Funds are provided to assess and improve Earth system model simulations of the carbon cycle, ecosystem climate feedbacks, and ecosystem impact, mitigation, and adaptation metrics. The simulations will focus on decadal timescales for forests of northern and eastern U.S. The research will simulate the decadal scale forcings including climate variability, climate change, and atmospheric CO2 trends and incorporate human perturbations from land use and nitrogen deposition. The simulation responses will include (i) the carbon cycle; (ii) the impacts on forest structure and community composition; and (iii) ecosystem feedbacks on climate variability and change. The research will test the hypothesis that land use and nitrogen deposition provide a larger perturbation to forest ecosystems, and resulting atmospheric feedback, than do climate variability, climate change, and atmospheric CO2 trends over decadal timescales. The Community Land Model (CLM), the land component of the Community Climate System Model/Community Earth System Model, includes the necessary statistical meteorological downscaling, carbon-nitrogen biogeochemistry, land use, and dynamic vegetation will be used to perform multi-scale simulations. Model simulations and comparisons with observational datasets will be used to test the role of land use history and resulting post-disturbance vegetation dynamics, biogeochemical cycles, nitrogen deposition, and their interactions for local- to regional-scale simulations.
This capacity and community building proposal establishes a framework to engage the university ecological, environmental sciences, and biogeoscience communities in the Community Land Model. Fellowships will be used to expand the education and research opportunities of six undergraduates, two graduate students, and one post-doctoral research associate beyond core ecological disciplines to include large-scale geophysical Earth system models. The CLM is a community model for university researchers. Developments gained from this award will allow regional and decadal simulations that take into account terrestrial ecosystems, their responses to environmental change, and their feedbacks on climate. The research extends the biogeochemical focus of Community Land Model from carbon and nitrogen biogeochemistry to include also stand characteristics such as age-structure, size-structure, canopy height, and community composition that are relevant for impact, mitigation, and adaptation studies. These model developments will allow for well-informed climate change adaptation and mitigation policy and stewardship of forest ecosystems in a changing environment
