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General declines in ecosystem service values (ESV) are acknowledged worldwide; however, rather few studies have used quantitative measurement to describe the relationship between urbanization and ESV. This paper characterized ESV changes and their relationships with urbanization in Shanghai peri-urban area (China), using the proxy based approach and geographically weighted regression (GWR). Results showed that between 1994 and 2006 total ESV decreased from 4718.1 to 3263.6 million RMB Yuan, with a net decline of 30.8%. Significant spatial autocorrelation was identified for the patterns of ESV changes. Adjacent districts exhibited similar trend of ESV changes. GWR signified that response of ESV changes to urbanization was spatially non-stationary. The obtained relationships presented identical nature but different strength in space. ESV changes were negatively correlated with urbanization indicators, suggesting that ESV would decline with economic increase and population growth. Districts with high proximity to central city and those located in the western area would experience higher rates of ESV declines as urbanization intensified. Our results demonstrated that GWR was superior to global regression in explaining relationship between ESV changes and urbanization. [ABSTRACT FROM AUTHOR]

Soil degradation by expansion-driven sealing increases at an unexpected rate globally, but the dynamics of agricultural soil sealing in peri-urban areas remain poorly understood. This study used aerial photographs to monitor patterns of built-up land expansion and subsequent agricultural soil sealing between 1994 and 2006 in peri-urban areas of Shanghai, China. Results indicated that a total of 152,706.5 ha of agricultural soils were sealed. In particular, residential land and industrial land were the major contributors. Buffer analysis demonstrated that agricultural soils with high proximity to roads and urban centers are more vulnerable to be sealed. Percentage of sealed agricultural soils of total agricultural soils had linear relationships with population growth and economic development. These results quantitatively document the impacts of urbanization on agricultural soil seating. From a management perspective, we argue that the protection of agricultural softs should be integrated with urban planning efforts in China. [ABSTRACT FROM AUTHOR]

Given the important role of land ecosystem in social-economic progress at regional, national, and international scale and concurrent degradation of land ecosystems under rapid urbanization, a systematic diagnosis of land ecological security (eco-security) for sustainable development is needed. A catastrophe model for land ecological security assessment was developed in order to overcome the disadvantages in subjectivity and complexity of the currently used assessment methods. The catastrophe assessment index system was divided into hierarchical sub-systems under the pressure-state-response framework. The catastrophe model integrated multiple assessment indices of land eco-security according to the inherent contradictions and relative importance of indices without calculating weights. Specifically, membership degree of higher level index was calculated based on the membership degrees of lower level indices that were subjective to suitable model, such as cusp, fold, swallowtail and butterfly model. This model was applied to evaluate the state of land eco-security in Shanghai. Mann-Kendall's test was utilized to characterize its temporal trend between 1999 and 2008. Significant downward trend was identified for land eco-security, in terms of pressure sub-index, state sub-index, response sub-index and synthetic index. All these implied that land ecosystem conditions were not optimistic for Shanghai and such situation should draw the attention of policy makers. The calculation procedure presented in this paper does not require a high level of technical expertise to determine the membership degree, making it simple and operational. Being applicable to similar land ecosystems, the catastrophe model is thus believed to provide an alternative approach to land eco-security assessment. [ABSTRACT FROM AUTHOR]