Why longer seasons with climate change may not increase tree growth
Many climate forecasts assume longer growing seasons enhance tree growth, yet emerging evidence challenges this idea. Studies across disciplines point to drought stress and internal physiological limits as key reasons why extended seasons may not boost growth. Because hypotheses are tested differently across species and fields, results often diverge. Integrating ecological theory, evolutionary history and cross‑disciplinary methods could help build a unified model predicting when longer seasons will—and will not—translate into greater tree growth, improving climate‑driven forecasts.
Subject Tags
- Carbon storage
- Climate impacts
- Forest
Abstract
Most climate change forecasts assume that longer growing seasons increase carbon storage through increased tree growth, but recent findings have challenged this assumption. Here we highlight divergent findings across studies, spanning diverse methods and disciplinary perspectives. Current hypotheses for why longer growing seasons may not always increase tree growth include drought-related effects and internal constraints. These hypotheses, however, are generally tested in different ways by different fields on different species, and rarely consider how external drivers and internal constraints interact. We outline how bridging these divides while integrating evolutionary history and ecological theory could help build a unified model across species for when longer seasons will—or will not—lead to greater tree growth, with major forecasting implications.
Citation
Wolkovich, E. M., Ettinger, A. K., Chin, A. R., Chamberlain, C. J., Baumgarten, F., Pradhan, K., ... & Hille Ris Lambers, J. (2025). Why longer seasons with climate change may not increase tree growth. Nature Climate Change, 1-10. https://doi.org/10.1038/s41558-025-02476-x
TNC Authors
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Ailene Ettinger
Senior Research Ecologist, Washington
The Nature Conservancy
Email: ailene.ettinger@tnc.org -
Catherine Chamberlain
Lead Climate and Resilience Scientist, North Carolina
The Nature Conservancy
Email: c.chamberlain@tnc.org