Minnesota Native Seed Consortium

Introduction

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Nearly 99% of native prairie habitat in Minnesota has been lost, and the remaining 250,000 acres are fragmented, as a result of drainage and plowing to support croplands. Intact native prairies in Minnesota (though rare) provide the unique opportunity to harvest diverse seeds for use in restoration. Restoration of native plant diversity supports broad pollinator communities which provide forage and pollination services throughout the ecosystem. Restoration especially benefits pollinators like the declining Monarch butterfly (Danaus plexippus).

Prairie conservation and restoration is a high priority in Minnesota, and recent state legislation allocated tax funds to these efforts through the Lessard Sams Outdoor Heritage Council. The 2010 Minnesota Prairie Conservation Plan organized Local Technical Teams (LTTs) composed of state, federal, and non-governmental organizations to implement prairie restoration and conservation projects. Within one LTT, conversations regarding the limitations and abilities of each stakeholder in procuring native plant materials revealed that the major limitation to most agencies was access to high-quality harvest sites. This realization led managers to develop The Northwest Minnesota Native Seed Consortium (the Consortium). To address the high cost of diverse, representative seed mixes and the unrepresentative composition of their less expensive alternatives, the Consortium facilitated the development of relationships between the Detroit Lakes Wetland Management District of the U.S. Fish and Wildlife Service (DLWMD), Minnesota Department of Natural Resources, and The Nature Conservancy to provide greater access to native prairies for harvest. 

Development of the Consortium accompanied two broad shifts in the prairie management paradigm of the region. The first is the shift from historically insular agency-specific management to collaborative land management models focused on prairie restoration. Second, previous prairie restoration at the DLWMD focused on increasing cover for waterfowl, but with precipitous recent declines in pollinator populations, restoration was now including pollinator conservation in recognition of their crucial role in maintaining healthy prairies.

Key Issues Addressed

Native prairie in northwest Minnesota has been greatly reduced. Habitat degradation and fragmentation has resulted in limited dispersal and recruitment of diverse native forbs and grasses. A diverse composition is necessary to support a variety of species, including pollinators, who aid in maintaining healthy prairies. 

The success of the plant community following restoration depends largely on the seeding mixture. Restoration practitioners relied on seed mixes that were not always representative of native prairies. This was due to practitioners commonly using base mixes dominated by warm-season grasses and adding hand-harvested seed. However, because forbs are sensitive to being overtaken by grasses, hand-harvested species were being over dominated by the higher amount of grasses in poor base mixes. This led to monotypic stands of grass, decreasing diversity.

Conversely, harvesting available land and adding hand-harvested native prairie mixes with enough forbs becomes cost prohibitive. Hand-harvested mixes allow practitioners to be more selective in seed ratios than combine-harvested mixes. However, combine-harvested seed mixes average $30 per pound, while hand-harvested seed mixes can range from $300 to $600 per pound. In order to reach 2 million live seeds per acre, restoration would cost $666 dollars per acre for these seed mixes alone. This is expensive for regional land managers who typically seed 500-800 acres per year. 

Sourcing seed for mixes that accurately represent native prairie in this region requires access to high-quality harvest sites. Previous base mixes were generally combine-harvested from easily accessible restored prairies. The best native harvest sites lie primarily on non-governmental land, however, which was inaccessible to state and federal land managers due to lack of collaboration between agencies. These land managers developed the interagency partnership of the Northwest Minnesota Native Prairie Seed Consortium to increase access to high-quality native harvest sites and address the high cost and unrepresentative composition of their previous seed mixes. 

Project Goals

• Reconstruct high-quality native prairies to improve habitat and connectivity for ecosystem health
• Diversify available seed mixes to better represent native tallgrass prairie composition in restoration projects
• Utilize existing partnerships to gain access to native prairies for seed harvest
• Reduce cost of seeding in restoration projects

Project Highlights

Plants for Pollinators: Increasing plant species diversity in the seed mix enhances habitat value for pollinators, and not just for monarch butterflies. Seed mixes can include species like leadplant (Amorpha canescens), purple prairie clover (Dalea purpurea), and golden alexanders (Zizia aurea), which host specialist pollinators. Leadplant alone is host to nine moth species. When constructing seed mixes, the ability to select for species like these is imperative to ensuring a rich pollinator community following restoration.

