Carbon Dioxide and Methane Emissions from Mangrove-Associated Waters of the Andaman Islands, Bay of Bengal
Carbon Dioxide and Methane Emissions from Mangrove-Associated Waters of the Andaman Islands, Bay of Bengal
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DOI：
10.1007/s12237-013-9674-4
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发表时间：
2014-03
影响因子：
2.7
通讯作者：
Neetha Linto;J. Barnes;R. Ramachandran;J. Divia;P. Ramachandran;R. Upstill‐Goddard
中科院分区：
文献类型：
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作者：
Neetha Linto;J. Barnes;R. Ramachandran;J. Divia;P. Ramachandran;R. Upstill‐Goddard
在2005年和2006年东北季风（旱季）之后和西南季风高峰（雨季）期间，我们通过在两条潮汐红树林小溪（Wright Myo; Kalighat）和连续浅海近岸水域的样带进行24小时采样，估计了安达曼群岛红树林相关水域的二氧化碳和甲烷排放量。潮高与溶解o2呈正相关，与pCO2、CH4、总碱度（TAlk）和溶解无机碳（DIC）呈负相关，且pCO2和CH4总是高度过饱和（330 ~ 1627% CO2; 339 ~ 26930% CH4）。这些数据与静水压力变化对潮汐泵的响应是一致的。在潮汐调查和近岸样带中，溶解的ch4没有季节性趋势，但pco2在2005年雨季的含量是其他时间的两倍左右。在潮湿季节，浑浊度增加了四倍，这与通过增加来自邻近红树林的有机质输入和/或富含二氧化碳的土壤水的冲刷，净底栖生物和/或水柱异养性升高相一致，这可能解释了这些二氧化碳数据。潮汐泵水中的TAlk/DIC关系最符合二氧化碳的成岩起源，主要是通过硫酸盐还原，还有有氧呼吸的额外输入。近岸样带中pCO2、CH4、TAlk和DIC随盐度的降低反映了潮汐抽水海水的离岸输送。估计潮汐溪平均排放量为~ 23-173 mmol m−2day−1co2和~ 0.11-0.47 mmol m−2day−1CH4。二氧化碳排放量是全球红树林相关水域的典型排放量，而ch4排放量则处于公布范围的低端。按比例计算，小河开放水域（2,700 km2）的年总排放量为3.6-9.2 × 1010mol co2和3.7-34 × 107mol CH4。我们估计来自邻近近海水域的排放量为~ 1.5 × 1011mol co2 - 1和2.6 × 108mol ch4 - 1，因此受红树林影响的水域总面积为~ 3 × 104km2，总排放量为~ 1.9 × 1011mol co2 - 1和~ 3.0 × 108mol ch4 - 1。在一系列红树林环境中评估这种排放对于解决全球红树林生态系统的温室气体平衡非常重要。未来的这类研究应成为更广泛的红树林碳平衡定量过程研究的组成部分。
We estimated CO2and CH4emissions from mangrove-associated waters of the Andaman Islands by sampling hourly over 24 h in two tidal mangrove creeks (Wright Myo; Kalighat) and during transects in contiguous shallow inshore waters, immediately following the northeast monsoons (dry season) and during the peak of the southwest monsoons (wet season) of 2005 and 2006. Tidal height correlated positively with dissolved O2and negatively with pCO2, CH4, total alkalinity (TAlk) and dissolved inorganic carbon (DIC), and pCO2and CH4were always highly supersaturated (330–1,627 % CO2; 339–26,930 % CH4). These data are consistent with a tidal pumping response to hydrostatic pressure change. There were no seasonal trends in dissolved CH4but pCO2was around twice as high during the 2005 wet season than at other times, in both the tidal surveys and the inshore transects. Fourfold higher turbidity during the wet season is consistent with elevated net benthic and/or water column heterotrophy via enhanced organic matter inputs from adjacent mangrove forest and/or the flushing of CO2-enriched soil waters, which may explain these CO2data. TAlk/DIC relationships in the tidally pumped waters were most consistent with a diagenetic origin of CO2primarily via sulphate reduction, with additional inputs via aerobic respiration. A decrease with salinity for pCO2, CH4, TAlk and DIC during the inshore transects reflected offshore transport of tidally pumped waters. Estimated mean tidal creek emissions were ∼23–173 mmol m−2day−1CO2and ∼0.11–0.47 mmol m−2day−1CH4. The CO2emissions are typical of mangrove-associated waters globally, while the CH4emissions fall at the low end of the published range. Scaling to the creek open water area (2,700 km2) gave total annual creek water emissions ∼3.6–9.2 × 1010mol CO2and 3.7–34 × 107mol CH4. We estimated emissions from contiguous inshore waters at ∼1.5 × 1011mol CO2year−1and 2.6 × 108mol CH4year−1, giving total emissions of ∼1.9 × 1011mol CO2year−1and ∼3.0 × 108mol CH4year−1from a total area of mangrove-influenced water of ∼3 × 104km2. Evaluating such emissions in a range of mangrove environments is important to resolving the greenhouse gas balance of mangrove ecosystems globally. Future such studies should be integral to wider quantitative process studies of the mangrove carbon balance.