Connecting genetic diversity to ecosystem functioning: links between genetic diversity, relatedness and trait variation in a seagrass community

越来越多的证据表明，关键鱼种种群内部和种群之间的遗传变异在海洋生态系统过程中发挥着重要作用。几个实验提供了令人信服的证据表明，组合中的基因型数量（基因型丰富度）可以影响关键的生态系统功能，包括生产力，抗干扰和入侵或殖民成功。然而，这些研究仅使用基因型的数量作为遗传多样性的衡量标准。最近的物种多样性实验分析表明，系统发育多样性可能是一个更可靠的预测生态系统功能比简单的物种数量。然而，这些方法尚未被应用于理解遗传学对生态系统功能的影响。虽然一个物种内的遗传相关性有可能预测种内相互作用的结果，以及依赖于这些物种的生态系统的功能，但我们目前几乎没有数据来评估这种关系的形状或强度。研究人员将建立在他们自己以前的工作，以及其他人，在鳗草（Zostera marina）生态系统中表现出对一系列关键生态系统过程的基因型丰富性的强烈影响。研究人员会问是否基因型丰富度，或-在物种多样性水平的研究-遗传相关性/距离更好地预测生态系统功能？如果遗传相关性措施是更好的预测，那么这种关系的基础是什么机制？遗传相关性能预测生态相关性吗？虽然目前的重点是鳗草，研究应该适用于许多系统。该项目将评估一个关键海洋基础物种的遗传相关性和表型独特性之间的关系，并利用操纵性实验来测试一个组合中基因型数量相对于其遗传相关性和特征多样性对生态系统功能的相对重要性。具体而言，实验将：（1）研究了不同基因型间的遗传相关性和性状相似性之间的关系，包括对气候变暖的反应，（2）比较了不同基因型间的遗传相关性和性状相似性对种内竞争互作结果的影响;以及（3）测试遗传相关性与基因型数目对荻生长的相对影响，其相关联的生态系统发挥其功能（例如，初级生产、营养动态、营养转移、生境提供和碎屑产生和分解）。更广泛的影响：海草生态系统为沿海地区提供重要服务，包括初级生产、养分循环、渔业物种栖息地和侵蚀控制。以前的研究表明，这些服务可以通过减少食草动物或基因型的物种的数量，但这项研究将允许一个更具预测性的方法，通过整合多样性的多个组件的影响，并澄清多样性的影响可以预测的遗传或生态独特性的组件基因型的程度多样性损失。研究所将继续参与向联邦和州机构及其他利益攸关方直接通报与生物多样性有关的研究结果。这笔赠款将整合生理，社区和遗传方法来研究海洋生态系统功能，并将在这个界面上培养一些年轻的科学家（博士后，格拉德生和本科生）。该项目将与4个外展/培训计划，包括NSF支持的本科生UBM合作计划，加州大学赞助的计划，使学生从历史上的黑人学院和大学加州大学戴维斯分校的夏季研究经验，在生态学和进化生物学的接口，GK-12计划在博德加海洋实验室侧重于沿海海洋科学;以及一个将小学班级带到校园进行一系列协调的互动实地考察的项目。

There is growing evidence that genetic variation within and among populations of key species plays an important role in marine ecosystem processes. Several experiments provide compelling evidence that the number of genotypes in an assemblage (genotypic richness) can influence critical ecosystem functions including productivity, resistance to disturbance and invasion or colonization success. However, these studies use only the number of genotypes as a measure of genetic diversity. Recent analyses of species diversity experiments show that phylogenetic diversity may be a more reliable predictor of ecosystem functioning than simply the number of species. However, such approaches have not yet been applied to understanding the effects of genetics on ecosystem functioning. While genetic relatedness within a species holds the potential to predict the outcome of intraspecific interactions, and the functioning of ecosystems that depend on those species, we currently have few data to assess the shape or strength of this relationship. The investigators will build on their own previous work, and that of others, in eelgrass (Zostera marina) ecosystems showing strong effects of genotypic richness on a spectrum of critical ecosystem processes. The investigators will ask whether genotypic richness, or - as in studies at the level of species diversity - genetic relatedness/distance better predicts ecosystem functioning? If genetic relatedness measures are better predictors, then what mechanisms underlie this relationship? Can genetic relatedness predict ecological relatedness? Although the current focus is on eelgrass, the research should be applicable to many systems. The project will assess the relationship between genetic relatedness and phenotypic distinctiveness of a key marine foundation species and use manipulative experiments to test the relative importance of the number of genotypes in an assemblage vs. their genetic relatedness and trait diversity for ecosystem functioning. Specifically, experiments will: (1) characterize the relationship between genetic relatedness and trait similarity among individual genotypes of eelgrass, including responses to experimental warming; (2) compare the effects of genetic relatedness and trait similarity among genotypes on the outcome of intraspecific competitive interactions; and (3) test the relative effect of genetic relatedness vs. number of genotypes of eelgrass on the growth of eelgrass, its associated ecosystem functions it (e.g., primary production, nutrient dynamics, trophic transfer, habitat provision, and detrital production and decomposition). Broader Impacts: Seagrass ecosystems provide important services to coastal regions including primary production, nutrient cycling, habitat for fisheries species, and erosion control. Previous studies have shown these services can be compromised by reduction in the numbers of species of grazers or genotypes, but this study will allow a more predictive approach to diversity loss by integrating the effects of multiple components of diversity and clarifying the extent to which diversity effects can be predicted by the genetic or ecological uniqueness of component genotypes. The PIs will continue to be involved in direct communication of findings of biodiversity-related research to federal and state agencies and other stakeholders. This grant will integrate physiological, community, and genetic approaches to studying marine ecosystem functioning and will train a number of young scientists (postdocs, grad students and undergrads) at this interface. This project will interface with 4 outreach/training programs, including an NSFsupported UBM collaborative program for undergrads, a University of California-sponsored program that brings students from Historically Black Colleges and Universities to UC Davis for summer research experiences at the interface of ecology and evolutionary biology, a GK-12 program based at Bodega Marine Lab focused on coastal marine science; and a program that brings elementary school classes to the campus for a coordinated series of interactive field trips.