Restoring and protecting Belle Isle's valuable forestry heritage
Investigate a historic sawmill and a rare forest ecosystem
By KATHLEEN LAVEY Michigan Department of Natural Resources
As the
son of Belle Isle’s engineer, Fred Rottach pretty much grew up on the 982-acre
park in the Detroit River.
When he
was a small child, his dad would let him flip the switches in his office that
changed the color of the lights illuminating the 125-foot-tall spray of the
James Scott Memorial Fountain.
As a
teenager and a college student, Rottach worked the island’s golf course, its
concession stands and its canoe rental.
He even
spent time working with foresters in Belle Isle’s 200-acre woods, a rare
wet-mesic flatwood forest that covers 20 percent of the island and includes
rare pumpkin ash and Shumard oak trees, as well as a variety of other hardwood
trees.
Rottach
even helped turn some of those trees – and trees removed from other Detroit
parks – into usable lumber at Belle Isle’s sawmill.
“We had a
couple of guys who were foremen. They lived down south or out west or up north,
and they knew how to run a sawmill,” Rottach recalled. “We had a ‘Fat Jack’ and
a ‘Whiskey’ and ‘Big Benny.’ They knew what they were doing, especially Fat
Jack and Whiskey. They could run a sawmill blindfolded.”
The date
is uncertain, but the Belle Isle sawmill closed sometime around 1980 – doors locked
with a 4-foot, circular sawblade rusting in place.
The
forest, which thrives on the proper balance of water, has been challenged by
the loss of trees to the emerald ash borer (an invasive insect pest) and a
fungal disease known as oak wilt, as well as things such as roads and culverts
that changed water flow through the woods.
However,
efforts are under way to protect and restore the unique forest and the sawmill
and its building, which were falling into decay when the Michigan Department of
Natural Resources first leased the park from the City of Detroit late in 2013.
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First comes the forest
Walk
through Belle Isle’s forest today, and you’ll see water pooled on the ground
and dead ash trees lying in the woods. To restore the unique forest to its
former glory, the DNR – with the help of EA Engineering, Science and
Technology, Inc. – is starting at the bottom: by studying the soil and water
where the trees take root.
That’s
key in a wet-mesic forest. Belle Isle’s is near the northern end of the range
of this forest type, which usually is found on glacial lake plains, and it’s
the largest of six remaining high-quality examples in Michigan. The ground in a
wet-mesic forest is typically damp and level, meaning even small alterations
can change forest dynamics.
“It’s
really a flat site, and because of that, microtopography is really important,”
said Glenn Palmgren, ecologist with the DNR’s Parks and Recreation Division. “A
few inches of rises and falls makes a difference.”
The study
includes a look at soil and water, and what changes – such as making
alterations to roads and trails or moving fallen trees that block water flow –
could make a difference to improve forest health.
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A headcount of animals that live in the woods is also included in the study, from tiny water-borne invertebrates to reptiles, amphibians, birds, coyotes and beavers that have built a dam across one of the island’s canals.
Migrating songbirds find seasonal haven in the trees of Belle Isle’s forest. Non-native European fallow deer munched their way through the forest’s understory for decades, but they have since been removed from the island.
The forest once was home to a record-holding pumpkin ash tree – a rare variety and state-threatened species in Michigan – that was killed by the emerald ash borer. A champion Shumard oak tree – with a girth of more than 13 feet and a crown spread of up to 70 feet – is still hanging on, thanks to human intervention.
Belle Isle is the northern end of the range for Shumard oaks, which are rare in Michigan and a species of special concern here. The trees are in the red oak family, which are most susceptible to death from oak wilt.
In 2017, with
the help of the Belle Isle Conservancy and the Michigan Invasive Species Grant
Program, which funded portions of the project, workers removed 112 oak trees from
the forest on Belle Isle to prevent the spread of the deadly fungus.
The trees
were lifted from the island with helicopters to help protect the unique ecology
of the forest.
Another
181 were protected from oak wilt by injecting them with a solution that keeps
any infection from getting worse.
The
forest also includes maples and many other varieties of oak. The understory
includes spicebush and a white version of the usually yellow trout lily.
“Trout
lily itself is pretty common, but the white variety that is on Belle Isle is
more unusual,” Palmgren said.
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Data collection for the $525,000 grant-funded hydrology study started last fall and will continue through August. Design work is expected to be completed in September.
The goal is not to return the forest to its previous state – before European settlers arrived in Detroit – but to restore the forest’s soil-water balance and allow it to thrive into the future. The changes also could make the forest more people-friendly.
