Testing the Success Rate of Establishing Multitrophic Vegetation for Stream Buffer Mitigation According to Georgia DOT Specifications on Different Slope Ratios

Multitrophic vegetative mitigation is required for stream buffers, wetlands, and retention basins within state waters. Downslopes adjacent to linear road construction are typically steep, which creates challenges for establishment and erosion control in disturbed areas requiring vegetation. A field experiment was conducted to test the establishment rate, persistence, and erosion control provided by multitrophic vegetative buffer mitigation plantings. Over the three-year period, native seed mixture was able to establish and persist at all slope ratios tested including 2:1, 2.5:1, 3:1, and 4:1. The increase in slope ratios did not reduce the establishment of plantings. Topdressing with local soil improved plant establishment by about 5% on several dates in the first year, but there was no residual benefit to plant cover or erosion control in the second and third year. The hierarchical rank of erosion levels from high to low among slopes evaluated were 2.5:1 > 2:1 > 3:1 > 4:1. The native species that established exhibited vegetative growth during the summer and fall, but declined in cover throughout the winter and spring months. Although the native species were able to establish regardless of slope, agronomists will need to implement management programs to minimize the invasion of weed species such as Italian ryegrass and Johnsongrass for long-term culture. Further research is needed to evaluate the effects of mowing programs, erosion mats, and seeding rates on the competition of species established for multitrophic vegetation.

Language

  • English

Media Info

  • Media Type: Digital/other
  • Edition: Final Report
  • Features: Figures; Photos; References; Tables;
  • Pagination: 31p

Subject/Index Terms

Filing Info

  • Accession Number: 01675151
  • Record Type: Publication
  • Report/Paper Numbers: FHWA-GA-17-1322, Research Project No. 13-22
  • Contract Numbers: PI# 0012803
  • Files: NTL, TRIS, ATRI, USDOT, STATEDOT
  • Created Date: Jul 11 2018 1:57PM