Resource Variance and Composition of Daphniid Assemblages

[421539]本文提出，浮游植物资源丰度的时空环境变化是维持滤食性浮游动物功能性生物多样性的机制。物种利用丰富资源条件和贫乏资源条件的能力是不同的，这种差异在每个物种和异质环境之间产生了独特的相互作用。拟议的研究将检查居住在美国中西部湖泊的水蚤物种多样性的广度，并使用广泛的自然资源组合来测试这种开发权衡的普遍性。利用一种新的方法从生物的角度量化资源丰富度，本研究还将研究湖泊和湖泊内垂直生境的组合组成与环境资源条件之间的关系。两项实验研究将探讨这种权衡对竞争和食物网相互作用的影响。水蚤在淡水湖生态中起着至关重要的作用，本研究旨在确定水蚤多样性调控的关键因素。该研究为消费者特征与生态群落多样性之间的联系提供了一个明确的检验。它还为探索重要生物群体内的生物多样性如何转化为生态系统层面的后果奠定了基础。

9421539 Tessier It is proposed that a mechanism by which functional biodiversity of filter-feeding zooplankton is maintained is by spatial-temporal environmental variation in phytoplankton-resource abundance. Species can be viewed as differing in their ability to exploit rich versus poor resource conditions, and such differences create unique interactions between each species and a heterogeneous environment. The proposed research would examine the breadth of species diversity within the Daphnia inhabiting the lakes of midwest U.S., and use a broad range of natural resource assemblages to test the generality of this exploitation tradeoff. Using a novel approach to quantify resource richness from the organisms's perspective, this research would also examine for an association between assemblage composition, and environmental resource conditions among lakes and vertical habitats within lakes. Two experimental studies will explore the consequences of this tradeoff to competitive and food web interactions. This research will identify key factors regulating the diversity of Daphnia, which play a pivotal role in the ecology of freshwater lakes. The research provides an explicit test of a general concept linking consumer traits and diversity of ecological communities. It also lays the groundwork to explore how biodiversity within an important group of organisms translates into consequences at the ecosystem level.