Mapping biodiversity corridors and mine rehabilitation opportunities

Currently, some of the major threats to biodiversity are habitat loss/change and fragmentation. These processes have a synergistic effect that results in progressively smaller patches of native ecosystems, divided by anthropogenic features and/or activities (e.g. agriculture, urbanisation, patches of land divided by the road or railroad networks, etc.).

However, long-term survival of species requires the availability of patches of land that are large and healthy enough to sustain reproducing populations and the exchange of individuals across populations (i.e. migration, dispersal). Thus, to counteract the negative effects of habitat loss/change and fragmentation, it is vital to ensure connectivity among patches of land. Such connectivity can be secured or provided by the protection or establishment of biodiversity corridors. These corridors provide links among larger patches of land, safeguarding the exchange of individuals required for the long-term survival of species.

Restoration efforts are now required in many areas impacted by anthropogenic activities to ensure corridors can provide adequate connectivity between core ecosystem patches (large areas that sustain flora and fauna populations).

Mining leaves important patches of land that severely impacted and legally require rehabilitation. However, the rehabilitation goal of each mine is defined/agreed between the regulatory government and the mining company. Thus, the type of rehabilitation varies among mines. For example, some mines may be required to rehabilitate the land for agricultural purposes, while others may be required to restore to native ecosystems that blend in with their surrounding environment.

Case study

To aid Queensland’s government decision making, we created a tool to understand rehabilitation opportunities by contrasting the potential effects of choosing one goal over the other. This project provided the biodiversity perspective, in terms of the availability of ecosystem cores and the connectivity between them. This was done for the Fitzroy Region, Queensland. The Fitzroy Region is a highly fragmented area, subject to mining, agriculture, urbanisation from towns and roads.

In this project, we created a multi-species habitat suitability model that was fed into a connectivity model, along with a land use map of the Fitzroy Region. We assessed the effect of each rehabilitation goal on the connectivity of the landscape based on connectivity maps created by changing the values given to the mining land class within the land use map. Then we quantified the connectivity gains from restoration outcomes over intensive agricultural outcomes, based on the area of influence, the connectivity strength, and the length of the potential corridors. In addition, we assessed the connectivity of the landscape under current conditions. This allowed, among other things, to identify stepping-stone corridors where restorative efforts may be required to reach the full potential of those corridors.