20To design robust protected area networks, accurately measure species losses, or understand the processes that maintain species diversity, conservation science must consider the organization of biodiversity in space. Central is beta-diversity-the component of regional diversity that accumulates from compositional differences between local species assemblages. We review how beta-diversity is impacted by 25 human activities, including farming, selective-logging, urbanisation, species invasions, overhunting, and climate change. Beta-diversity increases, decreases or remains unchanged by these impacts, depending on the balance of processes that cause species composition to become more different (biotic heterogenization) or more similar (biotic homogenization) between sites. While maintaining high beta-30 diversity is not always a desirable conservation outcome, understanding betadiversity is essential for protecting regional diversity and can directly assist conservation planning.

Climate change and biodiversity loss can be addressed simultaneously by well-planned conservation policies, but this requires information on the alignment of co-benefits under different management actions. One option is to allow forests to naturally regenerate on marginal agricultural land: a key question is whether this approach will deliver environmental co-benefits in an economically viable manner. Here we report on a survey of carbon stocks, biodiversity and economic values from one of the worldâ (tm) s most endemic-rich and threatened ecosystems: the western Andes of Colombia. We show that naturally regenerating secondary forests accumulate significant carbon stocks within 30 years, and support biodiverse communities including many species at risk of extinction. Cattle farming, the principal land use in the region, provides minimal economic returns to local communities, making forest regeneration a viable option despite weak global carbon markets. Efforts to promote natural forest regeneration in the tropical Andes could therefore provide globally significant carbon and biodiversity co-benefits at minimal cost. © 2014 Macmillan Publishers Limited

Declines in migratory species are a pressing concern worldwide, but the mechanisms underpinning these declines are not fully understood. We hypothesised that species with greater within-population variability in migratory movements and destinations, here termed ‘migratory diversity’, might be more resilient to environmental change. To test this, we related map-based metrics of migratory diversity to recent population trends for 340 European breeding birds. Species that occupy larger non-breeding ranges relative to breeding, a characteristic we term ‘migratory dispersion’, were less likely to be declining than those with more restricted non-breeding ranges. Species with partial migration strategies (i.e. overlapping breeding and non-breeding ranges) were also less likely to be declining than full migrants or full residents, an effect that was independent of migration distance. Recent rates of advancement in Europe-wide spring arrival date were greater for partial migrants than full migrants, suggesting that migratory diversity may also help facilitate species responses to climate change