## Global Prioritization Schemes: Impacts and Implications### IntroductionBiodiversity loss is a growing concern as human activities exert increasing pressure on ecosystems. Establishing protected areas (PAs) has been a cornerstone in efforts to counteract biodiversity decline. The Convention on Biological Diversity's (CBD) Aichi Target 11 set a goal of protecting at least 17% of ecologically representative terrestrial area globally by 2020.In the late 1990s to early 2000s, many prominent environmental non-governmental organizations created global biodiversity prioritization schemes, mapping areas they determined to be most critical for conservation. Two key schemes are:* **Biodiversity Hotspots:** Prioritized areas based on high levels of irreplaceability and threat, having >1500 endemic vascular plant species and >70% habitat loss.* **Last of the Wild (LOTW):** Prioritized the world's most pristine wilderness areas with the least human footprint.These schemes intended to guide effective PA establishment, but their impact has not been thoroughly evaluated.### Causal Analysis of Prioritization ImpactThis study used causal inference techniques to assess the impact of Hotspots and LOTW on PA placement over the past two decades. Matching methods and a Before-After Control-Impact analysis were applied to control for confounding factors and examine time-series trends in protection.### Key Findings* LOTW had a **positive causal impact** on PA growth within its priority areas, with a higher rate of protection than comparable non-priority areas.* Biodiversity Hotspots did **not** have a causal impact on PA coverage. This is likely due to Hotspots being in or near human-dominated landscapes, which may have hindered the implementation of protection measures due to opportunity costs.* In contrast, LOTW aligned with the tendency to protect areas **far from human use** and thus with lower implementation costs, resulting in greater uptake.### Discussion* The differing results between Hotspots and LOTW underscore that prioritization initiatives may not overcome the challenge of conserving areas under immediate threat due to human activities.* When prioritization schemes align with areas that are easier to protect, they can be effective, but when they conflict with human use, their implementation can be challenging.### Limitations and Research Directions* Matching criteria excluded a large proportion of priority cells from analysis, leading to a trade-off in sample size.* Future research could investigate the impacts of other prioritization schemes and potential biases in PA selection.### ConclusionWhile global prioritization schemes provide valuable information, they are only a small part of the actions needed for biodiversity conservation. Ensuring adequate resources for PA management, emphasizing the role of Indigenous Peoples and local communities, and investing in biodiversity conservation outside of PAs are crucial. Recognizing that local initiatives often play a more critical role in PA designation is essential.