TRAVERSE CITY — Fall without the blazing red, orange and yellow of changing leaves seems unthinkable.
But it’s a scenario that could come to pass, now that ash and beech trees are going the way of the elm and birch before them. Together the trees — ridden in recent years with pests and diseases that kill them — produce much of the golds and yellows in the region’s fall leaf show.
In fact, the color landscape already is changing, said photographer Bob Grzesiac, who co-leads seasonal photo tours on the Leelanau Peninsula. While the most colorful autumns depend on the weather, the mix of hardwoods is primarily responsible for the diversity of color.
“You get a lot of yellow with aspen and beech and birch and ash,” said Grzesiac, whose photo tours take participants to the Sleeping Bear Dunes National Lakeshore and other spots in Leelanau County. “And all but one is in real trouble. First it was the birch. The (emerald ash) borer just decimated the ash. And now it’s the beech. The aspen is one of the few yellows left.
“We used to find these huge spreads looking across from Miller Hill and overlooking the D.H. Day Barn and the little lake there. You used to see screaming yellows and incredible oranges and scarlet reds. And you don’t anymore. What you think is yellow, up close is really brown. There isn’t the prism of colors anymore. It’s like a rainbow on a dull day. It’s just not quite there,” Grzesiac said.
Forests throughout Michigan are undergoing big changes as millions of beech and ash trees are killed off by the emerald ash borer, an Asian beetle that can infect large, healthy trees, killing them within three years, and by beech bark disease, a complex disease caused by scale insects that weaken the trees, followed by the fungus neonectria, which kills the trees.
But how their demise will impact the $2.7 billion fall color tourism season remains to be seen.
“We’re not going to lose hardwoods, but the component within them is going to be different,” said Dan Heckman, a forest inventory and planning specialist with the Michigan Department of Natural Resources. “We’ll have ash and beech always as a part of them, but they’re going to be reinfected. It’s going to change the landscape.”
Heckman said it’s likely that 100 percent of the ash will be infected.
“We’ve never seen any ash trees resistant to emerald ash borer. When it moves in, it kills every single tree,” he said.
As for beeches, “now it’s hard to find a northern stand that doesn’t have bark scale. In 90 percent of stands you’re going to find some trees that are infected. And in some it’ll look like someone took toothpaste and splattered it on them,” he said.
The emerald ash borer was first reported in the Sleeping Bear Dunes National Lakeshore in 2011, the same year “Good Morning America” viewers voted the park the “Most Beautiful Place in America.” Now the pest is damaging ash trees at a “moderately high” level, said Kevin Skerl, the park’s chief of natural resources.
“We take down trees every season,” Skerl said. “Trees are dying as we speak.”
To help combat the problem, he said the park is treating a number of healthy ash trees, especially in more developed areas where they could be hazardous to visitors if they fell, with an injectable systemic insecticide that lasts a couple of years. The park also is working with the USDA’s Animal and Plant Health Inspection Service to perform biological controlled releases of parasitoids — tiny stingless wasps that prey on ash borer larvae.
So far the park doesn’t have any trees with the beech bark complex, though it has surveyed the trees the last two summers and is learning as much as it can about what to expect from other national parks, like the Pictured Rocks National Lakeshore, which is seeing severe tree losses from disease.
“We’re not sure what’s going to happen, but we’re very concerned, which is why we’re monitoring the trees,” Skerl said. “Worst case scenario is we lose 95 percent of those species and you’d see significant changes in the color landscape. You have to factor climate change into the mix, too. With climate change, some species are going to move into the area, and some out. Species from Kentucky and Tennesee could move up. We don’t know how it’s going to pan out. The bottom line is change is occurring now, rapidly, and change will occur slowly, over time, with climate change.”
The picture isn’t all doom and gloom, though it may seem that way. Heckman said the DNR has been collecting seeds from what appear to be healthy beech trees among stands of diseased trees to find out what in the healthy trees’ genetics keep them from getting infected. They’re also growing seedlings from the apparently immune trees in a downstate nursery.
“Once these trees are old enough to transfer, we’ll transplant them in the forests where we want to have beech, hopefully to replace the beechwood forest,” he said. “Over a couple hundred years, maybe we’ll keep beech in our landscape.”
Meanwhile, Heckman and Skerl say, keep your fingers crossed that oak wilt and the Asian longhorn beetle, which already are approaching, don’t move into the area. Wilt is a fungal disease which can quickly kill an oak tree, while the beetle targets the sugar maple, which can form a complete color wheel throughout the year, turning several shades of green, them from yellow to orange, and finally to red in the fall.
AAA spokeswoman Nancy Cain isn’t worried. With 150 tree species, Michigan will still have plenty of color for the fall tourist season, she said. And there will be plenty for travelers to do besides leaf peep.
“It’s a much bigger business than it used to be. People will plan a fall weekend and they’ll combine things, or they’ll plan a golf weekend, a spa weekend, winery tours. And there’s still apples and cider mills. It used to be a leisurely drive to look at the color. Now they’re much more involved in getting out there and doing things,” she said.
All that and more will likely keep drawing visitors to northern Michigan.
“Our chamber members don’t consider the season over until after the color season,” said Sally Guzowski, executive director for the Leelanau Peninsula Chamber of Commerce. “It slows down a little in September but we’re still seeing some pretty good numbers. We’ve had a lot of activity this September and fall color hasn’teven arrived.”