Tree Damage as an Ecological Process: Evidence from a Pantropical Monitoring Program

Authors

Daniel Zuleta¹* ([email protected]), Gabriel Arellano², Sean M. McMahon^1,3, Salomón Aguilar⁴, Sarayudh Bunyavejchewin⁵, Dairon Cárdenas⁶, Chia-Hao Chang-Yang⁷, Alvaro Duque⁸, Musalmah Nasardin⁹, Rolando Pérez⁴, I-Fang Sun¹⁰, Yao Tze Leong⁹, Renato Valencia¹¹, Stuart J. Davies¹, Jeffrey Chambers¹²

Institutions

¹Forest Global Earth Observatory, Smithsonian Tropical Research Institute, Washington, DC; ²Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI; ³Smithsonian Environmental Research Center, Edgewater, MD; ⁴Smithsonian Tropical Research Institute, Balboa, República de Panamá; ⁵Forest Research Office, Department of National Parks, Wildlife, and Plant Conservation, Bangkok, Thailand; ⁶Herbario Amazónico Colombiano, Instituto Amazónico de Investigaciones Científicas (SINCHI), Bogotá, Colombia; ⁷Department of Biological Sciences, National Sun Yat-sen University, Kaohsiung, Taiwan; ⁸Departamento de Ciencias Forestales, Universidad Nacional de Colombia–Sede Medellín, Colombia; ⁹Forestry and Environment Division, Forest Research Institute Malaysia, Selangor, Malaysia; ¹⁰Center for Interdisciplinary Research on Ecology and Sustainability, National Dong Hwa University, Hualien, Taiwan; ¹¹Escuela de Ciencias Biológicas, Pontificia Universidad Católica del Ecuador, Quito, Ecuador; ¹²Lawrence Berkeley National Laboratory, Berkeley, CA

URLs

• https://ngee-tropics.lbl.gov/

Abstract

Forests are key to mitigating climate change. However, large uncertainties remain on how these ecosystems will respond to future environmental changes, especially in the tropics, where high species diversity implies different responses to a particular stressor. Here, evidence is presented of a key, but underappreciated, ecological process in the dynamics of tropical forests: tree damage. Observations were used from 29 annual mortality and damage censuses across seven tropical forest plots of the Forest Global Earth Observatory network in the neotropics and Asia to study the role that damage to living trees has on forest dynamics. Tree damage was one of the most important mortality risk factors and contributed to a substantial, yet rarely quantified, proportion of total forest biomass losses in these forests. Researchers also showed that conventional forest inventories that ignore tree damage result in: (1) overestimates of aboveground biomass (AGB) stocks by 4% (1 to 17% range across forests) because they assume that trees are structurally completes, (2) underestimates of total AGB loss by 29% (6 to 57% range across forests) due to overlooked damage-related AGB losses, and (3) overestimates of AGB loss via mortality by 22% (7 to 80% range across forests) because of the assumption that trees are undamaged before dying. Damage on living trees is likely to become more important as the frequency and severity of forest disturbances increase.