We studied the waterbird population at Lashihai Lake, Yunnan Province, China, which is a Ramsar Site(Wetland of International Importance), to determine seasonal variation in the species composition and size of the wat...We studied the waterbird population at Lashihai Lake, Yunnan Province, China, which is a Ramsar Site(Wetland of International Importance), to determine seasonal variation in the species composition and size of the waterbird population. The study was conducted at five selected spots along Lashihai Lake at the same time each week from August 2011 to September 2013. In total, 62 waterbird species were recorded, of which 38.71%, 35.48%, 16.13%, and 9.68% were winter migrants, passage visitors, residents, and summer migrants, respectively. We found important seasonal changes in waterbird species composition and population size. Waterbird species richness was highest from September to the following April, with the total species numbers peaking in December. Total individual numbers peaked twice from late November to early December and mid-to-late February. However, waterbird species and individual numbers were comparatively lower from May to August. The change in species composition was determined by the arrival and departure dynamics of winter migrants and passage visitors. Winter migrants primarily caused the periodic changes in population size. Of concern,species and overall waterbird numbers seemed to be lower than the numbers in historical records. The decline of waterbird numbers implies that environmental changes caused by the implementation of the dam upstream of Lashihai Lake may have had adverse effects on this waterbird population. This study confirms the existence of major seasonal changes in species composition and size of the waterbird population at Lashihai Lake. Furthermore, the findings demonstrate that this wetland is of high conservation importance for waterbirds using the Central Asian–Indian and Asian–Pacific migratory routes.展开更多
The policy of land transfer has greatly influenced the macro economy of China with the commencement of another innovation of land use system. Therefore, it is urgent to put forward some rational and feasible suggestio...The policy of land transfer has greatly influenced the macro economy of China with the commencement of another innovation of land use system. Therefore, it is urgent to put forward some rational and feasible suggestions for local government to manage the market of land transfer. Moreover, it is important in the field of study on agricultural land use change to analyze the spatial differentiation and structural specification of land transfer, which are caused by rural households＇ behavior. This paper selected I l factors covering four aspects of rural households＇ family structure, family location, family income structure and the natural quality of land resources, all of which influence the behavior differentiation of rural households, to establish the index model indicating spatial differentiation of land transfer. Results show that the spatial differentiation of land transfer can be divided into four degrees and three categories through analyzing rural households＇ questionnaires from Shanghai, Nanjing and Taizhou in the Changjiang （Yangtze） River Delta. Since up to 80% of rural households belong to middle degrees, it can be concluded that the rural land market develops evenly in the study areas. And it is also indicated that the natural quality of land resources and the maximum income of rural land are most important factors influencing the spatial differentiation of land transaction. Considering different factors, the countermeasures can be carried out to enhance the spatial differentiation of land transfer so as to promote economic development and social security of rural China. All in all, both micro- factors and macro-factors influencing rural households＇ behavior of rural land transfer should be taken into account in order to make spatial differentiation and structural specification of rural land transfer notable.展开更多
The urban heat island （UHI） represents one of the most significant human impacts on the earth system. In recent decades, the number of the tourists has a remarkable increase in China and also other regions of the gl...The urban heat island （UHI） represents one of the most significant human impacts on the earth system. In recent decades, the number of the tourists has a remarkable increase in China and also other regions of the globe. However, it is still unclear whether or to what extent the tourism can affect the UHI. Here, we investigate the role of the tourism for the UHI during the Chinese New Year （CNY） holiday based on a case study in tropical Sanya City, which attracts many tourists for celebrating the CNY and enjoying the warm climate during the holiday. We find that the UHI effects expressed as daily mean （ATmean）, maximum （ATmax）, and minimum （ATmin） surface air temperature differences between urban and nearby nonurban stations averaged over the period of 1995-2004 during the CNY week were 0.48 ℃ （39 %）, 0.66 ℃ （61%）, and 0.42 ℃ （26 %） higher than those averaged over the background period （8 weeks including 4 weeks before and 4 weeks after the CNY week）, respectively. These changes are all significant at the 99 % confidence level. Our findings highlight previously unidentified impact of the tourism on the UHI based on a case study in Sanya City, Hainan Province of China.展开更多
