Hedin, LarsMeyers, Olivia2021-08-192026-09-292021-08-192026-09-292021-04-282021-08-19http://arks.princeton.edu/ark:/88435/dsp011v53k109shttps://theses-dissertations.princeton.edu/handle/88435/dsp011v53k109sProtected areas are the cornerstone of biodiversity conservation. Despite the assumption that protected areas (PAs) are permanent fixtures on the landscape, previous studies document widespread legal changes — protected area downgrading, downsizing and degazettement (PADDD) events — that undermine protected area durability. Costa Rica hosts 6% of the world's biodiversity and is recognized for its pioneering conservation policies, large PA estate, and being the poster child of ecotourism. Costa Rica's environmental consciousness coupled with a strong economic incentive to protect its PAs may position the country to be less vulnerable to PADDD events. In order to further understand the mechanisms and extent of PADDD, I investigated PADDD events in Costa Rica from 1955-2021. During this time, the government of Costa Rica enacted 22 PADDD events and proposed an additional 9 PADDD events. Collectively, enacted PADDD events affected 2.1% of the terrestrial PA estate (302 km2) while proposed events risked downgrading an absolute total area of 13,242 km2, representing 93% of the PA estate. Most PADDD events were associated with infrastructure development (n = 12, 46%), specifically geothermal plants (n = 5). Despite relying on the efficacy of its protected areas, Costa Rica is still vulnerable to PADDD; however, the ecological impacts remain unknown. Policy responses and government transparency are needed to address PADDD and support effective protected areas.application/pdfenPrinceton University Senior Theses