Forests' carbon sink may be weaker than photosynthesis alone implies

A study across 137 sites in the US finds tree growth often stops before the growing season ends, meaning wood production—and long‑term carbon storage—can lag behind the apparent carbon uptake from photosynthesis. In eastern sites about 36% of yearly uptake occurs after growth has ceased, and about 26% in California. Dry, hot conditions sharply limit wood growth, suggesting models that link carbon uptake directly to photosynthesis may overestimate future forest carbon sequestration as climate change raises aridity. The researchers plan to test if this decoupling occurs in other species and regions.