Aquatic mesocosms to study the influence of zooplankton migration on predator-prey dynamics

淡水浮游动物是研究生态和进化过程之间相互作用的模式系统，因为它们既有无性繁殖模式，也有有性繁殖模式，这使得研究竞争如何影响多样性的维持，以及有性重组在产生生活史多样性中所起的作用。使用浮游动物的实验室研究已经证明，通过将个体生命历史与种群和群落动态联系起来，在解决特定生物过程方面非常成功，但它们缺乏自然界中发现的非生物(如温度)和生物(如藻类密度)因素的时空变化。特别是，他们忽视了垂直迁移，这种垂直迁移使个别浮游动物暴露在强烈的环境条件梯度之下。在这项申请中，我要求建立一套六个中微体，旨在研究浮游动物的基因类型和物种的动态，其生活史已经在实验室中进行了现场研究。为了实现这一点，中层生态系统采用了一种“生物测定”的方法，即实验室饲养的浮游动物群落暴露在水柱周围的水和猎物密度中，并可以在几周的时间内以高时间分辨率跟踪其动态。为了摆脱空间异质性对迁移的影响，中尺度系统被设计成控制垂直迁移。这些新颖的中间生态系统将使我们能够测试在实验室中研究的各种生态和进化过程如何影响自然界的生物动力学。在设备的使用寿命(约10年)内，所需的MESSEM将用于培训约10名本科生研究助理和6-8名研究生现场实验、列举和分析。

Freshwater zooplankton are a model system for studying the interaction between ecological and evolutionary processes because they have both asexual and sexual models of reproduction that enables the study of how competition influences the maintenance of diversity, and the role that sexual recombination plays in generating life-history diversity. Laboratory studies using zooplankton have proven very successful at resolving specific biological processes by linking individual life-history to population and community dynamics, but they lack the temporal and spatial variation in abiotic (e.g., temperature) and biotic (e.g., algal density) factors found in nature. In particular, they ignore the vertical migration that exposes individual zooplankton to a strong gradient of environmental conditions. In this application, I am requesting a set of six mesocosms designed to study the dynamics of zooplankton genotypes and species, whose life-history has been studied in the laboratory, in a field setting. To accomplish this, the mesocosms utilize a 'bioassay' approach whereby communities of lab-reared zooplankton are exposed to ambient water and prey densities along the water column, and whose dynamics can be followed with high temporal resolution over several weeks. To disentangle the influence of spatial heterogeneity from migration, the mesocosms are designed to control vertical migration. These novel mesocosms will enable us to test how various ecological and evolutionary processes studied in the laboratory influence biological dynamics in nature. Over the lifespan of the equipment (~10yrs), the requested mescosms will be used to train approximately 10 undergraduate research assistance and 6-8 graduate students in field-based experimentation, enumeration, and analysis.