SNA Nature Notes - Fall 2020

minnesota department of natural resources

Nature Notes


Showy Lady's Slipper

Fall 2020

Minnesota Scientific and Natural Areas brand icon

Nature Notes is the Minnesota Scientific and Natural Areas quarterly newsletter. Here's what's in store this issue!


The Rare and Wild: Old Growth Forests of Minnesota


Learn more about one of the rare native plant communities that Scientific and Natural Areas protect in this 2020 series about the “Rare and Wild” in Minnesota!

AmberBeth VanNingen, SNA Northeast Regional Specialist

Old growth forests are evocative. They bring to mind towering trees and shadowy, ancient places. Entering one can feel like a gateway to a different world. Old growth forests can also surprise, looking nothing like what we expect.

What are they?

Old growth forests have canopies dominated by large trees from 120 to over 300 years old. In Minnesota, these canopies can be made up of sugar maple, ashes, red and white pine, white cedar, oaks, tamarack, and spruces. But old growth forests are more than just old, big trees. They contain trees of all sizes and ages including shade-tolerant species like ironwood, Canada yew, pagoda dogwood, and sugar maple and white cedar seedlings in the understory ready to break through and join the canopy when given the opportunity. The old trees themselves aren’t always that big. Old growth black ash swamps can be quite deceptive. The trees may only be 9-11” across, but can be over 120 years old! Regardless of the size of the old trees, old growth forests take time to develop and have generally been spared catastrophic disturbances that may replace the entire stand, such as major fires and windstorms, and human intervention such as roads, development, and logging. Evidence of this is seen in the large amounts of snags and fallen dead wood, including some of the largest trees as they are felled by wind, ice, and fire over time.

Fall colors of maple seedlings

Sugar maple seedlings carpet the forest floor at Lutsen SNA. Photo by John Gregor, © ColdSnap.


The DNR has a formal internal process for recognizing and designating old growth stands on its land. Much of this work was done in the 1990s for upland and lowland hardwood forests. To qualify, the stands have to be at least 120 years old, 20 acres in size, contain other old growth characteristics (e.g., snags), and have experienced little human disturbance. Potential sites were field checked and evaluations completed. In some areas of the state, future old growth forests (those less than 120 years, but with other old growth characteristics) were designated to ensure a diversity of old forest on the landscape. A process to designate lowland conifer old growth (white cedar, tamarack, and black spruce) is currently underway and the DNR will be publishing proposed designations for public review in the near future.

Where are they in Minnesota?

Old growth forests can be found almost anywhere there are forests in Minnesota, from the vast peatlands in the northcentral part of the state (such as Norris Camp Peatland SNA) to the cool shade of Townsend Woods in the Big Woods, to the sugar maple forests of Spring Beauty Northern Hardwoods SNA on the North Shore and many forests in between. Some of the best places to access old growth forests are state parks and SNAs, although they occur on just about every kind of state land and on other ownerships, such as in the Boundary Waters Canoe Area Wilderness and Nature Conservancy preserves. The DNR old growth website has a good list of places to visit on state lands.

Why are they important?

It is thought that about 51% of Minnesota’s forests were in old growth stages prior to European settlement in the late 1800s to early 1900s. Only about 4% of Minnesota's forested land remains old growth today. Their rarity is part of their importance. Old growth forests also provide important habitat for an abundance of species, from those shade tolerant shrubs (who also tend to not tolerate a lot of disturbance), to animals such as fisher, pine marten, and porcupines that need big old trees as dens for their young. Woodpeckers of all stripes flock to old growth, as the old trees and snags host a diversity of insects. Old growth provides a benchmark for us when restoring or managing younger forests as well.

Old trees are also important as long-standing witnesses and survivors. Kelly Applegate, Director of Resource Management for the Mille Lacs Band of Ojibwe, tells of a consultation with Elders on the possible removal of old trees at a building site. The Elders responded by asking, “Would you cut me down because I’m not young and fresh? Am I disposable?” For the answer to those questions, you can still see these old trees in front of the Band’s government building. Those trees are important.

Who works on them?

