BEE: Consequences of phenotypic plasticity for gene-to-ecosystem linkages: Multi-stress experiments across the climatic range of a foundation species

预测生态系统将如何应对环境变化是环境科学家面临的重大挑战。一种策略是专注于在其生态系统中发挥最关键作用的生物的特征(特征)。沿着河流，重要的树种，如棉杨，为广泛的其他物种提供荫凉、栖息地和食物。许多种类的昆虫以落入河里的树叶和垃圾为食。树叶的特性影响到这些昆虫的生存，进而影响到食物链上游的鸟类和鱼类。过去的研究表明，树叶的大小和化学成分等叶子特征在一定程度上是由树的基因决定的。然而，随着环境的变化，这些特征会发生什么，我们知之甚少。使用来自亚利桑那州各地的弗里蒙特白杨树，这项研究将评估树木如何进化来耐受过去的环境压力，包括不断变化的温度和昆虫的攻击。这些关于一棵树的压力历史的信息将被用来预测它在未来的环境压力下将扮演的角色。研究结果将有助于确定应该种植的树木类型，以支持健康的生态系统，从而帮助整个西南部正在进行的河流恢复项目。基础物种内的遗传变异是功能特征多样性的主要来源，这反过来又塑造了群落结构和生态系统过程。然而，当暴露在环境变化中时，不同的基因类型可能表现出不同的特性值。这种表型可塑性在不同的基因型之间可能不同，这是对气候变异性或食草动物活动的进化反应，产生了基因×环境(G×E)的交互作用。这项研究将检验这样一种假设，即了解当地适应的基因型的可塑性进化将加强对广泛景观尺度上遗传变异影响的预测。首先，这项研究将使用现有的三个普通花园来调查西南树种的不同基因如何在炎热和寒冷的条件下表达不同的叶片特征。在所有花园中，将使用草食动物损害的实验操作来调查非生物和生物胁迫对多种叶片性状的交互影响。其次，该项目将测试如何根据每个基因型所在地区过去的环境变化来预测性状的变异。最后，将利用落叶移植实验和调查来量化树叶特征变化对依赖这些树的整个陆生和水生昆虫群落的影响。研究物种范围内表型可塑性的进化原因和生态后果之间的反馈应该会极大地提高我们预测快速变化的景观中生态系统可持续性的能力。这一奖项反映了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。

Predicting how ecosystems will respond to environmental change is a major challenge for environmental scientists. One strategy is to focus on the traits (characteristics) of organisms that play the most critical roles in their ecosystems. Along rivers, key tree species such as cottonwoods provide shade, habitat, and food for a wide range of other species. Many types of insects feed on the leaves and on the litter that falls in the river. The traits of the leaves impact the survival of these insects, which then impacts birds and fish higher up the food chain. Past research shows that leaf traits like leaf size and chemistry are partly determined by a tree's genes. However, little is known about what will happen to these traits as the environment changes. Using Fremont cottonwood trees from across Arizona, this research will assess how trees have evolved to tolerate environmental stresses in the past, including both changing temperatures and attacks from insects. This information about a tree's history of stress will then be used to predict the role it will play under future environmental stress. The results will aid ongoing river restoration projects across the Southwest by helping identify the types of trees that should be planted to support healthy ecosystems.Genetic variation within foundation species is a major source of diversity in functional traits, which in turn shape community structure and ecosystem processes. However, individual genotypes may express different trait values when exposed to environmental change. This phenotypic plasticity can differ among genotypes as an evolved response to climatic variability or herbivore activity, producing genotype x environment (G x E) interactions. This research will test the hypothesis that understanding the evolution of plasticity in locally adapted genotypes will enhance prediction of the impacts of genetic variation at a broad landscape scale. First, the research will use three existing common gardens to investigate how genotypes of a southwestern tree species express different leaf traits in hot vs. cold conditions. Across all gardens, experimental manipulation of herbivore damage will be used to investigate interactive effects of abiotic and biotic stress on multiple leaf traits. Second, the project will test how variation in traits can be predicted from past variation in the environment at each genotype's home location. Finally, litter transplant experiments and surveys will be used to quantify the impacts of changing leaf traits on whole communities of terrestrial and aquatic insects dependent on these trees. Investigating feedbacks between the evolutionary causes and ecological consequences of phenotypic plasticity across a species' range should greatly improve our ability to predict ecosystem persistence across a rapidly changing landscape.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.