The Impact of Downgrading Protected Areas (PAD) on Biodiversity

TL;DR

This study quantitatively demonstrates that downgrading protected areas in the U.S. significantly reduces biodiversity, with notable declines in species abundance and economic losses, highlighting the importance of conservation policies.

Contribution

It provides the first comprehensive quantitative analysis of the biodiversity impacts of PAD events in the U.S., linking policy actions to ecological and economic outcomes.

Findings

Biodiversity decreases by 26% within 50 km of PAD events.

Overall species abundance declines by 32.3% after PAD enactment.

Economic losses due to biodiversity decline amount to approximately $690 million.

Abstract

We quantitatively assess the impacts of Downgrading Protected Areas (PAD) on biodiversity in the U.S.. Results show that PAD events significantly reduce biodiversity. The proximity to PAD events decreases the biodiversity by 26.0% within 50 km compared with records of species further away from the PAD events. We observe an overall 32.3% decrease in abundance after those nearest PAD events are enacted. Abundance declines more in organisms living in contact with water and non-mammals. Species abundance is more sensitive to the negative impacts in areas where PAD events were later reversed, as well as in areas close to protected areas belonging to the International Union for Conservation of Nature (IUCN) category. The enacted PAD events between the period 1903 to 2018 in the U.S. lead to economic losses of approximately $689.95 million due to decrease in abundance. Our results contribute to the understanding on the impact of environmental interventions such as PAD events on biodiversity change and provide important implications on biodiversity conservation policies.