The teams within the DNR that work on old growth designation and management are interdisciplinary, with foresters, ecologists, wildlife and nongame biologists, and recreation staff represented. Old growth management focuses on maintaining or enhancing the old growth characteristics for which it was designated and providing for recreation where appropriate. While it is true old growth is rarely actively managed, several tools such as prescribed fires and invasive species treatment are available to land managers. Itasca State Park is one place you can visit to see prescribed fire used in old pine and other forest types to encourage pine regeneration and manage fuel loads. Itasca Wilderness Sanctuary SNA, nested within the park, contains over 800 acres of designated old growth and has been included in this project.

Other types of management, such as timber harvesting is not allowed. This includes salvage sales after disturbances. Wildlife openings and browse regeneration development do not occur and pesticides cannot be used (except to protect against serious invasive species threats). No development such as new roads and trails can be made as well.

While old growth forests may seem eternal, they are just part of the forest cycle of life. The old trees will eventually die, blow over, or be burned in a fire and end up on the forest floor. The understory will change as opportunistic plants grow in the newly created gaps in the canopy. Animals that use forest gaps and younger forests will move in and the old growth forests of today will transition into the younger forests of tomorrow. Similarly, the young and middle-aged forests of today, if undisturbed, will grow into the old growth forests of tomorrow and the cycle will continue.

Broken trunk of a large fallen tree

A large, old white pine was felled by a wind storm at Lost 40 SNA in 2018. Photo by AmberBeth VanNingen, MN DNR.

Back to top

Meet Arika Preas, the SNA Naturalist in Northeast MN!


Woman in a natural area

Arika Preas has been a Naturalist for the Scientific and Natural Areas program with the Minnesota DNR since September 2019. She spends half of her time promoting the program through outreach events, school events, teaching master naturalist classes for partners, and other programing. The rest of her time, she focuses on SNA management activities. These include things like plant surveys, mending deer enclosures, and invasive species management. 

What does an SNA Naturalist do?

When you think of a Naturalist, most people think of that person at the nature center who can answer your questions and will lead hikes and nature programs. As an SNA naturalist that’s about half right. I don’t have a nature center for you to visit me at but I do lead programs such as hikes on our wonderful SNA’s. I also get to do fieldwork that most naturalists don’t get to do such as plant and animal surveys.

 What is the best part about your work?

I get the best of both worlds. I get to spend time outdoors in nature doing management and monitoring on the SNA’s, but I also get to talk to people about why each SNA is so amazing. I like the variety!

Why do you do this job?

I spend most of my free time doing the same thing anyways, might as well do it professionally?

What is your favorite native Minnesota plant or animal?

Currently, Sweet-fern (Comptonia peregrine) because it smells oh so good.

What is your favorite SNA?

I like all of them but if I had to pick just one, Little Too Much Lake SNA because it has such a fun name.

Back to top

Location of Lost 40 SNA in MN

Site Highlight: Lost 40

A New Partnership in Old Growth

Mary Nordeen, Public Affairs Specialist, Chippewa National Forest


On a hot July day, employees from the Chippewa National Forest and Minnesota DNR, Scientific and Natural Area (SNA) program installed new interpretive panels along the Lost 40 trail. In the hours it took to set up the signs, they counted almost 100 people hiking the trail. Even on a humid buggy mid-summer day, families were choosing to hike in the forest rather than spend a day at the lake. That’s the draw of the old-growth pine forest of the Lost 40, and the reason for this partnership project.


Interpretive signs on the trail

Three of the new interpretive signs in the parking area at the Lost 40 SNA. Photo by AmberBeth VanNingen.

The Lost 40 is approximately 32 acres of designated old-growth white pine and red pine forest crossing both state and federal lands. In 2019, staff from the state DNR’s SNA program and Forest Service staff discovered a shared interest in updating the interpretive panels at the Lost 40. Previous panels had been created separately, but now working together allowed for a shared message on importance of old-growth forests and diverse species found there.

A first step for the project was updating the existing interpretive plan for the Lost 40, highlighting key themes that not only included a theme on old-growth pine, but the diversity of plants and wildlife, geology, logging and fire history as well as the cultural significance of the old-growth forest. 

