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Wang W.,Peking University | Wang W.,Yunnan Key Laboratory of Pollution Process and Management of Plateau Lake Watershed | Guo H.,Peking University | Guo H.,Yunnan Key Laboratory of Pollution Process and Management of Plateau Lake Watershed | And 5 more authors.
Environmental Science and Policy | Year: 2014

Land use changes can affect ecosystem services values (ESVs). In this study, we used crop yield data, ESV empirical data for different terrestrial ecosystems, land use data, and development policies in China to examine the impact of land use changes on ESVs, to compare their spatial differences, and to optimize China's land use structure to maximize the total ESVs using a Linear Programming Model. We found that the assigned ESVs per unit in the three coastal regions presented relatively higher values than in the inland regions. A total of 21.1% of China's land has been converted to other land use types; the conversion rates for different regions indicate the following: east. >. northeast. >. mid-south. >. north. >. southwest. >. northwest. The total ESV decreased by 1.52% due to land use changes, which were mainly distributed in the northwestern, northeastern, and northern regions. The primary transitions that decreased ESVs, included an expansion of built-up land in most regions, decreased woodland in the northeast, and the degradation of grasslands in the northern, southwestern and northwestern regions of China. Our optimized land use structure for 2020 could increase the ESV by 1235.70 billion RMB; when compared with a comprehensive land use plan presented by Chinese government, this would increase the percentage by 8.05%. This result seems to be an effective approach for land managers to consider. © 2014 Elsevier Ltd. Source


Chuai X.,Nanjing University | Huang X.,Nanjing University | Lai L.,Nanjing University | Lai L.,Jiangsu Information Center | And 4 more authors.
Environmental Science and Policy | Year: 2013

Land use change is a main driver of carbon storage in terrestrial ecosystems. Based on land use data, research results related to carbon densities in vegetation and soil as well as government policies related to development in different regions of China, this paper optimized land use structure in 2020 for different regions with the goal of increasing terrestrial ecosystem carbon storage. We defined seven types of land use: (1) cultivated land, (2) garden land, (3) woodland, (4) pasture land, (5) other agricultural land, (6) urbanized land, and (7) a mixture of other land which we call mixed land which included open water, swamps, glaciers and other land as defined below. We found: (1) For most eastern regions, woodland has the highest carbon (C) densities while C densities of pasture land and cultivated land did not differ widely. Both have C densities higher than urbanized land while urbanized land has higher carbon densities than the areas placed in the mixed land type. (2) Under an optimized land use structure projected for 2020, the area of cultivated land will decrease compared with 2005 for most regions. The areas of garden land, pasture land and other agricultural land are much smaller compared with the mixed land use type, and the changes there are not obvious and their contributions to increased carbon storage are not significant. The area of woodland will increase the most obviously and it will contribute the most to increased carbon storage. The increasing urbanization of land and the decreasing trend of other land types make it difficult to change carbon storage patterns since the Chinese economy is expanding rapidly. (3) The optimized land use structure presented here will have effects on the entire country though with regional differences. Some inland regions will always have a larger potential to increase carbon storage than other areas because the potentialities in some coastal regions are limited by social and economic development. © 2012 Elsevier Ltd. Source


Chuai X.-W.,Nanjing University | Huang X.-J.,Nanjing University | Wang W.-J.,Nanjing University | Zhang M.,Nanjing University | And 3 more authors.
Pedosphere | Year: 2012

