Impact of polychaetes (Nereis spp. and Arenicola marina) on carbon biogeochemistry in coastal marine sediments.
Impact of polychaetes (Nereis spp. and Arenicola marina) on carbon biogeochemistry in coastal marine sediments.
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多芯（Nereis spp。和Arenicola Marina）对沿海海洋沉积物中碳生物地球化学的影响。
DOI：
10.1186/1467-4866-2-92
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发表时间：
2001-10-30
影响因子：
2.3
通讯作者：
Kristensen, E
中科院分区：
文献类型：
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作者：
Kristensen, E
总结和评估了北欧沿海水域常见多毛类动物（沙蚕属和沙蚕属）的生物扰动对沉积物碳成岩作用的已知影响。对所涉及的多毛类物种的灌溉和改造活动的物理影响进行了评估，并将其与其基本生物学联系起来。根据过去和现在的实验工作，得出的结论是，来自操纵实验室实验的生物扰动对碳成岩作用的影响不能直接外推到原位条件。实验室中发现的 45-260% 通量（例如二氧化碳释放）增强远高于通常在现场观察到的 (10-25%)。因此，动物区系诱导的自然沉积物中微生物碳氧化的增强反而会导致有机物库存的减少，而不是沉积物/水界面上二氧化碳释放的增加。有机物库存的相对减少 (Gb/Gu) 与微生物有机物腐烂能力 (kb/ku) 的相对增加成反比。该平衡由有机输入（有机物在沉积物表面的沉积）和生物扰动强度之间的平衡控制。将氧气引入地下沉积物和去除代谢物被认为是穴居动物刺激碳氧化的两个最重要的潜在机制。通过向下灌溉输送上覆含氧水或通过向上重新输送沉积物至含氧水柱，将氧气引入微生物活性较低的深层沉积物层，将增加厌氧难降解有机物的碳氧化。看来灌溉效应大于返工效应，并且在更大程度上取决于动物密度。通过去除代谢物（减少扩散规模）增强厌氧碳氧化可能会导致总沉积物代谢显着增加。这是由三种可能的机制引起的：（i）矿化和生物吸收相结合； (ii) 矿化和非生物沉淀相结合； (iii) 减轻代谢物抑制。最后，对生物扰动效应的未来工作提出了一些建议，包括：（i）生物扰动沉积物中代谢物抑制的实验验证； (ii) 生物扰动沉积物中金属作为电子受体的作用的绘图和量化； (iii) 利用新的分子生物学技术鉴定微生物群落组成。这三个主题并不旨在涵盖生物扰动的所有未解决的方面，而应被视为我们知识中明显差距的列表，并提出新的、有吸引力的方法。
Known effects of bioturbation by common polychaetes (Nereis spp. and Arenicola marina) in Northern European coastal waters on sediment carbon diagenesis is summarized and assessed. The physical impact of irrigation and reworking activity of the involved polychaete species is evaluated and related to their basic biology. Based on past and present experimental work, it is concluded that effects of bioturbation on carbon diagenesis from manipulated laboratory experiments cannot be directly extrapolated to in situ conditions. The 45–260% flux (e.g., CO2 release) enhancement found in the laboratory is much higher than usually observed in the field (10–25%). Thus, the faunal induced enhancement of microbial carbon oxidation in natural sediments instead causes a reduction of the organic matter inventory rather than an increased release of CO2 across the sediment/water interface. The relative decrease in organic inventory (Gb/Gu) is inversely related to the relative increase in microbial capacity for organic matter decay (kb/ku). The equilibrium is controlled by the balance between organic input (deposition of organic matter at the sediment surface) and the intensity of bioturbation. Introduction of oxygen to subsurface sediment and removal of metabolites are considered the two most important underlying mechanisms for the stimulation of carbon oxidation by burrowing fauna. Introduction of oxygen to deep sediment layers of low microbial activity, either by downward irrigation transport of overlying oxic water or by upward reworking transport of sediment to the oxic water column will increase carbon oxidation of anaerobically refractory organic matter. It appears that the irrigation effect is larger than and to a higher degree dependent on animal density than the reworking effect. Enhancement of anaerobic carbon oxidation by removal of metabolites (reduced diffusion scale) may cause a significant increase in total sediment metabolism. This is caused by three possible mechanisms: (i) combined mineralization and biological uptake; (ii) combined mineralization and abiogenic precipitation; and (iii) alleviation of metabolite inhibition. Finally, some suggestions for future work on bioturbation effects are presented, including: (i) experimental verification of metabolite inhibition in bioturbated sediments; (ii) mapping and quantification of the role of metals as electron acceptors in bioturbated sediments; and (iii) identification of microbial community composition by the use of new molecular biological techniques. These three topics are not intended to cover all unresolved aspects of bioturbation, but should rather be considered a list of obvious gaps in our knowledge and present new and appealing approaches.