Michigan Nature Monday: Dunes

Snow blankets much of Michigan now, which may have you dreaming of summer vacations to the beach, and for good reason – Michigan has plenty to choose from! But sandy shores and their hilly companions—dunes—support more than just a retreat from the daily grind.

Vegetation grows on a dune. Photo by Andrew Bacon.

Dunes in Michigan are unique because, unlike their desert counterparts, they are impacted greatly by the water of the Great Lakes. Fluctuating lake levels contribute to dune formation by stabilizing the dunes with increased water levels as well as increased wave action in high years. These impacts are usually so slow-moving that they go unnoticed, but recent erosion along Lake Michigan due to increased lake levels had the dramatic effect of damaging some houses built close to the edges of these dunes.

One distinguishing characteristic of Michigan’s dunes is the amount of vegetation that can be found on them. There is a limited supply of sand in the Great Lakes being deposited on the dunes. This in time allows for various grasses and trees to take root and grow, further slowing or stopping the movement of the sand and allowing for more vegetation to grow. These plants are therefore critical to preventing erosion and dune migration.

Several rare plant types are supported by these dune habitats including Pitcher’s thistle, Houghton’s goldenrod, and Lake Huron tansy, just to name a few. At MNA’s Lake Huron Sand Dunes Plant Preserve in Chippewa County, a unique natural community known as a “wooded dune and swale complex” exists as a series of sandy ridges and low, swampy areas that were formed in multiple stages as lake levels receded around 12,000 years ago.

Lake Huron tansy. Photo courtesy Peggy & Jerry Keeney.

As with many natural communities throughout Michigan, a major threat to the health of this sanctuary is the impact of invasive species. Particularly at Lake Huron Sand Dunes Plant Preserve, invaders such as Spotted knapweed and European Marsh thistle are aided by habitat disturbance. MNA monitors the sanctuary regularly for signs of disturbance and works to remove invasive species before they become too widespread.

So as you plan your next Michigan beach vacation, remember that the sand is part of a much larger and ever-changing habitat complex.

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Michigan Nature Monday: Vernal Pools

This week’s Michigan Nature Monday features the amazing natural habitat of vernal pools. The Michigan Nature Association has been a lead partner in the Michigan Vernal Pools Partnership for several years, and we are proud to have added to that commitment this year with a dedicated staff member – our Michigan Vernal Pools Partnership Coordinator–and the production of the Ephemeral video, produced in partnership with the award-winning videography team of Fauna Creative.

If you have spent time exploring Michigan’s forests in the spring, you may have come across small, shallow pools of water scattered throughout the landscape. These small wetlands are called vernal pools because they are typically filled with water in the spring (“vernal” means spring) but they usually dry up and “disappear” during the summer. Vernal pools are special types of wetlands– because they regularly dry up and are usually isolated from other wetlands and waterbodies, vernal pools cannot support permanent fish populations. Due to the lack of fish predators, vernal pools provide critical habitat for certain animal species that rely on these fishless habitats for their survival and/or reproduction. These include a number of invertebrate and amphibian species, such as fairy shrimp, wood frogs, spotted salamanders, and blue-spotted salamanders. Vernal pools also provide habitat for many other animal and plant species, including rare, threatened, and endangered species. 

Vernal pools play an important role in maintaining healthy forest ecosystems. Because they provide habitat for diverse and unique animal species and provide other important ecological functions, some have referred to vernal pools as the “coral reefs of Northeastern forests.” However, these vernal pools are vulnerable to a number of threats and are not well-protected under current wetland laws and regulations.

If you are interested in learning more about vernal pools and efforts to protect them, visit mivernalpools.com

Ten Years After Major Wildfire, Swamp Lakes Moose Refuge Sees Remarkable Recovery

On June 15, 2012 after burning more than 21,000 acres including part of MNA’s Swamp Lakes Moose Refuge Nature Sanctuary in Luce County, the Duck Lake Fire was officially contained. Now, 10 years later, we are taking a look at what has changed at this sanctuary as a result of the fire.

The sanctuary derives its name from the surrounding area known as the Swamp Lakes which is of significant importance as a large block of wildlife habitat. This area is known to be frequented by moose, gray wolf, pine marten, and numerous other species of wildlife requiring a landscape intermingled with forests and wetlands.

