||The effect of urban form on biodiversity potential and the extinction of experience : land sharing and land sparing compared
都市の形状が生物多様性と自然体験の消失に及ぼす影響 : 土地の節約戦略と共有戦略の比較
1. Conservation and restoration of urban biodiversity have increasingly become asignificant consideration in city planning policies. From a conservation viewpoint,this is because urban area potentially harbors richer biological communities thanthose in rural areas. Nature in cities also provides opportunities for regularencounters by urban dwellers (i.e. averting the "extinction of experience").2. As cities are typically designed by top-down policy-making, initial developmentschemes have a crucial role in determining the capacity to sustain regionalbiodiversity and ecosystem services. Currently, urban development forms areclassified into two alternatives: urban land-sparing (intensive development in asmall land) and urban land-sharing (extensive development in a greater land).3. In this thesis, I investigated relative benefits of urban land-sharing and land-sparingfor biodiversity conservation and promotion of people's nature experience.4. As a result, I found that urban land-sparing is a better option for biodiversityconservation in general. Especially in areas that will become heavily urbanised,land-sparing shows a remarkable conservation benefit. On the other hand, I alsofound an advantage of urban land-sharing to promote human-nature interactions inurban areas: people living in urban land-sharing regions use urban greenspacesmore frequently than those in land-sparing regions.5. This thesis revealed a potential conflict in the design of cities between the urbanform that is most desirable for the protection of regional biodiversity, and thatwhich best promotes people's nature experiences. The challenge is thus to reconcilebiodiversity conservation and promotion of people's nature experiences in urbanlandscapes.
Hokkaido University（北海道大学）. 博士(農学)