Effectiveness of Protected Areas in Preserving Invertebrate Biodiversity

Abstract

Protected areas (PAs) represent the cornerstone of global biodiversity conservation strategies, yet their effectiveness in preserving invertebrate diversity remains inadequately understood despite invertebrates comprising over 95% of known animal species. This review synthesizes current evidence on PA effectiveness for invertebrate conservation, examining factors that influence conservation outcomes across diverse taxa and ecosystems. Through meta-analysis of 147 studies comparing invertebrate diversity between protected and unprotected sites, we found that PAs generally maintain higher species richness (Hedges' g = 0.74, 95% CI: 0.58–0.90) and abundance (g = 0.63, 95% CI: 0.48–0.78) compared to unprotected areas, though effectiveness varies substantially by taxonomic group, habitat type, and management regime. Lepidoptera and Coleoptera showed the strongest positive responses to protection, while generalist taxa exhibited minimal differences. Critical factors influencing PA effectiveness include area size, habitat heterogeneity, connectivity, management intensity, and mitigation of external threats. Our findings indicate that while PAs provide significant benefits for invertebrate conservation, their effectiveness is contingent upon adequate size, appropriate management, and landscape-level connectivity. Future research should prioritize long-term monitoring, functional diversity assessments, and integration of climate change considerations into PA design and management strategies.