Fate of organic carbon added as diatom cells to oxic and anoxic marine sediment microcosms
Fate of organic carbon added as diatom cells to oxic and anoxic marine sediment microcosms
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作为硅藻细胞添加到含氧和缺氧海洋沉积物微观世界中的有机碳的命运
DOI：
10.3354/meps134225
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发表时间：
1996
影响因子：
2.5
通讯作者：
Andersen Fø
中科院分区：
文献类型：
--
作者：
Andersen Fø
将用 I4C 标记的活中肋骨骨藻（硅藻）细胞添加到 10 个含有加拿大温哥华岛萨尼奇湾潮间沉积物的岩心的沉积物表面。 5 个岩心沉积物上的水被喷射大气，而其他 5 个岩心则被喷射新西兰。 I4CO2 在好氧核心中立即开始释放，在第 3 至 4 天达到最大值，而在缺氧核心中释放较慢，在 6 至 9 天后达到最大值。 DO1'C（溶解有机碳）的释放最初也表现出较高的速率，但在缺氧核心中释放量最高。降解为TO 2 和D0I4C 可以通过代表2个可分解部分的2个连续指数衰减来描述。 80 天后，在好氧和缺氧核心中，58% 和 42% 的添加标记以 I4CO2 形式释放，2% 和 13% 以 D0I4C 形式释放。孔隙水中仅含有少量 I4CO2 和 DO1"C。然而，好氧核心显示出最低浓度，表明这些核心中动物区系增强的溶质通量。80 天后，31% 至 37% 的添加标签以 P0I4C（颗粒有机碳）形式保留在沉积物中。在好氧和缺氧条件下，添加的藻类 POC 中损失了类似数量的溶解碳 ('4C02+D01T)。但缺氧岩心沉积物中释放的 D0I4C 量较大，表明 D0I4C 的厌氧矿化速度较慢。
Live Skeletonerna costatum (diatom) cells labeled with I4C were added to the sediment surface in 10 cores containing intertidal sediment from Saanich Inlet, Vancouver Island, Canada. The water overlying the sediment in 5 cores was sparged with atmospheric air, whereas the other 5 cores were sparged with NZ. Release of I4CO2 started immediately in the oxic cores, reaching a maximum at Days 3 to 4 , whereas release in the anoxic cores was slower with a maximum after 6 to 9 d. DO1'C (dissolved organic carbon) release also exhibited high rates initially, but w ~ t h the highest release in the anoxic cores. Degradation to ' T O 2 and D0I4C could be described by 2 successive exponential decays representing 2 decomposable fractions. After 80 d, 58 and 42 % of the added label had been released as I4CO2, and 2 and 13% were released as D0I4C in the oxic and anoxic cores, respectively. The porewater contained only small amounts of I4CO2 and DO1"C. However, oxic cores showed the lowest concentrations, indicating faunally enhanced solute fluxes in these cores. Between 31 and 37% of the added label remained as P0I4C (particulate organic carbon) in the sediment after 80 d. Similar amounts of dissolved carbon ( '4C02+D01T) were lost from the added algal POC under oxic and anoxic conditions, but the larger amounts of D0I4C released from the sediment in the anoxic cores ind~cated a slower anaerobic mineralization of D0I4C.