Biogeochemical and hydrological controls on carbon export from a forested catchment in central Japan
Biogeochemical and hydrological controls on carbon export from a forested catchment in central Japan
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DOI：
10.1007/s11284-005-0050-0
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发表时间：
2005-03
影响因子：
2
通讯作者：
M. Kawasaki;N. Ohte;M. Katsuyama
中科院分区：
文献类型：
--
作者：
M. Kawasaki;N. Ohte;M. Katsuyama
本文综述了温带森林流域水文过程与控制溶解有机碳（DOC）和溶解无机碳（DIC）动态的生物地球化学环境之间的联系。此外，我们还给出了原始实验的结果。通过对日本中部森林水源集水区基本地下水文过程的观测，研究了DIC和DOC浓度的时空变化。土壤co2气体浓度随深度增加而增加，是DIC的来源。地下水水文特征也影响了地下水中溶解CO2分压（pCO2）的空间变化。土壤co2气体浓度和地下水pco2值的时间变化表明，DIC的动态受到生物活性的强烈影响。然而，DIC淋溶的地理差异不仅受到气候条件和生物活动之间联系的影响，还受到地貌条件等其他因素的影响。垂直渗透过程中，疏水酸选择性去除，DOC浓度降低。金属有机配合物在土壤固体中的滞留和DOC在下层土壤中的分解是去除DOC的主要机制。暴雨期间DIC和DOC浓度对流量变化的响应可以用DIC和DOC浓度的空间变化来解释。河流中DOC浓度的季节变化不仅受表层土壤中DOC浓度的时间变化（可能受生物活性的影响）影响，还受水体运动（将DOC从表层土壤输送到河流中）的影响。这些结果表明，生物地球化学方法和评价碳动态的水文效应的方法对于阐明森林生态系统的碳积累和释放过程至关重要。
Here we review research on the links between hydrological processes and the biogeochemical environment controlling the dynamics of dissolved organic carbon (DOC) and dissolved inorganic carbon (DIC) in temperate forested catchments. In addition, we present the results of original experiments. The spatial and temporal changes in DIC and DOC concentrations were investigated in tandem with observations of elementary belowground hydrological processes for a forested headwater catchment in central Japan. The soil CO2gas concentration, which is the source of DIC, increased with depth. The hydrological characteristics of groundwater also affected the spatial variation of partial pressure of dissolved CO2(pCO2) in groundwater. The temporal variations in the soil CO2gas concentration and the pCO2values of groundwater suggested that the dynamics of DIC were strongly affected by biological activity. However, the geographical differences in DIC leaching were affected not only by the link between climatological conditions and biological activity, but also by other factors such as geomorphologic conditions. The DOC concentrations decreased with selective removal of hydrophobic acid during vertical infiltration. The major DOC-removal mechanisms were retention of metal-organic complexes to soil solids in the upper mineral soil layer and decomposition of DOC in the lower mineral soil layer. The responses of the DIC and DOC concentrations to changes in discharge during storm events were explained by the spatial variation in the DIC and DOC concentrations. Seasonal variation, which represents a long-term change, in stream water DOC concentrations was affected not only by the temporal variation in DOC concentrations in the topsoil, which may be affected by biological activity, but also by water movement, which transports DOC from the topsoil to stream water. These results indicate that both a biogeochemical approach and a method for evaluating the hydrological effects on carbon dynamics are critical for clarifying the carbon accumulation-and-release processes in forested ecosystems.