Tree mode of death and mortality risk factors across Amazon forests

Nat Commun. 2020 Nov 9;11(1):5515. doi: 10.1038/s41467-020-18996-3.

Abstract

The carbon sink capacity of tropical forests is substantially affected by tree mortality. However, the main drivers of tropical tree death remain largely unknown. Here we present a pan-Amazonian assessment of how and why trees die, analysing over 120,000 trees representing > 3800 species from 189 long-term RAINFOR forest plots. While tree mortality rates vary greatly Amazon-wide, on average trees are as likely to die standing as they are broken or uprooted-modes of death with different ecological consequences. Species-level growth rate is the single most important predictor of tree death in Amazonia, with faster-growing species being at higher risk. Within species, however, the slowest-growing trees are at greatest risk while the effect of tree size varies across the basin. In the driest Amazonian region species-level bioclimatic distributional patterns also predict the risk of death, suggesting that these forests are experiencing climatic conditions beyond their adaptative limits. These results provide not only a holistic pan-Amazonian picture of tree death but large-scale evidence for the overarching importance of the growth-survival trade-off in driving tropical tree mortality.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biomass
  • Brazil
  • Carbon Dioxide
  • Carbon Sequestration
  • Ecology*
  • Ecosystem
  • Environmental Monitoring
  • Forests*
  • Models, Biological
  • Proportional Hazards Models
  • Risk Factors
  • Trees / growth & development*
  • Tropical Climate

Substances

  • Carbon Dioxide