Uniting demographic life history theory and pollination biology to understand the ecological consequences of pollinator declines

在世界各地，传粉者正在减少。鉴于近90%的开花植物依赖动物授粉，人们担心许多植物将与它们的传粉者一起濒临灭绝。授粉很重要，因为它确保植物能够结出种子，长成新的植物，并维持物种的生存。然而，有很多理由认为，植物数量下降和传粉者数量下降之间的联系并不那么简单。例如，尽管当周围的传粉者较少时，植物会产生较少的种子是有道理的，但如果新植物竞争生存的地方，种子较少并不一定意味着新植物较少。较少的种子实际上可能会导致新植物之间的竞争减少，从而使更多的植物得以生存。此外，植物可能会使用其他不是专门用来制造种子的资源来生长更大、存活更长时间，因此在他们的一生中有更多的机会繁殖。这些例子说明，尽管产生的种子较少，但可以培育出足够的新植物来维持物种的生存。一个更大的教训是，生态是复杂的；各种隐藏的策略在你仔细观察之前是不明显的。该项目将跟踪数千种植物的命运，这些植物暴露在不同数量的传粉者面前，从而帮助科学家识别最有可能受到传粉者衰退影响的植物物种，并了解为什么其他植物处于或不处于危险之中。除了数据收集，参与该项目的科学家还将帮助培训下一代生态学家，并将通过教育电影、博客和永久互动展览来吸引公众。基于个体的种群模型(积分投影模型)将用来自田间试验的数据进行参数化，在该试验中，5种多年生植物接受不同的授粉处理：(I)增加授粉，(Ii)减少授粉，(Iii)年度间可变授粉，和(Iv)未经处理的对照。所有植物都将被贴上唯一的识别号，并每年对其人口状况进行评估。另外的萌发实验将被用来通过密度依赖的萌发和幼苗存活来确定授粉对招募的影响。种群模型的预测将显示授粉对植物种群动态的影响。最后，生命表响应实验将阐明授粉影响或不影响植物种群增长率的特定生活史机制(例如，通过生长和繁殖之间的权衡)。该项目将提供必要的经验证据，以弥合传粉生物学、生活史理论和种群动态之间的概念差距，并为理解和预测传粉者减少的生态后果提供一个框架。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。

Around the world, pollinators are in decline. Given that almost 90% of flowering plants rely on animal pollination, there is concern that many plants will decline towards extinction alongside their pollinators. Pollination is important because it ensures that plants can make seeds, grow into new plants and keep the species going. Yet, there are many reasons to think that the link between declining numbers of plants and declining numbers of pollinators is not so simple. For example, although it makes sense that a plant would make fewer seeds when there are fewer pollinators around, fewer seeds do not necessarily mean fewer new plants if, for example, the new plants compete for places to live. Fewer seeds could actually result in less competition among new plants, allowing more of them to survive. Furthermore, plants may use other resources not devoted to making seeds to grow larger and survive longer, thus having more chances to reproduce within their lifetime. These examples illustrate how, despite making fewer seeds, enough new plants could be made to keep the species going. A bigger lesson is that ecology is complex; all sorts of hidden strategies are not apparent until you take a closer look. This project will follow the fates of thousands of plants that are exposed to different numbers of pollinators, thereby helping scientists to identify plant species most at risk from pollinator declines and to understand why others are or are not at risk. In addition to data collection, the scientists on this project will help train the next generation of ecologists and will engage the public through an educational film, a blog, and a permanent interactive exhibit. Individual-based population models (integral projection models) will be parameterized with data from a field experiment in which five species of perennial plants receive different pollination treatments: (i) increased pollination, (ii) reduced pollination, (iii) interannually variable pollination, and (iv) an unmanipulated control. All plants will be tagged with a unique identification number and their demographic status assessed annually. Additional germination experiments will be used to parameterize the effect of pollination on recruitment through density-dependent germination and seedling survival. Projections of the population models will show the consequences of pollination for plant population dynamics. Finally, life table response experiments will elucidate specific life history mechanisms by which pollination does or does not affect plant population growth rates (e.g., via trade-offs between growth and reproduction). This project will provide the empirical evidence necessary to bridge conceptual gaps among pollination biology, life history theory, and population dynamics, as well as providing a framework for understanding and predicting the ecological consequences of pollinator declines.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.