基金funded by the“Technology Supporting Programme” of the “State Wetland Conservation Project for Lashihai Wetland”
文摘We studied the waterbird population at Lashihai Lake, Yunnan Province, China, which is a Ramsar Site(Wetland of International Importance), to determine seasonal variation in the species composition and size of the waterbird population. The study was conducted at five selected spots along Lashihai Lake at the same time each week from August 2011 to September 2013. In total, 62 waterbird species were recorded, of which 38.71%, 35.48%, 16.13%, and 9.68% were winter migrants, passage visitors, residents, and summer migrants, respectively. We found important seasonal changes in waterbird species composition and population size. Waterbird species richness was highest from September to the following April, with the total species numbers peaking in December. Total individual numbers peaked twice from late November to early December and mid-to-late February. However, waterbird species and individual numbers were comparatively lower from May to August. The change in species composition was determined by the arrival and departure dynamics of winter migrants and passage visitors. Winter migrants primarily caused the periodic changes in population size. Of concern,species and overall waterbird numbers seemed to be lower than the numbers in historical records. The decline of waterbird numbers implies that environmental changes caused by the implementation of the dam upstream of Lashihai Lake may have had adverse effects on this waterbird population. This study confirms the existence of major seasonal changes in species composition and size of the waterbird population at Lashihai Lake. Furthermore, the findings demonstrate that this wetland is of high conservation importance for waterbirds using the Central Asian–Indian and Asian–Pacific migratory routes.
基金Under the auspices of the National Natural Science Foundation of China (No. 70373029)
文摘The policy of land transfer has greatly influenced the macro economy of China with the commencement of another innovation of land use system. Therefore, it is urgent to put forward some rational and feasible suggestions for local government to manage the market of land transfer. Moreover, it is important in the field of study on agricultural land use change to analyze the spatial differentiation and structural specification of land transfer, which are caused by rural households＇ behavior. This paper selected I l factors covering four aspects of rural households＇ family structure, family location, family income structure and the natural quality of land resources, all of which influence the behavior differentiation of rural households, to establish the index model indicating spatial differentiation of land transfer. Results show that the spatial differentiation of land transfer can be divided into four degrees and three categories through analyzing rural households＇ questionnaires from Shanghai, Nanjing and Taizhou in the Changjiang （Yangtze） River Delta. Since up to 80% of rural households belong to middle degrees, it can be concluded that the rural land market develops evenly in the study areas. And it is also indicated that the natural quality of land resources and the maximum income of rural land are most important factors influencing the spatial differentiation of land transaction. Considering different factors, the countermeasures can be carried out to enhance the spatial differentiation of land transfer so as to promote economic development and social security of rural China. All in all, both micro- factors and macro-factors influencing rural households＇ behavior of rural land transfer should be taken into account in order to make spatial differentiation and structural specification of rural land transfer notable.
基金supported by the National Natural Science Foundation of China(41275089 and 41305071)the National Basic Research Program of China(2012CB955604)Jingyong Zhang was supported by the Jiangsu Collaborative Innovation Center for Climate Change
文摘The urban heat island （UHI） represents one of the most significant human impacts on the earth system. In recent decades, the number of the tourists has a remarkable increase in China and also other regions of the globe. However, it is still unclear whether or to what extent the tourism can affect the UHI. Here, we investigate the role of the tourism for the UHI during the Chinese New Year （CNY） holiday based on a case study in tropical Sanya City, which attracts many tourists for celebrating the CNY and enjoying the warm climate during the holiday. We find that the UHI effects expressed as daily mean （ATmean）, maximum （ATmax）, and minimum （ATmin） surface air temperature differences between urban and nearby nonurban stations averaged over the period of 1995-2004 during the CNY week were 0.48 ℃ （39 %）, 0.66 ℃ （61%）, and 0.42 ℃ （26 %） higher than those averaged over the background period （8 weeks including 4 weeks before and 4 weeks after the CNY week）, respectively. These changes are all significant at the 99 % confidence level. Our findings highlight previously unidentified impact of the tourism on the UHI based on a case study in Sanya City, Hainan Province of China.
