The urban population and urbanized land in China have both increased markedly since the 1980 s. Urban and suburban developments have grown at unprecedented rates with unknown consequences for ecosystem functions. In p...The urban population and urbanized land in China have both increased markedly since the 1980 s. Urban and suburban developments have grown at unprecedented rates with unknown consequences for ecosystem functions. In particular, the effect of rapid urbanization on the storage of soil carbon has not been studied extensively. In this study, we compared the soil carbon stocks of different land use types in Beijing Municipality. We collected 490 top-soil samples(top 20 cm) from urban and suburban sites within the Sixth Ring Road of Beijing, which cover approximately 2400 km2, and the densities of soil organic carbon(SOC), soil inorganic carbon(SIC), and total carbon(TC) were analyzed to determine the spatial distribution of urban and suburban soil carbon characteristics across seven land use types. The results revealed significant differences in soil carbon densities among land use types. Additionally, urban soil had significantly higher SOC and SIC densities than suburban soil did, and suburban shelterbelts and productive plantations had lower SIC densities than the other land use types. The comparison of coefficients of variance(CVs) showed that carbon content of urban topsoil had a lower variability than that of suburban topsoil. Further findings revealed that soil carbon storage increased with built-up age. Urban soil built up for more than 20 years had higher densities of SOC, SIC and TC than both urban soil with less than 10 years and suburban soil. Correlation analyses indicated the existence of a significantly negative correlation between the SOC, SIC, and TC densities of urban soil and the distance to the urban core, and the distance variable alone explained 23.3% of the variation of SIC density and 13.8% of the variation of TC density. These results indicate that SOC and SIC accumulate in the urban topsoil under green space as a result of the conversion of agricultural land to urban land due to the urbanization in Beijing.展开更多
With the rapid changes of demographic and socio-economic structure, various ecological and environmental problems have emerged in peri-urban areas. Studies on the correlation between socio-economic development and eco...With the rapid changes of demographic and socio-economic structure, various ecological and environmental problems have emerged in peri-urban areas. Studies on the correlation between socio-economic development and eco-environmental preservation are inadequate. This paper analyzes the landscape pattern of peri-urban areas to address this issue. First, it studies the differentiation of economic development levels in Beijing peri-urban areas. Then, it explores the correlation between economic development level of each town and its landscape pattern using Pearson Correlation and grade difference indices. Furthermore, it summarizes the problems within current landscape pattern. Three conclusions are drawn from the analysis: (1) on the whole, the economic de- velopment level in Beijing peri-urban areas basically matches with landscape pattern; (2) landscape contagion degree decreases with the growth of economic development level in as much as 30% of Beijing peri-urban areas. This is an irrational phenomenon accord- ing to our judgment; (3) landscape fragmentation grades in more than half of the towns are higher than their economic development grades, suggesting that attention should be paid to excessive fragmentation of land use.展开更多
Tourist agriculture, based on agriculture,is a new cross combination of agriculture and tourism from 1970s.Ithas appeared some original features by now, and weshould use the successful experience of the tourist agricu...Tourist agriculture, based on agriculture,is a new cross combination of agriculture and tourism from 1970s.Ithas appeared some original features by now, and weshould use the successful experience of the tourist agriculture in Taiwan of China for reference to standardize all the aspects of work.Support it more in policy,fund, technology, and propaganda, and strengthen the combination of the program of city and suburb to promote the development of the tourist agriculture in Mianyang.展开更多
This study aimed to examine the relationship between meteorological variables and the clearness index for three sites in Cuiaba city and one site in Chapada dos Guimaraes city, Brazil during 2007. It described the mic...This study aimed to examine the relationship between meteorological variables and the clearness index for three sites in Cuiaba city and one site in Chapada dos Guimaraes city, Brazil during 2007. It described the microclimate of each site on the basis of constructive elements and their surroundings, considering sky coverage using a daily clearness index. The results were that micrometeorological values were influenced by the natural elements and construction within the surrounding site, with higher air temperatures in more urbanized areas and sites with high diffuse radiation. When determining the sky coverage, on average, the days were partly cloudy or cloudy due to two reasons： （a） during the wet season, rainfall created cloudy conditions and （b） during the dry season, increases of particulates in the atmosphere as a result of anthropogenic emissions of gases and aerosols in this region of the state resulted in sky conditions classified as partly cloudy and cloudy. Future research should aim to better quantify the measurements taken inside an urban area, considering the topography and vegetation cover. This will improve the models that support urban planning, therefore favoring the thermal comfort of areas already occupied or to be urbanized.展开更多
Japan＇s aging rate has exceeded 26%, ahead of any other country in the world. Aging is progressing rapidly in both rural and urban areas. Recently, super-aging in old suburbs is remarkable. Recently, Japanese old sub...Japan＇s aging rate has exceeded 26%, ahead of any other country in the world. Aging is progressing rapidly in both rural and urban areas. Recently, super-aging in old suburbs is remarkable. Recently, Japanese old suburban housing estates are declining. They are facing several serious problems. Most serious problems are aging of residents and decreasing population, and these are caused by long-term dwelling. Because many Japanese think that ＂Japanese Dream＂ is occupancy of detached house in suburb. Japanese suburban residents tend to stay after child rearing. And another severe problem is the increasing vacant houses. In this study, the authors try to clarify the conditions of shrinking suburbs in Japanese cities and will introduce some activities for revitalization in suburbs. As for aging of suburban residents, in old housing estates, the first generation of migrants grew older and continued to live in their own house in suburban areas. Furthermore, their children grew up and moved out. These are caused by the failure of town planning, which supplied the same type of houses in short term. Furthermore, increases in vacant houses are seen throughout every old suburban housing estate, and it induces new uneasiness and social troubles and drop in housing price.展开更多
