Analyzing How Climate Change Influences the Health, Diversity and Productivity of Forests

Peter Reich, PhD, is the director of the Institute for Global Change Biology (IGCB) at the University of Michigan School for Environment and Sustainability. Reich, who has conducted global change research on plants, soils and ecosystems, joins this episode of Michigan Minds to talk about the research of the IGCB, and how climate change influences the health, diversity and productivity of forests and grassland.

“The mission of the institute is to improve our ability to understand and predict and hopefully prevent the worst outcomes of global change. And what our institute aims at in terms of global change are carbon dioxide and associated climate changes, including climate warming and changes in precipitation, and increases in events such as droughts, fires, floods and other kinds of major climate disasters.”

Reich’s recent research conducting a five-year experiment was recently published in Nature. It was part of a larger set of studies by researchers who are trying to understand what will happen to northern forests in the U.S., Canada and around the world as the climate changes. This research found that even relatively modest climate warming and associated precipitation shifts may dramatically alter Earth’s northernmost forests, which constitute one of the planet’s largest nearly intact forested ecosystems and are home to a big chunk of terrestrial carbon.

“Even though sometimes people think, ‘Oh, it’s cold up in Canada and in Scandinavia and even in northern Michigan, or Wisconsin, or Minnesota—won’t warming be good for these forests, they’ll grow faster?’ And unfortunately, the answer is largely no, not entirely no, but largely no,” says Reich. 

The species of trees that live in these northern areas have adapted to those systems and the cool temperatures and moist conditions, he says. Reich references the different research methods used to analyze how forests are changing, including long-term observations using repeated surveys, satellites over North America and other large geographical areas and models to predict how forests might respond to changes. 

For the experiment published in Nature, Reich and his team planted 20,000 seedlings—which are heated using infrared lamps above ground and buried wires below soil—in 72 plots of forest. The team then visits these lots to measure growth. One of the findings showed that northern species of trees, including spruce, fir, jack pine and paper birch found in Canada, Northern Michigan, Wisconsin, and Minnesota, don’t grow well with even a degree or two of warming.

“Their growth is slower and they actually die a lot more frequently, like a much greater proportion of the seedlings will die every year. And this actually turns out to be due, not to just a degree of temperature difference, but the fact that with a higher temperature…plants and soils lose water much faster and they dry out faster,” he says. “So even with the same amount of rainfall in the future, even a degree of warming will dry out soils faster and forests will be more droughted.”

Reich notes the importance of recognizing the impact that climate change is currently having, instead of focusing on what may happen in the future. For example, incredibly heavy rainfalls are causing floods due to the inability of street sewer systems to control that amount of rain since they were designed for lower rainfall events. 

“The main thing people really need to realize is that climate change is impacting nature and people now, it’s not just something that’s going to happen 30, 40, 50 years down the road. And the impacts now, but even more so in a decade or two from now, will be enormously harmful to both natural systems and human systems.”

The impact on infrastructure can be economically damaging, but even more importantly, it can also harm the biodiversity of nature. That, he explains, is what allows our grasslands, wetlands and forests to be resilient in the face of climate change.

“We need to realize this is not just about saving nature, it’s about saving nature and saving people, our own communities and our societies because we need to do this and we need to do it now.”

Reich says that stopping climate change is a far better ethical and economic strategy than ignoring it. The  idea that saving the environment comes at a cost to our economic well-being is totally out of date because it’s actually the opposite, he says.

“If we don’t stop climate change, our economy is going to spiral down the drain. So stopping climate change will be required for us to save our economy, our society and our well-being—and along the way, we’ll save or help preserve much of biodiversity. And in fact, we can do all of those at the same time.”

This series is ongoing throughout April 2023. Subscribe to Michigan Minds for more episodes.