Forests of the United States are primary sources of food, fiber and energy. They play a fundamental role in the earth's climate system by sequestering in plant biomass carbon that might otherwise form the molecular backbone of atmospheric greenhouse gases such as carbon dioxide. Forests' capacity to capture atmospheric carbon dioxide and build biomass may change substantially with age and disturbance. Scientists have long theorized a decline in growth and carbon uptake as forests age. New observations, however, suggest that low levels of disturbance, such as those originating from insect pests, fungal pathogens, and extreme weather, in aging forests may, counter-intuitively, sustain or even increase forest carbon sequestration and growth. The mechanisms underlying these higher-than-expected rates of forest carbon sequestration are unknown. This study seeks to identify the mechanisms underpinning forest growth resilience to disturbance, and their thresholds. The researchers will also evaluate if, how, and why different computer simulations, critical to predicting future forest carbon storage and growth and yield, fail to replicate this resilience. Furthermore, they will determine whether evergreen forests in the western United States and deciduous forests in the East, with different prevailing disturbance regimes and climates, follow unique age-forest growth trajectories. The benefits of this project to society, forest and land managers, grade school educators, university students, and forest scientists are far-reaching. By combining biologically-informed field and simulation experiments with a synthesis of North American forests, this study will significantly advance our ecological thinking about forest disturbance, while producing results immediately relevant and accessible to ecosystem and earth system simulations, and to forest managers working to maximize carbon storage, growth, and timber production in increasingly disturbed forest landscapes. The project will produce openly available instructional materials for grade school teachers, train several graduate and undergraduate students, provide open and transparent sources of data and computer code to scientists and land managers, and form a student training partnership between a United States Department of Energy laboratory and an academic institution.