The Response of Ecologically Functional Land to Changes in Urban Economic Growth and Transportation Construction in China.

Understanding the impact of urban economic growth on ecologically functional land (EFL) change and the relevant mechanisms is necessary for adaptive ecological management and regional policy. The present study aims to explore the relationship between EFL change, urban economic growth and transportation construction based on reliable land survey data from 2000 and 2015, as well as natural and socio-economic data for over 2600 counties in China. We use the Two-Stage Least Squares (2SLS) technique to empirically analyze the temporal changes in their relationships and alleviate endogenous bias and use the Geographically Weighted Regression (GWR) model to explore the spatial heterogeneity across the country. The results indicate that the secondary and tertiary industries' development had a significantly negative effect on EFL changes, and transportation construction is a major driver of urban economic growth in China, especially in the central region. From 2000 to 2015, the negative impact of urban economic growth on EFL changes decreased, and the contribution of transportation construction to urban economic growth increased. The regions (such as the central region) where transportation construction contributes more to the secondary and tertiary industries had a proportionally greater reduction in EFL. It appears that excessive dependence on transportation to drive the development of secondary and tertiary industries is the underlying reason for EFL reduction. The findings of this study can assist in formulating regional policies and advancing the coordination of urban economic development and ecosystem protection.

Changes in ecological networks and eco-environmental effects on urban ecosystem in China's typical urban agglomerations.

Exploring the changes in ecological networks (ENs), its eco-environment effects and the differences in urban agglomerations in various urbanization stages are important for achieving sustainable ecosystem management and a better layout of ecological network. In this study, China's three typical urbanization agglomerations, Beijing-Tianjin-Hebei urban agglomeration (BTH), Yangtze River Delta urban agglomeration (YRD), and Pearl River Delta urban agglomeration (PRD), were selected as the study area. Spatiotemporal changes in ENs, the changing patterns, its eco-environment effects, and impacts of rapid urbanization were analyzed by environment indices, buffer analysis, and correlation analysis. The results showed a great lost in ENs from 2000 to 2015. Four patterns were seen in changing ENs: decomposition process (DP), internal change process (ICP), polycondensation process (PP), and external change process (ECP). ICP was dominated in YRD and PRD. ECP was the main pattern in core areas of BTH. The correlation analysis with YRD as the example showed that the changes in ENs had a certain impact on the eco-environment, especially in the 10-km buffer zone. The decrease of ENs was related to the increase of developed land, and the closer to the core area, the higher the correlation coefficient was. Reduction of ENs would slow down to a certain extent, when the agglomeration is in a higher urbanization stage. Different directions of restoration and optimization of ENs were proposed for the three urban agglomerations. The study will provide support for sustainable management and restoration and optimization of ENs for China's agglomerations.

Assessing ecological risks caused by human activities in rapid urbanization coastal areas: Towards an integrated approach to determining key areas of terrestrial-oceanic ecosystems preservation and restoration.

Rapid urbanization and industrialization in the coastal zone have caused increasingly serious impacts on coastal ecosystems. It is necessary to assess the ecological risk caused by human activities to determine key areas of terrestrial-oceanic ecosystems preservation and restoration to ensure sustainable ecological management in the coastal zone. Key areas of ecosystem preservation and restoration were studied through the assessment of the impacts of ecological pressure sources related to human activities from the perspective of terrestrial-oceanic ecosystems, using the habitat risk assessment (HRA) and habitat quality (HQ) models in the Chinese coastal zone. The results showed that the impact of human activities on the terrestrial ecosystems in the South of China was significantly lower than that in the North. An improvement rate of habitat quality was noticed only in the south and central coastal areas when further away from industrial land. Agricultural production, urban expansion, and industrial pollution had major negative impacts on the habitat quality of terrestrial ecosystems in the Chinese coastal zone, and also threatened the health of marine ecosystems. The ecological risks caused by human activities in the offshore areas of northern Shandong and eastern Jiangsu were relatively low. Mineral development in the north, excessive nitrogen and phosphorus emissions from agricultural production in the south, and port operations were important drivers of increased ecological risks in offshore areas. There were regional spatial differences in the key ecosystem preservation and restoration areas. The provinces of Shandong, Jiangsu, Hebei, Liaoning, and Guangdong are key areas for strengthening the preservation and restoration of terrestrial-oceanic ecosystems. This study provides a reference for large-scale territorial spatial planning and ecosystems conservation.

Effects of land-use patterns on PM2.5 in China's developed coastal region: Exploration and solutions.

While land-use models have often been used to determine the spatial distribution of air pollutant concentrations at urban spatial scales, the effects of land use on PM2.5 concentrations and removal are rarely investigated at regional spatial scales. We studied these effects in Jiangsu Province, which is part of the Yangtze River Delta Urban Agglomeration. Results showed that forest lands and industrial lands had greater effects on the PM2.5 concentration than did other land-use types. In addition, industrial lands and built-up lands had greater effects on the PM2.5 concentrations in winter than in summer. The spatiotemporal change in the PM2.5 concentration was mainly impacted by industrial distribution and development, while the spatiotemporal change in PM2.5 removal was mainly impacted by forest land distribution and change. Therefore, PM2.5 removal was generally higher in rural areas than in urban areas. The spatial PM2.5 concentration slowly increased with net primary productivity (NPP) first and then decreased with NPP, with an inflection point at 19 g C m-2 a-1 NPP. However, the spatial PM2.5 removal per unit area exponentially increased with NPP. The average removal rate of PM2.5 by forests was about 0.03% in Jiangsu Province, while the absolute removed amount of PM2.5 was about 3013 tons in 2015. It was concluded that the impact of forests on air quality in terms of PM2.5 is significant at regional spatial scales. Therefore, scientific trade-offs and decision-making are necessary to maintain forest ecosystem services in order to improve air quality and human health.

Spatial imbalance and changes in supply and demand of ecosystem services in China.

Human activities and regional land development have caused intense interference to ecosystems. With rapid development of economy and urgent needs of life quality improvements in China, sustainable ecosystem management is crucial for national ecological civilization construction. However, few studies have focused on supply-demand patterns of ecosystem services on a national scale in China. The aim of this study was to analyze the spatial-temporal patterns and changes in the supply-demand of ecosystem services and to explore their interactive relationship in the context of economic development and urbanization drivers. The ecosystem services provision index (ESPI) and land development index (LDI) were proposed to indicate the supply and demand for ecosystem services. The results indicated that the Low supply-High demand (L-H) pattern accounted for 3.27% of the total land area in China and was mainly concentrated in developed regions and some capital cities, where 28.95% of the total population and 51.93% of the country's GDP was generated in 2015. The spatial imbalance in the supply-demand of ecosystem services was obvious. From 2000 to 2015, the imbalance was shrinking, and regions with negative changes in supply-demand patterns were declining. During 2000-2008, there was an obvious transformation from Low supply-Low demand (L-L) to High supply-Low demand (H-L), which accounted for 12.44% of the total land area due to Grain for Green and other ecological protection policies. The proportion of ecological land to total land area, vegetation cover and elevation were significantly correlated with the supply of ecosystem services. In the meantime, ESPI was negatively correlated with LDI in most regions in China. There were also regional differences in their relationships. The rapid economic growth and the intensive land development resulted in a more significant decrease in ESPI in the developed regions than that in the undeveloped North and Northeast China. The results of this study could contribute to sustainable ecosystem management and decision-making for Chinese ecological civilization construction.