Ecosystem services response to rural-urban transitions in coastal and island cities: A comparison between Shenzhen and Hong Kong, China

Abstract

Understanding the ecosystem services response to rural-urban transitions is critical for urban planning that aims to achieve sustainable urban development, in particular for coastal and island cities where economic development and the maintenance of ecosystem services are in conflict. In the present study, the responses of ecosystem services to rural-urban transitions in coastal and island cities were investigated and compared taking Shenzhen and Hong Kong, China as case studies. For both cities, the ecosystem service value was quantified using a unit value-based quantification approach, while the urban, peri-urban and rural areas were identified by combining a hexagonal sampling method with cluster analysis. The results suggested that, between 2000 and 2015, the mean value of ecosystem services of rural hexagons was the highest, followed by peri-urban and urban hexagons. For each city, the mean ecosystem service values of the same hexagon type did not differ significantly over time. Both similarities and differences in the response of ecosystem services to rural-urban transitions were detected between the two cities. A persistent downward trend in the value of ecosystem services was observed for both cities, although the decline in Shenzhen was much stronger than in Hong Kong. This was because urban expansion in Hong Kong as an island city was much slower as it was constricted by the availability of land, compared to the extremely rapid urbanization of Shenzhen. The above findings suggested that, compared to island cities where the expansion of urban areas was restricted by the limited availability of land resources, the ecosystem services of coastal cities were more significantly reduced as the urban land continuously expanded to inland remote areas. Correspondingly, towards the maintenance of ecosystem services, specific policy implications for urban planning have been identified for each city.