Michigan State University researchers spent 25 summers counting nearly 190,000 baby trees in the Manistee National Forest. Their findings offer a striking preview of how warming temperatures and shifting rainfall could reshape Michigan’s woodlands for generations to come.
The future of Michigan’s forests may not be written in towering oaks or ancient maples — it may be written in seedlings barely as tall as a human toe. A new study from Michigan State University, drawing on 25 consecutive years of field data, offers one of the most detailed long-term portraits ever assembled of how young trees respond to a changing climate.
A Quarter Century of Counting
Every summer since the late 1990s, a research team led by Richard Kobe, a professor in MSU’s Department of Forestry, has traveled to Manistee National Forest in northwestern Lower Michigan to identify and count freshly sprouted tree seedlings. The work is painstaking: at 12 sites spread across a 370-square-mile area, researchers walk transects and record every seedling under a year old, along with measurements of air temperature, soil moisture, soil fertility and light levels reaching the forest floor. Many of the seedlings they catalog consist of little more than a thin stem and two leaves.
By the end of the most recent field season, the team had documented 188,821 individual seedlings across 10 common species. The data, published April 9 in Global Change Biology Communications, now reveal meaningful patterns about which trees are likely to define Michigan’s forest canopy decades into the future.
Winners and Losers in a Warming World
The study’s core finding is stark: not all tree species are adapting equally well to shifts in temperature and precipitation. Species including white oak, red oak, black cherry, red maple and ironwood appear positioned to keep pace with warmer, wetter conditions anticipated across the region. Others — among them sugar maple, American beech, white ash, basswood and black oak — face a far less certain outlook.
“These species might become less common in Michigan’s forests in the future,” co-author Bailey McNichol, a postdoctoral scholar in forestry and MSU’s Ecology, Evolution, and Behavior program, said in a news release.
The implications extend well beyond ecology. Michigan’s forests blanket roughly half the state, support more than 90,000 jobs, and contribute an estimated $27 billion to the state’s economy annually. They also filter air and water, curb erosion, supply timber, and shelter countless other species. A shift in forest composition, even a gradual one, could ripple through communities and industries alike.
Why Seedlings Are the Key
For trees, the seedling stage is uniquely precarious. Unlike mature trees with deep root systems, young seedlings are highly vulnerable to drought and heat because their roots are shallow.
“This is also the stage when trees are most at risk from diseases and grazing deer,” McNichol added. “It’s the point in a tree’s life when it has passed the first series of gauntlets — it’s made it through germination and it’s starting to sprout — but it still has a long way to go.”
The researchers also found that forest canopy cover can act as a buffer, creating cooler and moister microclimates that help shelter vulnerable seedlings from the worst effects of temperature extremes. That protective effect could become increasingly important as the Great Lakes region warms — average temperatures there have already risen by 2.3 degrees Fahrenheit since the 1950s and are projected to climb an additional 6 to 11 degrees by 2100.
What Comes Next
Even seedlings that survive their first year face a long road. Before a tree can reproduce, it typically needs several more decades of growth — during which disease, pest outbreaks, or deer browse could cut its life short. To build a more complete picture, the MSU team plans to extend their tracking beyond the first year of life, following trees through the sapling stage and beyond.
“The idea is to tease out factors that don’t just influence where tree seedlings show up, but how long they stick around,” added McNichol.
That kind of longitudinal data is rare in forest ecology, and it may prove essential for land managers trying to make decisions about timber, conservation and restoration in a climate that is already shifting.
Why It Matters for Students
For students studying environmental science, ecology, forestry or climate policy, this research illustrates how long-term observational studies can yield insights that shorter experiments simply cannot. It also underscores how climate change operates on timescales that exceed most human planning horizons — the seedlings being counted today may not reach maturity until current college students are well into middle age.
Source: Michigan State University