Yuki Sampei

Fill material flows created by land development earthworks are anthropogenic agents that generate massive energy use from their heavy loads. However, formal quantification of these flows has been neglected. We use Osaka Prefecture in Japan as a case study to quantify fill flows and associated CO₂ emissions. We collected data on fill flows, including fill generation and acceptance. We mapped these publicly uncounted fill flows and calculated the CO₂ emissions from the associated energy use. We also simulated a scenario in which optimized shortest-distance matching is achieved between fill generators and acceptors. We estimated the current fill flows based on distance and weight and broke down the total by type of site and activity. We compared our estimates of current fill flows with estimates from our matching simulation and found the simulation could achieve an 8448 km reduction in flow length and a 5724 t-CO₂ reduction in emissions associated with transportation. We discussed the implications of flexible matching, especially in different construction sectors, and the importance of continuous, spatially geo-referenced monitoring of these fill flows toward further environmental impact mitigation. The approach presented here could apply to assessing environmental loads arising from landform changes in other cities and lead to development of a new regional- and global-scale fill material science in the Anthropocene.

The Minabe-Tanabe Ume System in central Japan is defined as a Globally Important Agricultural Heritage System (GIAHS) by the United Nations Food and Agriculture Organization. This study examined relationships between parcel-level plant diversity and land use, management, and development in traditional sloped Ume (Japanese apricot; Prunus mume) orchards and adjoining level orchards recently developed through large-scale cut-fill land development. We constructed and overlaid past (1974) and present (2015) digital land-use maps to assess land use and topography. We conducted field vegetation surveys in land parcels with different development and management histories. Although 249 ha (4.6% of the total 2015 area) were developed using cut-fill methods, 5148 ha remain a traditional orchard surrounded by coppice forests. Vegetation surveys and a two-way indicator species analysis revealed that traditional orchards had more native species and a higher plant diversity index. Cut-fill orchards contained a higher proportion of alien species; however, the degree depended on parcel history and management. Overall, this area remains a dynamic mosaic landscape containing a core of long-standing Ume orchards. We suggest that biodiversity conservation in this area should focus on conservation measures such as indirect land-use regulations, including some acceptable landform transformations, to promote continued farming of this ecologically important area.

This paper focuses on the Minabe-Tanabe Ume system, which was designated as a Globally Important Agricultural Heritage Systems (GIAHS) in December of 2015. Because landholdings reflect historical social connections among various landscape units, we quantitatively examined the landscape characteristics of the system by preparing digitized spatial data and performing geographic information system analysis. We also examined the consensus building process among different stakeholders toward GIAHS recognition, as well as the emergent local spatial structure of the stakeholder network through interviews with key stakeholders and participatory monitoring. Our spatial analysis of the landscape generally supported the traditional knowledge of the area as a watershed-based mosaic of coppice forests on ridges, Ume orchards on sloped areas, and villages with rice paddies and dry fields in the plains. Our stakeholder network visualization identified several key persons as important nodes that could connect different types of land use now and may have done so in the past. Moreover, because our GIAHS site has compact agglomerations of watersheds with ranges within a ~30-min drive, most stakeholders, who turned out to have graduated from the same local school, are able to maximize their social capital to reorganize the remaining nodes among different land uses, thereby contributing to the formation of the land-use system and its further promotion through dynamic conservation measures.