Infludence of topsoil-till cover depth and amendments on ecosystem reclamation of a closed tailings storage facility

The mining industry plays a pivotal role in British Columbia’s economic development. Yet, its presence often intersects with the province’s ecologically fragile grassland ecosystems, highlighting the importance of reclamation practices to return the disturbed grassland to a sustainable ecosystem. This study explores strategies to enhance reclamation efforts by conducting a field experiment in a reclaimed tailings storage facility (TSF) and a companion greenhouse experiment to investigate the effects of different topsoil and subsoil cover depths (i.e. 10 cm topsoil, 20 cm subsoil and 15 cm topsoil and 15 cm subsoil), and amendments including zeolite, leonardite, and compost in different ratios on soil and plant community properties. Furthermore, the effects of tilling a closed and reclaimed TSF after ~20 years post-reclamation on soil and plant community properties were examined. The results of this study revealed that covering tailings with 15 cm topsoil and 15 cm subsoil resulted in an increase in above-ground biomass and demonstrated the potential of zeolite and compost as sustainable tools for tailings storage facility reclamation. The study also examined the influence of tillage on reclaimed sites, which resulted in a lower carbon-to-nitrogen ratio and a negative impact on alpha diversity in comparison to the reclamation practices on bare tailings. The findings of this research provide valuable insights into the use of different amendments and topsoil-subsoil cover depths for a sustainable reclamation of tailings storage facilities in the semiarid interior of BC