Evaluation of methods for Canada thistle-free habitat restoration
Tallgrass prairie is one of the most imperiled ecosystems on Earth, and nowhere more so than in the upper Midwestern United States. The persistence of tallgrass prairie, and the species it supports, are increasingly dependent on management actions to restore and reconstruct native prairie plant communities. The goal of this study was to improve the practice of prairie reconstruction on former cropland by experimentally testing the effects of seeding method (broadcast or drill), planting time (dormant or growing season), and seed mix diversity (10, 20 or 32 species), on cover and diversity of native prairie plants and cover of invasive exotic plants, especially the noxious weed, Canada thistle ( Cirsium arvense). The study was begun in 2005, sampling continued through 2010 and is slated to occur again in 2015. As of 2010, results clearly showed that planting more species did result in greater species richness. Broadcasting seed during the growing season was never the best strategy, although it worked well for dormant season planting. Surprisingly, many of the “weedy” native species in the seed bank were quite effective at reducing infestation by exotic species during the early years of the reconstruction. Results of the 2015 surveys will clarify the longer-term effectiveness of the methods we tested.
Diane L Larson
- Effects of planting method and seed mix richness on the early stages of tallgrass prairie restoration
- Evaluation of Restoration Methods to Minimize Canada Thistle (Cirsium arvense) Infestation
- Seeding method influences warm-season grass abundance and distribution but not local diversity in grassland restoration
- Using prairie restoration to curtail invasion of Canada thistle: the importance of limiting similarity and seed mix richness