Soil organic carbon (SOC) plays a key role in the global carbon cycle. In this study, we used statistical and geostatistical methods to characterize and compare the spatial heterogeneity of SOC in soils of Jiangsu Province, China, and investigate the factors that influence it, such as topography, soil type, and land use. Our study was based on 24 186 soil samples obtained from the surface soil layer (0-0.2 m) and covering the entire area of the province. Interpolated values of SOC density in the surface layer, obtained by kriging based on a spherical model, rang ed between 3.25 and 32.43 kg m-3. The highest SOC densities tended to occur in the Taihu Plain, Lixia River Plain, along the Yangtze River, and in high-elevation hilly areas such as those in northern and southwest Jiangsu, while the lowest values were found in the coastal plain. Elevation, slope, soil type, and land use type significantly affected SOC densities. Steeper slope tended to result in SOC decline. Correlation between elevation and SOC densities was positive in the hill areas but negative in the low plain areas, probably due to the effect of different land cover types, temperature, and soil fertility. High SOC densities were usually found in limestone and paddy soils and low densities in coastal saline soils and alluvial soils, indicating that high clay and silt contents in the soils could lead to an increase, and high sand content to a decrease in the accumulation of SOC. SOC densities were sensitive to land use and usually increased in towns, woodland, paddy land, and shallow water areas, which were strongly affected by industrial and human activities, covered with highly productive vegetation, or subject to long-term use of organic fertilizers or flooding conditions. © 2012 Soil Science Society of China. Source


Zhang M.,Nanjing University | Tan J.,Nanjing University | Huang X.,Nanjing University | Lai L.,Jiangsu Information Center | Chuai X.,Nanjing University
International Conference on Geoinformatics | Year: 2013

Due to the important role land use behaviors play in carbon emissions, research on land use related carbon emissions has gradually become an academic focus in recent years. However, few studies have been done on the comprehensive land use related carbon emissions at the provincial level, including both carbon emissions from the natural ecosystems caused by land cover changes and carbon emissions from anthropogenic sources carried by different land use types. This paper proposed a GIS based method for estimating comprehensive land use related carbon emissions. After that, application of this method was conducted with relevant data of Henan Province. The results proved this method to be feasible, and it was found that land use behaviors on urbanized land were responsible for more than 90% of the total carbon emissions of Henan Province in 2010. © 2013 IEEE. Source


Chuai X.,Nanjing University | Lai L.,Nanjing University | Lai L.,Jiangsu Information Center | Huang X.,Nanjing University | And 3 more authors.
Journal of Geographical Sciences | Year: 2012

Study on regional carbon emission is one of the hot topics under the background of global climate change and low-carbon economic development, and also help to establish different low-carbon strategies for different regions. On the basis of energy consumption and land use data of different regions in China from 1999 to 2008, this paper established carbon emission and carbon footprint models based on total energy consumption, and calculated the amount of carbon emissions and carbon footprint in different regions of China from 1999 to 2008. The author also analyzed carbon emission density and per unit area carbon footprint for each region. Finally, advices for decreasing carbon footprint were put forward. The main conclusions are as follows: (1) Carbon emissions from total energy consumption increased 129% from 1999 to 2008 in China, but its spatial distribution pattern among different regions just slightly changed, the sorting of carbon emission amount was: Eastern China > Northern China > Central and Southern China > Southwest China > Northwest China. (2) The sorting of carbon emission density was: Eastern China >s Northeast China > Central and Southern China > Northern China > Southwest China > Northwest China from 1999 to 2003, but from 2004 Central and Southern China began to have higher carbon emission density than Northeast China, the order of other regions did not change. (3) Carbon footprint increased significantly since the rapid increasing of carbon emissions and less increasing area of productive land in different regions of China from 1999 to 2008. Northern China had the largest carbon footprint, and Northwest China, Eastern China, Northern China, Central and Southern China followed in turn, while Southwest China presented the lowest area of carbon footprint and the highest percentage of carbon absorption. (4) Mainly influenced by regional land area, Northern China presented the highest per unit area carbon footprint and followed by Eastern China, and Northeast China; Central and Southern China, and Northwest China had a similar medium per unit area carbon footprint; Southwest China always had the lowest per unit area carbon footprint. (5) China faced great ecological pressure brought by carbon emission. Some measures should be taken both from reducing carbon emission and increasing carbon absorption. © 2012 Science China Press and Springer-Verlag Berlin Heidelberg. Source

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