基金Under the auspices of National Key Technology Research and Development Program(No.2007BAC28B01)Innovation Project of State Key Laboratory of Urban and Regional Ecology of China
文摘The urban population and urbanized land in China have both increased markedly since the 1980 s. Urban and suburban developments have grown at unprecedented rates with unknown consequences for ecosystem functions. In particular, the effect of rapid urbanization on the storage of soil carbon has not been studied extensively. In this study, we compared the soil carbon stocks of different land use types in Beijing Municipality. We collected 490 top-soil samples(top 20 cm) from urban and suburban sites within the Sixth Ring Road of Beijing, which cover approximately 2400 km2, and the densities of soil organic carbon(SOC), soil inorganic carbon(SIC), and total carbon(TC) were analyzed to determine the spatial distribution of urban and suburban soil carbon characteristics across seven land use types. The results revealed significant differences in soil carbon densities among land use types. Additionally, urban soil had significantly higher SOC and SIC densities than suburban soil did, and suburban shelterbelts and productive plantations had lower SIC densities than the other land use types. The comparison of coefficients of variance(CVs) showed that carbon content of urban topsoil had a lower variability than that of suburban topsoil. Further findings revealed that soil carbon storage increased with built-up age. Urban soil built up for more than 20 years had higher densities of SOC, SIC and TC than both urban soil with less than 10 years and suburban soil. Correlation analyses indicated the existence of a significantly negative correlation between the SOC, SIC, and TC densities of urban soil and the distance to the urban core, and the distance variable alone explained 23.3% of the variation of SIC density and 13.8% of the variation of TC density. These results indicate that SOC and SIC accumulate in the urban topsoil under green space as a result of the conversion of agricultural land to urban land due to the urbanization in Beijing.
文摘With the rapid changes of demographic and socio-economic structure, various ecological and environmental problems have emerged in peri-urban areas. Studies on the correlation between socio-economic development and eco-environmental preservation are inadequate. This paper analyzes the landscape pattern of peri-urban areas to address this issue. First, it studies the differentiation of economic development levels in Beijing peri-urban areas. Then, it explores the correlation between economic development level of each town and its landscape pattern using Pearson Correlation and grade difference indices. Furthermore, it summarizes the problems within current landscape pattern. Three conclusions are drawn from the analysis: (1) on the whole, the economic de- velopment level in Beijing peri-urban areas basically matches with landscape pattern; (2) landscape contagion degree decreases with the growth of economic development level in as much as 30% of Beijing peri-urban areas. This is an irrational phenomenon accord- ing to our judgment; (3) landscape fragmentation grades in more than half of the towns are higher than their economic development grades, suggesting that attention should be paid to excessive fragmentation of land use.
基金Partachievementsof the projectof the science and research fund in MianyangNormal University.
文摘Tourist agriculture, based on agriculture,is a new cross combination of agriculture and tourism from 1970s.Ithas appeared some original features by now, and weshould use the successful experience of the tourist agriculture in Taiwan of China for reference to standardize all the aspects of work.Support it more in policy,fund, technology, and propaganda, and strengthen the combination of the program of city and suburb to promote the development of the tourist agriculture in Mianyang.
文摘This study aimed to examine the relationship between meteorological variables and the clearness index for three sites in Cuiaba city and one site in Chapada dos Guimaraes city, Brazil during 2007. It described the microclimate of each site on the basis of constructive elements and their surroundings, considering sky coverage using a daily clearness index. The results were that micrometeorological values were influenced by the natural elements and construction within the surrounding site, with higher air temperatures in more urbanized areas and sites with high diffuse radiation. When determining the sky coverage, on average, the days were partly cloudy or cloudy due to two reasons： （a） during the wet season, rainfall created cloudy conditions and （b） during the dry season, increases of particulates in the atmosphere as a result of anthropogenic emissions of gases and aerosols in this region of the state resulted in sky conditions classified as partly cloudy and cloudy. Future research should aim to better quantify the measurements taken inside an urban area, considering the topography and vegetation cover. This will improve the models that support urban planning, therefore favoring the thermal comfort of areas already occupied or to be urbanized.
文摘Japan＇s aging rate has exceeded 26%, ahead of any other country in the world. Aging is progressing rapidly in both rural and urban areas. Recently, super-aging in old suburbs is remarkable. Recently, Japanese old suburban housing estates are declining. They are facing several serious problems. Most serious problems are aging of residents and decreasing population, and these are caused by long-term dwelling. Because many Japanese think that ＂Japanese Dream＂ is occupancy of detached house in suburb. Japanese suburban residents tend to stay after child rearing. And another severe problem is the increasing vacant houses. In this study, the authors try to clarify the conditions of shrinking suburbs in Japanese cities and will introduce some activities for revitalization in suburbs. As for aging of suburban residents, in old housing estates, the first generation of migrants grew older and continued to live in their own house in suburban areas. Furthermore, their children grew up and moved out. These are caused by the failure of town planning, which supplied the same type of houses in short term. Furthermore, increases in vacant houses are seen throughout every old suburban housing estate, and it induces new uneasiness and social troubles and drop in housing price.
