Model of particulate organic carbon transport in an agriculturally impacted stream
Model of particulate organic carbon transport in an agriculturally impacted stream
复制标题
DOI：
10.1002/hyp.9569
复制
发表时间：
2014-01-30
影响因子：
3.2
通讯作者：
Fox, James F.
中科院分区：
文献类型：
--
作者：
Ford, William I.;Fox, James F.
目前的贡献集中在对受农业土地利用影响的低地溪流的总颗粒有机碳(POC)和底栖生物有机碳迁移进行建模。验证了一个质量平衡的河段尺度模型，该模型考虑了水、沉积物和POC的迁移，沉积物和POC的临时储存和与河床的交换，以及底栖动物碳库的产生和降解。我们发现POC负荷在不同的水文事件中变化很大，并且受到混合碳源输送的影响，包括陆源、河岸源和底栖源。研究发现，底栖生物的POC储量和运输量随季节和年度变化，但处于长期平衡状态。平衡是由负反馈机制控制的，即极端水文事件和高频水文事件导致的高POC输出减少了底栖POC储量，并抑制了底栖POC的增长。底栖POC占河流主干POC年负荷量的22%或4tCy(-1)，占整个流域POC产量的8.9tCy(-1)或48%。这些结果表明，在为低级河流系统估算河流生态系统碳时，应进一步关注底栖生物衍生的POC。版权所有(C)2012 John Wiley&Sons，Ltd.
The present contribution focuses on modeling the total particulate organic carbon (POC) and benthic POC transport from a lowland stream impacted by agricultural land-use. A mass balance, reach scale model is verified that accounts for water, sediment and POC transport, sediment and POC temporary storage and exchange with the streambed, and production and degradation of carbon pools in the benthos. We found that the POC load is highly variable during individual hydrologic events and is influenced by transport of mixed carbon sources including upland, streambank and benthic POC sources. Benthic POC stocks and transport were found to vary seasonally and annually but are in a state of long-term equilibrium. Equilibrium is governed by negative feedback mechanisms whereby high POC export due to extreme hydrologic events and high-frequency hydrologic events reduces benthic POC stocks and inhibits benthic POC growth. Benthic POC accounted for 4 tC y(-1) or 22% of the total annual POC loading in the stream's main stem and 8.9 tC y(-1) or 48% of the POC yield for the entire watershed. These results suggest that further attention should be given to benthic-derived POC when budgeting stream ecosystem carbon for low-order stream systems. Copyright (c) 2012 John Wiley & Sons, Ltd.