National Park Core Zones Do Not Buffer Insect Pollinators Against Occupancy Declines

Abstract

Aim

To assess the extent to which French national parks mitigate pollinator declines and support biodiversity outcomes across protection gradients.

Location

Eight French national parks, including core zones, buffer zones, and surrounding non-park landscapes.

Methods

We analysed 290,540 occurrence records representing 610 pollinator species (Lepidoptera, Hymenoptera and Diptera) from 2000 to 2023. Species-level occupancy trends were estimated across core, buffer and non-park zones using standardised occupancy modelling frameworks applied consistently across taxa and protection levels. We quantified temporal changes in occupancy, species richness and community turnover, and compared patterns between rare and common species as well as among major taxonomic groups.

Results

Pollinator occupancy decreased by −41.1% in core zones, −34.0% in buffer zones and −26.6% outside of national parks over the period. Declines were disproportionately driven by losses of common species, which became ‘rarer’ while rare species became more ‘common’. Core zones harboured 27%–50% more rare species than non-park areas and reduced declines in common species richness by approximately 31%. Butterfly (205 sp.) occupancy declined more slowly in core zones (−0.62% year⁻¹) than outside of parks (−2.23% year⁻¹), whereas the occupancy of moths (324 sp.) declined more rapidly in core zones (−5.18% year⁻¹) than elsewhere.

Main Conclusions

French national parks partially mitigated pollinator declines by supporting rare species and slowing losses of some taxa, but they did not halt overall declines, even within strictly protected core zones. These findings suggest that protected areas alone are insufficient to reverse insect declines and that stronger or more targeted management interventions may be required if parks are to contribute meaningfully to pollinator conservation.