Elucidating patterns and processes structuring protist biodiversity across salinity gradients

阐明跨盐度梯度构建原生生物多样性的模式和过程

• 批准号: RGPIN-2014-05461
• 负责人: WegenerParfrey, Laura
• 金额: $ 2.33万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=611658
• 关键词: Elucidating; patterns; processes; structuring; protist

Most organismal diversity is microbial, including the numerous lineages of protists that are related to animals and plants. Protists are incredibly diverse, abundant, and have huge impacts on aquatic ecosystems because they influence the flow of nutrients and energy. Powerful sequencing approaches now enable us to rapidly characterize microbial communities and assess biodiversity on an unprecedented scale. We will use these tools to ask how protist diversity is distributed across environments and how different ecological and evolutionary forces, including selection and dispersal, combine to produce these biodiversity patterns. The transition from freshwater to marine ecosystems is of the strongest divisions in microbial diversity, with very different types of organisms inhabiting these environments. Environmental factors such as salinity and pH are thought to be largely responsible for this difference because together they constitute a large physiological barrier and crossing it usually requires evolutionary innovation. However, it is also possible that interactions among organisms are important, and they may reinforce the environmental boundary by out-competing or preferentially preying on newly arrived microbes. We will collect data on environmental parameters and the whole microbial community (protists and bacteria) to address this question from the perspective of the whole community for the first time. This research will use correlative studies along replicate salinity gradients combined with manipulative experiments that directly test what happens to community composition when salinity changes or a large predator is added, for example. We will also transplant entire communities to new environments under different conditions to see which microbes survive. Together these results will help uncover the mechanisms that determine which species of protists live in different environments, and how these processes differ within and between habitats, across local and regional scales, and over time. Along the way, we will also assess the role of dispersal plays in structuring microbial communities and test general ecological theories of biogeography and the maintenance of biodiversity. This research takes place in coastal environments and estuaries that are characterized by salinity gradients. Coastal ecosystems and estuaries deliver numerous ecosystem services that benefit humans, but these important ecosystems are threatened by human activities including agricultural runoff and sewage effluent. Coastal ecosystems are also on the frontlines of impending effects of climate change such as ocean acidification and increased variability in weather. Thus, understanding the processes that govern microbial eukaryotic community assembly in coastal ecosystems will enable better predictions of the response of microbial organisms to environmental changes that are among the most pressing concerns of our time and how these systems work in general.

大多数生物多样性都是微生物，包括与动物和植物相关的生物的众多谱系。原生物非常多样，丰富，并且对水生生态系统产生巨大影响，因为它们会影响养分和能量的流动。现在，强大的测序方法使我们能够快速地表征微生物群落并以前所未有的规模评估生物多样性。我们将使用这些工具来询问如何在环境中分布原生物多样性，以及如何使用不同的生态和进化力，包括选择和分散，以产生这些生物多样性模式。 从淡水到海洋生态系统的过渡是微生物多样性中最强的分裂，居住在这些环境中的生物非常不同。盐度和pH等环境因素被认为在很大程度上是造成这种差异的原因，因为它们共同构成了较大的生理障碍，并且越过它通常需要进化创新。但是，生物体之间的相互作用也很重要，它们可能通过超出竞争或优先捕食新到达的微生物来增强环境边界。我们将第一次从整个社区的角度收集有关环境参数和整个微生物社区（原生和细菌）的数据。这项研究将使用重复的盐度梯度以及操纵实验的相关研究，这些实验直接测试盐度变化或添加大捕食者时社区成分发生的事情。我们还将在不同条件下将整个社区移植到新环境中，以查看哪些微生物的生存。这些结果共同有助于发现确定哪种生物种类生活在不同环境中的机制，以及这些过程在栖息地，跨地区和区域尺度以及随着时间的流逝之间的差异。在此过程中，我们还将评估分散作用在结构微生物群落和测试生物地理学的一般生态理论和维持生物多样性中的作用。 这项研究发生在以盐度梯度为特征的沿海环境和河口进行。沿海生态系统和河口提供许多使人类受益的生态系统服务，但是这些重要的生态系统受到人类活动的威胁，包括农业径流和污水污水。沿海生态系统也处于气候变化迫在眉睫的影响（例如海洋酸化和天气变化增加）的前线上。因此，了解沿海生态系统中微生物真核生物社区组装的过程将更好地预测微生物对环境变化的反应，而环境变化是我们这个时代最紧迫的关注点以及这些系统如何运作。