SG: Broadening biodiversity-ecosystem functioning research to include mutualist networks

地球正在迅速失去生物多样性。这种生物多样性丧失对人类所依赖的生态系统功能（如水过滤、碳储存和授粉）的影响尚不清楚。在简化生态群落的实验中，生态系统的功能可以由少数物种维持。然而，生物多样性在自然界中可能更为重要，因为那里的生态群落更为复杂。这种复杂性的一个方面是，在自然界中，大多数物种都依赖于与其他物种的有益互动，或互利关系。例如，开花植物需要蜜蜂等动物为它们授粉，传粉者需要开花植物作为食物来源（花蜜和花粉）。然而，迄今为止，这些互利互动的网络在很大程度上被排除在生物多样性对生态系统功能的重要性的研究之外。因此，目前对生态系统功能将如何随着生物多样性丧失而变化的预测可能过于简单化。除了解决一个关键的保护问题外，拟议的工作将有助于培训STEM劳动力。该研究项目将把互利共生纳入生物多样性和生态系统功能的研究，使用本地蜜蜂物种和它们为野生植物提供的授粉作为模型系统。PI将使用其研究小组成员在美国大西洋中部收集的数据。总的来说，数据包括500个物种的116，000个个体传粉者和339个植物物种。在49个植物传粉者网络中，PI将首先确定哪些蜜蜂物种是每个植物物种最重要的传粉者。然后，她将评估至少一种植物授粉所需的蜜蜂物种数量如何随着所考虑的植物物种数量的增加而增加。因此，该项目将揭示，当包括整个互利网络，而不是只有一个或几个目标物种时，生物多样性对生态系统功能的重要性如何增加。假设蜜蜂和植物物种之间的随机相互作用的随机模型将用于将由于随机效应而导致的这种增加的成分与由于生物学而导致的成分分开。将通过比较49个网络的结果来寻求普遍性。该项目的一个明确目标是探索稀有物种在生态系统功能中的作用。以前的研究集中在传递给一个或几个物种的功能，往往发现稀有物种并不重要。 然而，在整个群落中罕见的蜜蜂物种仍然可能是特定植物的重要授粉者，这使得稀有物种对整个网络的功能非常重要。这项工作的成果将拓宽我们对生物多样性及其在复杂自然世界中对生态系统功能的重要性的理解。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The earth is rapidly losing its biodiversity. The consequences of this biodiversity loss for ecosystem functions that humanity relies on, such as water filtration, carbon storage, and pollination, are not well understood. In experiments done with simplified ecological communities, ecosystem functions can be maintained by a small number of species. However, biodiversity may be more important in nature, where ecological communities are more complex. One aspect of this complexity is that in nature, most species rely on beneficial interactions with other species, or mutualisms. For example, flowering plants need animals such as bees to pollinate them, and pollinators require flowering plants as a source of food (nectar and pollen). Yet to date, these networks of mutualist interactions have largely been left out of research on the importance of biodiversity for ecosystem functioning. Thus, the current predictions for how ecosystem functions will change with biodiversity loss might be overly simplistic. In addition to addressing an issue of critical conservation concern, the proposed work will contribute to training the STEM workforce. This research project will bring mutualism into the study of biodiversity and ecosystem function, using native bee species and the pollination they provide to wild plants as a model system. The PI will use data already collected by members of her research group in the Mid-Atlantic USA. In total, the data include 116,000 individual pollinators of 500 species, and 339 plant species. Within each of 49 plant-pollinator networks, the PI will first determine which bee species are the most important pollinators of each plant species. She will then assess how the number of bee species that are needed for the pollination of at least one plant species increases with the number of plant species considered. Thus, the project will reveal how the importance of biodiversity to ecosystem function increases when entire mutualist networks, as opposed to only one or a few target species, are included. Null models that assume random interactions among bee and plant species will be used to separate the components of this increase that are due to stochastic effects from those that are due to biology. Generalities will be sought by comparing results across the 49 networks. An explicit goal of the project is to explore the role of rare species in ecosystem function. Previous studies focused on the function delivered to one or a few species often find that rare species are not important. However, a bee species that is rare in the overall community might still be an important pollinator of a particular plant, making rare species important to the functioning of the network as a whole. The results of this work will broaden our understanding of biodiversity and its importance to ecosystem functioning in the complex natural world.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.