生物扰动对沉积物侵蚀和沉积的影响

Impact of Macrobenthic Bioturbation on the Sediment Dynamics

关键词:  大型底栖动物  沉积物侵蚀和沉积  水层-底栖界面  耦合

Key words:  macrobenthos  sediment erosion and deposition  water-sediment layer  coupling

摘要:

海洋沉积物的侵蚀和沉积过程对海底地形地貌具有重要的作用,侵蚀和沉积速率的相对比值不仅影响沉积层的稳态过程,还能改变沉积层的理化属性。侵蚀和沉积过程涉及因素复杂,不仅包括物理因素(海流、潮汐、沉积物性质)、化学因素(浑浊度、间隙水的离子组成),还包括生物因素(海草、海藻的丰度以及生物扰动作用)。生物扰动是海洋生态学重要的研究内容之一,是水层-底栖界面的耦合过程中的关键生物影响因子。自20世纪50年代以来,生物扰动逐步得到重视,尤其是在水层-底栖界面耦合过程中的作用,并逐步由定性研究过渡到定量研究,进入室内生态模拟、现场测试和构建模型相结合的阶段。但生物扰动对沉积物侵蚀和沉积的影响研究起步相对较晚,10余年前才开始得到较多关注。本文综述生物扰动对沉积物侵蚀和沉积的影响,包括目前研究状况,常用的研究材料和方法以及研究热点,为今后深入研究关键生物种群的生物扰动对沉积物侵蚀的影响以及地形地貌的形成提供参考。

Abstract:

The sediment erosion and deposition processes play an essential role in the forming of seabed topography.The net ratio between the process of sediment erosion and deposition not only influences the sediment stabilization, but also changes the physical and chemical properties of the sediment.Many factors involve in this process, including physical (tide, current, and sediment properties), chemical (turbidity, pore-water properties) and biological factors (seagrass, sea algae density, bioturbation).Bioturbation is the key factor between the bottom water and sediment layers, which is urgently needed to be studied in marine ecosystem.The bioturbation has been drawn more attention since 1950s, and gradually changed from quality study to the status of quantity study, combining with the simulation experiments in laboratory, measurement in situ, and integrated with the numerical modelling.However, the research on the sediment erosion and deposition affected by the bioturbation was relatively poor, and more studies begun with only 10 years before.The aim of this paper is to review recent field and laboratory studies using flumes to quantify the erodability of sediments as a function of bioburbation, including the current status, materials and methods to be adopted recently and some previous results on this topics, which provide reference for further study on the sediment erosion by bioturbation effects from key species of macrobenthic assemblages.