Bill
Collins, Executive Director, Thumb Land Conservancy
Since taking over stewardship in 2011 of the Saint Clair
County Road Commission and Pro-Tel Development preserves along the east side of
Michigan Road, between Dove Road and the Canadian National Railway, in Port
Huron Township, it was clear that control of invasive Glossy Buckthorn is the
big management issue out there. Refer back two posts ago to “Michigan Road Preserve Stewardship” for
more details about these preserves. Glossy Buckthorn – Rhamnus frangula, recently renamed as Frangula alnus, is native to Eurasia and North Africa. It was
introduced to North America about 200 years ago, first as an ornamental hedge
plant, and later as a planting for wildlife and other conservation uses. Like so
many other shrubs brought to North America for these purposes, including Common
Privet, Tartarian Honeysuckle, and Autumn-olive, Glossy Buckthorn became highly
invasive, especially in open forests and shrub swamps. It forms very dense
shrub thickets that shade-out and displace nearly every other plant species
that once grew in the same area.
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Glossy Buckthorn on the west edge of the Road Commission preserve. |
The best control for Glossy Buckthorn is pulling the smaller
plants and cutting the larger, usually combined with herbicide applications. This
is very labor-intensive, requiring a lot of people and time to make significant
progress against large areas of Glossy Buckthorn such as on the west sides and
interior shrub swamps on both Michigan Road preserves. And herbicide has the
disadvantage of not always being so selective in which plants it kills. We are
aware that some land managers have had tremendous success in controlling Glossy
Buckthorn in shrub swamps by burning. This is usually more effective in open
wetlands where there is more herbaceous growth and therefore, more fuel for
burning. Except during autumn leaf fall, there is not typically a large amount
of dry fuel on the ground of mature forests, and therefore, burning is more
difficult.
Another aspect of the burning is that, to some extent, the northern plant community on these preserves and across drier sandy soils in the Port Huron area, is probably fire-dependent. Oaks, Paper Birch, blueberry, Wintergreen, Bunchberry, and other species on the upland sand ridges on the preserves all thrive in response to burning. Fire should help to restore some of the natural structure of the vegetation among other benefits.
We decided to try burning on the west side of the two
Michigan Road preserves to see how the buckthorn would be affected in the swamp
forest. We considered burning in the shrub swamp portions of the preserves, but
we didn’t want to decrease the Tag Alder – Alnus
incana cover which appears to be competing with the Glossy Buckthorn, and we
don’t want to open these areas to further invasion by Reed – Phragmites australis which dominates the
lower wetter areas.
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Typical mix of Tag Alder and Glossy Buckthorn down in the shrub swamp. |
I had been in contact with Port Huron Township Fire Chief,
Craig Miller, since the winter of 2011-2012 about conducting small test burns
on the preserves http://porthurontownship.org/TownshipDepts/FireDepartment.aspx . Craig is an old friend from school and Boy Scouts so it was
nice to talk with him again after so many years. But, the spring of 2012 passed
without the TLC being granted permission to burn by the Township. The summer
drought of 2012 made burning a very hazardous proposition, so any pursuit of
burning was dropped for 2012.
In the meantime, with the help of the Michigan Prescribed Fire
Council http://firecouncil.org/ and a few
burn consultants, Mike Appel http://www.appelenvironmental.com/
and David Borneman http://www.restoringnaturewithfire.com/
I wrote burn plans for each of the Michigan Road preserves as well as the TLC
Dead End Woods Sanctuary and Peltier Beach Ridges Sanctuary. Most of the work
for these plans is actually in gathering all the current landowner names that
surround the preserves so they can be notified of a burn. I then submitted the
plans to the Port Huron Township and Fort Gratiot Township Fire Chiefs for
their review. I even thought about showing them my old JFBA - Junior Fire Bug
Association membership card from Troop 169 to see if that might help, but
decided to hold off.
The burn plans seemed to help because in the spring of
2013, with Chief Miller’s help, the TLC received permission to burn. However, the
spring was so wet and cool that burning was not possible before the emergence
of forest herbs. Of particular concern is the possible occurrence of Michigan
Endangered Painted Trillium – Trillium
undulatum, which normally emerges from the ground in mid-May. We considered
conducting a burn in the fall of 2013, but again, conditions were generally
unsuitable with frequent rains.
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Painted Trillium |
Finally, thanks again to rather last-minute accommodations
by Chief Miller and the generous help of several volunteers on the Port Huron
Township Fire Department, we were able to conduct two small burns on April 12
of 2014. Our burn window opened suddenly. Conditions were warm and dry enough
only for a few days before turning cold and wet again all the way through May.
To my surprise, when we arrived at the fire department that
morning, I was greeted by another old Scouting friend, John Bachman. I hadn’t
seen him I guess since he was barely out of high school. He knew who I was, but
before I recognized him, he had to give me a jab about being some kind of
ecology nut or something. I was probably his instructor for Environmental
Science merit badge at summer camp. Then later on our first burn site, Chief
Craig Miller came out, the first I’d seen him since our Scouting days. Both
Craig and John were in Troop 178 from Port Huron Township. I knew several of
the guys in their troop. Their Scoutmaster, Don McColeman, was even a friend in
later years. In 1974, after my first summer camp at Silver Trails with my Troop
169 from Fort Gratiot, I stayed a second week with Troop 178. It was a very
nice reunion that morning and a reminder of the contribution Scouts make to our
emergency services throughout the US, and probably across the world. And it
seems Scouts and fire just naturally go together.
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Captain John Bachman monitoring the situation. |
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Typical burn intensity on the Road Commission preserve. |
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One of the crew sweeping along a control line. |
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Post-burn on the Road Commission preserve. |
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Spraying the north edge of the Road Commission preserve after the burn. |
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Burn line on the Pro-Tel preserve. |
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Post-burn on part of the Pro-Tel preserve. |
The test burns were conducted largely according to the plans
submitted to the Township. We adjusted the location of the burn on the Road
Commission preserve somewhat because part of the proposed area was too wet. On
the Pro-Tel preserve, we burned a slightly larger area than the proposed
100-foot by 100-foot test size, simply for ease of establishing a better south
control line with good access. Leaf litter and twigs on the forest floor burned
fairly well on both sites, interrupted only by lower saturated soils and lack
of fuel in some spots. Almost no material above the ground surface, such as dry
branches, burned to any significant degree. The fire crew did a great job
sweeping along the control lines to make sure the fire didn’t burn beyond, and we had no trouble at all. Actually, I think we were all hoping for more
burn intensity, but the fuel was a bit thin and the soil still mostly damp.
During the summer 2014 preserve monitoring, some decrease
in the number and density of small-diameter, less than 0.5-inch, woody vegetation
was noted in each burn area. The results will be clearer in 2015 due to delayed
resprouting of some stems, but it appears that burning under a forest canopy,
combined with hand-pulling and cutting, is likely to be effective in helping to
control Glossy Buckthorn in the forested portions of the preserves.