A logging module added in FATES allows the impacts of forest degradation be represented in Earth system models.
The Science
A team of scientist in NGEE-Tropics developed a selective logging module for the Functionally Assembled Terrestrial Ecosystem Simulator (FATES), a new generation ecosystem demography model for representing vegetation dynamics in Earth system models. This module represents logging practices that span the range from complete clear-cuts to highly selective logging treatments practices. Benchmarking of the module against selective logging experiments in the Tapajós National Forest in Brazil showed that the model is able to capture important effects of logging on forest structure and carbon, water, and energy fluxes.
The Impact
Tropical forest degradation not only alters carbon stocks and carbon fluxes, but also impacts physical land surface properties. Such impacts are poorly quantified to date due to difficulties in accessing and maintaining observational infrastructures, as well as the lack of proper modeling tools. The new module creates a foundation for future model developments to include a wider set of land use transitions and regionally- and temporally-resolved variation in logging practices to better simulate the effects of forest degradation in the Earth system.
Summary
The module is designed to mimic the ecological, biophysical, and biogeochemical processes at a landscape level following a logging event. This is achieved by specifying the timing and aerial extent of logging events, splitting the logged forest patch into disturbed and intact patches, determining the survivorship of cohorts in the disturbed patch, and modifying the biomass and necromass pools following logging. The logging module is parameterized to reproduce a selective logging experiment at the Tapajós National Forest in Brazil and benchmarked against available field measurements. Our results suggest that the model permits the coexistence of early and late successional functional types following disturbance. The model also realistically characterizes the seasonality of water and carbon fluxes and stocks, the forest structure and composition, and the ecosystem succession after disturbance.
Contacts (BER PM): Daniel Stover, Terrestrial Ecosystem Science, Daniel.Stover@science.doe.gov
PI Contact: Jeff Chambers, Lawrence Berkeley National Laboratory, jchambers@lbl.gov
Ruby Leung, Pacific Northwest National Laboratory, Ruby.leung@pnnl.gov
Funding
This research has been supported by the U.S. Department of Energy, Office of Science (grant no. 66705), the São Paulo State Research Foundation (grant no. 2015/07227-6), the National Aeronautics and Space Administration (grant no. 80NM0018D004), and the National Science Foundation (grant no. 1458021).
Publications
Huang, M., Xu, Y., Longo, M., Keller, M., Knox, R. G., Koven, C. D., and Fisher, R. A.: 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, 17, 4999–5023, https://doi.org/10.5194/bg-17-4999-2020, 2020.