Collaborative Research: Climate Change Impacts on Forest Biodiversity: Individual Risk to Subcontinental Impacts

气候变化正在以当前科学没有预料到的方式迅速改变着全球大部分地区的森林。大规模的森林枯萎，显然与干旱、温暖的冬季和其他物种的相互作用有关，正在变得令人担忧地频繁。生物多样性和气候模型没有提供关于是否、在哪里或何时会发生这种反应的指导。相反，模型倾向于提供潜在的灭绝数量，但这样的预测与可能导致灭绝的过程没有任何机械性的联系。建模和实地研究都依赖于对物种存在或不存在的综合衡量，或者它们在区域尺度上的相对丰度。然而，气候会对个人产生影响。将个别树木的数据聚合到整个物种的水平上，可以隐藏甚至可能改变对气候影响的预测。这项研究旨在通过采样和分析气候条件下整个范围和相应范围内个体的数据，将个体尺度的树木过程与区域物种水平的反应联系起来。它将使用现有研究站点的数据，以及形成新的国家生态观测网络核心的站点平台。这些数据将被集体合成并用于开发计算机模型，这些模型可以帮助确定何时何地预测气候对生物多样性的影响是一个看似合理的目标。这些模型还将揭示可能发生意外的地方，并可以提供对个体树木健康和易受环境变化影响的预期的反馈。这项研究将首次预测森林生物多样性对气候变化的脆弱性，气候变化与最敏感的生物过程有直接联系。其目标是为构成国家森林的树种的分布、生长、繁殖和死亡风险提供预测。这些预测将帮助科学家、森林管理者和政策制定者预测干旱加剧和生长季延长的综合风险。在该项目期间制定的方法和成果将通过为若干大学的资源管理人员以及研究生和博士后助理举办的培训讲习班加以传播。

Climate change is rapidly transforming forests over much of the globe in ways that are not anticipated by current science. Large scale forest diebacks, apparently linked to interactions involving drought, warm winters, and other species, are becoming alarmingly frequent. Models of biodiversity and climate have not provided guidance on if, where or when such responses will occur. Instead models tend to provide potential numbers of extinctions, but such forecasts are not linked in any mechanistic way to the processes that could cause them. Both modeling and field studies rely on aggregate measures of species presence or absence, or their relative abundance at regional scales. However, climate acts on individuals. Aggregating data on individual trees to the level of a whole species hides or may even change predictions of climate effects. This study aims to link individual scale tree processes to regional species level responses by sampling and analyzing data about individuals across their entire range and corresponding range in climate conditions. It will use data from existing research sites, plus the platform of sites that form the core of the new National Ecological Observatory Network. These data will be collectively synthesized and used to develop computer models that can help determine when and where predicting climate impacts on biodiversity is a plausible goal. The models will also reveal where surprises are likely to occur and can provide feedback to expectations of individual tree health and vulnerability to environmental changes. This study will provide the first forecasts of the vulnerability of forest biodiversity to changes in climate that are directly linked to the biological processes that are most sensitive. The goal is to provide forecasts of the distribution, growth, reproduction and risks of mortality for tree species making up the nation's forests. These predictions will help scientists, forest managers and policy makers anticipate the combined risks of increasing drought and longer growing seasons. Methods and results developed during this project will be disseminated through workshops for training resource managers, as well as graduate students and postdoctoral associates at a number of universities.