05/25/2026
So cool!
New research shows something surprising about our forests. When caterpillars eat heavily one year, trees remember it and delay leaf‑out the next spring by about three days. That small shift throws caterpillars off schedule and cuts damage by more than half. This isn’t just a local quirk — satellites picked it up across entire landscapes. It means spring timing isn’t driven only by temperature. Trees are adjusting based on last year’s insect pressure too.
This matters for Tennessee. Our forests are dominated by oaks, the very species in the study. From the Plateau to West Tennessee bottomlands, these trees may be using this same strategy to stay resilient during insect outbreaks. It also helps explain why some springs feel “late” after a bad caterpillar year — the trees are protecting themselves.
As Tennessee warms, this built‑in defense could slow down how quickly our forests shift their spring timing. It’s a reminder that climate and biology are always interacting, and our forests are more dynamic than we think.
This message brought to you by the Tennessee Urban Forestry Council. For more information, visit https://tufc.com/. To become a member, click https://tufc.com/membership/.
