Underlying and proximate drivers of biodiversity changes in Mesoamerican biosphere reserves

Significance

Given the current biodiversity crisis, understanding the ability of protected areas to safeguard biodiversity has never been more important. We examined such potential in a sample of 14 Mesoamerican biosphere reserves, using expert-provided data. During the last 30 y, there was an overall impoverishment of biodiversity and a significant replacement of disturbance-sensitive plant and animal guilds with disturbance-tolerant guilds. Forest loss and isolation promoted by the expansion of agriculture and road networks drove biodiversity change. High human population density and low availability of nonfarming occupation around reserves were the main underlying drivers of biodiversity change. We posit that to mitigate anthropogenic threats to biodiversity within biosphere reserves, it is critical to promote nonfarming sustainable livelihood opportunities around reserves.

Abstract

Protected areas are of paramount relevance to conserving wildlife and ecosystem contributions to people. Yet, their conservation success is increasingly threatened by human activities including habitat loss, climate change, pollution, and species overexploitation. Thus, understanding the underlying and proximate drivers of anthropogenic threats is urgently needed to improve protected areas’ effectiveness, especially in the biodiversity-rich tropics. We addressed this issue by analyzing expert-provided data on long-term biodiversity change (last three decades) over 14 biosphere reserves from the Mesoamerican Biodiversity Hotspot. Using multivariate analyses and structural equation modeling, we tested the influence of major socioeconomic drivers (demographic, economic, and political factors), spatial indicators of human activities (agriculture expansion and road extension), and forest landscape modifications (forest loss and isolation) as drivers of biodiversity change. We uncovered a significant proliferation of disturbance-tolerant guilds and the loss or decline of disturbance-sensitive guilds within reserves causing a “winner and loser” species replacement over time. Guild change was directly related to forest spatial changes promoted by the expansion of agriculture and roads within reserves. High human population density and low nonfarming occupation were identified as the main underlying drivers of biodiversity change. Our findings suggest that to mitigate anthropogenic threats to biodiversity within biosphere reserves, fostering human population well-being via sustainable, nonfarming livelihood opportunities around reserves is imperative.