Study Questions Whether Trees Actually Increase Biomass
New research published in the journal Science Advances challenges the long-held assumption that trees reliably boost biomass as they absorb carbon dioxide over extended periods. Lead author Mukund Palat Rao from the Columbia Climate School points out that a large portion of the carbon trees take in is quickly released back into the atmosphere, rather than being locked away for centuries as previously thought.
Tree Growth Patterns Under the Microscope
The analysis drew on satellite imagery, trunk diameter fluctuation sensors, and oak tree ring data from regions across the eastern United States and California. In the eastern U.S., oak forests showed active growth from May through July, but their photosynthesis continued well into October. The study found that nearly 36% of the region's annual carbon absorption occurred after the trees had stopped growing in height and width.
In California, trees grew from December to April, while carbon dioxide uptake persisted until August. Here, roughly 26% of carbon absorption took place after growth had halted. The research also highlights that the formation of new wood depends on internal water pressure within plant cells—a pressure that drops significantly during summer heatwaves and drought conditions.
“Increased photosynthesis driven by global change does not guarantee greater wood production in the future.”
Mukund Palat Rao
These findings could reshape how scientists and policymakers approach climate mitigation strategies. Since forests have traditionally been viewed as vital carbon sinks, this new evidence casts doubt on their long-term effectiveness for carbon storage. It may prompt a reevaluation of forestry policies and natural resource management, especially as nations look for reliable ways to combat climate change.