Carbon Cycle: Effects of disturbance and atmospheric change on vegetation
Improved understanding of plant processes for prediction and management
Photo Credit: Berkeley Lab
Recent science & program advances
Development of state-of-the-science next-generation dynamic vegetation model–Functionally Assembled Terrestrial Ecosystem Simulator (FATES)–for integration with ELM and CLM, and application in tropical systems.
FATES allows explicit representation of disturbance, competition, plant size, and individual plant-scale dynamics in an ESM-tractable formulation. We have also developed and are testing the ability to represent plant hydraulics, selective logging, photosynthesis-associated nutrient constraints, respiration, and allocation. The FATES approach is based on a framework for scaling complexity in land surface models to allow for scaling between simple configurations that allow controlled experiments (e.g, to high-complexity multi-process-resolved representations.
Pioneering a new approach to tropical forest research that closely integrates modeling and experiments (ModEx), and integrates observations from bedrock to canopy.
EESA is globally recognized for providing well-tested state-of-the-science vegetation dynamics for ESMs, and for addressing high-impact science questions at the land-atmosphere interface. An international team of ~90 scientists is working in ModEx teams on problems like plant hydraulics and subsurface water dynamics, leaf-to-canopy gas exchange, carbon metabolism and respiration–and their effects on drought- and heat-wave resilience.
Fieldwork on tropical post-disturbance vegetation establishment and recovery shows that forest-atmosphere exchange depends on shifts in vegetation structure and competitive interactions among cohorts, and thus cannot be predicted by conventional land models
AmeriFlux observations combined with machine learning reveal that drought impacts are underestimated by satellite monitoring, challenging current scaling approaches
Explored role of wildfire in boreal and tundra systems carbon cycling, and showed that expected 21st century fire regimes will substantially alter forest and tundra vegetation composition and carbon sink potential
Analyzed the prevailing paradigm, used widely in Earth System Models, that leaf photosynthesis is primarily limited by nutrients constrained under fixed allocation. EESA research suggests instead that plants allocate to optimize photosynthetic performance, and we are implementing these ideas in DOE’s E3SM Land Model to quantify the global effect.
Using machine learning, we showed that drought impacts can be larger than is inferred from existing satellite-based estimates for photosynthetic activity. This information, when combined with observations from Free Air CO2 Enrichment (FACE) experiments, suggest that growth in atmospheric CO2 concentrations is having a greater-than-expected impact on the carbon sink.
Using a fully coupled Earth System Model, we demonstrated a positive feedback between earlier leaf-out and warming in the North using an Earth System Model (Xu et al. 2020), highlighting the importance of accurately representing plant phenology in global land models.
Combined satellite observations from 1982-2010, CMIP5 ESM predictions, and functional response analyses of vegetation cover to infer ecosystem response to temperature change, and the likely future decline in temperature limitation of vegetation in the world’s cold regions.
EESA benefits from rich partnerships with our collaborators and sponsors. See project & program links above for more information.
Perspectives on the Future of Land Surface Models and the Challenges of Representing Complex Terrestrial Systems, Journal of Advances in Modeling Earth Systems, 2020
The Central Amazon Biomass Sink Under Current and Future Atmospheric CO2: Predictions From Big-Leaf and Demographic Vegetation Models, Journal of Geophysical Research: Biogeosciences, 2020
Assessing Impacts of Selective Logging on Water, Energy, and Carbon Budgets and Ecosystem Dynamics in Amazon Forests Using the Functionally Assembled Terrestrial Ecosystem Simulator, Biogeosciences Discussions, 2019
Greening of the Land Surface in the World’s Cold Regions Consistent with Recent Warming, Nature Climate Change, 2018
Growth and Opportunities in Networked Synthesis through AmeriFlux, The New Phytologist, 2019
Benchmarking and Parameter Sensitivity of Physiological and Vegetation Dynamics Using the Functionally Assembled Terrestrial Ecosystem Simulator (FATES) at Barro Colorado Island, Panama, Biogeosciences, 2020
Forest Responses to Simulated Elevated CO2 under Alternate Hypotheses of Size- and Age-Dependent Mortality, Global Change Biology, 2020
Global Photosynthetic Capacity Is Optimized to the Environment, Ecology Letters, 2019
Earlier Leaf-out Warms Air in the North, Nature Climate Change, 2020
Wildfires and Climate Change Changing Alaska Forests