Climate Sensitive Size-dependent Survival in Tropical Trees
Survival of trees in the tropics can be grouped into four types and the abundance of each type is related to climatic factors.
Discovered size-dependent survival of tropical tree species is classifiable into four major categories of plants, is not related to common plant traits and whose abundance is related to climatic factors.
Our work indicates the size-dependent models of forest dynamics can represent tropical forests survival dynamics with four groups of species. This can have a major impact on how we model forests at the global scale and improve our predictions of carbon in tropical forests which is an outstanding area of uncertainty thus far.
We found species were classifiable into four “survival modes” that explain life-history variation that shapes carbon-cycling and the relative abundances within forests. Frequently collected functional traits, such as wood density, leaf mass per area, and seed mass, were not generally predictive of species’ survival modes. Mean annual temperature and cumulative water deficit predicted the proportion of biomass of survival modes, indicating important links between evolutionary strategies, climate, and carbon cycling. The application of survival modes in demographic simulations predicted biomass change across forest sites. Our results reveal globally identifiable size-dependent survival strategies that differ across diverse systems in a consistent way. The abundance of survival modes and interaction with climate ultimately determine forest structure, carbon storage in biomass, and future forest trajectories.
Contacts (BER PM)
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Pacific Northwest National Laboratory
The development of this project benefited from ForestGEO workshops in 2015, 2016 and 2017 (NSF DEB-1046113 to S.J. Davies). Contributions by C. Xu, J. Chambers, S. Davies and N. McDowell were supported by the Next-Generation Ecosystem Experiments (NGEE-Tropics) project, funded by the U.S. Department of Energy, Office of Biological and Environmental Research. D. Johnson was supported by Los Alamos National Laboratory (Director’s Post-doctoral Fellowship).
DJ Johnson et al. (47 coauthors), “Climate sensitive size-dependent survival in tropical trees.” Nature Ecology and Evolution (2018). (in press)]