Local leakage effects of establishing protected areas in multi-use forests

Strengthening protection of multi-use lands used for forestry production is a central pillar for achieving global area-based conservation targets. However, there are concerns that this can lead to “leakage” effects or the displacement of resource extraction activities to unprotected lands, which can undermine biodiversity goals. To assess this risk, we applied a causal inference framework to New South Wales, Australia, which has a long-running program of converting government-owned multi-use land into protected areas. We estimated the historical leakage effects arising from displaced harvesting activities and isolated them from other drivers of forest clearing. Our results show that these leakage effects were small when averaged across the years and rarely exceeded the amount of clearing that the new protected area helped avoid. Leakage effects were statistically significant and increased clearing in nearby areas in the early years of the program (2001), when large amounts of forests were added to the national parks estate each year. However, these estimated effects were much smaller in later years (2006-2011) when fewer protected areas were created annually. Overall, our findings suggest that despite the potential for conservation to shift activities and cause local leakage, strengthening protection on multi-use land still delivered net-positive conservation outcomes. Our findings highlight that while strengthening protection on multi-use lands can deliver conservation outcomes, there is a strong need for similar programmes to be accompanied by monitoring and evaluation that includes estimates of local leakage effects.