Context-Dependency of Marine Biodiversity-Ecosystem Function Relationships

由于物种调节关键的生物地球化学过程并发挥独特的生态作用，生态系统中物种多样性和组成的变化可以改变该系统的功能。越来越多的工作表明，生物多样性的变化可以对海洋生态系统的功能产生深远影响。然而，在海洋生物多样性和生态系统功能之间的关系方面，仍然存在一些关键的悬而未决的问题。特别是，很少有研究评估生产者多样性和食草动物多样性之间的相互作用，特别是在野外。此外，绝大多数实验只在一个地点评估了生物多样性变化的后果，因此对环境背景如何改变多样性与功能的关系知之甚少。这项研究将在实地考察环境背景如何塑造海洋多样性-功能关系，特别是在横跨新英格兰海岸线500公里的三个地点的潮间带生态系统消费者和生产者多样性变化之间的相互作用。这些析因实验将操纵马萨诸塞州东点、缅因州张伯伦点和缅因州Quoddy Head的海藻和食草动物多样性。本研究提出以下问题：1)海藻多样性如何影响初级和次生生产力等关键海洋生态系统过程？2)草食动物多样性如何影响软体动物食草动物对潮间带海藻群落的自上而下的影响？3)在驱动潮间带群落和生态系统结构和功能方面，食草动物和海藻多样性之间的反馈是什么？4)环境背景如何改变生物多样性变化对潮间带生态系统功能的自上而下和自下而上的影响？本研究将通过考虑两个相邻营养层的多样性变化之间的反馈，对海洋生态学做出重要的智力贡献。这项工作将在多个地点进行，这些地点跨越各种近岸海洋和气候条件，增强了工作的一般性，并能够评估环境背景对多样性--功能关系的影响。生物多样性在各个尺度上都在发生变化，从局部到全球，必须了解这些变化的后果，以便更好地预测和改善其对社区和生态系统的影响。这项研究将对多样性、营养相互作用和生态系统功能之间的联系提供更全面的了解，从而促进海洋和其他生态系统更有效的养护和管理战略。它将为所有教育水平的学生提供培训和研究经验。调查人员将让研究生和本科生参与研究的所有阶段，并将每年为海岸海洋科学学院(COSA)的一名高中生提供暑期研究实习机会，由东北大学海洋科学中心的外联工作人员授课。COSA学生主要来自大波士顿地区代表性不足的群体。最后，研究结果将通过中心的外展和公共教育计划向公众传播。

Because species mediate key biogeochemical processes and play unique ecological roles, changes in the diversity and composition of species in an ecosystem can alter how that system functions. A growing body of work has demonstrated that changes in biodiversity can have profound effects on the functioning of marine ecosystems. However, key unresolved issues remain with respect to relationships between marine biodiversity and ecosystem functioning. In particular, few studies have evaluated interactions between producer diversity and herbivore diversity, especially in the field. Furthermore, the vast majority of experiments have evaluated the consequences of biodiversity changes at only one location, so there is very little knowledge of how diversity-function relationships are modified by environmental context. This study will examine, in the field, how environmental context shapes marine diversity-function relationships and particularly the interaction between changes in consumer and producer diversity in intertidal ecosystems at three sites spanning 500 km of the New England coastline. These factorial experiments will manipulate seaweed and grazer diversity at East Point, Massachusetts; Chamberlain Point, Maine; and Quoddy Head, Maine. The research asks the following questions: 1) How does seaweed diversity influence key marine ecosystem processes such as primary and secondary productivity? 2) How does herbivore diversity affect the top-down impacts of molluscan grazers on intertidal seaweed assemblages? 3) What are the feedbacks between grazer and seaweed diversity in driving intertidal community and ecosystem structure and function? And 4) How does environmental context modify the top-down and bottom-up effects of biodiversity change on intertidal ecosystem functioning?This study will make important intellectual contributions to marine ecology by considering feedbacks between diversity change at two adjacent trophic levels. The work will be conducted at multiple sites which span a range of nearshore oceanographic and climatic conditions, enhancing the generality of the work and allowing for evaluation of the effects of environmental context on diversity-function relationships. Biodiversity is changing at all scales, from local to global, and it is essential to understand the consequences of these changes in order to better predict and ameliorate their impacts on communities and ecosystems. This research will provide a more holistic understanding of the links between diversity, trophic interactions and ecosystem function that will facilitate more effective conservation and management strategies in marine, as well as other, ecosystems. It will provide training and research experience for students at all educational levels. The investigators will involve graduate and undergraduate students in all phases of the research and will also offer a summer research internship each year to a high school student from the Coastal Ocean Science Academy (COSA) that is taught by the Northeastern University Marine Science Center's Outreach staff. COSA students are primarily from under-represented groups in the greater Boston area. Finally, the results of the research will be communicated to the public through the outreach and public education program at the Center.