A scenario approach for population ‘shrinking’ society: A case study on range expansion of Sika deer

Abstract

 The report of Population census of Japan in 2015 shows that population of Japan has started to decline for the first time since the census started. Population decline are predicted to continue, and population in 2060 are predicted to reach to 2/3 of the current population. These changes may cause significant changes in ecosystem via land-use change. To discuss the solution, scenario approach will be one option to adapt to the uncertain future. We analyzed the effect of future land-use change under population ‘centralization’ and ‘decentralization’ on sika deer range expansion. Although total area of sika deer range was slightly larger at ‘centralization’ scenario, total area of agricultural land-use overlapping with sika deer range was larger at ‘decentralization’ scenario. Scenario approach will contribute to analyze trade-off between policies, and it will become tools to discuss future direction under declining population.