DIMENSIONS: COLLABORATIVE RESEARCH: Biodiversity Gradients in Obligate Symbiotic Organisms: A Case Study in Lichens in a Global Diversity Hotspot

维度：合作研究：专性共生生物的生物多样性梯度：全球多样性热点地衣的案例研究

• 批准号: 1542629
• 负责人: Erin Tripp
• 金额: $ 103.53万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-15 至 2021-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1542629&HistoricalAwards=false
• 关键词: DIMENSIONS; COLLABORATIVE; RESEARCH; Biodiversity; Gradients

Obligate symbioses are relationships between two or more species that depend entirely on each other for growth and survival. Such symbioses characterize some of the most common and ecologically important relationships on Earth, ranging from human gut bacteria and diseases to corals and specialized plant-pollinator relationships. Yet, many of these obligate symbioses are imperiled by unprecedented rates of environmental change and permanent biodiversity losses. Compared to single branches on the tree of life such as birds, flowering plants, or mammals, much less is known about the factors that facilitate or limit the distributions of the obligate symbioses that abound in nature. Moreover, research on biodiversity distributions has focused largely on abiotic factors (e.g., temperature, precipitation, elevation) rather than on biotic factors (i.e., interactions with other organisms) that influence geographical distributions. This project will uncover the factors that impact diversity and distributions of obligate symbiotic lichens as a model system. The geographic focus is the southern Appalachian Mountains of the southeastern U.S. -- a global lichen diversity hotspot and unique natural laboratory. In addition, this project will develop human capital and infrastructure in U.S. lichenology through student training, collaborations, and outreach to resource managers and the public. It will establish a publicly available, high quality dataset and improve physical and digital resources that advance lichen conservation for a global biodiversity hotspot.Despite generations of research on, and proposed theories for factors that generate and maintain biodiversity, consensus is lacking. Biotic factors have long been proposed as drivers, but they are rarely studied due to the difficulty of assessing the multitude of possible interactions. Because of the inherent biotic interaction between obligate symbionts, lichens offer a unique opportunity to explore both biotic and abiotic drivers of biodiversity across multiple dimensions. This project will utilize both field and genomic inventories of lichens in a global biodiversity hotspot. The research will generate and synthesize data from multiple symbiotic biodiversity dimensions initiated from a single information source: a unique museum voucher. Across local, regional, and landscape scales, the project will record site-specific metrics for phylogenetic (including taxonomic) and functional diversity together with site-specific metrics for a mostly unexplored genetic dimension, potential of diversity, that quantifies the availability of compatible symbiont propagules in the environment. Analysis of these metrics in light of biotic and abiotic variables enables assessment of factors that impact the dimensions of biodiversity. These analyses will also permit understanding of interactions among dimensions, for example, whether all are positively correlated and predicted by the same sets of variables, or in what contexts other types of correlations exist. This project is designed to yield two major conceptual advances in ecology and evolutionary biology. First, it will reveal new, emergent properties of biodiversity gradients in symbiotic organisms. Second, deconstructing constraints on individual partners of the symbiosis and quantifying feedbacks between and among them will make possible a full analysis, including biotic constraints, of the factors that impact diversity and distribution of the symbiotic organism as a whole.

专性共生是指两个或多个物种之间的关系，它们的生长和生存完全依赖彼此。这种共生关系是地球上一些最常见和最重要的生态关系的特征，从人类肠道细菌和疾病到珊瑚和专门的植物-传粉者关系。然而，由于环境变化的空前速度和生物多样性的永久性丧失，许多这种强制性共生关系受到了威胁。与鸟类、开花植物或哺乳动物等生命之树上的单个分支相比，我们对促进或限制自然中大量的专性共生分布的因素知之甚少。此外，对生物多样性分布的研究主要集中在影响地理分布的非生物因素（如温度、降水、海拔），而不是生物因素（即与其他生物的相互作用）。本项目将作为一个模式系统，揭示影响专性共生地衣多样性和分布的因素。地理焦点是美国东南部的阿巴拉契亚山脉南部-全球地衣多样性热点和独特的自然实验室。此外，该项目将通过学生培训、合作以及与资源管理者和公众的接触，发展美国地衣学的人力资本和基础设施。它将建立一个公开可用的高质量数据集，并改善物理和数字资源，以促进全球生物多样性热点的地衣保护。尽管对产生和维持生物多样性的因素进行了几代人的研究，并提出了理论，但缺乏共识。生物因素长期以来一直被认为是驱动因素，但由于难以评估大量可能的相互作用，它们很少被研究。由于专性共生体之间固有的生物相互作用，地衣为探索生物多样性的生物和非生物驱动因素提供了一个独特的机会。该项目将利用全球生物多样性热点地区地衣的野外和基因组清单。该研究将生成和综合来自多个共生生物多样性维度的数据，这些数据来自单一信息源：一个独特的博物馆代金券。在地方、区域和景观尺度上，该项目将记录特定地点的系统发育（包括分类）和功能多样性指标，以及大多数未开发的遗传维度的特定地点指标，多样性潜力，量化环境中相容共生繁殖体的可用性。根据生物和非生物变量对这些指标进行分析，可以评估影响生物多样性各方面的因素。这些分析还将允许理解维度之间的相互作用，例如，是否所有维度都是正相关的，并由同一组变量预测，或者在什么情况下存在其他类型的相关性。该项目旨在产生生态学和进化生物学的两个主要概念进展。首先，它将揭示共生生物中生物多样性梯度的新特性。其次，解构对共生个体的约束，量化它们之间的反馈，从而全面分析影响共生生物整体多样性和分布的因素，包括生物约束。