Ecosystem Development in Post-Mining Landscapes.

Post-mining ecosystems typically develop on waste materials (overburden dumps or tailing storage facilities) and often the mined-out landscape (in open-cut mining). Reconstructing sustainable ecosystems on these materials requires clear ecological targets, knowledge of the characteristic of the potential growth substrates, and an understanding of how the new ecosystem is to function. Often pre-mining systems are selected to provide clear success criteria and local (similar) systems are chosen as reference sites against which to benchmark the progress of ecosystem development.

Soil handling and management in the systems is critical for the success of mine site reclamation schemes where the loss of physiochemical and biological attributes in stockpiled soil is to be avoided. Further, the development of the new post-mining ecosystem is highly dependent on the development of the incipient soil system that underpins successful and sustainable ecosystem restoration.

As ecosystems develop on mine sites they are involved in a feedback process between plants, soils, and organisms. I will show how terrestrial ecosystems have developed in a number of contrasting study sites and how understanding the development of post-mining soils are key in underpinning sustainable ecosystem development. Key to this is carbon flows into soil and its effect on microbial biomass, communities and functions.  I will show that the development of the microbial functions towards that of native benchmark communities was driven by quantity of carbon substrates and its utilisation. Colonisation of soils by roots and mycorrhizal fungi followed contrasting patterns, and established unique communities, depending on the nature of the developing ecosystem.