Reclamation Soils Index of Biological Integrity (IBI)

One approach to measure ecosystem recovery is to compare markers of ecosystem function in reclaimed soils to those within the natural ecosystem. Currently, it is unclear which soil features indicate a successful reclamation trajectory, so the goal of this project was to assess whether biological features, such as soil mesofauna and/or microbial communities, can be used to assess soil function and determine similarity of reclaimed soils to undisturbed reference soils. We characterized mesofauna diversity, density, and composition and bacterial genetic and functional diversity in soils collected from undisturbed reference soil sites, sites with vegetation removed, and reclaimed soils. We also characterized mesofauna density and taxonomy, bacterial genetic diversity and functional diversity, and gathered soil chemistry data to evaluate interactions between soil parameters and biological features.

This preliminary study indicated that soil mesofauna and bacteria could be useful tools for estimating the distance of these communities in reclaimed soils from the range of natural variability in undisturbed natural soils. Reclamation treatments should be optimized, in part, to minimize the distance from the range of natural variability in these biotic soil factors. These biotic soil factors should be incorporated into a robust program of reclamation monitoring and may be a factor that could be used by operators to argue for reclamation certification from regulators.