RAPID: Cascading effects of rapid and widespread mortality of a foundation tree species on animal communities in Hawaii

森林覆盖了地球陆地面积的三分之一，提供了许多生态、经济和社会效益。然而，随着入侵性害虫和病原体爆发的频率上升，世界各地的森林越来越容易受到大规模树木死亡的影响。由于引入的病原体，北美的美洲栗树和欧洲和北美的榆树等优势树种几乎灭绝，这突显了疾病如何从根本上改变森林的物种组成，并对依赖的动物群落产生级联效应。该项目将测量依赖夏威夷原生森林的动物群落如何应对一种新的真菌疾病，这种疾病导致生态上最重要和最丰富的原生树木迅速而广泛地死亡。这项研究提供了一个独特的机会，可以实时测量动物群落对快速和持续的树木死亡的反应，而大多数其他记录树种广泛死亡影响的研究提供了在下降后很长时间内的追溯数据。在这个项目中，研究人员将通过对本科生的直接培训，直接涉及代表性不足的群体，包括夏威夷原住民和其他太平洋岛民。该项目还将在整个夏威夷岛召开教育活动，以交流研究成果。很少有研究定量记录陆地生态系统中的生态群落如何应对基础物种的大规模丧失，而基础物种介导生态系统过程并为居住物种创造稳定的条件。最近的森林结构变化正在夏威夷的整个景观中蔓延，这是由于夏威夷森林的基础树种——多形叶杉（ohia lehua）因疾病而迅速死亡的结果。真菌病原体（Ceratocystis spp.）的蔓延对夏威夷现存的原生森林和赖以生存的动植物的多样性、结构和功能构成了直接而严重的威胁。利用录音技术的进步和声景生态学发展的声景分析工具，研究人员将快速评估在不同基线和整个景观中ohia死亡率变速率的区域内可听鸟类，昆虫和两栖动物物种的生物多样性变化。研究人员还将评估林下其他植物物种的多样性和组成是否会调节动物群落对森林冠层结构变化的反应。夏威夷简化的岛屿生态系统使研究能够更直接地梳理出森林生态系统中支持群落组成和功能的相互作用，这将广泛应用于正在经历大规模森林树木死亡的更复杂和多样化的系统。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。

Forests cover a third of all land area on Earth, providing numerous ecological, economic, and social benefits. However, forests worldwide are increasingly vulnerable to large-scale tree mortalities as the frequency rises of invasive pest and pathogen outbreaks. The near elimination of dominant tree species such as American chestnut trees in North America and elm trees in Europe and North America, as a result of introduced pathogens, highlights how diseases can fundamentally change the species composition of forests and lead to cascading effects on dependent animal communities. This project will measure how animal communities reliant on native Hawaiian forests change in response to a new fungal disease causing rapid and widespread mortality to the most ecologically important and abundant native tree. This research provides a unique opportunity to measure in real time changes to animal communities as a response to rapid and ongoing tree mortality, whereas most other studies documenting the effects of widespread mortality of tree species provide retroactive data long after declines. In this project researchers will directly involve underrepresented groups including Native Hawaiian and other Pacific Islanders through the direct training of undergraduate students on the research project. This project will also convene educational events throughout Hawaii Island to communicate the research results.Few studies have quantitatively documented how ecological communities in terrestrial ecosystems respond to the large-scale loss of a foundation species that mediates ecosystem processes and creates stable conditions for inhabitant species. Recent changes in forest structure are expanding across the Hawaiian landscape as a result of rapid, disease-induced mortality of ohia lehua (Metrosideros polymorpha), the foundation tree species of Hawaiian forests. The spreading fungal pathogen (Ceratocystis spp.) poses an immediate and serious threat to the diversity, structure, and function of Hawaii's remaining native forests and reliant plants and animals. Using advances in recording technology and soundscape analysis tools developed within the growing field of soundscape ecology, the researchers will rapidly assess changes in the biodiversity of audible birds, insects, and amphibian species in areas with different baselines and rates of change in ohia mortality across the landscape. The researchers will also evaluate whether the diversity and composition of other plant species within the understory mediates how animal communities respond to structural changes in the forest canopy. The simplified island ecosystem in Hawaii allows research to more directly tease apart the interactions that support community composition and function within forest ecosystems, which will have wide application to more complex and diverse systems that are experiencing large-scale forest tree mortality.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.