An international team of scientists, led by researchers from the Chinese mainland, has unveiled groundbreaking findings on how tree trunks adapt to rising temperatures, potentially reshaping our understanding of climate change.
Published in the journal Science, the study introduces a new theoretical model that explains and predicts the thermal adaptation of tree trunk respiration. By establishing a global database of plant trunk respiration, the team confirmed that trees worldwide adjust their respiration in response to warming temperatures—a process known as thermal acclimation.
“We found that as temperatures increase, tree trunks adapt by reducing their respiration rates,” said Wang Han, associate professor at the Department of Earth System Science, Tsinghua University, and the study’s corresponding author. “This means that trees could emit less carbon dioxide than previously predicted, which has significant implications for our climate models.”
Traditionally, it was believed that higher temperatures would drastically boost tree respiration, releasing more carbon dioxide (CO2) and accelerating global warming. However, the new research suggests that trees are more resilient than thought.
Reducing Carbon Emissions
The study projects that by 2100, thermal adaptation in tree trunks could reduce carbon emissions from terrestrial ecosystems by 24% to 46%. Given that trunk respiration currently accounts for approximately 27 billion tonnes of carbon emissions annually, this adaptation could play a crucial role in mitigating climate change.
To develop their model, the team relied on the Ecological Evolutionary Optimality (EEO) principle. Their predictions showed that for every 1℃ increase in ambient temperature, the basal respiration rate per unit mass in tree trunks decreases by about 10.1%, and the respiration rate at growth temperature decreases by approximately 2.3%.
To test their theory, the researchers compiled a comprehensive database comprising 8,782 sets of observational data from 68 field sites across various climate zones, covering 187 tree species. They also conducted a warming experiment in a controlled greenhouse environment.
“The observational results matched our theoretical predictions closely,” explained Wang. “This strong agreement confirms the reliability of our model.”
Implications for Climate Models
The findings suggest that existing Earth System Models (ESMs) may overestimate the positive feedback effect between climate and carbon because they do not account for the thermal acclimation of stem respiration.
“This discovery provides a critical foundation for revising global carbon budgets and improving climate predictions,” said Wang. “By integrating our model into ESMs, we can enhance the accuracy of global carbon cycle simulations.”
Looking Ahead
The research team plans to further investigate how factors like soil moisture and carbon dioxide concentration affect trunk respiration. They aim to incorporate their findings into climate models to support better climate governance decisions.
“This is just the beginning,” added Wang. “Understanding the mechanisms behind tree trunk adaptation can help us develop more effective strategies to combat climate change.”
Collaborators from Western Sydney University, the University of Reading, Imperial College London, the University of Exeter, the University of California, Berkeley, and other institutions contributed to this groundbreaking study.
