CAREER: Coffee fungi below and aboveground: agroecological experiments for teaching and learning about fungal diversity and ecosystem function

人类依靠生物多样性，即地球上生命的多样性来维持生计和生存，然而，我们目前对地球自然资源的管理已经导致许多不同类型的生物多样性迅速丧失。由于农业是造成生物多样性丧失的最大因素，因此迫切需要清楚地了解不同农业做法对生物多样性丧失的相对重要性。真菌发挥着至关重要的作用，作为分解者，加速营养物质返回到作物可以利用的形式，作为引起植物疾病的病原体，作为生活在植物内并保护它们免受害虫和病原体侵害的有益内生菌，以及作为分枝寄生虫，真菌以其他真菌为食并减少其危害作物的潜力。目前对农业实践对这些不同真菌类群生物多样性的影响以及真菌生物多样性的变化如何改变真菌的关键功能知之甚少。这项研究将确定遮荫、氮肥和杀菌剂对咖啡真菌生物多样性丧失的相对重要性，咖啡是一种对全球经济以及对美国咖啡生产商、加工商、供应商和消费者至关重要的作物。它将研究真菌生物多样性对真菌在农业生态系统中的关键功能的重要性，特别是真菌多样性在减少作物病害和改善作物养分循环中的作用。该项目将提供高影响力的跨文化研究机会，培训美国本科生和研究生在国际环境中作为科学家有效地工作，并传播两个教育模块，以提高本科生物学课程的具体学习成果。在过去的30年里，生物多样性生态系统功能（BEF）的研究已经清楚地证明了多样性对生态系统功能的重要性，但真菌仍然存在严重的空白。真菌群落高度多样化，它们的非生物和生物相互作用往往是神秘而复杂的，真菌多样性对关键生态系统过程的重要性，如分解和疾病调节，仍有待确定。咖啡是研究真菌多样性丧失及其对生态系统功能影响的理想生态系统，因为咖啡资源随遮荫和施肥水平而变化，而杀菌剂会抑制真菌多样性。本项目将1)结合真菌元条形码的两个操作田间实验，确定遮荫、无机氮、杀菌剂和凋落叶多样性在真菌群落结构和功能多样性中的相对重要性；b)测量真菌群落功能多样性差异对生态系统功能的影响；2)使用基于培养的技术来鉴定目前未描述的真菌，将形态与DNA条形码联系起来，并筛选分离的功能基团。该奖项将促进对真菌多样性在生态系统功能中的作用的理解，特别是多样性对分解速率和植物疾病发病率和严重程度的影响。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。

Humans depend on biodiversity, the diversity of life on Earth, for our sustenance and survival, yet our current management of Earth’s natural resources has generated rapid losses of biodiversity across many different types of living organisms. Because agriculture is the largest contributor to this loss, a clear understanding of the relative importance of different agricultural practices to biodiversity loss is urgently needed. Fungi play essential roles as decomposers that speed the return of nutrients to forms that crops can use, as pathogens that cause plant disease, as beneficial endophytes that live within plants and protect them from pests and pathogens, and as mycoparasites, fungi that feed on other fungi and reduce their potential to harm crops. Currently little is known about the effects of agricultural practices on biodiversity in these different fungal groups and about how changes in fungal biodiversity may alter critical functions of fungi. This study will determine the relative importance of shade, nitrogen fertilizers, and fungicides for fungal biodiversity loss in coffee, a crop of critical importance to the global economy and to coffee producers, processors, purveyors, and consumers in the United States. It will examine the importance of fungal biodiversity for key functions of fungi in an agroecosystem, particularly the role of fungal diversity in reducing crop diseases and in improving crop nutrient cycling. This project will provide high impact, cross-cultural research opportunities for training both U.S. undergraduate and graduate students to work effectively as scientists in international settings, as well as disseminating two educational modules to improve specific learning outcomes in undergraduate biology courses.Over the last 30 years, biodiversity ecosystem function (BEF) research has clearly demonstrated the importance of diversity for ecosystem function, yet critical gaps remain for fungi. Fungal communities are highly diverse, their abiotic and biotic interactions are often cryptic and complex, and the importance of fungal diversity for key ecosystem processes, such as decomposition and disease regulation, remains to be determined. Coffee represents an ideal ecosystem to study contributors to fungal biodiversity loss and their effects on ecosystem function, since resources vary with levels of shade and fertilization, and fungicides act to suppress fungal diversity. This project will 1) combine two manipulative field experiments with fungal metabarcoding to a) determine the relative importance of shade, inorganic nitrogen, fungicides and leaf litter diversity in structuring fungal communities and their functional diversity, and b) measure the effects of differences in functional diversity in fungal communities on ecosystem function; and 2) use culture-based techniques to identify currently undescribed fungi, link morphology to DNA barcode, and screen isolates for functional groups. This CAREER award will advance understanding of the role of fungal diversity in ecosystem function, particularly the effects of diversity on decomposition rates and plant disease incidence and severity.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.