Transformation and fate of microphytobenthos carbon in subtropical shallow subtidal sands: A 13C‐labeling study
Transformation and fate of microphytobenthos carbon in subtropical shallow subtidal sands: A 13C‐labeling study
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亚热带浅层潮下沙中微型底栖植物碳的转化和归宿：13C标记研究
DOI：
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
J. Middelburg
中科院分区：
文献类型：
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作者：
J. Oakes;B. Eyre;J. Middelburg
微植物底栖生物（MPB）在透光性沉积物是高生产力的，但这种生产的命运仍然不确定。在33天内，亚热带浅水潮下带沙中添加碳酸氢盐的13 C示踪显示，MPB衍生的碳迅速转移到更深的沉积物中;低于2 cm（60 h内31%）和5 cm（18%）。尽管它们的周转率很高（5.5 d），仅占沉积物有机碳的8%，但MPB占沉积物中保留的13 C的35%，表明大量的碳循环。碳迅速转移到异养生物，但它们对沉积物13 C的贡献与它们的生物量贡献相似（< 0.1%至3.8%），除了有孔虫Cellanthus criculatus，它占沉积物中13 C的33%。通过溶解有机碳（DOC）流出（3%）或再悬浮（最小），MPB衍生碳的损失很小。呼吸是主要的损失途径（63%），反映了低纬度地区典型的高微生物量。考虑到MPB从上覆水中吸收溶解的无机碳（DIC），并且它们固定的碳以DIC的形式释放，亚热带沙子中的MPB不太可能显著改变离岸运输的碳的形式（即，没有转化为DOC），但在沉积物中的处理可能会改变其δ 13 C值。考虑到31%的固定碳在33 d后仍保留在沉积物中，亚热带沙地可能充当碳汇，从而影响离岸碳的输送量。
Microphytobenthos (MPB) in photic sediments are highly productive but the fate of this production remains uncertain. Over 33 d, tracing of 13C from added bicarbonate in subtropical shallow subtidal sand showed rapid transfer of MPB‐derived carbon to deeper sediment; below 2 cm (31% within 60 h) and 5 cm (18%). Despite their high turnover (5.5 d) and only representing ~ 8% of sediment organic carbon, MPB represented up to 35% of the 13C retained in sediments, demonstrating substantial carbon recycling. Carbon was rapidly transferred to heterotrophs, but their contribution to sediment 13C was similar to their biomass contribution (< 0.1% to 3.8%), with the exception of the foraminifera Cellanthus craticulatus, which accounted for up to 33% of the 13C within sediment. There was little loss of MPB‐derived carbon via dissolved organic carbon (DOC) effluxes (3%) or resuspension (minimal). Respiration was the major loss pathway (63%), reflecting the high microbial biomass typical of lower latitudes. Given that MPB take up dissolved inorganic carbon (DIC) from overlying water, and the carbon they fix is released as DIC, MPB in subtropical sands are unlikely to substantially alter the form of carbon transported offshore (i.e., there is no conversion to DOC), but processing within the sediment may alter its δ13C value. Given that 31% of fixed carbon remained in sediments after 33 d, subtropical sands may act as a carbon sink, thereby affecting the quantity of carbon transported offshore.
影响因子：
1.4
作者：
Bellinger, B. J.;Underwood, G. J. C.;Gretz, M. R.
通讯作者：
Gretz, M. R.