Dissolved ion analyses of stream water from bamboo forests: Implication for enhancement of chemical weathering by bamboo
Dissolved ion analyses of stream water from bamboo forests: Implication for enhancement of chemical weathering by bamboo
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DOI：
10.2343/geochemj.1.0175
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发表时间：
2012-01-01
影响因子：
0.8
通讯作者：
Sasaki, Shigeyuki
中科院分区：
文献类型：
--
作者：
Akagi, Tasuku;Hayashi, Misuzu;Sasaki, Shigeyuki
在相似的地质环境下，每个月对三个不同竹盖度的集水区的溪水进行溶解离子分析，为期一年。随着竹盖度的增加，溶解Si、非海盐Na、K、Mg和碱度的浓度增加，竹对化学风化的作用显著。基于3个集水区水体Cl浓度全年相似且恒定的特点，对系统进行了蒸散发校正和基础径流影响的简化。由于在河床沉积物中未检测到方解石，因此假定非海盐Na和Ca来源于斜长石，从而计算了斜长石的风化速率。据估计，竹林斜长石的风化速率大于1000 mol ha(-1) yr(-1)，是对照竹林的两倍。两个竹林流域的溶解硅输出速率为0.11 mol/m(2)/yr，高于无竹林流域或世界其他地区河流的报告数据。我们进一步讨论了竹林的硅循环，并与无竹林进行了比较。
Dissolved ion analyses of stream water were conducted monthly in three catchments of varying bamboo coverage of similar geological setting for one year. We found that the concentration of dissolved Si, non-sea salt Na, K, Mg, and alkalinity increased with the increase of bamboo coverage and we concluded that bamboo significantly contributes to chemical weathering.Based on the similar and constant Cl concentrations in stream water in the three catchments throughout the year, we simplified the system with respect to the evapotranspiration correction and basal runoff influence. Since calcite was not detected in the streambed sediment, non-sea salt Na and Ca are assumed to have originated from plagioclase, and thus the plagioclase weathering rate was calculated. The plagioclase weathering rate in bamboo forests was estimated to be more than 1000 mol ha(-1) yr(-1): twice as high as that in a control bamboo-free forest. The dissolved Si export rate of 0.11 mol/m(2)/yr from the two bamboo catchments is greater than that of bamboo-free catchment or reported data from rivers in other parts of the world. We discuss further the Si cycle in bamboo forests, comparing with that of bamboo-free forests.