With so many people hiking the trail, new directional signs were also created. These small maps include tree identification tips. As staff worked to post the signs at the trailhead, it was clear hikers welcomed the new information. Many stopped to read the signs leaning against the truck prior to the crew even getting them in the ground! Thanks to this partnership, visitors will be able to wrap their arms around those big pines while gaining greater understanding of the importance of old-growth. Thanks go out to the Chippewa National Forest wildland fire and recreation crews for their help installing the signs.


Tops of pine trees

Tall red and white pines silhouetted against the sky at the Lost 40 SNA. Photo by Kelly Randall.

Lost 40 Highlights

  • The oldest white pine at the Lost 40 is about 194 years old. White pine can live up to 450 years, but most live to around 200 years.
  • The oldest red pine here is about 250 years old. The oldest recorded red pine at the Lost 40 was 307 years old.
  • Most of the mature red and white pine are up to 250 years old and between 22 and 48 inches in diameter.
  • Did you know? The oldest individual trees within the SNA are in a stand of red pines 230-240 years old. The stand on adjoining land within Chippewa National Forest reportedly originated as early as 1745, and includes the "co-champion red pine" of Minnesota's Native Big Tree Registry, measuring in at 115" in circumference and 120' high.
  • The last Self-guided Bioblitz of the summer is at the Lost 40 and ends on September 30!

Back to top

Visit the SNA Facebook page!

A note on Diversity, Equity, and Inclusion


The Scientific and Natural Areas (SNA) Program strongly embraces diversity, whether in the ecological diversity of the lands we protect, or in the lived experiences of the people we serve. SNA sites are open to everyone, and all are welcome at SNA events and programs. Unfortunately, it’s understandable that some people may feel unwelcome or unsafe due to prejudice in outdoors spaces. We want to help change that. If you think that someone you know or an organization/group you have ties with might be interested in exploring a natural area with us, please connect us to them at

Fall Colors


Autumn is here. Do you know what that means? Fall colors!

Every week, we will post a fall color update featuring photos from the past week on the Scientific and Natural Areas Facebook page. Have you seen some fall colors while hiking an SNA? Send your photos to to be featured in this week’s update!


fall foliage forest

Fall colors at Greenwater Lake SNA. © ColdSnap Photography.

Share your SNA photos on our flickr group!

Notes from Site Stewards


Site stewards monitor SNAs across Minnesota. Their observations provide valuable information to the SNA Program. Here are some interesting notes from recent reports.

  • Site steward Janet Nelson visited Pennington Bog SNA several times this season to document species, check site conditions, and photograph rare Calypso orchids (Calypso bulbosa var. americana). She brought along a friend who fulfilled his bucket list desire to see and photograph Calypsos. Note this site is open by permit only.
  • Andrew Tri, the new site steward of Big Island SNA, visited the SNA in spring and again in late summer and noticed pelicans swimming around the island in spring, and saw a couple bald eagles fishing along the shore in late summer. He noted that he was “walking among lots of huge basswoods and maples, which is really rare to see this ecotype in north Minnesota.”
  • Site steward Marsha Kurka visited Boot Lake SNA on September 14, noting several exciting bird finds, including 10 trumpeter swans on the lake, a lone eagle sitting up in a tree above its nest, a hairy woodpecker and a red-bellied woodpecker, and heard sandhill cranes calling several times.
  • Jerry and Karen Ibberson, site stewards of Clinton Falls Dwarf Trout Lily SNA, have been very busy this season eradicating invasives like dame’s rocket, Siberian squill, buckthorn and garlic mustard at the site.
Swans on a lake

Trumpeter swans at Boot Lake SNA in early fall, taken by Site Steward Marsha Kurka.

Thanks for all the work you do, SNA stewards!

Back to top

SNA Events


Self Guided Bioblitz

We are halfway through the last SNA Self-Guided Bioblitz! This is your last chance to join in on this summer series. Check out the Lost 40 Bioblitz page on iNaturalist to see how you can join in!

Check out the SNA events page for all the latest information on SNA events.

Back to top

Sign up for SNA event reminders

Nature Notes is the Minnesota Scientific and Natural Areas quarterly newsletter (archive online). It seeks to increase interest, understanding and support of natural areas while promoting involvement in the protection of these special places. Contact us directly at


Funding for this project was provided by the Minnesota Environment and Natural Resources Trust Fund as recommended by the Legislative-Citizen Commission on Minnesota Resources (LCCMR).