Vegetation recovery and simulation of colonisation process of dominant species after open-cut mining at Boggabri, NSW, Australia

Abstract

Australia has abundant minerals and coal resources with mining operations being carried out across the country. Although mining disturbance is a temporary change in land use, its impact on the environment may last longer than most other disturbances. In particular, open-cut mining entirely removes the previous topsoil, plants and animals, and destroys the previous ecosystem. The deposit of waste materials such as overburden, alters the topography, causes variation in soil chemistry, and may pollute surface and ground waters. The goal of mine rehabilitation is to return the disturbed area to a stable vegetated and productive condition that is ecologically sustainable over the long term. Recovery involves vegetation colonisation that may take considerable time to demonstrate ecological sustainability, and it is difficult to judge the success of sustainable rehabilitation from short term monitoring. Prediction of vegetation colonisation patterns and rehabilitation efforts will help stakeholders to make sure that the rehabilitation practice satisfies the aims and purpose of the intended land use. Rehabilitation research has been undertaken for decades and, although some models have been developed, there is no appropriate model that can be applied to predict rehabilitation at mining sites. The aims of this study are to assess the structural and compositional changes of vegetation communities on an open-cut mining site over time; to understand the vegetation colonisation process and dynamic interactions from the individual plant level to the ecosystem level; and then to develop a simulation model to predict vegetation colonisation and subsequent long-term development during the rehabilitation process, so as to determine the potential sustainability of the developing ecosystem and to provide management advice for decision-making.