• Collaboration and Common Goals:Through the Consortium, historically insular agencies identified a common goal of collaboratively providing diverse, representative seed mixes to simulate native prairie and holistically support the prairie ecosystem, especially for pollinators. The Consortium implements collaborative seed harvests, in which vendors contracted through an agency combine-harvest native prairie seed from partner lands regardless of ownership. Partner agencies now regularly collaborate throughout the restoration process. 
• Native Seed Harvest: Over the first four years, seed was harvested from 30 native prairie tracts in northwest Minnesota managed by the MN Department of Natural Resources and The Nature Conservancy, as well as U.S. Fish and Wildlife Service lands. So far, the Consortium has harvested seed from 975 acres of prairie. These yielded 103,000 pounds of pure live seed, enough to seed 4,000 acres of restored prairie at 2 million pure live seed per acre, at a significantly reduced cost when compared to previously used seed mixes. The reduced cost per acre allows greater acreage to undergo restoration.
• Improving Seed Mix Diversity: Through the Consortium, seed has been harvested from the most diverse native prairies in northwest Minnesota, giving restoration practitioners the ability to select for highly diverse, forb-dominated seed mixes that support diverse pollinator communities. Seed mixes harvested from native prairies through the Consortium are composed of 65-85% forbs and the remainder grasses, surpassing previously set goals for seed mix diversity. Seed diversity in past mixes was often highly variable, and frequently dominated by only a few species of grass. In one representative pre-Consortium seed mix, 86% of the 35 species represented were grasses. Furthermore, 63% of the total mix was a single grass species, big bluestem (Andropogon gerardii). Managers noted using grass-dominated seed mixes such as these frequently led to monotypic stands.

Lessons Learned

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Collaboration and communication allowed land managers to design representative seed mixes. The Detroit Lakes Wetland Management District’s Habitat Management Plan previously set a goal of 50:50 or 60:40 forbs to grasses ratio in seed mixes to reduce the dominance of grasses in restored prairies. Interagency access to previously inaccessible native prairie lands allowed managers to exceed this initial goal and combine-harvest seed mixes consisting of 65-85% forbs.  

Increased access to diverse native prairies through partnerships ultimately reduced the cost of restoration activities for all stakeholders. Previous efforts used combine-harvest techniques on sites which lacked diversity and added in purchased hand-harvested seeds. Managers now rely on combine-harvested diverse prairies, minimizing the costly and labor-intensive need to add additional hand-harvested mixes. The Consortium’s seeding cost is $73 per acre, 90% lower than the estimated $666 per acre using other techniques.

 Adjusting the timing of harvest allows for selection of specific species and aids in designing better mix ratios. By waiting until grass seed fell in the fall and forb seeds hardened, managers reduced the amount of grass seed they were collecting and increased the number of forbs in the mix.

Next Steps

• Monitor sites restored with seeds from the Consortium to assess restoration outcomes: Immediately following seeding, managers noted that a flush of weedy growth often occurs. This growth tends to be dominated by non-native thistle species (Cirsium spp.and Carduus spp.), and yellow and white sweet clover (Melilotus albus Medik., Melilotus officinalis (L.) Lam.). The timing of monitoring varies based on the partner and restoration site. Monitoring is especially important when comparing pre- and post- prescribed fire community assembly. 
• Conduct prescribed fires on restoration sites: Because managers must wait until a site will carry a fire, the time between seeding and the first prescribed burn prescribed burn
  A prescribed burn is the controlled use of fire to restore wildlife habitat, reduce wildfire risk, or achieve other habitat management goals. We have been using prescribed burn techniques to improve species habitat since the 1930s.
  
  Learn more about prescribed burn varies. After the first burn, managers conduct prescribed burns every three to five years in accordance with historical fire regimes. 
• Expand seed storage capacity atThe Minnesota Department of Natural Resources through the construction of new storage facilities in order to facilitate greater harvest capacity 

Funding Partners

• Lessard Sams Outdoor Heritage Council
• Minnesota’s 2008 Legacy Amendment
• Duck Stamp Sales

Resources

• NW Minnesota Seed Consortium Overview Video
• NW Minnesota Native Prairie Seed Consortium Pollinator CoP Presentation
• NW MN Prairie Seed Consortium Native Prairie Species Found In Combine-Harvested Seed Tests
• Minnesota Department of Natural Resources, Scientific and Natural Areas Program
• U.S. Fish and Wildlife Service, Detroit Lakes Management Area

Contacts

• Shawn May, Wildlife Biologist, Detroit Lakes Wetland, U.S. Fish and Wildlife Service: shawn_may@fws.gov
• Travis Issendorf,  ABR Prairie Recovery Specialist, The Nature Conservancy: tissendorf@tnc.org

CART Lead Author

Madison Bigham & Nicolas Katz (CART Student Writers, University of Arizona) and Shawn May (USFWS)

Suggested Citation

Katz, N.A., Bigham, M.D., and May, S. (2021). “Northwest Minnesota Native Prairie Seed Consortium”. CART. Retrieved from https://www.fws.gov/project/minnesota-native-seed-consortium.