Summer 2020

Nature Notes is the Minnesota Scientific and Natural Areas quarterly newsletter. Here's what's in store this issue! The Rare and Wild: Saline Prairie Meet the Northwest region Management Specialist Site Highlight: Pembina Trail SNA Upcoming Events

The Rare and Wild: Saline Prairie

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!

Fred Harris, Minnesota Biological Survey

If you cross low, wet ground between the shorelines left by glacial Lake Agassiz in some of Northwestern Minnesota’s large prairie preserves, you might find thinly vegetated zones with whitish salt deposits on the soil surface. You may be surprised to learn this is a specific type of wet prairie: saline prairie, one of the rarest and least-studied prairie types in Minnesota.

Highly saline spot in a Polk County Prairie. Photo by Fred Harris.

What is saline prairie?

Saline prairie forms in the western part of Minnesota within calcareous (calcium-carbonate-rich) deposits left by a massive tongue of glacial ice (the Des Moines lobe) that covered the region over 11,000 years ago. One such landscape is the zone of gravelly ridges marking the former shores of glacial Lake Agassiz. These beach ridges and inter-beach zones are especially conducive to saline prairie formation because they lie on a gradually sloping land surface. Groundwater becomes enriched in minerals as it percolates horizontally through the calcareous deposits and emerges farther downslope. Evaporation of the groundwater concentrates the minerals at the surface.

The elevated salt content of the soils creates extreme growing conditions where only salt-tolerating (“halophytic”) plant species grow. As a result, saline prairie is less diverse than other prairie types, but contains several species found nowhere else in the state. You can often spot these areas of high soil salinity from a distance because they are typically marked by the feathered seed heads of foxtail barley grass (Hordeum jubatum) waving in the breeze. Other dominant species include very slender sedge (Carex praegracilis), also called freeway sedge because it shows up in accumulations of road salt; scratchgrass (Muhlenbergia asperifolia), forming fluffy white or pinkish clouds of seed heads; and little bluestem (Schizachyrium scoparium). Strongly saline areas are packed with salt grass (Distichlis spicata), a relatively short grass with straw-colored seed heads when mature.

What else grows here?

Several rare plants grow in saline prairie, many of which are Great Plains species at the very eastern edges of their U.S. distributions in western Minnesota. These include grasses or sedges, such as: alkali cordgrass (Spartina gracilis), which is shorter and more narrow-leaved than the common prairie cordgrass; Hall’s sedge (Carex hallii), forming stiff, nearly leafless stems topped with 2-3 cylindrical spikes; and Plains bluegrass (Poa arida), which is similar to but more robust than the non-native Kentucky bluegrass (Poa pratensis).

Plants to look for include: seaside arrowgrass (Triglochin maritima), known for its succulent leaves that exude a strong, musky scent of cilantro (from a cyanide compound) when crushed; alkali plantain (Plantago eriopoda), which forms clumps of narrow, leathery, strongly-veined leaves with reddish bases; and alkali buttercup (Ranunculus cymbalaria), growing in diminutive clumps with tiny yellow flowers. One of the rarest and most rewarding saline prairie forbs to find in the Agassiz beach ridges is the northern gentian (Gentiana affinis) which typically hides among the grasses in late summer, its blue flowers dotted with pale freckles.

Northern gentian (Gentiana affinis). Photo © Otto Gockman.

Where is it in Minnesota?

In the Agassiz beach ridges; look for saline prairie on the east sides of marshes.  Places to go include the Crookston Prairie Unit of the Pembina Trail SNA in Polk County; Twin Valley Prairie SNA and Sandpiper Prairie SNA in Norman County; and Western Prairie SNA in Clay County.  Other locations in Polk County include the Nature Conservancy’s South Unit of the Pankratz Memorial Preserve and the Dugdale State Wildlife Management Area.

In southwestern Minnesota, saline prairie is much harder to find. It occurs in drainages that run along the northeast edge of the Prairie Coteau, in western Lac Qui Parle and Yellow Medicine Counties, and in the upper Minnesota River valley. A good place to see it is in the Antelope Valley SNA located just southeast of Canby--if you go, look for low swales in the former hay meadow in the southeast corner of the SNA.

Saline Prairie at Twin Valley Prairie SNA. Photo by Fred Harris.

To the casual observer, saline prairie may not look like much to crow about. However, to the informed observer, these prairies are an intriguing part of the diverse array of habitats that make up our prairie landscape.

