CORVALLIS, OR -- A new Oregon State University study found warming temperatures may have a bigger impact on our forests than initially thought. Scientists once thought canopy leaves maintain their own temperature for photosynthesis, despite the air around them. Not anymore. "If leaves get cooked by high temperatures, they’re essentially non-functional," says OSU Prof. Christopher Still. 

His team mounted thermal cameras atop forests around the U.S. and Panama. He says they found the leaves took a long time to cool down to an effective temperature when the weather warmed signficantly. Still admits there are no easy solutions, "Where you can actually irrigate them, like orchards, that is certainly very helpful. But for most natural forests, it’s tricky to figure out what it is that we can do in the face of these heatwaves."

Thinning was once thought to help reduce trees' competition for water. But, he says, "Depending on the kind of forest, and all that, that opens up the canopies a lot more and, in some cases, they may heat up more than they were before."

He says foliage die-offs recorded after Oregon’s 2021 "heat dome" are a prime example of how quickly trees can be impacted by extreme heat. He wants to see more done to protect the trees we rely on to clean the air we breathe. Still tells KBND News, "A long-term answer is to cut emissions as much as we can to mitigate climate change in the present. And I think the use [for this study] will be adding this into our understanding, trying to project what happens in the future to forests, using these more complicated models to project what may happen 10, 20, 30, 40 years down the line as the climate changes and the amount of carbon dioxide in the atmosphere changes."