The restoration of the riparian vegetation disturbed by human activities is one of the hotspots of watershed ecology. Through interpreting the images of Remote Sensing in 1985 and 1999, the basic information of forest...The restoration of the riparian vegetation disturbed by human activities is one of the hotspots of watershed ecology. Through interpreting the images of Remote Sensing in 1985 and 1999, the basic information of forest resources of Lushuihe Forest Bureau, which is a typical forest area of Changbai Mountain, was obtained with support of GIS. By dividing Land covers of Lushuihe area into 10 types (water body, residential land, stump land, farming land, wetland, mature conifer forest, midlife conifer forest, mature broadleaf forest, midlife broadleaf forest, and man-made young forest) and dividing the riparian zone into four buffers (in turn, 1000, 2000, 3000, 4000 m away from the river), the changes of riparian forest resources during 1985-1999 were analyzed. The results showed that the deforestation intension has obviously decreased and the whole environment has been evidently improved, but the riparian ecosystem was still flimsy. In buffer 1, 2, 3, the area of midlife conifer forest increased largely, but the areas of other types of land covers all decreased. Midlife conifer forest had a comparatively good status in the three buffers. In buffer 4, midlife conifer forest, mature conifer forest, and mature broadleaf forest formed a forest-age rank that is helpful to stabilize the forest ecosystem and exert its functions. Area percentage of wetland decreased in buffer 1, buffer 2, and buffer 3, even in buffer 4 in which forest ecosystem rehabilitated comparatively well, so protecting and rehabilitating wetland is a very difficult task.展开更多
This paper analyses the diversity and spatial pattern of the altitudinal belts in the Hengduan Mountains in China. A total of 7 types of base belts and 26 types of altitudinal belts are identified in the study region....This paper analyses the diversity and spatial pattern of the altitudinal belts in the Hengduan Mountains in China. A total of 7 types of base belts and 26 types of altitudinal belts are identified in the study region. The main altitudinal belt lines, such as forest line, the upper limit of dark coniferous forest and snow line, have similar latitudinal and longitudinal spatial patterns, namely, arched quadratic curve model with latitudes and concave quadratic curve model along longitudinal direction. These patterns can be together ealled as ＂Hyperbolic-paraboloid model＂, revealing the complexity and speciality of the environment and ecology in the study region. This result further validates the hypnosis of a common quadratic model for spatial pattern of mountain altitudinal belts proposed by the authors. The spatial pattern of altitudinal belts is closely related with moisture-related exposure effect in the Hengduan Mountains. Different combinations （spectra） of altitudinal belts and different base belt types appear in windward and leeward flanks and even in the same flanks of different ranges. This is closely related with the parallel mountain ranges of the Hengduan Mountains, which, at nearly right angle with the moving direction of prevailing moisture-laden air masses from west and east, hold up the warm and humid monsoon wind from moving into the core region and result in different moisture conditions in windward and leeward flanks. However, how to quantitatively describe the moisture-related exposure effect needs further study. In addition, the data quality and data accuracy at present also affect to some extent the result of quantitative modeling and should be improved with RS/GIS in the future.展开更多
The suitability of constructed wetland （CW） in were developed. The first experiment focused on zinc and treating acid mine drainage （AMD） was investigated. Two experiments nutrients removals. Four units of horizon...The suitability of constructed wetland （CW） in were developed. The first experiment focused on zinc and treating acid mine drainage （AMD） was investigated. Two experiments nutrients removals. Four units of horizontal subsurface flow CWs were used, two cells planted with Phragmites mauritianus, one cell with Typha domingensis and one cell unplanted （control cell）. Artificial high concentrated AMD was used. It was mixed with domestic wastewater from the anaerobic waste stabilization pond （WSP） to ensure nutrient supply to the plants in the CW cells. The second experiment tested the tolerance of locally available macrophytes to the harsh acidic environment, while providing required condition for treatment of AMD. To accomplish this, another set of four CW cells planted with different types of macrophytes, namely Typha domingensis, Phragmites mauritianus, Vetiver grass and Papyrus, were used thereby subjecting them to varying acid concentration ofpH of 3.5, 3.0, 2.9 and 2.7. The study demonstrated adequate zinc removal from AMD which is related to sulphide precipitation. A CW cell planted with Typha domingensis showed higher zinc removal （80%-84%） compared to other cells. Different macrophytes showed different nutrient removal efficiency, but overall, for the type of wetland plants studied, phosphorous removal increased with decreasing pH while nitrogen removal behaved quite opposite. On the other hand, Typha domingensis, Phragmites mauritianus and Papyrus were observed to tolerate high acidity as low pH as 2.7 and therefore are suitable macrophytes for AMD treatment with CW.展开更多
