Study On The Assessment And Regulation Of Ecological Space

The rapid global urban growth poses great changes to the natural ecosystem, including the transformation of the natural landscape, alteration of biophysical processes and biological habitat, and modification of major biogeochemical cycles. These changes in turn affect the structure and function of natural ecosystem. In recent decades, China has witnessed a fast sprawl of urban space and it has threatened the health and function of ecological space which is vital to sustaining and fulfilling human life. As the urbanization is still in progress in China, the urban built-up areas will continue to expand in the future. To support the sustainable urban expansion and natural ecosystem conservation, this study improved the theoretical basis and supplied several practical techniques of the assessment method and regulation approach of ecological space.In this study, the main content included three assessment methods of ecological space, five regulation approaches of ecological space and a framework for the evaluation of ecological space policy. Three assessment methods:(1)The sensitivity assessment method combined with ecological resilience This method took account of the spatial heterogeneity of ecological sensitivity response through integrating the ecological resilience of different land use types into the comprehensive assessment of single eco-sensitive elements. Comparing with ordinary assessment method, this method was better in line with the actual ecological conditions.(2)The assessment method of the spatial heterogeneity of ecosystem services This method combined the land use type and coefficients of spatial heterogeneity for each ecosystem services in the assessment process. It improved the assessment accuracy of the spatial heterogeneity of ecosystem services. This method can identify the sections of terrestrial ecosystem with better vegetation cover as the high value region, which were neglected in ordinary assessment method. It demonstrated the superiority of this method.(3)The modeling of ecosystem services and the analysis of their tradeoff This study mapped five ecosystem services (carbon storage, timber production, water yield, water-quality improvement and sediment retention) using In VEST, a leading modeling suite in this field. Then, scenario analysis was carried out on the tradeoff effect among ecosystem services in the ecological space policy, based on the evaluation framework for ecological space policy that proposed by this study. Result showed that the spatial policy for the conservation of some ecosystem services would not conserve other services. So, the conservation planning should be based on the comprehensive analysis of ecosystem services. Five regulation approaches:(1) The regulation based on the driving forces of built-up area expansion Based on the analysis of the driving forces of built-up area expansion, this study proposed the regulation strategy of urban sprawl to conserve the ecological space:â‘ Restrain the excessive GDP growth supported by extensive built-up area expansion,â‘¡Encourage the tertiary industry which is less depended on the expansion of built-up area,â‘¢Implement intensive development and increase the output of per capita and each unit of built-up area.(2)The regulation based on the ecological space couplingThe study area was divided into feasible construction region, limited construction region and forbidden construction region, based on the spatial coupling of the results of ecological sensitivity assessment and ecosystem services evaluation. The effects of this regulation policy were evaluated, using the evaluation framework for ecological space policy that proposed by this study. The result showed that the occurrence of ecological risk and disturbance to ecosystem services would be reduced, if the expansion of built-up area was controlled and the construction was restricted in feasible construction region.(3) The regulation of elastic ecological patternBased on the modeling of ecosystem services and the ordered weighted averaging method (a multicriteria evaluation method), priority areas for the conservation of ecosystem services were identified and the elastic ecological pattern was constructed. The multicriteria evaluation method can take the tradeoffs among ecosystem services into account and conserve multiple ecosystem services simultaneously. The elastic ecological pattern can generate different spatial scenarios according to the conservation policy needs.(4) The regulation of ecological function zoningOrganization theory of ecological space was proposed on the basis of the synthesis of policy theory, spatial heterogeneity analysis and synergetic theory through the three paradigms of organization theory. Based on this theory, ecological function zoning was worked out and incentive policy was made for each ecological zone.(5)The leaf regulation system of ecological spaceBased on the principle of bionics, this study proposed the leaf regulation system of ecological space, including the regulation of ecological boundaries, ecological structure and ecological indicators. The regulation system was applied to the ecological space of Fuzhou city.The framework for the evaluation of ecological space policy:The framework was composed of the scenario simulation and scenario analysis. At first, the scenarios of urban expansion were simulated, taking account of spatial policy guidance, spatial pattern and limiting factor of urban expansion, scenario controlling factors, ecological optimization principles. Then, these scenarios were compared with each other and with the actual process. Based on these comparative analyses, the effects of ecological space policies can be evaluated.In sum, this study focused on the assessment method and regulation approach of ecological space, improved the theoretical basis and provided practical techniques. It can help to make the natural ecosystem conservation and sustainable urban planning more effective and defensible.