SNA Nature Notes - Winter 2017

minnesota department of natural resources

Minnesota Scientific and Natural Area


Showy lady's-slipper

Winter 2017

Restoration of a Rare Jack Pine Woodland at La Salle Lake SNA

By Tyler Janke, SNA Specialist

In 2012 a windstorm caused a catastrophic blow-down at the La Salle Lake Scientific and Natural Area, located 20 miles southwest of Bemidji, Minnesota. During this event nearly all mature trees in a rare jack pine woodland were toppled. This native plant community, known as a Jack Pine – Bush Honeysuckle Woodland, has become increasingly rare; it is ranked critically imperiled in Minnesota and is threatened globally. Following the blow-down, restoration efforts at La Salle have focused on reestablishing jack pine as a canopy tree. Harvest activities to salvage the downed trees were designed to assist jack pine regeneration by disturbing the ground to expose mineral soil. After the downed trees were removed jack pine seed collected from the site was hand-sown across the area.

Jack pine woodland
Jack Pine – Bush Honeysuckle Woodland before blow-down.
Jack pine blow-down
Jack Pine – Bush Honeysuckle Woodland after blowdown. Photo Blaine Klemek

DNR ecologists began monitoring jack pine germination and establishment once restoration activities were completed. In the first year following restoration, it was clear that new trees were starting to grow, as seedling counts totaled more than 1,300 jack pine seedlings per acre. However, by the spring of 2016, it became apparent that hungry deer would be a major threat to the survival of the young jack pine seedlings. The first signs of widespread deer damage came in late April of 2016 when an evaluation of the site showed that as many as 75% of jack pine seedlings had sustained browse damage over the previous winter. Luckily, follow up observations indicated a majority of the browsed seedlings recovered, but DNR ecologists knew that sustained heavy browsing over a number of years would kill many of the young pines.   

Jack pine seedling in protective cage

Seedlings needed to be protected from the deer. Two likely options included bud capping or whole tree caging (see adjacent photo of caged jack pine seedling). Bud capping is an inexpensive method involving stapling a small piece of paper around the growing tip of a seedling. Caps need to be reapplied every year until the trees grow beyond deer browsing height. Whole tree caging offers greater seedling protection and only needs to be done once, but it is more expensive than bud capping. Site managers decided to test both methods.  In the fall of 2016 some jack pine seedlings were bud capped while others (approximately 50 seedlings) were surrounded with 5 foot tall woven wire cages.  

The following spring, a survey of the site quickly determined that paper bud caps were ineffective at stopping deer browse. The deer had learned to pull off the bud caps to get to the tender pine seedling tips.  Meanwhile, none of the 50 caged seedlings were damaged. It was clear that caging was the needed, but how to go about caging thousands of individual seedlings scattered over more than 30 acres? The answer was to build one big cage around the whole site. SNA staff and wildlife specialists designed a fence capable of keeping deer out of the recovering woodland. It was determined that a fence enclosing about 30 acres would protect the core of the best jack pine regeneration. Construction of the 10 foot tall, woven wire fence began in June following a required archeological survey of the site. The survey was needed because the La Salle Lake area contains a number of important prehistoric Native American sites, and construction of the fence had the potential to damage artifacts. As it turned out the survey did locate a new cultural resource site containing chert chips (chert is a type of stone similar to flint) from prehistoric tool making. The final layout of the fence was modified to avoid the newly identified prehistoric site and completed by mid-summer with financial support from the Minnesota Environment and Natural Resources Trust Fund.

Construction of deer fencing
Portion of deer exclosure fence following construction. Photo by Tyler Janke

The prospects for recovery of the Jack Pine – Bush Honeysuckle woodland at the La Salle Lake SNA are much better now that damage from deer has been addressed. However, the young jack pine seedlings remain vulnerable to other stresses including drought, wildfire and competition from faster growing tree species, like aspen. SNA managers will continue to monitor the recovery of this site and are ready to respond to future management needs as they arise. With a little time and luck, future generations of Minnesotans will once again be able to walk among mature jack pine in a jack pine woodland at La Salle Lake SNA.

Map of deer fencing
Location of restoration areas and deer exclosure fence at La Salle Lake SNA

An Insight into Hill’s Thistle Populations at Blanket Flower Prairie 

By Kylie Jensen, Student at North Dakota State University 

Hill’s thistle (Cirsium pumilum var. hillii) is a species with narrow habitat requirements and very limited range in Minnesota; it is dependent on well-drained dry prairies. This species has many ecosystem benefits, among them, providing a nectar source for pollinators, seed as food for birds, insects and small mammals, and seed head fibers used by various fauna. Yet, the continued loss of prairie has contributed to a decline in Hill’s thistle populations. Because of this decline and rarity, Hill’s thistle  is listed as a species of special concern in Minnesota. The population at the Blanket Flower Prairie SNA is at the far western edge of its range.

    Hill's Thistle
    Hill’s thistle plant, including seed head. Photo by Linda Norland


    This fall semester (2017) at North Dakota State University (NDSU) my advisor Jack Norland and I developed a research project to monitor the Hill’s thistle population at Blanket Flower Prairie SNA. We developed a monitoring system to help identify changes in Hill’s thistle population over time at the SNA. I used past population counts and locations of this species for reference. I then used a randomized function to select 10 random locations to sample. Within these 10 locations, I created 50 meter transects in a GIS system, which were assigned geographic coordinates to the transect end points. 

