Mechanical and biotic strategies for post-mine reclaimed grasslands

Global energy production is in high demand and is expanding its development into new landscapes, including grasslands. This expansion has intensive impacts on above and belowground components of grasslands which need to be addressed during reclamation to promote long-term ecological integrity. This study was conducted to ascertain how alternative reclamation practices may improve soil structure (i.e., compaction) while aiding in the creation of conditions that are conducive for both the establishment and continued growth of native grassland plant species. The grassland was reclaimed with different combinations of seeding mixtures (grass or grass and forb), ripping techniques (subsoil ripping or topsoil ripping), and the integration of mulch into the soil profile. Species composition and abundance of the vegetation community was estimated, and volumetric soil moisture and penetration resistance readings were obtained. Year, seed mixtures, ripping techniques and their interactions significantly affected community composition and species diversity. Topsoil-ripping and grass-forb treatment had a higher association with native, perennial grasses while subsoil-ripping and grass treatment favor more short-lived species. Similar trends persisted across penetration resistance and soil moisture readings where topsoil-ripping and grass-forb treatment were different from subsoil-ripping and Grass treatments (p<0.10). Additionally, Kentucky bluegrass, an invasive grass species, increased 76% over one year and was more common in the topsoil-ripping and grass-forb treatments. While early in the reclamation process, results suggest topsoil-ripping and grass-forb treatment are a promising combination reclamation practice that can establish a native grassland community and initiate the improvement of compacted soil conditions.