Measuring and modeling dispersal of adult zooplankton
Measuring and modeling dispersal of adult zooplankton
复制标题
成年浮游动物扩散的测量和建模
作者：
M. Allen
栖息地的破碎化给元群落动态带来了一个固有的问题，因为隔离的增加和斑块的丧失阻碍了群落之间的分散。湿地就是这样一个近年来遭受过度破坏和破碎化的系统。这些群落内的浮游动物历来被认为是频繁且广泛的扩散者，但对浮游动物扩散的直接、定量测量却很少。在这项研究中，我进行了两项实验来量化浮游动物的扩散并确定主要的扩散载体。我首先在一个孤立的池塘周围 10、30、60、120 和 180 米处设置了一系列陷阱，以收集分散的个体。距离池塘 180 m 的诱捕器捕获了近 1,500 只成年浮游动物，其中距离池塘 10 m 的诱捕器捕获了约 60% 的扩散动物。使用开放式且排除动物的陷阱进行的第二项实验表明，大型动物是这些浮游动物的主要扩散媒介。使用这些数据的子集，我拟合了四个模型来描述该地点成年枝角类动物扩散的形状和程度。所有模型均显示大多数枝角类动物沉积在非常靠近源池的地方，其中三个模型表明诱捕区域涵盖了 67% 或更多的扩散距离。这些结果表明，在水生栖息地丰富的地区，成年浮游动物在池塘之间的移动可能很重要。然而，近年来，气候变化和人为干扰减少了世界许多地区水生栖息地的数量和规模，在许多情况下可能限制了个体的有效运输。因此，支离破碎的浮游动物元群落可能会经历更大的扩散限制、更强的优先效应、更高水平的近交和针对产生高扩散性的性状的选择。
Habitat fragmentation poses an inherent problem for metacommunity dynamics, as dispersal among communities is hindered by increasing isolation and the loss of patches. Wetlands are one such system that have undergone excessive destruction and fragmentation in recent years. Zooplankton within these communities have historically been considered frequent and widespread dispersers, but direct, quantitative measures of zooplankton dispersal are rare. In this study, I performed two experiments to quantify zooplankton dispersal and to identify the primary dispersal vectors. I first set up an array of traps at 10, 30, 60, 120 and 180 m around an isolated pond to collect dispersing individuals. Nearly 1,500 adult zooplankton were captured in traps up to 180 m from the pond, with approximately 60% of dispersers being captured in traps at 10 m from the pond. A second experiment using open and animal-excluded traps suggested that large animals were the primary dispersal vector for these zooplankton. Using a subset of these data, I fit four models to describe the shape and magnitude of adult cladoceran dispersal at this site. All models showed the majority of cladocerans were deposited very close to the source pond, with three models suggesting that the trapping area encompassed 67% or more of the dispersal distances. These results suggest that adult zooplankton movement among ponds may be significant in areas where aquatic habitats are plentiful. Yet, in recent years climate change and anthropogenic disturbances have reduced the number and size of aquatic habitats in many regions of the world, likely curtailing effective transport of individuals in many cases. As a result, fragmented zooplankton metacommunities may experience increased dispersal limitation, stronger priority effects, higher levels of inbreeding and selection against traits engendering high dispersability.