OOS 31-3 - Crown damage, growth, and life-history trade-offs: Direct and indirect effects on tropical tree mortality

Friday, August 16, 2019: 8:40 AM
M103, Kentucky International Convention Center

ABSTRACT WITHDRAWN

Gabriel Arellano, University of Michigan, Ann Arbor, MI, Nagore G. Medina, Department of Botany, University of South Bohemia, Ceske Budjovice, Czech Republic, Sylvester Tan, Forest Department Sarawak, Kuching, Malaysia, Mohizah Mohamad, Sarawak Forestry Department, Kuching, Malaysia and Stuart J. Davies, Forest Global Earth Observatory, Smithsonian Tropical Research Institute, Washington, DC
Gabriel Arellano, University of Michigan; Nagore G. Medina, University of South Bohemia; Sylvester Tan, Forest Department Sarawak; Mohizah Mohamad, Sarawak Forestry Department; Stuart J. Davies, Smithsonian Tropical Research Institute

Background/Question/Methods

What causes individual tree death in tropical forests remains a major gap in our understanding of the biology of tropical trees and leads to significant uncertainty in predicting global carbon cycle dynamics. We measured individual characteristics (diameter at breast height, wood density, growth rate, crown illumination and crown form) and environmental conditions (soil fertility and habitat suitability) for 26,425 trees ≥ 10 cm diameter at breast height belonging to 416 species in a 52-ha plot in Lambir Hills National Park, Malaysia. We used structural equation models to investigate the relationships among the different factors and tree mortality.

Results/Conclusions

Crown form (a proxy for mechanical damage and other stresses) and prior growth were the two most important factors related to mortality. The effect of all variables on mortality (except habitat suitability) was substantially greater than expected by chance. Tree death is the result of interactions between factors, including direct and indirect effects.Crown form/damage and prior growth mediated most of the effect of tree size, wood density, fertility and habitat suitability on mortality. Large-scale assessment of crown form or status may result in improved prediction of individual tree death at the landscape scale.