Climate change is shifting the growing seasons of plants, affecting species performance and biogeochemical cycles. Yet how the timing of autumn leaf senescence in Northern Hemisphere forests will change remains uncertain. Using satellite, ground, carbon flux, and experimental data, we show that early-season and late-season warming have opposite effects on leaf senescence, with a reversal occurring after the year's longest day (the summer solstice). Across 84% of the northern forest area, increased temperature and vegetation activity before the solstice led to an earlier senescence onset of, on average, 1.9 ± 0.1 days per °C, whereas warmer post-solstice temperatures extended senescence duration by 2.6 ± 0.1 days per °C. The current trajectories toward an earlier onset and slowed progression of senescence affect Northern Hemisphere-wide trends in growing-season length and forest productivity.

College of Water Sciences Beijing Normal University Beijing 100875 China

Department of Biology Washington University in St Louis Saint Louis MO 63130 USA

Department of Civil and Environmental Engineering Massachusetts Institute of Technology Cambridge MA 02139 USA

Department of Experimental Plant Biology Charles University Prague CZ 128 44 Prague Czech Republic

Institute of Geography University of Bern 3012 Bern Switzerland

Institute of Integrative Biology ETH Zurich 8092 Zurich Switzerland

Oeschger Centre for Climate Change Research University of Bern 3012 Bern Switzerland

WSL Swiss Federal Institute for Forest Snow and Landscape Research 8903 Birmensdorf Switzerland

Citace poskytuje Crossref.org

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