Actionable science, Restoration, Working lands
Grassland Restoration Treatment for Wildlife and Pollinators
Case Study by the Conservation and Adaptation Resources Toolbox
Status
Ongoing

Location

States

Missouri

Subject

Agriculture
Birds
Grasslands
Mammals
Outreach
Plants
Pollinators
Reptiles
Vegetation
Water quality
Working lands

Introduction

An individuals pours water into a man-made structure with 3 small bowls in a prairie
Image Details

Human Development and land-use changes have contributed to the loss of grasslands across the Great Plains. At least 42% of native grasslands in the Great Plains have disappeared (World Wildlife Fund 2018). Prairie grasslands provide a multitude of benefits, including erosion prevention, carbon sequestration, and wildlife habitat; however, rising human populations and increased demand for food result in development and other land-use changes, such as agricultural production, that diminish grasslands. As such, these pressures will reduce the benefits these grasslands provide. 

Nevertheless, grasslands and agriculture can coexist. In fact, native grasses can increase crop yields and energy production. Additionally, grasses can help stabilize soil and water quality while wildlife could help eat agricultural pests or help pollinate crops. Researchers and agricultural and energy companies alike have long sought to understand how best to integrate agricultural systems with grasslands, while maintaining all the benefits that these ecosystems provide. (Asbjornsen et. al. 2013) Companies like Roeslein Alternative Energy seek to restore native grasslands, expand their use in agricultural systems, and communicate conservation information to landowners. Roeslein uses plant biomass and hog manure to produce natural gas through a process called biodigestion. Roeslein and other grassland researchers wanted to understand how the seed diversity used in grassland restoration projects impacted native pollinators, bird, and small mammal populations. 

Iowa State University researchers and Roeslein Alternative Energy studied the impact of restoring prairie fields on local biodiversity. They converted farm fields in Northern Missouri into native grasslands with varying degrees of seed diversity to better understand grassland restoration and its impact on human systems and ecosystems alike.

Key Issues Addressed

Grassland restoration currently presents numerous obstacles for landowners and managers. The common perception is that grassland restoration could threaten a farm's productivity and economic outlook, especially if the restoration techniques and treatments are novel and costly. Communication addressing these concerns has often led to tension and mistrust despite restoration benefits.

Researchers currently do not have a solid picture of how restoration impacts ecosystem roles. Pollinators, like bees, can help pollinate native plants and crops. Some farmers and industries are almost entirely reliant on pollinators to grow their crops and expand their operations. Community-wide impacts on birds and small mammals are unknown as well. Researchers hoped to find a way to understand how land restoration techniques influence wildlife biodiversity across the entire working landscape.  

There is little research on how the seed diversity of restored grasslands impacts wildlife and native plant cover. Past research, such as the STRIPS project (Science-based Trails of Rowcrops Integrated with Prairie Strips) at Iowa State University, has not focused on the relationship between wildlife and seed diversity. The STRIPS project studies how strategically placing strips of prairie into soybean and cornfields provides wildlife habitat while still supporting economic interests. Farmers have planted over 14,000 strips, but more information on seed diversity could help managers and farmers use restoration treatments that best support wildlife under human land uses like monoculture agriculture. 

Project Goals

  • Study how different seed diversity mixes influence plant biodiversity
  • Monitor how bird populations, small mammals, and bees respond to grassland restoration
  • Disseminate study results to apply to other conservation projects and research 

Project Highlights

Early Planting: Researchers planted the study fields in late January and early February, which resulted in optimum germination in the spring. 

  • High Diversity, High Success: The high-diversity mix resulted in native grass cover increasing 9% and forbs increasing 33%. In low-diversity fields, native grasses increased 15% and forbs increased 20% during the same time period. Native foliage increased by over 40% cover over the 3 years of the study. Non-native grasses which first dominated slowly gave way to native grasses. Researchers observed native Switchgrass (Panicum virgatum) and Little and Big Bluestem (Schizachyrium scoparium and Andropogon gerardi respectively) first in the study. Native Indiangrass (​​Sorghastrum nutans) appeared late over the course of the study.
  • Wildflowers flourish: Regardless of the diversity in seed mixes,Coreopsis (Coreopsis tripteris), bergamot (Monarda fistulosax), and coneflower (Echinacea purpurea) were more common than compass plant (Silphium lacinatum) or lead plant (Amorpha canescens) in study fields, which tend to take 3 years before observers can see their growth. This supported biodiversity, especially pollinators, across the landscape.
  • Birds stayed at healthy levels: Overall, bird communities maintained abundance and density under the restored treatments. 60% of the birds observed were Red-winged Blackbirds and Dickcissels. Red-winged Blackbirds particularly thrived in low diversity fields.
  • Small mammals and snakes experienced population growth: Both mammals and snakes groups increased in population size in both study fields. Grassland restoration supported over 1500 individuals from at least 15 species.
  • Pollinators responded differently to restoration: Bee populations were higher in abundance and richness in high-diversity fields by year three of the study. However, bee populations did not change until year three. Over the course of the study, researchers recorded at least 71 bee species. There were more bee species in areas with high forb cover.
  • Ag benefits: Restored grasslands around lakes and rivers increased water quality for surrounding farms. This grass has helped filter the water to maintain its quality for a multitude of human and environmental benefits.

Lessons Learned

A square placed around a spot of wildflowers on a prairie
Image Details

Restoration success occurs on a longer timeline than a year. While many landowners and researchers want restored grasses to sprout and grow in the first year after planting, it often takes two or three years to see a noticeable change in diversity. Native grasses were not the majority of grasses until year three of the study. This is not a novel finding, but its importance should not be understated. 

Researchers found that bird, snake, and small mammal numbers are not dependent on the diversity of grasses in grassland restoration. The study showed improvements or the stabilization of wildlife regardless of the seed mix. While bird community density and abundance remained relatively unchanged, all other populations studied increased densities and populations regardless of the number of seeds and species in a grassland. 

Pollinators took longer to respond to the land changes than other wildlife, as change did not occur until year 3. Pollinator data directly after restoration may not reflect the true impact restoration has on pollinators. These groups take longer to respond to land-use changes than other wildlife populations in an area, such as birds and small mammals. 

Communicating intention with landowners is critical for success. Communicating the benefits of grassland restoration can be a challenge, especially if there is a lack of trust with federal agencies and companies in the restoration areas. Managers and researchers found that utilizing workshops with open discussions for local farmers to share knowledge, express concerns, and learn from each other increased the impact and scale of restoration projects. Coming from positions of equality helped gain trust between parties. 

Next Steps

  • Expand pollinator monitoring to include more than just bees and flies.
  • Implement audio recording methods to monitor bird communities.
  • Both the researchers and Roselin will look into ways to apply findings to simpler ecosystems with multiple land uses.
  • Researchers will continue finding ways to incorporate agricultural systems with grasslands for the mutual benefit of agriculture and ecosystems. Water quality and quantity in agricultural lands as a result of grasses have yet to be explored.
  • Explore if manure applications on grassland restoration projects impact grassland plant and pollinator growth.
  • Roeslein will use the findings to help achieve their goal of restoring 30 million acres of grassland in the next 30 years. 

Funding Partners

Resources

Contacts

CART Lead Author

  • Sam Johnson, Pollinator Conservation in Grasslands - Stories of Adaptive Management Intern, U.S. Fish and Wildlife Service

Suggested Citation

Johnson, S.E., and Giese, J. (2022). “Grassland Restoration Treatment for Wildlife and Pollinators.” CART. Retrieved from https://www.fws.gov/project/grassland-restoration-wildlife-and-pollinators.

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