CAREER: Using a multilayer plant-pollinator and fruit-frugivore network along a defaunation gradient to understand the combined influence of mutualisms on forest communities

植物需要授粉和种子传播才能再生，而许多物种依靠动物来完成这两个过程。大约90%的植物是动物授粉的，75%-90%的热带森林树木是动物传粉的。然而，尽管入侵物种、栖息地退化和过度捕捞等全球变化驱动因素对动物有广泛的影响，但研究往往孤立地关注这两个相互作用。然后，这些影响可能会级联，影响植物的授粉和传播。该项目确定了西太平洋马里亚纳群岛天然石灰岩森林中的植物-传粉者和植物-种子传播者之间的相互作用。该项目将测试授粉和种子传播的联合考虑是否会改善对哪些植物物种最依赖动物以及哪些动物最关键的预测。此外，这项研究利用了岛屿上的违约梯度，范围从基本完好的动物群落到极度退化的群落。这种梯度使研究人员能够将动物灭绝对植物的预测影响与植物群落的实际变化进行比较。这些结果将对指导传粉者和传播者物种减少的地区的保护和恢复行动具有重要意义。最后，首席研究员将为太平洋岛民本科生和研究生、高中教师和研究生技术员建立一个指导网络，在马里亚纳群岛开发一个高中科学模块和课后方案，并与群岛的土地管理人员分享科学成果，为管理决策提供信息。该项目以元生物编码方法和多层物种相互作用网络方法的最新发展为基础，这些方法有助于在群落一级对物种相互作用进行抽样，以确定单个物种在相互作用类型(即授粉和种子传播)中的作用。研究小组将采集无脊椎动物和脊椎动物传粉者的花粉，并观察传粉者对西太平洋塞班岛(动物群完好无损)、罗塔岛(部分缺省)和关岛(缺省)上15种常见森林树种的访问情况。研究人员将进行授粉实验，以确定每种植物对传粉者的依赖程度，并使用稳定的同位素来确定传粉者对植物的依赖程度。植物传粉者网络将与同一森林社区的水果食果者网络进行比较，该网络使用之前收集的数据汇编而成。使用这两个网络，研究人员将比较物种在这两种相互作用类型中的角色，并确定沿着违约梯度的变化。最后，这两个网络将被合并为一个多层网络，以确定仅当同时考虑多种交互类型时才会出现的模式。这些结果将增进对人口减少和灭绝对森林社区的影响的了解，并为马里亚纳群岛的恢复提供可行的建议。该项目由环境生物学/人口和社区生态学部门和既定的激励竞争研究计划(EPSCoR)共同资助。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Plants require pollination and seed dispersal for regeneration, and many species rely on animals for both of these processes. Approximately 90% of plants are animal-pollinated, and 75-90% of tropical forest trees are animal-dispersed. However, research often focuses on these two interactions in isolation, even though global change drivers like invasive species, habitat degradation, and overharvesting have broad effects on animals. These effects could then cascade to affect pollination and dispersal of plants. This project identifies the plant-pollinator and plant-seed disperser interactions in native limestone forest of the Mariana Islands in the Western Pacific. The project will test whether joint consideration of pollination and seed dispersal improves predictions of which plant species are most dependent on animals and which animals are most critical. In addition, the research takes advantage of a defaunation gradient across the islands, ranging from a mostly intact animal community to an extremely degraded community. This gradient allows researcher to compare predicted impacts on plants of animal extinction to actual changes in plant communities. These results will be important for guiding conservation and restoration actions in areas where pollinator and disperser species are in decline. Finally, the lead researcher will build a mentoring network for Pacific Islander undergraduate and graduate students, high school teachers, and postgraduate technicians, develop a high school science module and after-school program in the Mariana Islands, and share scientific results with land managers in the Islands to inform management decisions. The project builds on the recent development of metabarcoding methods, which facilitate sampling of species interactions at the community-level, and multilayer species interaction network approaches, to identify the role of individual species across interaction types (i.e. pollination and seed dispersal). The research team will sample pollen from invertebrate and vertebrate pollinators and make observations of pollinator visitation to 15 common forest tree species on the islands of Saipan (fauna intact), Rota (partially defaunated), and Guam (defaunated) in the Western Pacific. The researchers will conduct a pollination experiment to determine how much each plant species depends on pollinators, and use stable isotopes to determine how much pollinators depend on plants. The plant-pollinator network will be compared to a fruit-frugivore network for the same forest communities compiled using previously collected data. Using these two networks, the researcher will compare species' roles across these two interaction types and identify changes along the defaunation gradient. Finally, both networks will be combined into a single multilayer network to identify patterns that emerge only when multiple interaction types are considered simultaneously. These results will advance understanding of the impact of population declines and extinctions on forest communities, and provide actionable recommendations for restoration in the Mariana Islands. This project is jointly funded by the Division of Environmental Biology/Population and Community Ecology program and the Established Program to Stimulate Competitive Research (EPSCoR).This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.