    For the field portion of my research, my team and I used a GPS receiver to locate the end points of the 50 meter transects and marked them with flags. Next, we split into two to four person teams and walked each side of the transect from one flag to the next. This created a 4-meter-wide sample belt along the 50 meter transect. As we walked, we counted all individuals (rosettes and whole plants) that were found as I recorded the data. 

    Field search for Hill's thistle
    The team searching for Hill’s thistle at Blanket Flower Prairie SNA. Photo by Linda Norland

    After the data were recorded from each sample belt transect, I was able to calculate the population density for each location. Next, I compared thistle numbers to past population counts at each location. I learned that thistle number had declined along all but three of the transects. This comparison used different sampling protocols, and so may not reflect the actual trend in population numbers. In the future, the surveys will use this newly created protocol to ensure better estimation of population trends.

    Hill's thistle population comparison chart
    Individual Hill’s thistle plants per GPS point number.


    Continued monitoring of Hill’s thistle at Blanket Flower Prairie SNA and throughout its native range is important to build a clear picture of how thistle populations are faring. 

    I would like to give a special thank you to my advisor Jack Norland and the NDSU Natural Resource Management Program for guidance throughout this project. I would also like to thank Linda Norland for sharing her pictures of the field day and the NDSU Natural Resource Management Club and volunteers for helping with the field work. 

    Brochure and Statewide Map Now Available


    In the last issue of Nature Notes, we mentioned a forthcoming Scientific and Natural Area (SNA) brochure, noting that it and a statewide map would be printed soon. We are happy to report these publications are now available and we have begun distributing them across the state. If you are interested in getting copies for yourself or a supply for your organization please contact the DNR Information Center at 888-646-6367 or by email at

    The program hasn’t had a brochure for many years. It is hoped this communication tool will introduce the program to those unfamiliar with us. For those who know us already we’ve highlighted goals, program focus areas, and encouraged you to get involved. 


    Statewide SNA Map
    Sample of updated statewide SNA map showing sites in the Mille Lacs Lake/Brainerd area.


    The statewide map is an redesigned update. It includes locations of all current sites, a new grid for finding SNAs, and directions to each site on the back of the map. You can also download a digital copy of the map.

    We hope you find these publications useful and informative!

    New State Forest Maps Available

    You may be interested in one of six newly published state forest maps available in two options, a geoPDF and paper map. Users can download the geoPDF version of the map onto a mobile device using a variety of map apps, which will allow you to track your own location as a blue dot on the displayed map. The new user-friendly paper maps highlight the unique recreation features of each forest and include pop-out maps for popular campgrounds and day-use areas.

    New geoPDF and paper maps are now available for:

    Free paper maps of these, and other state forests, are available at local DNR offices or the DNR Information Center at 888-646-6367 or by email at


    Site Highlight: La Salle Lake SNA

    By Shelby Bauer, SNA Web and Social Media Specialist

    Just north of Itasca State Park, escape the crowds and take in the wild beauty of the Mississippi River at La Salle Lake Scientific and Natural Area.

    This Natural Area protects a rare jack pine woodland. However today you might not make this observation too quickly. A 2012 wind storm blew down much of the jack pine and nearly wiped the plant community off the landscape.

    But, that was five year ago. Today you can walk down a rolling trail through the grass, lined with a few interpretive signs, and observe the restoration of this rare jack pine woodland. Here and there jack pine saplings tower over dense bracken fern and beaked hazelnut. Quaking aspen quiver in the wind and the sweet scent of lowbush blueberry and bush honeysuckle drift in a warm summer’s breeze. 

    The end of the trail takes you up a small hill, topped by a single old jack pine; where on hot summer days you can smell the pine’s sap as you gaze out over the Mississippi River.


    Overlook at La Salle Lake SNA
    Overlooking the Mississippi River at La Salle Lake SNA. Photo by Shelby Bauer

    SNA Events

    Events are a nearly year-round affair at Lost Valley Prairie SNA! In winter months the focus is on cutting and burning brush. Join in on one of these fun stewardship projects.  A full list of fun is available on the SNA Events Calendar. Check back frequently as new events are added, including a winter exploration of Sugarloaf Point SNA!


    Brush pile burning
    Brush pile burning at Lost Valley Prairie SNA. Photo by Brett Whaley

    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 stewards Bill Marengo and Ester Gasik reported watching several birds October 17 and 18 at Mound Spring Prairie SNA. Their observation report included ruby-crowned kinglet, eastern bluebird, cedar waxwing, fox sparrow, and western meadowlark. They also saw a sharp-tailed grouse, which is very uncommon to see in southwestern Minnesota.
    • On November 26, newly enrolled site steward Lee Lewis made some observations during his first visit to Black Lake Bog SNA. Noted were winter birds such as pileated woodpecker and snow buntings. There were also a few hunting parties seen on the road/trail to the SNA. 
    • Downed trees and invasive buckthorn were noted as items that need work at Quarry Park SNA. This assessment was based on a November 4 and December 3 visits by site steward Julie Snarland with assistance from Laura Kundrat.

    Thanks for all the work you do for SNAs stewards!

    Volunteer Opportunity

    Do you love Minnesota winters? How about taking photographs? If you said yes to both, we have an opportunity for you! Volunteer to photograph Scientific and Natural Areas this winter and share them on the Minnesota SNA Flickr group!

    More information about the types of photos we are looking for and which SNAs to take them at can be found online at DNR Volunteer Opportunities.


    Winter photography
    Winter grasses at Joseph A. Tauer Prairie SNA. Photo by Dale Bohlke

    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).