Achieving Multi-Purpose Roadside Vegetation: Reducing Weed Invasion and Fire Risk while Enhancing Pollinator Habitat

Details

• Creators:
  Stewart, Erika ; Grinath, Josh
• Corporate Creators:
  Idaho State University
• Corporate Contributors:
  United States. Department of Transportation. Federal Highway Administration ; Idaho Transportation Department. Highways Construction and Operations, Contracting Services, Research Program
• Subject/TRT Terms:
  Habitat Invasion Resistance Native Plants Pollinators Restoration Restoration Ecology Roadside Vegetation Control Vegetation Management
• Publication/ Report Number:
  FHWA-ID- 25-295
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States
• Edition:
  Final Report: 03/01/2021 – 05/31/2025
• Corporate Publisher:
  Idaho Transportation Department
• Abstract:
  Roadside vegetation management efforts often target a single desirable outcome; however, we often have multiple management goals for restoration. Theoretically, multiple goals can be achieved by establishing native vegetation, but the efficacy of methods used to establish native plant communities are largely unclear. The overall objective of this research is to identify roadside restoration methods that simultaneously reduce weed invasion and fire risk, and enhance pollinator habitat. We hypothesized that combining plant management methods to establish native vegetation would meet these goals. To investigate our hypothesis, we implemented a nested experimental design comprising three experiments. The first experiment assessed restoration practices using mowing and seeding treatments. The second and third experiments assessed restoration practices using soil amendment treatments. We did not find treatment combinations that simultaneously met all of our restoration goals. However, in experiment 1, we found positive effects of seeding a forb-dominant seed mix on native plant establishment, including increasing native forb diversity, meeting the overall goal to increase pollinator habitat. Mowing had mixed results, benefiting both native forbs and introduced plants. In experiment 2, we found that additions of the microbial amendment in conjunction with the micronutrient fertilizer tended to positively affect native grass establishment, while simultaneously suppressing introduced forbs. In experiment 3, we found trends that the microbial amendment had positive effects on native plant establishment, and that the wool pellet fertilizer also reduced fire fuel loading. Overall, our results suggest that select vegetation management methods can be used, and for the greatest return on investment, we recommend that restoration practitioners apply forb-dominant seed mixes at the standard seeding rate, along with soil amendments.
• Format:
  PDF
• Funding:
  T103357
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:511c6a6b920c12e197e4af5c195f1f386b758d82d0b207c9c6be6eb18c5b2006f5a703d02dadf02381b492f20dc35a4e5f2852dfc9b116ae5a3197838660a5d8
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/90125/dot_90125_DS1.pdf
• File Type:
  [PDF - 1.74 MB ]