Influence of coagulation, sedimentation, and grazing by zooplankton on phytoplankton aggregate distributions in aquatic systems
Influence of coagulation, sedimentation, and grazing by zooplankton on phytoplankton aggregate distributions in aquatic systems
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浮游动物的凝结、沉积和放牧对水生系统中浮游植物聚集体分布的影响
DOI：
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发表时间：
1998
期刊：
影响因子：
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通讯作者：
S. Grant
中科院分区：
文献类型：
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作者：
A. Boehm;S. Grant
生长在湖泊和海洋表面的浮游植物通过重力沉积和/或浮游动物放牧而从水体中去除。这两个过程都受到浮游植物聚集状态的影响。哪个。反过来，可以通过颗粒-颗粒凝结来改变。在这项研究中，我们对这些现象进行了数学分析，试图更好地了解控制水生系统中浮游植物浓度的物理和生物因素。浮游植物大量繁殖期间。食草动物浓度相对较低。混合层中浮游植物浓度高，表层浮游植物的产生受到混凝和沉降的抵消。在这种情况下，动态标度理论表明总浮游植物聚集体的浓度N 0 和浮游植物的体积分数N 应按照深度z:N 0 z -γ 和N 1 Z -e 的幂律衰减。幂律指数 y 和 e 的值由给定系统中负责凝结和沉降的物理和化学过程决定。在非气球条件下，食草动物的集中度相对较高。浮游植物浓度相对较低，表面产生的浮游植物通过放牧很快转移到较高营养层。在这种情况下，N 0 和N 1 随着深度以近似指数方式衰减。这些结果表明，自然水生系统中浮游植物从水柱中去除的主要机制可能通过N 0 和N 1 的深度演化来区分。
Phytoplankton growing at the surface of lakes and oceans are removed from the water column by gravitational sedimentation and/or zooplankton grazing. Both of these processes are influenced by the aggregation state of the phytoplankton. which. in turn, may be altered through particle-particle coagulation. In this study, we present a mathematical analysis of these phenomena in an attempt to better understand the physical and biological factors that control phytoplankton concentrations in aquatic systems. During phytoplankton blooms. grazer concentrations are relatively low. the concentration of phytoplankton in the mixed layer is high, and phytoplankton production at the surface is countered by coagulation and sedimentation. In this case, dynamic scaling theory indicates that the concentration of total phytoplankton aggregates N 0 and the volume fraction of phytoplankton N should decay as power laws of depth z:N 0 z -γ and N 1 Z -e . The values of the power law exponents y and e are determined by the physical and chemical processes responsible for coagulation and sedimentation in a given system. Under nonbloon conditions, the concentration of grazers is relatively high. the phytoplankton concentrations are relatively low, and phytoplankton generated at the surface are quickly transferred to higher-trophic levels by grazing. In this case, N 0 and N 1 decay with depth in an approximately exponential fashion. These results suggest that the principle mechanism hy which phytoplankton are removed from the water column in natural aquatic systems may he differentiated by the depth evolution of N 0 and N 1 .