Tree size shapes forest carbon dynamics and determines how trees interact with their environment, including a changing climate. Here, we conduct the first global analysis of among-site differences in how aboveground biomass stocks and fluxes are distributed with tree size. We analyzed repeat tree censuses from 25 large-scale (4–52 ha) forest plots spanning a broad climatic range over five continents to characterize how aboveground biomass, woody productivity, and woody mortality vary with tree diameter. We examined how the median, dispersion, and skewness of these size-related distributions vary with mean annual temperature and precipitation. In warmer forests, aboveground biomass, woody productivity, and woody mortality were more broadly distributed with respect to tree size. In warmer and wetter forests, aboveground biomass and woody productivity were more right skewed, with a long tail towards large trees. Small trees (1–10 cm diameter) contributed more to productivity and mortality than to biomass, highlighting the importance of including these trees in analyses of forest dynamics. Our findings provide an improved characterization of climate-driven forest differences in the size structure of aboveground biomass and dynamics of that biomass, as well as refined benchmarks for capturing climate influences in vegetation demographic models.
Bibliographical noteFunding Information:
CP was supported by the ForestGEO network of the Smithsonian Tropical Research Institute. We thank all technicians, volunteers and students who participated in field data collection. Acknowledgments for the support that the 25 sites included in this study received are provided in the Notes S2 .
© 2022 The Authors. New Phytologist © 2022 New Phytologist Foundation.
- climate gradients
- tree size distribution
- woody mortality
- woody productivity
PubMed: MeSH publication types
- Journal Article
- Research Support, Non-U.S. Gov't