Projecting impacts of global land-use scenarios on biodiversity change across scales and species groups.

Abstract

Habitat destruction via land-use change is considered to be a primary driver for both biodiversity and ecosystems changes. As the pressure on land use is expected to increase in the future, there is an urgent need to develop the ability to assess in more detail the full range of responses of biodiversity to future land use change. Scenario analysis of alternative plausible futures is often used as a tool to explore and evaluate the extensive uncertainties associated with such possible future developments. Here, we use the countryside species-area relationship (cSAR) model to project future (2015-2100) changes in both alpha and gamma diversity of birds species and assess the dynamics between two bird functional species groups resulting from land use changes following three distinct scenarios of land use change and climate mitigation (i.e. the land use harmonization (LUH) database that represent alternative representative concentration and shared socio-economic pathways (RCP-SSP). We then compared future and current (1900-2015) rates of biodiversity loss. Across the different scenarios, we observe minimal losses to small increases in mean local species diversity (alpha diversity), although with significant declines of forest specialists, which are compensated by increases in generalist and open-habitat species. While global species loss (gamma diversity) seems to decrease around two percent, across the three scenarios, with significant losses of generalist and open-habitat species, rendering the tree scenarios similar when all bird species are taken together. Our results highlight the importance of assessing how different patterns of land-use affect biodiversity and how different choices will affect different components of biodiversity. We discuss how these considerations can help integrate human development and nature stewardship in a more sustainable way.