17.58 ng·(m2·h)-1] >灌木林[16.87 ng·(m2·h)-1] >常绿阔叶林[14.32 ng·(m2·h)-1];不同植被覆盖下土壤释汞通量在季节变化上呈现相似的规律性,但不同植被覆盖类型之间也存在明显差异,主要体现在暖季汞释放通量高于冷季;缙云山地区不同林植被覆盖下土壤释汞通量存在明显的日变化;气象因素光照强度、气温、土温和相对湿度,对土/气界面汞释放通量影响也不相同,气温为常绿阔叶林,灌木林与楠竹林的主要影响因子,光照强度为草地的主要影响因子. |
英文摘要 |
In order to reveal the characteristics of mercury release flux and exchange across the soil/atmosphere interface under different vegetation cover types, four of these types (evergreen broad-leaved forest, bamboo forest, shrub, and grassland) were chosen as research samples at Jinyun Mountain National Nature Reserve, Chongqing, Continuous monitoring of the different vegetation covers, soil/atmosphere interface, and mercury release flux was conducted, at the same time as the effects of environmental factors were also considered. Results show that the annual average Hg emission flux for the four kinds of forest cover have obvious differences. The overall emission performance of Hg is ranked as:bamboo forest[17.77 ng·(m2·h)-1] > grassland[17.58 ng·(m2·h)-1] > shrubbery[16.87 ng·(m2·h)-1] > evergreen broad-leaved forest[14.32 ng·(m2·h)-1]. There are obviously seasonal differences between Hg emission and the four kinds of forested stands in Jinyun mountain and there are significant differences among the different forests. These differences mainly reflect that emissions in the warm season are higher than in the cold season. There is also an obvious diurnal variation of soil mercury release flux from different forested stands in Jinyun Mountain. Meteorological factors of light intensity, air temperature, soil temperature, and relative humidity also effects the soil/air interface meaning that mercury flux is not the same across land cover types. Temperature is the main factor affecting evergreen broad-leaved forest, shrub forests, and bamboo forests. Light intensity is the main influencing factor for grasslands. |
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