Estimation of the possible influence of future climate changes on biodiversity in terrestrial ecosystem

Abstract:

In recent decades, climate change has progressed worldwide and their influences on ecosystem structure and function that provide various goods and services to humans’ well-being are of the greatest concerns. The ecosystem function and services are tightly coupled with the biodiversity, particularly via food web and biogeochemical cycles and here carbon is one of the central elements. The photosynthetic carbon fixation by plants, which forms the basis of the food web, is known to be highly sensitive to meteorological changes including radiation, temperature, precipitation and CO₂ concentration. Thus an analysis of the effect of future climate change on the carbon cycle processes including photosynthetic production in a biogeographical region, which is important from the viewpoint of the biodiversity conservation, such as “biodiversity hotspot”, might enable us to discuss the relevance between climate change and biodiversity.
In ISI-MIP (Inter-Sectoral Impact Model Intercomparison Project) phase 1, we have estimated NPP (net primary production), plant biomass and soil organic carbon by seven global biome models under climate conditions from 1901 to 2100 based on four RCPs (Representative Concentration Pathways for 2.6, 4.5, 6.0, and 8.5 W m^-2 stabilization targets) and five global climate models. In the present study, we analyzed these outputs to reveal the effects of changes on NPP, plant biomass and soil organic carbon in 20 biodiversity hotspots in various climatic regions. Although NPP of whole world tended to increase under RCP 8.5 W m^-2 scenario, some biome models have shown that NPP of the hotspots in tropical regions decrease.