What lesson for mine closure we can learn from unassisted soil and ecosystem development

Abstract

We used chronosequences of post-mining sites combined with long-term observation of individual sites to compare soil and ecosystem development in post-mining sites undergoing unassisted ecosystem development, and sites reclaimed by various reclamation technologies in different climatic conditions. Using these approaches that allow comparison of individual trials over long periods of time is essential, as in many cases early stage ecosystem development may not be a good indicator of long-term trends. Here, the overview of major mechanisms that determine soil formation and ecosystem development in various climatic conditions are given. We also explore soil formation under various restoration technologies. In suitable climatic conditions, on no toxic overburden, spontaneous processes have the potential to produce valuable ecosystems. In many types of landscapes, namely those with intensive agriculture such as the many parts of Europe, spontaneous recovery of post-mining sites brings a unique opportunity to restore natural habitats. Post-mining landscapes have very high potential for soil carbon sequestration, and in suitable situations, soil formation can be rapid, resulting in development of 10 cm deep A horizon in several decades. Studies of spontaneous processes can be useful for improving reclamation technologies, namely the selection of proper target vegetation and reconsidering or modification of some operations during reclamation.