The forest here is dominated by Jack and Red Pines which, once mature, create a dormant understory of easily burning materials—a critical part of the Jack Pine life cycle as their cones will not release seeds except under the extreme heat of fire.

But the Jack Pine isn’t the only benefactor of wildfire. As William Rapai wrote in the July/August issue of Jack Pine Warbler, “Only days after the fire was brought under control, bark beetles moved in to eat the damaged trees. And where there are insects, there are insect-eating birds—including the Black-backed Woodpecker, a species of special concern in Michigan… That woodpecker species is associated with burned areas because one of its primary foods—the bark beetle—attacks trees damaged by fire.”

Water levels in many of the affected areas were very low for the season as seen in this photo from the Swamp Lakes Moose Refuge Nature Sanctuary taken one month after the fire. MNA Archives.

Other species that were observed returning to or newly entering the area shortly after the fire were white-tailed deer, black bear, snowshoe hare, and gray wolf.

Beaver are common to the area, and have been able to expand their territory without human intervention in the years since the fire. At Swamp Lakes Moose Refuge, beaver activity has restored the wetlands and allowed much regrowth to occur.

Possibly the most significant result of the fire is the potential for thousands of acres of new habitat for the Kirtland’s Warbler, which prefer nesting in young (5-20 years old) Jack Pine forests. These formerly endangered neotropical migrants have experienced population recovery after many years of habitat management efforts in the northern Lower Peninsula. While MNA does not have record of Kirtland’s Warbler at the Swamp Lake Moose Refuge Nature Sanctuary, the existence of young Jack Pines in the nearby forest gives hope for future populations.

Not all areas are expected to see the same recovery. Fire suppression efforts resulted in a significant amount of leaf litter and dead wood accumulating in the path of the fire, allowing the fire to burn much hotter and longer (nearly a month) than the soil is able to tolerate. “In some places, the Duck Lake Fire destroyed all the organic matter and microorganisms for some depth,” wrote William Rapai, “Particularly damaging will be the loss of the mycorrhizal fungus that is critical in the lifecycle of many species. The fungus has a symbiotic relationship with plants, helping them to absorb nurtients.”

Live at Swamp Lakes Moose Refuge Nature Sanctuary is abundant as seen in this photo taken from the same location as the photo above, in June 2022. Many beaver inhabit the area, as indicated by the beaver lodge at center. Photo by Andrew Bacon.

A month after the fire, early indications were that the natural communities within Swamp Lakes Moose Refuge would recover without restoration efforts. Given the sanctuary’s wetland composition, the fire has proved beneficial, thinning out the canopy and allowing other plants like bracken fern, blueberry, and leatherleaf to regenerate. MNA will continue to monitor nature’s recovery from the fire and the landscape changes through the years.

Celebrating Michigan’s Wilderness on World Rewilding Day

Today, March 20^th, Michiganders across the state are celebrating the start of spring. We, too, look forward to all that this season brings including wildflowers, bird migration, and more. But today, we are especially excited about World Rewilding Day—established in 2021, World Rewilding Day raises awareness of the need for large, ‘wild’ habitat in the fight against climate change-driven extinctions.

An aerial photograph showing the Ottawa National Forest. Photo by Jason Whalen | Fauna Creative

Our recently-released video “Keep the U.P. Wild” explores one such effort in Michigan’s Upper Peninsula. The Keep the U.P. Wild Coalition last year began a campaign to add federal Wilderness designation to more than 40,000 acres of land in the western U.P., and has since grown to include more than 300 organizations.

Designation requires congressional action, which would provide the highest level of federal land protection for the four areas within the one-million-acre Ottawa National Forest in the western Upper Peninsula: The Trap Hills, Ehlco Area, Norwich Plains, and Sturgeon River Gorge Wilderness Addition.

If successful, wilderness designation would protect these areas for biological diversity, not resource extraction, while still providing opportunities for their respectful use, enjoyment, and economic benefit.

 “The scientific community has learned … that connections and scale really play an important role in the ability of many species to exist over time,” said MNA Conservation Director, Andrew Bacon. Wilderness designation at this scale would most certainly benefit the flora and fauna and provide for the natural processes that help reduce the effects of carbon in the atmosphere—one of the leading drivers of climate change.

Watch our video today, and learn more about this campaign and the coalition members at keeptheupwild.com.