What Would Warmer Look Like?

Years - and reams of data - later, B4Warmed is finding answers

They wanted warming, and they got it.

Seven years ago, researchers started the “B4Warmed” project at the Hubachek Wilderness Research Center and the Cloquet Forestry Center. They wanted to simulate the effects of climate change on the boreal forest by artificially warming small plots of trees and understory. Now, with reams of data to tease apart, the project’s focus is shifting.

One of the big changes over the project was that researchers began simulating the effects of drought via a system that diverts 40 to 45 percent of seasonal rainfall off some of the research plots and into rain barrels, says Artur Stefanski (’09–M.S., integrated biosciences), the research fellow who’s managed the B4Warmed project since it began. The project is led by Department of Forest Resources Regent's Professor Peter Reich, with co-investigators Rebecca Montgomery and Sarah Hobbie, from the forest resources and ecology, evolution and behavior departments respectively, and researchers Jacek Oleksyn and Roy Rich.

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Originally, the project included 96 plots, each 10 feet in diameter; in 2011, the 24 control plots that weren’t being artificially warmed were dropped from the project, Stefanski says. The remaining plots are either heated via underground cables or infrared lamps, to either 1.7 or 3.4 degrees warmer than the ambient temperature. Half of each plot is planted as if trees had been clear cut, and half includes understory. The heat is turned on for eight or nine months a year, usually from March or April until November.

Along with the overall growth and performance of the transplanted seedlings and volunteer herbaceous plants, researchers also are looking at how seeds establish themselves in warmer, drier conditions, Stefanski says. An insect component also has been added that compares the phenology of insects to that of the plants at the site. In the future, the plots could be used for other research on the effects of climate change, he adds. “Our invention works pretty well. Looking at things on this scale can change our understanding of how things work.”

So what have researchers learned? A lot, with more to come, Stefanski says. The biggest difference for the trees and plants is in the spring and from late summer into fall; in the spring, a warmer climate is beneficial because the plants grow faster. But in the fall, the warmer air becomes a negative because the plants lose moisture more quickly. The good news, however, may be that plants are showing their adaptability even in just a few years of simulated warmer and drier air. “They’re already adjusting,” he says, “just like athletes adapt to warmer temperatures.”

–Becky Beyers