Back to top

Meet Tyler Larson

Tyler Larson has been the SNA Management Specialist for the DNR Northwest Region since December 2019. He provides technical and professional support in carrying out natural resource management activities on public and private lands administered by the Scientific and Natural Areas Program. This includes Scientific and Natural Areas, lands enrolled in Native Prairie Bank and Prairie Tax Exemption. Most of his work focuses on grassland management activities such as prescribed fire, invasive species management and habitat restoration. What is the best part about your job? The best part of my job is implementing management activities and witnessing the response of native plants and animals. Whether it is the buzz of pollinators on a freshly planted prairie restoration, regeneration of lush vegetation after a prescribed fire or booming prairie chickens on a lek. It is very rewarding knowing that we have made a positive impact on these special places. Why do you do this work? I have a great deal of respect and passion for the outdoors. Ever since I can remember, I have been fascinated with animals. I remember watching “Wild America” and playing outside in the woods as a child. I grew up in Minnesota lakes country spending summer breaks on the lake fishing and catching turtles. I became a hunter as a teenager when my uncles took me deer and duck hunting. Hunting really connected me with wild animals and the places they call home. In high school, I had a strong interest in biology and life sciences. Later in college, I decided to follow my lifelong interests and pursue a career in wildlife management (my initial college major was aviation). After, I began working in native prairies and wildland fire fighting. I really became interested in grassland ecosystems, specifically remnant prairie, when I went back to school for my master’s degree. My thesis project focused on identifying the components of high quality grassland restorations. This is when I decided I wanted to have a role in conserving and enhancing these incredible places. What is your favorite native Minnesota plant or animal? It is hard to pick a favorite when you like so many. Through work and studies, I have become very interested in plants. I admire the purple flush of Liatris (Blazing Star) in late summer. I think my favorite one is Dotted Blazing Star, which grows in bunches on dry prairies. However, I cannot resist the citrus aroma that comes from crushing the leaves of a Purple Prairie Clover.   What is your favorite SNA? “Sand Dunes, Gnarly Bur Oaks and Native Prairie”. My favorite SNA is Agassiz Dunes. Agassiz Dunes lies within the transitional zone of western prairies and eastern forests. The community type is very complex consisting of dry barrens oak savanna and bur oak aspen forest. Amongst the bur oak covered sand dunes is a mix of short and tallgrass prairie. High quality oak savanna is extremely rare and presents a challenge for managers; its intense, yet precise disturbance history of fire and grazing is hard to mimic. What do you like to do outside of work? When not at work, I love spending my time with my wife and three kids. This usually involves some sort of outdoor activity such as fishing, hunting, boating, biking or downhill skiing. I look forward to connecting them with the outdoors and giving them the opportunity to experience nature as I did.

Back to top

Site Highlight: Pembina Trail SNA   Kelly Randall, SNA Outreach Coordinator   The Pembina Trail Scientific and Natural Area sits as a cornerstone of a much larger complex of native and reconstructed habitat in the Aspen Parklands of northwestern Minnesota. Established in 1981, the site consists of the Crookston Prairie, Pembina Trail Preserve (owned by The Nature Conservancy) and Foxboro Prairie.

Wildflowers dot the vast prairie expanses at Pembina Trail SNA. Photo © ColdSnap Photography.

The land is host to a mosaic of upland prairie, wet prairie, wet meadow and marsh communities in hummocks and shallow swales formed by glacial Lake Agassiz. Interspersed aspen forest and aspen-oak woodland occur, as do some old fields. Look too for an uncommon prairie type, saline prairie (see article above).

This SNA contains over 200 native plants, including several rare species. Of special note is the federally-threatened western fringed prairie orchid which has been studied here for many years. It provides sandhill cranes, prairie chickens, moose and other animals the large expanse of native habitat they require. 

Pembina Trail SNA anchors the west side of the massive Glacial Ridge National Wildlife Refuge. Created by a transfer from The Nature Conservancy in 2004, the Wildlife Refuge has grown to over 20,000 acres in a combination of native prairie and reconstructed prairie, along with natural and restored wetlands. Other public and private land partnerships here have contributed to a project that has become the nation’s largest prairie and wetland restoration.

What feels truly unique here is a sense of vastness. The large tracts of undeveloped public and private land. The uninterrupted sounds of the wind, with an occasional bird call. Even a vehicle passing anywhere nearby is rare. It all combines to give one the idea of stepping back into a time long-ago. Luckily, these places exist today for us to experience. Yet, even if we don’t see them ourselves, it’s satisfying to know Pembina Trail SNA and its surrounding landscapes give nature an expansive place to thrive.

Prairie cordgrass in a wet prairie at Pembina Trail SNA. Photo by Kelly Randall.

Back to top

Introducing the Minnesota Prairie Landowner Network

Are you a prairie landowner looking for a way to connect with other prairie landowners, discuss management ideas and ask questions? Prairie partners from across the state are readying the Minnesota Prairie Landowner Network just for you. Check out the first part of the network: a Facebook group dedicated to helping you manage your Minnesota prairie. Join in the discussion!

Return of the Prairie Pod

The third season of the Prairie Pod begins on July 7. New episodes drop every Tuesday. Check it out and #DiscoverThePrairie!

SNA Events

This summer, check out the Summer self-guided bioblitz series on Scientific and Natural Areas! For two weeks each month a different SNA will host a self-guided bioblitz through the citizen science app, iNaturalist. Can’t make it to the SNA? You can still participate by identifying observations online! The first self-guided bioblitz at St Croix Savanna SNA ends on June 24. But don’t worry, another SNA will be announced soon for July’s bioblitz! Stay up to date with this summer series and other SNA events by subscribing to the event reminder emails. Check out the SNA events page for all the latest information.

Back to top

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 sna.dnr@state.mn.us.

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).