Study: Climate Change Means Early Spring, Late Fall in Northern Forests

Aug 29, 2018

A study by a Flagstaff scientist found climate change will likely lengthen the growing season in forests—but paradoxically, trees may suffer more from frost. KNAU’s Melissa Sevigny reports.

The SPRUCE experiment in Northern Minnesota.
Credit U.S. Forest Service Northern Research Station

Andrew Richardson of Northern Arizona University set up the experiment in bubble-like chambers in Northern Minnesota which mimic a range of possible future conditions on Earth. The chambers are heated and exposed to elevated carbon dioxide, but are still open to rain and snow.

Richardson set up digital cameras inside the chambers to monitor the greenness of the trees. He says, "What we could see was that in the warmest chambers things were starting to get green earlier in spring, and they stayed green later in the autumn," stretching the growing season by nearly a week for every degree Celsius of warming.

Richardson adds spruce trees growing in the warmest chambers received more damage from a sudden spring frost. That suggests plants in a warmer climate might lose their tolerance for cold snaps. The paper appeared in the journal Nature.