Overview
- Peer-reviewed research in Nature Plants analysed 83 years of data from 203,721 trees across 2,724 long-term sites to track background mortality.
- The study excluded trees lost to logging, clearing and fires and accounted for stand density to isolate underlying death rates.
- Mortality rose across all biomes, including a doubling in tropical rainforests (0.5% in 1963 to 1.3% in 2020), higher losses in tropical savannas (about 1.5% in 1996 to 2.7% in 2017), and increases in warm and cool temperate forests.
- Researchers report deaths are outpacing growth, indicating declining forest stocks and a likely weakening of the forests’ carbon storage capacity with implications for carbon accounting and offset schemes.
- The authors warn that many monitoring plots have been abandoned—warm temperate sites fell from about 900 to fewer than 100—undercutting future tracking and efforts to pinpoint the physiological causes of heat- and drought-related tree deaths.