Evaluating ecosystem protection and fragmentation of the world's major mountain regions.

Conserving mountains is important for protecting biodiversity because they have high beta diversity and endemicity, facilitate species movement, and provide numerous ecosystem benefits for people. Mountains are often thought to have lower levels of human modification and contain more protected area than surrounding lowlands. To examine this, we compared biogeographic attributes of the largest, contiguous, mountainous region on each continent. In each region, we generated detailed ecosystems based on Köppen-Geiger climate regions, ecoregions, and detailed landforms. We quantified anthropogenic fragmentation of these ecosystems based on human modification classes of large wild areas, shared lands, and cities and farms. Human modification for half the mountainous regions approached the global average, and fragmentation reduced the ecological integrity of mountain ecosystems up to 40%. Only one-third of the major mountainous regions currently meet the Kunming-Montreal Global Biodiversity Framework target of 30% coverage for all protected areas; furthermore, the vast majority of ecosystem types present in mountains were underrepresented in protected areas. By measuring ecological integrity and human-caused fragmentation with a detailed representation of mountain ecosystems, our approach facilitates tracking progress toward achieving conservation goals and better informs mountain conservation.

Evaluación de la protección y fragmentación ambiental de las principales regiones montañosas del mundo Resumen La conservación de las montañas es importante para proteger a la biodiversidad pues tienen una alta diversidad beta y endemismos, facilitan el movimiento y proporcionan numerosos beneficios ambientales para las personas. Con frecuencia creemos que las montañas tienen niveles más bajos de modificaciones humanas y que contienen más áreas protegidas que las tierras bajas que las rodean. Para evaluar lo anterior, hicimos una comparación entre los atributos biogeográficos de la región montañosa más grande y contigua en cada continente. En cada región generamos ecosistemas detallados con base en las regiones climáticas de Köppen­Geiger, ecorregiones y relieves detallados. Cuantificamos la fragmentación antropogénica de estos ecosistemas con base en las clases de modificación humana de las grandes áreas silvestres, tierras compartidas y ciudades y granjas. Las modificaciones humanas en la mitad de las regiones montañosas se aproximaron al promedio mundial, mientras que la fragmentación redujo la integridad ecológica de los ecosistemas montañosas hasta un 40%. Sólo un tercio de las principales regiones montañosas cumplen actualmente con el objetivo de 30% de cobertura para todas las áreas protegidas del Marco Mundial de Biodiversidad de Kunming­Montreal; además, la gran mayoría de los tipos de ecosistemas presentes en las montañas estaban subrepresentados dentro de las áreas protegidas. Con la medida de la integridad ecológica y la fragmentación antropogénica mediante una representación detallada de los ecosistemas montañosos, nuestra estrategia facilita el seguimiento del progreso hacia la obtención de los objetivos de conservación e informa de mejor manera a la conservación de las montañas.

Ecological filtering shapes the impacts of agricultural deforestation on biodiversity.

The biodiversity impacts of agricultural deforestation vary widely across regions. Previous efforts to explain this variation have focused exclusively on the landscape features and management regimes of agricultural systems, neglecting the potentially critical role of ecological filtering in shaping deforestation tolerance of extant species assemblages at large geographical scales via selection for functional traits. Here we provide a large-scale test of this role using a global database of species abundance ratios between matched agricultural and native forest sites that comprises 71 avian assemblages reported in 44 primary studies, and a companion database of 10 functional traits for all 2,647 species involved. Using meta-analytic, phylogenetic and multivariate methods, we show that beyond agricultural features, filtering by the extent of natural environmental variability and the severity of historical anthropogenic deforestation shapes the varying deforestation impacts across species assemblages. For assemblages under greater environmental variability-proxied by drier and more seasonal climates under a greater disturbance regime-and longer deforestation histories, filtering has attenuated the negative impacts of current deforestation by selecting for functional traits linked to stronger deforestation tolerance. Our study provides a previously largely missing piece of knowledge in understanding and managing the biodiversity consequences of deforestation by agricultural deforestation.