A novel crown damage module in the Functionally Assembled Terrestrial Ecosystem Simulator provides new capabilities for testing hypotheses related to disturbance and recovery in tropical forests.
The Science
Forest trees are exposed to a variety of disturbances such as windstorms and lightning. These disturbances can result in significant damage to their crowns, the part of a tree made up of branches and leaves. Little is known about how tree crown damage influences the growth and survival rates of trees, or interactions among different tree species. Now, however, a team of scientists have introduced a way to represent crown damage in a vegetation model. This new capability allows scientists to test how tree crown damage impacts forest dynamics and the carbon cycle.
The Impact
Forests cycle large amounts of water, energy and carbon with the atmosphere and play an important role in regulating the Earth’s climate. However, forest disturbances that cause crown damage are predicted to become more severe and more frequent in the future. Understanding how forests will respond to these disturbances is critical for understanding the long term role of forests in the biosphere.
Summary
A multi-institutional team of scientists introduce a crown damage module into the Functionally Assembled Terrestrial Ecosystem Simulator (FATES), a submodel of the DOE’s Energy Exascale Earth System Model (E3SM). Using this new functionality, scientists were able to test how crown damage alters forest dynamics relative to equivalent increases in tree mortality. Simulated growth and survival rates were benchmarked against data from Barro Colorado Island in Panama. Results revealed how the largest impact of crown damage on aboveground biomass and carbon residence time are due to increases in mortality associated with crown damage. However, simulated crown damage caused changes to forest canopy organization and competitive dynamics between plant functional types. Representing crown damage in vegetation models is important to capture the legacy effects of disturbance and the ways that disturbances that overlap in space or time may interact to increase forest mortality.
Contact: Jessica Needham, Research Scientist, Lawrence Berkeley National Laboratory, jfneedham@lbl.gov
Funding
This research was supported as part of the Next Generation Ecosystem Experiments-Tropics, funded by the U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research. CK also acknowledges support from the DOE Early Career Research Program. LBNL is managed and operated by the Regents of the University of California under prime contract number DE-AC02-05CH11231. BCI dendrometer data collection was supported by the HSBC Climate Partnership and Smithsonian ForestGEO.
Publication
Needham, J.F., Arellano, G., Davies, S.J., Fisher, R.A., Hammer, V., Knox, R., Mitre, D., Muller-Landau, H.C., Zuleta, D., Koven, C.D., “Tree crown damage and its effects on forest carbon cycling in a tropical forest”, Global Change Biology (2022) DOI:10.1111/gcb.16318