PubMed · 2026-05-22
A warming climate doesn't uniformly boost tree seed production: it depends on when during the growing season temperatures rise. Two long-term studies found that oak mast years and the mouse populations they fuel increased in Maine but not in New York, suggesting local seasonal warming patterns determine whether forests and the animals depending on them benefit or stay the same.
Acorn production, mouse abundance, and mouse body mass all increased over time in Maine but showed no directional increase in New York despite warming in both locations.
The acorn-to-mouse relationship held strong in both systems, confirming that seed availability remains the primary driver of rodent population swings.
The divergent outcomes suggest that the season during which warming occurs, tied to species-specific reproductive timing, determines whether climate change translates into greater seed production.
