How is the effectiveness of terrestrial protected areas to conserve biodiversity measured? A systematic map

Protected areas (PAs) are central to global biodiversity conservation strategies, but how do we know if they are truly effective?
This systematic map synthesises findings from 275 articles and 280 studies worldwide to assess how terrestrial PAs are monitored and evaluated for biodiversity outcomes. It identifies key trends, gaps, and methodological patterns in the evidence base, offering insights into:

• Geographic and biome representation
• Monitoring methods and biodiversity metrics
• Experimental designs (e.g., CI vs. BACI)
• Underrepresented ecosystems and PA categories
• Use of Essential Biodiversity Variables (EBVs)

The map reveals a growing but uneven research field, with most studies being short-term, site-specific, and focused on forested biomes. It highlights the need for more long-term, landscape-scale, and species-level monitoring, as well as better representation of alpine, desert, and wetland ecosystems.

This resource supports researchers, policymakers, and conservation practitioners in identifying evidence gaps, prioritising future monitoring efforts, and designing more robust evaluation frameworks aligned with global targets such as the Kunming-Montreal Global Biodiversity Framework and the EU Biodiversity Strategy for 2030.