Wildrye is a plant used to suppress buckthorn throughout much of Minnesota.
Photo Credit: Mike Schuster.
Scientific Frontline: Extended "At a Glance" Summary: Revegetation Seeding for Buckthorn Suppression
The Core Concept: Revegetation seeding is an ecological management strategy that involves scattering seeds of native grasses and wildflowers immediately after removing invasive species like common buckthorn. This technique utilizes native plant growth to compete for sunlight and nutrients, actively preventing the invasive shrub from re-establishing itself in cleared woodlands.
Key Distinction/Mechanism: Unlike traditional removal methods—such as simply cutting down buckthorn, which often fails because the plant rapidly recovers in the newly available sunlight—revegetation proactively fills the ecological void. By quickly establishing native grasses and sedges (such as Canada Wildrye), the native flora outcompetes young buckthorn seedlings for essential resources, suppressing their growth and reducing seedling size by approximately 45%.
Major Frameworks/Components:
- Resource Competition: Leveraging fast-growing native flora to aggressively compete for sunlight, water, and soil nutrients against invasive seedlings.
- Targeted Vegetative Cover: Prioritizing native grasses and sedges over forbs, as empirical data demonstrates they contribute most effectively to the rapid suppression of buckthorn.
- Citizen Science Integration: Validating a decentralized, accessible model of ecological restoration that can be executed by everyday stakeholders and volunteers without formal ecological training.
Branch of Science: Restoration Ecology, Plant Community Ecology, Forestry, and Conservation Biology.
Future Application: This scalable, low-barrier approach provides a standardized blueprint for land managers and citizen scientists to execute widespread, on-the-ground forest restoration. Ongoing research aims to explore secondary ecological benefits of these revegetated landscapes, such as improving habitats for native pollinators and assisting woodlands in recovering from fungal pathogens.
Why It Matters: Common buckthorn poses a severe threat to forest health and overall ecosystem function by rapidly crowding out native flora. Revegetation seeding provides a reliable, cost-effective, and permanent solution to reclaim woodlands, ensuring the sustainable enhancement of natural environments and preventing invasive ecological monopolies.
Throughout Minnesota's forests, the invasive shrub common buckthorn poses serious threats to forest health and ecosystem function. This fast-spreading invader crowds out native plants and can quickly take over woodland spaces, making it a top target for land managers and restoration crews across the state.
Cutting down buckthorn often fails to provide a permanent solution. When given sufficient sunlight and space, it can rapidly recover and re-establish itself in the same location within just a few years.
However, researchers at the University of Minnesota have found a clever way to tip the odds against this woody invader. Their findings were recently published in Restoration Ecology.
Past studies show that scattering seeds of native grasses and wildflowers right after buckthorn is removed can help keep buckthorn from coming back. The native plants compete for sunlight and nutrients alongside buckthorn seedlings, making it harder for young buckthorn to gain a foothold. This management strategy, called revegetation seeding, has shown promising results in small experimental plots.
To see whether revegetation could help forests across the state, University of Minnesota researchers teamed up with science volunteers to try the technique in woodlands throughout Minnesota.
Buckthorn removal and revegetation of native species can be successfully carried out by stakeholders throughout the state without specialized training to equipment.
“This study helps us to better understand the role that everyday people can play in on-the-ground forest restoration regardless of skill level or formal ecological knowledge,” said Mark Fuka, co-author of the study and a plant community ecologist in the University of Minnesota College of Food, Agricultural and Natural Resource Sciences.
“We’ve shown how native plants like Canada Wildrye can help suppress buckthorn in our earlier works, but this study takes a big leap forward,” said Mike Schuster, co-author of the study and a researcher in the University of Minnesota College of Food, Agricultural and Natural Resource Sciences. “Not only did we find that seeding native grasses and wildflowers helped keep buckthorn out of Minnesota woodlands, we found that that was true across a huge diversity of site conditions and more than 100 different practitioners. This is a winning strategy that almost anyone can use.”
According to the study’s authors, the results suggest that revegetation seeding can work at a large scale to help keep buckthorn in check. For land managers hoping to try the approach, the most effective seed mixes appear to be those rich in native grasses and sedges, which quickly fill in the space and compete with young buckthorn seedlings.
As for next steps, the research team is now looking ahead to what these restored forests might become over time. Important questions remain regarding the many other impacts revegetation might have on forests, ranging from improving habitat for pollinators to helping woodlands recover from fungal pathogens. The researchers are optimistic that this approach will provide many diverse benefits to the forests of Minnesota and beyond.
“Although we often focus on the largest buckthorn during removal efforts, it’s generally the little buckthorn that trip up restoration efforts,” said Schuster. “Without further intervention, those little plants grow up fast and easily replace their felled relatives; this work shows that we can reliably shut those little plants out by reseeding native species in many of Minnesota’s broadleaf forests.”
Funding: University of Minnesota’s Minnesota Invasive Terrestrial Plants and Pests Center, supported by the Minnesota Environment and Natural Resources Trust Fund as recommended by the Legislative-Citizen Commission on Minnesota Resources.
Authors: Mark E. Fuka, Michael J. Schuster, Peter D. Wragg, Nicholas J. Partington, Lori Knosalla, Abbie Anderson, Andrew D. Kaul, and Peter B. Reich
Source/Credit: University of Minnesota
Reference Number: eco032326_01
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