How long do mining impacts persist? Quantifying biodiversity recovery trajectories in post-mining landscapes

The clean energy transition is catalyzing an unprecedented surge in mineral extraction, frequently placing climate mitigation goals in direct conflict with biodiversity conservation. While ecological restoration is often cited as the primary mechanism to offset these impacts, it is rarely implemented effectively; globally, only a small fraction of mines undergo successful rehabilitation, with estimates in Australia as low as 4% for inactive sites. To effectively manage nature-related risks, we must move beyond the assumption of restoration and integrate quantitative estimates of recovery times into impact models. Without understanding the specific temporal costs required for ecosystems to return to reference conditions, we fail to account for the "added biodiversity loss" that accumulates over decades of recovery, which is crucial for biodiversity accounting in sustainable mining practices.

Here, we present quantitative estimates of restoration times derived from a meta-analysis of 51 Australian studies. We utilized multilevel meta-regression models to assess recovery trajectories for species richness, diversity, and vegetation structure (measured as canopy cover), accounting for interactions with commodity types and management interventions.

Our results reveal a distinct hierarchical recovery process. Flora richness takes approximately 13 years to reach reference levels, while vegetation structure restores after 17 years. However, faunal recovery is significantly slower, with richness requiring over 25 years and diversity estimated to take more than 40 years to match unmined systems. Broad taxonomic comparisons indicate that invertebrates recover faster than vertebrates, while sites utilizing complex active restoration techniques, combining topsoil, seeding, and planting, significantly outperform simpler methods.

Crucially, these findings largely reflect outcomes from active restoration, which is expensive and rare in practice. Moreover, while structural metrics may recover in decades, the restoration of full ecosystem complexity and functioning often spans centuries. Therefore, current restoration practices alone are likely insufficient to offset the biodiversity footprint of mineral extraction. To reconcile mineral demand with global biodiversity targets, the industry must prioritize avoidance and adopt biodiversity-inclusive mining practices rather than relying solely on post-closure remediation.