MSB-ECA: A generalized framework for modeling the impacts of forest insects and pathogens in the Earth System

摘要：MSB-ECA：森林昆虫和病原体对地球生态系统影响的模拟框架森林昆虫和病原体是全球生态系统扰动的媒介。在美国，昆虫和病原体造成的树木压力和死亡率为美国市政当局和个人业主带来了数十亿美元的成本。昆虫和病原体之间的相互作用以及气候变化等其他干扰因素的不确定性很高，但在许多情况下，气候变化预计会增加昆虫和病原体的活动。该项目将制定一个框架，通过一种通用方法模拟和预测森林昆虫和病原体的影响，准确捕捉其影响的巨大多样性。该框架将用于模拟美国大陆森林中昆虫和病原体爆发的潜在影响，并调查两种入侵昆虫的具体影响。舞毒蛾和铁杉绵球蚜这项研究的一个主要好处是，它将提高模拟未来昆虫和病原体对森林的影响以及干旱，热浪和极端降雨事件等其他干扰的能力。这项研究还将通过对本科女性进行尖端定量方法的培训来增加美国STEM劳动力的多样性。森林昆虫和病原体，森林和气候变化之间的未来反馈在区域到大陆的空间尺度上没有得到很好的理解，部分原因是地球系统模型中没有昆虫和病原体控制的过程。这项研究提出了一个通用的框架，其中昆虫和病原体对植物生理的影响被放大到生态系统水平的过程，可以集成到地球系统模型。在此框架下，本研究检验了关于森林对昆虫和病原体响应的三个假设：1）在低强度下，昆虫和病原体增加了树木多样性，增加了森林碳储量，促进了水分循环，但在高强度下，昆虫和病原体造成了大规模的死亡; 2）昆虫和病原体影响广泛的宿主物种的能力将不太可能改变森林树种组成，但更有可能影响碳和水循环; 3）昆虫和病原体造成持续的压力，而不是周期性的入侵，更有可能引发气候变化放大的影响。这些假设将通过美国各地的理论建模实验进行测试，并通过第二组建模实验进行测试，重点是美国东部的两种入侵昆虫：1)周期性入侵的通才，落叶舞毒蛾，和2）缓慢和持续的压力，从物种特异性，韧皮部喂养铁杉羊毛球蚜。而不是建模昆虫和病原体作为直接代理人的死亡率，这个框架将更准确地模拟在个别主机树的生理变化，并在生态系统过程中产生的变化。为了便于将这一框架纳入其他地球系统模型，这项研究将开发两个开放源码培训模块。拟议的研究还将通过培训本科女性从事使用先进计算方法和发展科学交流技能的研究，帮助发展多元化和有竞争力的STEM劳动力。

Abstract: MSB-ECA: A generalized framework for modeling the impacts of forest insects and pathogens in the Earth SystemForest insects and pathogens are global agents of ecosystem disturbance. In the United States, tree stress and mortality from insects and pathogens creates billions of dollars in costs for U.S. municipalities and individual property owners. The interactions between insects and pathogens and other disturbances, such as climate change, are highly uncertain, but in many cases climate change is expected to increase insect and pathogen activity. This project will develop a framework to simulate and forecast the impacts of forest insects and pathogens through a generalized method that accurately captures the large diversity of their impacts. This framework will be used to simulate the potential impacts of insect and pathogen outbreaks in forests across the continental U.S. and to investigate the specific impacts of two invasive insects ? gypsy moth and hemlock woolly adelgid ? in the eastern U.S. A key benefit of this research is that it will improve the ability to simulate future impacts of insects and pathogens on forests in combination with other disturbances like drought, heat waves, and extreme rainfall events. This research will also increase the diversity of the U.S. STEM workforce by training undergraduate women in cutting-edge quantitative methods. Future feedbacks between forest insects and pathogens, forests, and climate change are not well understood at regional to continental spatial scales, due in part to the absence of the processes controlled by insects and pathogens within Earth System models. This research proposes a generalized framework in which impacts of insects and pathogens on plant physiology are scaled up to ecosystem-level processes that can be integrated into Earth System models. With this framework, this research tests three hypotheses regarding the response of forests to insects and pathogens: 1) at low intensities, insects and pathogens increase tree diversity, increase forest carbon storage, and increase water cycling, but at high intensities insects and pathogens create large-scale mortality; 2) the ability of insects and pathogens to impact a wide range of host species will be less likely to shift forest tree species composition but more likely to impact carbon and water cycling; 3) insects and pathogens that create a continuous stress, rather than periodic irruptions, are more likely to initiate impacts that are amplified by climate change. These hypotheses will be tested with theoretical modeling experiments across the continuous U.S. and with a second set of modeling experiments focused on two invasive insects in the eastern U.S.: 1) periodic irruption of the generalist, defoliating gypsy moth, and 2) slow and continuous stress from the species-specific, phloem-feeding hemlock woolly adelgid. Rather than modeling insects and pathogens as direct agents of mortality, this framework will more accurately simulate changes in individual host tree physiology and resulting changes in ecosystem processes. To facilitate the incorporation of this framework into other Earth System models, this research will develop two open-source training modules. The proposed research will also help to develop a diverse and competitive STEM workforce by training undergraduate women in research that uses advanced computational methods and develops skills in scientific communication.