Climate Change in Michigan

How can we prioritize forest management efforts to have the greatest impact on diversity and resilience? This is the question that Dr. Catherine Henry set out to answer as TNC’s current Essel and Menakka Bailey Conservation Fellow. A recent doctoral graduate from Michigan State University, Catherine used U.S. Forest Service data to analyze patterns of tree regeneration—the emergence of small seedlings and saplings that will eventually become the new forest canopy—in the Northwoods.

Although some factors influencing species richness cannot be changed, like water availability and average temperature, Catherine’s research highlighted other factors that can be influenced by forest management. For example, her results show that timber harvests have the potential to promote tree diversity, by increasing light availability and allowing species with a variety of light preferences to thrive.

One common theme in her findings was that certain important species aren’t regenerating as much as they used to, which suggests that forest composition is going to shift in the future. “The long-term data supports what managers and scientists have been concerned about for decades—declining regeneration of key species, like sugar maple in northern hardwood forests or northern white cedar in cedar stands,” Catherine says. “However, the data also highlights opportunities to adapt management approaches to improve forest resilience.”

Science matters, especially at this critical turning point for nature. TNC’s grounding in rigorous science informs our conservation—from idea to impact—in all areas of our work, including the priority geography of the Great Lakes Northwoods.

The Northwoods, a lushly forested region covering northern Michigan, Wisconsin and Minnesota, is vital to the health and future of the Great Lakes region. These expansive forests moderate regional climate, store carbon, filter the headwaters of the Great Lakes, provide wildlife habitat and support timber, recreation and tourism.

One of the largest unbroken swaths of hardwood forest remaining in North America, the Northwoods include some of the most climate-resilient sites in the country, as identified in TNC’s landmark Resilient Connected Network project. These are places that will be important for biodiversity in a changing climate, due to their unique topographies, geologies and local connectedness.

“Understanding the science behind the Northwoods—the climate and use trends that are shaping them, as well as the factors that help them thrive—is key to developing forest restoration projects that have tangible, lasting results,” says Dr. Doug Pearsall, TNC’s Senior Conservation Scientist. Every day, TNC staff are working on projects that advance the scientific conversation for the Northwoods. 

TNC acquired the nearly 24,000-acre Two Hearted River Forest Reserve in 2005 as part of the “Big U.P. Deal.” Since then, TNC has managed the reserve to restore the tree age, size and species diversity that it had historically. In a fellowship role generously sponsored by the DTE Energy Foundation, TNC Conservation Fellow Alex Verdeja recently completed a comprehensive review of more than a decade and a half of monitoring data and activities on the reserve.

“It’s been great to have the chance to work on projects like this as a fellow with The Nature Conservancy,” Alex says. “It gives me the opportunity to provide the science, with hard data to back it, that can truly make an impact in how natural resources are managed.

”Alex’s analysis measures our restoration progress in the Two Hearted River Forest Reserve to date, including:

• Improved groundcover and tree species diversity,
• Increased water quality and river connectivity,
• Compliance with Michigan’s Commercial Forest Act and Forest Stewardship Council Certification standards, and 
• Contributions to local economies, by hiring local forestry workers and providing recreational opportunities for hiking, hunting and fishing.

Recently, we’ve begun increasing our focus on carbon sequestration outcomes as well as strategic outreach and collaboration. By sharing lessons-learned from the reserve, TNC aims to establish it as an education and research center for ecologically based land management.

TNC and the Northern Institute of Applied Climate Science, a forest management collaborative, have partnered on a series of guides for landowners and foresters designed to help them make climate-smart decisions about the forests they manage. Released this fall, Michigan’s new guide, “Climate Change Field Guide for Northern Michigan Forests,” describes 10 practices that can increase the amount of carbon that forests pull from the air and store in trees and soils. The guide reflects the best available science with extensive input from foresters, landowners, loggers, scientists, state agencies and conservation organizations.

“Forests have a lot to contribute in the way of natural climate solutions, but the practices that achieve those benefits need to be adapted to the specific location,” says TNC’s Forest Project Manager, Alex Helman, who contributed to the guide. “This information can help landowners and forest managers choose the practices that will safeguard their forests and secure carbon benefits, across nine northern Michigan forest types.”