Description:    Severe water erosion is notorious for its harmful effects on land-water resources as well as local societies. The scale effects of water erosion, however, greatly exacerbate the difficulties of accurate erosion evaluation and hazard control in the real world. Analyzing the related scale issues is thus urgent for a better understanding of erosion variations as well as reducing such erosion. In this review article, water erosion dynamics across three spatial scales including plot, watershed, and regional scales were selected and discussed. For the study purposes and objectives, the advantages and disadvantages of these scales all demonstrate clear spatial-scale dependence. Plot scale studies are primarily focused on abundant data collection and mechanism discrimination of erosion generation, while watershed scale studies provide valuable information for watershed management and hazard control as well as the development of quantitatively distributed models. Regional studies concentrate more on large-scale erosion assessment, and serve policymakers and stakeholders in achieving the basis for regulatory policy for comprehensive land uses. The results of this study show that the driving forces and mechanisms of water erosion variations among the scales are quite different. As a result, several major aspects contributing to variations in water erosion across the scales are stressed: differences in the methodologies across various scales, different sink-source roles on water erosion processes, and diverse climatic zones and morphological regions. This variability becomes more complex in the context of accelerated global change. The changing climatic factors and earth surface features are considered the fourth key reason responsible for the increased variability of water erosion across spatial scales. Content Type Journal Article Pages 127-143 DOI 10.1007/s11769-012-0524-2 Authors Wei Wei, State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing, 100085 China Liding Chen, State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing, 100085 China Lei Yang, State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing, 100085 China Bojie Fu, State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing, 100085 China Ranhao Sun, State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing, 100085 China Journal Chinese Geographical Science Online ISSN 1993-064X Print ISSN 1002-0063 Journal Volume Volume 22 Journal Issue Volume 22, Number 2

Description:    To quantitatively assess the effects of agricultural practices on methane (CH 4 ) emissions from rice fields, a two-year (2005/2006) field experiment with 2 3 factorial designs was conducted to assess the effects of three driving factors on CH 4 emissions in South China: continuously flooded (W0) and mid-season and final drainages (W2), straw (S1) and nitrogen fertilizer (N1) applications and their controls (S0, N0). Results showed that averaged across all the treatments about 75 % of the seasonal total CH 4 occurred between the rice transplanting and booting stage, while constituted only 33 % of the seasonal total rice biomass during the same period. Averaged across the treatments in 2006, CH 4 emissions were substantially decreased by mid-season drainage up to 60 % (15.6 vs. 39.0 g m −2 ). The decreased CH 4 emissions represented almost all of the decrease in the total global warming potentials. Without straw incorporation CH 4 emissions substantially decreased up to 59 % (15.9 vs. 38.7 g m −2 ). The stimulating effects of straw were significantly greater for W0 than W2 treatment, being also greater in the 2005 than in the 2006 season. A significant inter-annual difference in CH 4 emissions was found when averaged across straw incorporation and N fertilizer applications for the W2 treatment (42.8 and 15.4 g m −2 in 2005 and 2006, respectively). Moreover, N fertilization has no significant effect on CH 4 emissions in this study. Our results demonstrate that although straw effects varied greatly with specific management, both straw managements and water regimes are equally important driving factors and thus being the most promising measures attenuating CH 4 emissions while achieving sustainable rice production. Content Type Journal Article Category Original Article Pages 1-10 DOI 10.1007/s10705-012-9503-3 Authors Jinyang Wang, Jiangsu Key Laboratory of Low Carbon Agriculture and GHGs Mitigation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095 China Xiaolin Zhang, Jiangsu Key Laboratory of Low Carbon Agriculture and GHGs Mitigation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095 China Zhengqin Xiong, Jiangsu Key Laboratory of Low Carbon Agriculture and GHGs Mitigation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095 China M. A. K. Khalil, Department of Physics, Portland State University, P.O. Box 751, Portland, OR 97207, USA Xu Zhao, State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008 China Yingxin Xie, National Engineering Research Center for Wheat, Henan Agricultural University, Zhengzhou, 450002 China Guangxi Xing, State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008 China Journal Nutrient Cycling in Agroecosystems Online ISSN 1573-0867 Print ISSN 1385-1314

Description:    In this paper, we proposed a framework for evaluating the performance of ecosystem strategies prepared for enhancing vulnerability reduction in the face of hazards due to climate change. The framework highlights the positive effects of human activities in the coupled human and natural system (CHANS) by introducing adaptive capacity as an evaluation criterion. A built-in regional vulnerability to a certain hazard was generated based upon interaction of three dimensions of vulnerability: exposure, sensitivity and adaptive capacity. We illustrated the application of this framework in the temperate farming-grazing transitional zone in the middle Inner Mongolia of the northern China, where drought hazard is the key threat to the CHANS. Specific indices were produced to translate such climate variance and social-economic differences into specific indicators. The results showed that the most exposed regions are the inner land areas, while counties located in the eastern part are potentially the most adaptive ones. Ordos City and Bayannur City are most frequently influenced by multiple climate variances, showing highest sensitivity. Analysis also indicated that differences in the ability to adapt to changes are the main causes of spatial differences. After depiction of the spatial differentiations and analysis of the reasons, climate zones were divided to depict the differences in facing to the drought threats. The climate zones were shown to be similar to vulnerability zones based on the quantitative structure of indexes drafted by a triangular map. Further analysis of the composition of the vulnerability index showed that the evaluation criteria were effective in validating the spatial differentiation but potentially ineffective because of their limited time scope. This research will be a demonstration of how to combine the three dimensions by quantitative methods and will thus provide a guide for government to vulnerability reduction management. Content Type Journal Article Pages 1-13 DOI 10.1007/s11769-012-0583-4 Authors Xiaoqian Liu, Laboratory for Earth Surface Processes, Ministry of Education, College of Urban and Environmental Sciences, Peking University, Beijing, 100871 China Yanglin Wang, Laboratory for Earth Surface Processes, Ministry of Education, College of Urban and Environmental Sciences, Peking University, Beijing, 100871 China Jian Peng, Laboratory for Earth Surface Processes, Ministry of Education, College of Urban and Environmental Sciences, Peking University, Beijing, 100871 China K. Braimoh Ademola, Global Land Project, Sapporo Nodal Office, Hokkaido University, Sapporo, 060-0809 Japan He Yin, Geomatics Laboratory, Geography Department, Humboldt-Universität zu Berlin, Berlin, 10099 Germany Journal Chinese Geographical Science Online ISSN 1993-064X Print ISSN 1002-0063