ORCC: Determining the synergistic effects of global warming on tropical insect herbivore fundamental vital rates, fitness, and predation

预测生物体对新温度的反应仍然是生态学中主要的概念挑战之一。由于地球上的所有生物都面临着快速变化的气候，确定在新温度环境中种群持续存在或灭绝的原理也是一个紧迫的保护问题。面临灭绝的一类生物是热带昆虫。目前的灭绝模型是基于生理反应，总是高估热耐受性。为了更准确地估计生物对未来温度的反应，这项研究将确定温度对昆虫生存、繁殖力和种群增长或下降速度的影响。利用一组在热带雨林中被充分研究过的食草昆虫，这项拟议的研究将确定饮食和温度对具有通用性和专用性饮食的昆虫种群增长的协同效应。这个项目的一个更雄心勃勃的目标是确定全球变暖通过与捕食者和拟寄生物的相互作用对食草昆虫适应性的间接影响。这项研究将提高我们对全球变暖如何通过破坏生命网络中生物之间的联系而间接影响种群的认识。这个项目更广泛的影响是两个在线教育模块的概念和发现的整合。这些模块将在该领域的研讨会上使用，本科生将学习与估计生物对全球变暖的反应有关的概念和探索方法。尽管灭绝是一个人口统计过程，但我们对全球变暖对昆虫生存、寿命、繁殖力和适应性的直接影响的了解非常有限。一个额外的复杂性是，变暖很可能会同时影响捕食者和拟寄生物的数量和组成。香蕉状植物——香蕉目植物的幼叶形成卷叶栖息地，被头足属（金虫科：鞘翅目）的食草动物及其相关的捕食者和拟寄生物占据。本研究的重点是气候变暖对与青叶虫相关的多面手和专门手食草动物适应能力的直接和间接影响。通过对十种昆虫的实验人口统计学方法，本研究将确定通才食草动物是否比专门性食草动物更能适应变暖。如果这种情况是真的，昆虫群落将由多面手物种主导。野外的加热实验将确定食肉动物是否比猎物更不能忍受温度的升高，以及变暖是否会为食草动物创造敌人的自由空间。如果变暖减少了猎物的数量，就会产生营养级联。人口统计学模型将综合考虑温度和饮食对基本生存率的影响，以及捕食对每种食草动物种群增长的影响。这项研究解决了全球变暖最不为人所知的影响之一：生物相互作用在生物体对气候变化的反应中的作用。由此产生的模型将提高我们的预测能力，以确定在何种温度下昆虫种群将达到灭绝的临界点。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。

Predicting how organisms will respond to novel temperatures remains one of the main conceptual challenges in ecology. Identifying the principles involved in population persistence or extinction in novel temperature environments is also an urgent conservation issue, as all organisms on earth are facing rapidly changing climates. One group of organisms facing extinctions are tropical insects. Current extinction models are based on physiological responses, which invariably overestimate thermal tolerance. To more accurately estimate organismal responses to future temperatures, this study will determine the effects of temperature on insect survival, fecundity, and the speed at which populations will grow or decline. Using a well-studied group of insect herbivores in a tropical rain forest, this proposed research will determine the synergistic effects of diet and temperature on population growth in insects with generalist and specialist diets. An even more ambitious goal of this project is to determine the indirect effects of global warming on insect herbivore fitness through interactions with predators and parasitoids. This study will improve our knowledge on how global warming will indirectly affect populations by disrupting the connections among organisms in the web of life. A broader impact of this project is the integration of concepts and discoveries in two online educational modules. These modules will be used during workshops in the field, where undergraduate students will learn concepts and explore methodologies related to the estimation of biotic responses to global warming.Despite the fact that extinction is a demographic process, our understanding of the direct consequences of global warming on insect survival, longevity, fecundity, and fitness is extremely limited. An additional complexity is that warming most likely will concomitantly affect the abundance and composition of predators and parasitoids. Young leaves of plants in the order Zingiberales – the banana-like plants – form rolled-leaf habitats, which are colonized by herbivores in the genus Cephaloleia (Chrysomelidae: Coleoptera) and their associated predators and parasitoids. This research focuses on the direct and indirect effects of warming on fitness in generalist and specialist Cephaloleia herbivores associated with Zingiberales. Using an experimental demography approach for ten insect species, this study will determine if generalist herbivores are more resilient to warming than specialists. If this scenario is true, insect communities will become dominated by generalist species. Heating experiments in the field will determine if predators are less tolerant to increasing temperatures than their prey, and if warming will generate enemy free space for herbivores. If warming reduces prey abundance, warming will generate trophic cascades. Demographic models will integrate the effects of temperature and diet on fundamental vital rates, and the effect of predation on population growth for each herbivore species. This study addresses one of the least understood effects of global warming: the role of biotic interactions in organismal responses to climate change. The resulting models will increase our predictive power to determine at which temperatures insect populations will reach tipping points to extinction.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.