Understanding changes in a plant-pollinator network over a century of global change

缺乏跨越数十年的长期研究并记录这些变化，阻碍了理解人类对生物多样性的影响。这类研究非常罕见，因为它们难以维持，而且往往需要几十年的时间才能得出长期发生的全球变化的见解。可以重复记录过去生态条件的研究的历史数据集，以更好地了解人类对生物多样性的影响。像授粉这样的互惠关系支持着大量的生物多样性，并且被认为在面对环境变化时特别容易受到破坏。我们依靠传粉媒介来提供生态系统服务。该项目将通过对Clements和Long（1923）进行的一项关于群落范围内植物-传粉者相互作用的百年经典研究的数据重新采样，评估不同植物-传粉者网络的长期变化。有影响力的生态学家弗雷德里克·e·克莱门茨和他的同事弗朗西丝·l·朗从1910年开始，仔细记录了美国科罗拉多州派克峰地区多种植物和传粉媒介之间的相互作用。克莱门茨和朗的研究是特别的，因为它的详细数据的丰富性超越了物种的发生，包括观察植物与传粉者的相互作用，物候（日期）和传粉者的访问率。克莱门茨和朗研究的栖息地被保留了下来，使该项目的研究人员能够评估全球变化的作用，这些变化具有不确定的影响，如潜在的昆虫减少和气候引起的物候不匹配（与广泛的栖息地丧失和破碎化等影响相比，这些影响具有巨大的、有充分记录的影响）。该项目将提供培训和吸引学生的机会。这项工作的发现将以各种方式传播给广泛的受众，包括当地的K-12户外解说节目、博物馆展览、向公众和管理人员介绍以及网络视频，以广泛传播这项工作。该项目将通过提供一个难得的机会来了解相互作用网络在一个世纪的时间尺度上是如何变化的，从而促进对生物多样性变化和生态网络的认识。这项工作将确定植物-传粉者网络的组成和结构是如何变化的，以及是否有证据表明物候变化和传粉者减少，这反过来可以解释相互作用的变化。本项目的研究问题是：(1)赏花游客的丰度和丰富度在历史和当代数据集之间是如何变化的？（2a）植物、传粉者及其相互作用的时间（物候学）在历史和当代数据集之间是如何变化的；（2b）植物和传粉者物候重叠的变化是否预示着相互作用的丧失？(3)派克峰植物-传粉者网络的结构和组成在历史和当代之间发生了怎样的变化？只有另一项研究在可比的时间尺度上考察了植物传粉者网络的长期变化，而且是在高度改变的、人类主导的景观中进行的。它记录了传粉媒介物种的减少和网络的解体，表明物种进一步丧失的易感性增加。然而，未被破坏和破碎的生境的长期变化及其后果仍然不确定。这种不确定性引发了关于昆虫是否在自然生态系统中大规模减少的争论。这项工作将为这场辩论提供信息，并解释生物多样性变化的原因和后果。此外，它将研究生态网络的时空维度，这是该领域一个新兴的话题。该奖项反映了美国国家科学基金会的法定使命，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。

Understanding human impacts on biodiversity is hindered by a lack of long-term studies spanning decades and documenting these changes. Such studies are so rare because they are difficult to maintain and because they often take decades to yield insights about global changes that occur over long time spans. Historical datasets from studies documenting past ecological conditions can be repeated to better understand human impacts on biodiversity. Mutualisms like pollination support a great deal of biodiversity and are thought to be particularly susceptible to disruption in the face of environmental change. We depend on pollinators for the ecosystem services they provide. This project will evaluate the long-term change in a diverse plant-pollinator network by re-sampling data from a century-old classic study on community-wide plant-pollinator interactions conducted by Clements and Long (1923). The influential ecologist, Frederic E. Clements, and his protégée, Frances L. Long, carefully documented interactions between a diverse assemblage of plants and pollinators in the region of Pikes Peak, CO, USA, starting in 1910. Clements and Long’s study is special due to the richness of its detailed data which go beyond species occurrences and include observations of plant-pollinator interactions, phenology (dates), and pollinator visitation rates. The habitat of the Clements and Long study has been preserved, allowing researchers in this project to assess the roles of global changes with uncertain impacts such as potential insect declines and climate-induced phenological mismatches (compared to impacts like extensive habitat loss and fragmentation which have large, well-documented impacts). The project will provide opportunities to train and engage students. Findings from this work will be disseminated to broad audiences in various ways which include local K-12 interpretive outdoor programs, museum exhibits, presentations to the general public and managers, and web video to disseminate this work widely. This project will advance knowledge of biodiversity change and ecological networks by providing a rare opportunity to understand of how interaction networks change over the temporal scale of a century. This work will determine how the composition and structure of the plant-pollinator network has changed and whether there is evidence for changes in phenology and pollinator declines, which could in turn explain changes in interactions. The research questions in this project are: (1) How has the abundance and richness of flower visitors changed between historical and contemporary datasets? (2a) How has the timing (phenology) of plants, pollinators and their interactions changed between historical and contemporary datasets; (2b) and do shifts in phenological overlap of plants and pollinators predict interaction loss? (3) How have the structure and composition plant-pollinator networks on Pikes Peak changed between historical and contemporary times? Only one other study examined long-term changes in plant-pollinator networks at comparable time scales and it has done so in highly modified, human-dominated landscapes. It recorded declines in pollinator species and disassembly of networks indicating increased susceptibility to further species loss. However, the long-term changes and their consequences in habitats that have not been destroyed and fragmented remains uncertain. This uncertainty has led to debate about whether wholesale insect declines have occurred in natural ecosystems. This work will inform that debate and explain the causes and consequences of biodiversity change. Additionally, it will examine spatiotemporal dimensions of ecological networks, a burgeoning topic in the field.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.