Bird species richness in High-Andean forest fragments : habitat quality and topography matter

Montane forests worldwide are known centers of endemism and biodiversity but are highly threatened by fragmentation processes. Using data collected in 15 Polylepis forest remnants covering 2000 hectares, we investigated how bird species richness and bird community composition, particularly for species of conservation concern, are influenced by habitat quality and topography in the Tunari National Park in the High Andes of Bolivia. Bird species richness was highest in topographically complex, low-elevation Polylepis patches located in areas with a high potential to retain rainwater. Bird communities differed strongly between Polylepis lanata and P. subtusalbida remnants, each supporting different threatened and endemic species. Within the P. subtusalbida forest, high-elevation fragments characterized by high amounts of sunlight and low anthropogenic disturbance were more likely to contain threatened species. Surprisingly, we found no effect of fragment size on the diversity or composition of bird communities or the presence of bird species of conservation concern. The presence of exotic plantations (Pinus and/or Eucalyptus spp.) in or outside forest remnants was negatively associated with the number of bird species as well as with occurrence of the endangered Cochabamba-mountain finch (Compsospiza garleppi). To support the different communities found in Polylepis forests, these results suggest that conservation efforts should be directed towards both forest types (P. subtusalbida and P. lanata) present in the area. For an efficient management of avian diversity, exotic plantations should be established away from native remnants while existing patches should be managed to maintain or increase habitat quality. Finally, the importance of local topography in determining avian species richness and community composition in forest fragments, mainly through topographic controls on moisture distribution and the amount of sunlight received by the fragments, should be considered when planning conservation and reforestation schemes

Pathways to achieve the Sustainable Development Goals

As we are closing in on the deadline set by the Convention on Biological Diversity (CBD) to achieve the protection of 17% of land and freshwater areas and 10% of marine areas by 2020 (i.e. Aichi Targets), and biodiversity decline continues unabated, conservationists are divided as to how much natural space should conserved to protect biodiversity. Some argue that if fully achieved, the Aichi Targets for protected area expansion and habitat restoration will suffice to avert further extinctions. On the other hand, there is a growing support for the ‘Half-Earth’ vision, which aims to secure at least half the planet for nature conservation. Some recent studies have shown that such goals may be achievable, provided that some ecosystems would be restored. However, these studies often ignore other societal goals, and the socioeconomic reality of economic growth and food security, both important drivers of biodiversity changes worldwide and generally at odds with biodiversity conservation. We determine which socioeconomic pathways and policies are required post-2020 to achieve goals for biodiversity conservation and ensure food security worldwide. We use optimization algorithms and targets for species conservation and food production under alternative socio-economic scenarios to 2030 to plan at the same time for both biodiversity and food security. We integrated both Half-Earth and Aichi targets 11 and 12 with different scenarios aiming to reduce habitat loss by increasing agricultural efficiency, changing diets and reducing human population growth. We highlight the key socio-economic changes needed for achieving future visions for biodiversity conservation to be feasible and the areas of the world where most protection and restoration are needed to achieve these visions.peerReviewe

Identifying trade-offs between biodiversity conservation and ecosystem services delivery for land-use decisions

Sustainable land-use management must account for the potential trade-offs between biodiversity conservation, productive land uses and ecosystem services. In this study, we used Marxan with Zones to generate land use plans that optimize conservation, farming and forestry land uses to reach biodiversity targets while minimizing the opportunity cost for local communities in an inhabited but data-poor National Park in the Andes of Bolivia. Based on six alternative land-use plans, we identified the synergies and trade-offs between the biodiversity benefits achieved in the different plans and the delivery of four locally important water-related ecosystem services modeled with the web-based tool AguAAndes. Although we find synergies between the conservation of high altitude Polylepis woodlands and their associated avifauna and three of the ecosystem services investigated, soil erosion levels were actually higher in scenarios with higher achieved biodiversity benefits. Our study shows how systematic conservation planning and ecosystem service delivery modelling can be used to solve land-use conflicts and identify trade-offs between biodiversity conservation and ecosystem services in a data-poor tropical area