Dimensions US–China: Collaborative Research: Consequences of diversity in Asian and American tree syngameons for functional variation, adaptation and symbiont biodiversity

世界上大约有425个橡树物种，即使通过杂交与它们的近亲交换基因，也保持着物种的同一性。这种进化和基因交流的历史塑造了北半球生态系统的生物多样性。橡树在生态上是多样化的，相关物种通常生长在很近的地方，但专门生长在土壤质地和水分水平或自然火灾频率不同的森林景观区域。基因交换可以在橡树物种之间转移这种生态专门化，扩大它们的范围和应对气候变化的能力。这些基因交换的影响可能会超出橡树本身。据估计，全世界有1000种五倍子黄蜂和高度多样化的真菌群落，这些真菌与它们的根(作为菌根)和叶内(作为内生菌)有关。通过配对的实地调查和常见的花园实验，PI将评估杂交和导入对美国和中国的局部橡树物种及其共生体的遗传、系统发育和功能多样性的影响。这项工作还将提供基于探究的K-12、本科和研究生教育；通过橡树物候学社区科学倡议向公众提供关键的自然史培训；以及将向公众带来研究的出版物。两个跨学科的研究团队，一个在美国，一个在中国，将调查橡树的基因组、功能和系统发育多样性如何塑造与它们相关的菌根真菌、内生真菌、五倍子和其他昆虫群落。研究将集中在两个相关的杂交物种群体：美国的橡树和近亲，以及中国的宝丽和近亲。该项目有三个目标，每个目标分别在中国和美国并行进行。在目标1中，两个团队将对自然种群进行范围广泛的系统发育调查，以重建基因组马赛克，描述叶片功能性状的地理模式，并表征相关菌根真菌、叶片内生真菌和五倍子的功能和系统发育多样性。在目标2中，将跨气候梯度种植普通园林，以评估遗传变异和种群分化对不同气候条件下栎树功能和光谱特性以及相对适合度的影响，以及这些因素如何影响与栎树相关的真菌和昆虫群落的系统发育和功能多样性。在目标3中，研究小组将使用第二套常见的花园实验来评估植物群落和系统发育多样性如何影响局部橡树物种的遗传、系统发育和功能多样性。该项目将提供一个综合的视角，了解物种内和物种间的橡树多样性如何影响北半球以橡树为主的生态系统的广泛多样性。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。

The world’s approximately 425 oak species maintain species identity even while exchanging genes with their close relatives through hybridization. This history of evolution and genetic exchange has shaped the biodiversity of northern hemisphere ecosystems. Oaks are ecologically diverse, with related species often growing in close proximity but specializing on areas of the forest landscape that differ in soil texture and moisture level or in the frequency of natural fires. Gene exchange can move such ecological specializations between oak species, broadening their ranges and ability to respond to climate change. The impacts of these genetic exchanges may extend beyond the oaks themselves. Oaks host an estimated 1000 gall wasp species worldwide and highly diverse communities of fungi associated with their roots (as mycorrhizae) and inside their leaves (as endophytes). Using paired field surveys and common garden experiments the PIs will evaluate the effects of hybridization and introgression on the genetic, phylogenetic, and functional diversity of focal oak species and their symbionts in the US and China. This work will also provide inquiry-based K-12, undergraduate, and graduate education; critical natural history training to the public through a community-science initiative in oak phenology; and publications that will bring research to public audiences.Two interdisciplinary teams of researchers, one based in the US and one in China, will investigate how genomic, functional, and phylogenetic diversity of oak trees shape the mycorrhizal fungi, endophytic fungi, and gall wasp and other insect communities that associate with them. Research will focus on two related groups of interbreeding species: bur oak (Quercus macrocarpa) and relatives in the US and bao li (Quercus serrata) and relatives in China. The project has three objectives, each conducted in parallel in China and the U.S. In Objective 1 the teams will perform range-wide phylogenomic surveys of natural populations to reconstruct genomic mosaics, characterize geographic patterns of leaf functional traits, and characterize functional and phylogenetic diversity of associated mycorrhizal fungi, leaf endophytic fungi, and gall wasps. In Objective 2 common gardens will be planted across climatic gradients to evaluate the effects of genetic variation and population differentiation on oak functional and spectral traits and relative fitness in different climates, and how these influence the phylogenetic and functional diversity of oak-associated fungal and insect communities. In Objective 3 the teams will use a second set of common garden experiments to evaluate how plant community and phylogenetic diversity affects focal oak species genetic, phylogenetic, and functional diversity. The project will provide an integrative perspective on how oak diversity within and among species impacts the broad diversity of oak-dominated ecosystems across the northern hemisphere.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.