What's happened
A Guardian study finds trees absorb carbon mainly when wood growth occurs, not merely during photosynthesis. Across 137 sites in the US, growth stops earlier than photosynthesis in hot, dry periods, limiting long-term carbon storage. Scientists warn models may overestimate forest sinks if they rely on photosynthesis alone. Researchers will expand to more species and regions.
What's behind the headline?
Key takeaways
- Photosynthesis does not guarantee wood growth; drought and heat disrupt growth, reducing long-term carbon storage.
- Models that tie carbon uptake directly to photosynthesis may overestimate future forest sinks.
- The work expands to test other species and regions to gauge robustness.
Implications
- Climate strategies relying on forests as a carbon sink may need to account for growth bottlenecks during hot, dry seasons.
- Protecting forests from extreme drought and heat becomes central to maintaining carbon storage capacity.
How we got here
Researchers tracked carbon uptake and wood growth across multiple sites to understand how forests store carbon. The study suggests drought and aridity limit growth even as photosynthesis continues, affecting long-term climate mitigation strategies. This challenges assumptions used in climate models about coupled growth and photosynthesis.
Our analysis
The Guardian reports on a study across 137 sites in the US showing decoupling of photosynthesis and wood growth, with authors including Mukund Palat Rao of Lamont-Doherty. The Times and others reference broader climate discussions, but the study itself focuses on forest carbon dynamics.
Go deeper
- What specific regions or tree species will be next in the study?
- How might this change forest management policies to maximize wood growth during drought?
- Will climate models be updated to separate photosynthesis and growth metrics?