“It will also be something people will enjoy more,” said Heidi Frei of the DNR Parks and Recreation Division’s stewardship team. “If you go there now, there’s a lot of standing water.”
Even in its current state, the forest serves important functions, including as a home for birds and other animals. Frei recalls walking through the forest shortly after the DNR signed the Belle Isle lease, tramping 5 or 6 miles throughout the woods.
“Even in the state it is now, there are certain pieces of the forest where it’s beautiful, it’s spectacular,” she said. “Then we popped out of the forest and there was the skyline of Detroit. For a minute, I had forgotten I was in Detroit.”
Refurbishing the sawmill
Walk into
the building that houses Belle Isle’s sawmill, and it’s like stepping back in
time.
A rusty, 4-foot-high
sawblade still stands in place as if workers were about to slide logs towards
it. A hand-penciled diagram with the notation “do not erase” on a whitewashed
stair support near the mill shows the diagram for putting belts in place on the
equipment.
This is
where Rottach worked with all of those colorfully named colleagues in the early
1970s. It’s also a building that Joe Aiken and others with the Arboriculture
Society of Michigan Foundation would like to see used to teach Belle Isle
visitors the history of forestry, particularly the urban variety.
He said
the city sawmill dates to the early 1900s.
“They
were so ahead of their time in a lot of things,” Aiken said. “Back then, they
didn’t go to Home Depot. Trees that came down in the city of Detroit were
carried to Belle Isle and processed for material.”
Rottach
recalls that lower-grade wood produced at the mill would be used to build park
benches or repair other outdoor installations.
“If it
was really nice wood like oak or maple or ash, it would be cut to the specs
that they had given us at the carpenters’ shop,” he said. “Some of it was made
into coat racks, book cases and cabinets for use in city offices.”
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A Detroit News newsreel from the 1920s era shows a crew of
workers pushing logs into a steam-powered sawmill. Aiken said he believes the
mill was converted to electricity in the 1940s, when the current building was
constructed.
After
decades of neglect, a membrane covering was placed on the building’s roof in
2016. Coming this spring is a physical assessment of the building, to figure
out how much it might cost to save it. The next step after that is a historic
structures report, to guide the building’s restoration.
“Then we
could start talking about programming and interpretation,” said Amanda
Treadwell, urban area planner for the DNR.
Aiken is
looking forward to that.
“The
Foundation really wants to be the lead on the fundraising, the restoration and
supplying the volunteers to walk people through the sawmill and the historical
building,” Aiken said. “We’ve got all these people ready to donate.”
Do you want
to help?
The DNR
makes volunteer opportunities available on Belle Isle and in other state parks.
If you’d like to help, go to michigan.gov/dnrvolunteers
and click on the Volunteer
Calendar link. You can search by month.
Opportunities
include Belle Isle Stewardship Saturdays, where volunteers help to restore the
flatwoods by removing invasive species.
To
subscribe for free to upcoming Showcasing the DNR stories, visit michigan.gov/dnr to sign-up or to visit
the Showcasing archive go to michigan.gov/dnrstories.
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/Note to editors:
Accompanying photos are available below for download. Suggested
captions follow. Credit: Michigan Department of Natural Resources, unless
otherwise noted.
Blade: A
closeup of one of the huge blades at the Belle Isle sawmill.
Building:
This building near the 200-acre forest at Belle Isle Park serves as
headquarters for the forestry staff; the sawmill is located nearby.
Diagram:
Fred Rottach remembers working at Belle Isle’s sawmill as part of a team with
skilled co-workers with colorful nicknames. Maybe one of them drew this belt
diagram in pencil on a stair support in the sawmill building.
Forest:
Volunteers have held many work sessions to remove invasive species from Belle
Isle, especially the rare, 200-acre wet-mesic flatwoods forest.
Invasive:
Volunteers have turned out to help in Belle Isle’s rare wet-mesic flatwood
forest. Among their jobs: pulling out invasive species so native trees can
flourish.
Sawmill:
The sawmill building has overhead doors on either side so logs can come in and
lumber can come out. The mill has been powered by electricity since the 1940s but
ran on steam prior to that.
Vertical:
The huge saw blade that once sliced logs into lumber is still in place. Joe
Aiken, who is among those working to restore the sawmill, said the blades date
to the 1960s or 1970s, while the building dates to the 1940s.
Water:The balance of water is critical in Belle Isle’s forest, where canals, dams and
the eradication of ash trees by the emerald ash borer have made things too wet.
A study is being conducted in the forest to determine what the best steps are
to return it to its natural condition.
Workers:
In this undated photo, workers move a log into the sawmill building on Belle
Isle./
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