Construction and case analysis of an index for the sustainability of ecosystem services

Natural resources are finite, and a sustainable land use structure and layout are important for promoting the sustainable development of ecosystem services. In this study, we constructed a sustainability index for ecosystem services using three indicators-namely the value, vulnerability, and spatial trade-offs of ecosystem services. Additionally, we attempted to investigate the factors which influence the sustainability of ecosystem services (ESS), as well as the effect of different calculation methods on the calculated sustainability. The "Golden Triangle of Southern Fujian"-a marine-terrestrial zone urban agglomeration-was taken as a case study to investigate the ESS. Results showed that: (1) Factors of regional economic density, population density, and land use changes significantly influence the ESS, while the geographical location and urban infrastructure construction have little impact; (2) A method involving the multiplication and superposition of the positive and negative index was found to be reasonable for calculating the ESS; (3) In the research area, the ESS is generally high, with the sustainability indices of most counties reaching 0.3-0.5 (ordinary quality) and above. During the study periods (2005-2010 and 2010-2015), the sustainability indices of cultivated land, forest land, water area, and grassland decreased by 5.61, 5.90, 2.62, and 7.35%, respectively, while the sustainability indices of construction land and unused land increased by 4.85%, 32.10%, respectively. The number of counties whose ESS was classified as weak (0-0.1) or relatively weak (0.1-0.3) decreased to zero during the study periods. This research provides a method for the quantitative evaluation of the ESS and has theoretical and practical significance.