Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA, USA.
Department of Applied Ecology, North Carolina State University, Raleigh, NC, USA.
Glob Chang Biol. 2017 Jun;23(6):2166-2178. doi: 10.1111/gcb.13625. Epub 2017 Feb 20.
Humans have drastically altered the abundance of animals in marine ecosystems via exploitation. Reduced abundance can destabilize food webs, leading to cascading indirect effects that dramatically reorganize community structure and shift ecosystem function. However, the additional implications of these top-down changes for biogeochemical cycles via consumer-mediated nutrient dynamics (CND) are often overlooked in marine systems, particularly in coastal areas. Here, we review research that underscores the importance of this bottom-up control at local, regional, and global scales in coastal marine ecosystems, and the potential implications of anthropogenic change to fundamentally alter these processes. We focus attention on the two primary ways consumers affect nutrient dynamics, with emphasis on implications for the nutrient capacity of ecosystems: (1) the storage and retention of nutrients in biomass, and (2) the supply of nutrients via excretion and egestion. Nutrient storage in consumer biomass may be especially important in many marine ecosystems because consumers, as opposed to producers, often dominate organismal biomass. As for nutrient supply, we emphasize how consumers enhance primary production through both press and pulse dynamics. Looking forward, we explore the importance of CDN for improving theory (e.g., ecological stoichiometry, metabolic theory, and biodiversity-ecosystem function relationships), all in the context of global environmental change. Increasing research focus on CND will likely transform our perspectives on how consumers affect the functioning of marine ecosystems.
人类通过开发利用极大地改变了海洋生态系统中动物的丰度。动物丰度的降低会破坏食物网的稳定性，导致级联的间接效应，从而剧烈重组群落结构并改变生态系统功能。然而，通过消费者介导的养分动态（CND）对这些自上而下的变化对生物地球化学循环的额外影响，在海洋系统中通常被忽视，特别是在沿海地区。在这里，我们回顾了强调这种自下而上控制在沿海海洋生态系统中的局部、区域和全球尺度上的重要性的研究，以及人为变化对这些过程产生根本影响的潜在影响。我们关注消费者影响养分动态的两种主要方式，重点强调其对生态系统养分容量的影响：（1）生物量中养分的储存和保留，以及（2）通过排泄和排遗供应养分。在许多海洋生态系统中，消费者生物量中的养分储存可能特别重要，因为消费者通常比生产者更主导生物量。至于养分供应，我们强调了消费者如何通过压力和脉冲动态来增强初级生产。展望未来，我们探讨了 CND 对于改善理论（例如，生态化学计量学、代谢理论和生物多样性-生态系统功能关系）的重要性，所有这些都是在全球环境变化的背景下进行的。对 CND 的研究关注增加，可能会改变我们对消费者如何影响海洋生态系统功能的看法。
