The cold‐water coral community as hotspot of carbon cycling on continental margins: A food‐web analysis from Rockall Bank (northeast Atlantic)
The cold‐water coral community as hotspot of carbon cycling on continental margins: A food‐web analysis from Rockall Bank (northeast Atlantic)
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DOI：
10.4319/lo.2009.54.6.1829
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发表时间：
2009-11
影响因子：
4.5
通讯作者：
D. Oevelen;G. Duineveld;M. Lavaleye;F. Mienis;K. Soetaert;C. Heip
中科院分区：
文献类型：
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作者：
D. Oevelen;G. Duineveld;M. Lavaleye;F. Mienis;K. Soetaert;C. Heip
我们提出了冷水珊瑚群落的定量食物网分析，即活珊瑚，死珊瑚枝和沉积物的组合，与罗克尔海岸800米深的巨型碳酸盐丘上的Lophelia pertusa造礁有关。通过整合生物量、船上呼吸、δ15N值以及同化和生长效率的文献约束，利用线性逆模型重建了20个生物和非生物隔间中的140个碳流。珊瑚群落的碳通量为75.1 mmol C m−2 d−1，主要分布在植物碎屑（81%）和浮游动物（19%）之间。活珊瑚的碳吸收量仅占整个群落碳吸收量的9%，主要分布在植物碎屑（72%）和浮游动物（28%）中。群落的碳循环以悬浮和滤食性大型动物为主，这些动物与死珊瑚枝有关。安装在海底着陆器上的沉积物捕集器捕获了0.77 mmol C m−2 d−1（年平均值），几乎比珊瑚群落的总碳摄入（75.1）和呼吸（57.3 mmol C m−2 d−1）低两个数量级。这种差异可以用两种方式来解释：珊瑚群落拦截了原本不会沉淀在海底的有机物，通过它们作为生态系统工程师的作用，珊瑚框架和边界层中有机物的耗竭所产生的湍流增加了流入珊瑚群落的量。大型动物生物量和呼吸数据与软沉积物的比较表明，珊瑚群落是大陆边缘生物量和碳循环的热点。
We present a quantitative food‐web analysis of the cold‐water coral community, i.e., the assembly of living corals, dead coral branches and sediment beneath, associated with the reef‐building Lophelia pertusa on the giant carbonate mounds at ~800‐m depth at Rockall Bank. Carbon flows, 140 flows among 20 biotic and abiotic compartments, were reconstructed using linear inverse modeling by merging data on biomass, on‐board respiration, δ15N values, and literature constraints on assimilation and growth efficiencies. The carbon flux to the coral community was 75.1 mmol C m−2 d−1 and was partitioned among (phyto)detritus (81%) and zooplankton (19%). Carbon ingestion by the living coral was only 9% of the carbon ingestion by the whole community and was portioned among (phyto)detritus (72%) and zooplankton (28%). Carbon cycling in the community was dominated by suspension‐ and filter‐feeding macrofauna associated with dead coral branches. Sediment traps mounted on a bottom lander trapped 0.77 mmol C m−2 d−1 (annual average), which is almost two orders of magnitude lower than total carbon ingestion (75.1) and respiration (57.3 mmol C m−2 d−1) by the coral community. This discrepancy is explained in two ways: the coral community intercepts organic matter that would otherwise not settle on the seafloor, and through their action as ecosystem engineers, the increased turbulence generated by the coral framework and organic‐matter depletion in the boundary layer augment the influx to the coral community. A comparison of macrofaunal biomass and respiration data with soft sediments reveals that coral communities are hot spots of biomass and carbon cycling along continental margins.