Based on comparative studies on four regional floras from northwest, west, south and southeast of Yunnan respectively, the formerly suggested two biogeographical lines, i.e. the “Tanaka Line" and the “Ecogeogra...Based on comparative studies on four regional floras from northwest, west, south and southeast of Yunnan respectively, the formerly suggested two biogeographical lines, i.e. the “Tanaka Line" and the “Ecogeographical Diagonal Line", both going from northwest to southeast of Yunnan, and their significance are discussed. In family and generic levels, similarity coefficients among the four compared floras are more than 93% and 60% separately, which indicate the close floristic affinities among them. The highest similarity coefficient, i.e. 98.7% in family level and 78.6% in generic level separately, is found between the regional flora of northwest Yunnan and the flora of southeast Yunnan although these two regions are the most distant away each other among the compared regional floras. The flora of northwest Yunnan is also the most similar to the flora of southeast Yunnan in floristic composition. These support the idea of “Ecogeographical Diagonal Line". In specific level, the relatively high similarity coefficient is between the regional flora of west Yunnan and the one of south Yunnan. The floristic affinities among these regional floras and some distribution patterns could be explained by the geological history and tectonic theory of Yunnan.展开更多
The features of physical geography in the transitional region between Qinling Mountains and Huanghuai Plain possess transitional characters evidently in two directions: one is from the western mountain to the eastern ...The features of physical geography in the transitional region between Qinling Mountains and Huanghuai Plain possess transitional characters evidently in two directions: one is from the western mountain to the eastern plain and the other is from southern subtropical zone to northern temperate zone. Torrential rain, especially strong torrential rain is frequent in the transitional region, and there are many torrential rain centers. A majority of torrential rain is distributed among 100-200 m asl. The winter temperature at 100-400 m asl is higher than that in Huanghuai Plain whose altitude is lower than that of the transitional region, and the highest temperature in January appears at 350-400 m asl.The thickness of warm slope belt in the transitional region varies from 100 m to 250 m asl. The formation of torrential rain and warm slope belt is the result of joint action of atmospheric circulation and local terrain. Frequent torrential rains and warm slope belt had tremendous influences on the soil properties, plant distribution and local climate in the transitional region.展开更多
Cassava is vulnerable to frost and snow, so it is suitable for planting in tropical and subtropical region. Low temperature is an important environment factor affecting the growth and development and production of cas...Cassava is vulnerable to frost and snow, so it is suitable for planting in tropical and subtropical region. Low temperature is an important environment factor affecting the growth and development and production of cassava, and the region with annual average temperature below 15 ℃ is not conducive to its normal growth and development. The improvement of cold resistance of cassava can increase the planting area and improve the yield and quality of cassava. In this study, morphological,physiological and biochemical and molecular researches on cold resistance of cassava, as well as the latest research progress,were reviewed in this paper. At the same time, some potential difficulties in the research on cold resistance of cassava were put forward, and the future work focus was also discussed.展开更多
Eco-geographic regional system is formed by division or combination of natural features based on geographic relativity and comparison of major ecosystem factors(including biological and non-biological) and geographic ...Eco-geographic regional system is formed by division or combination of natural features based on geographic relativity and comparison of major ecosystem factors(including biological and non-biological) and geographic zonality.In previous studies, soil types were often taken as a basis for soil regionalization.However, the quantitative characteristics of soil indicators are fitter than the qualitative ones of soil types for modern regionalization researches.Based on the second China's national soil survey data and the provincial soil resource information, by principal analysis and discriminant analysis, this paper discusses the appropriate soil indicators as the complement of eco-geographic region indicator systems and the relationships between these soil indicators and soil types in regionalization.The results show that five indicators are used in eco-geographic zonality in mid-temperate zone of eastern China which are organic matter content, cation exchange capacity, pH, clay content and bulk density in topsoils.With a regression-kriging approach, the maps of soil indicators in mid-temperate zone of eastern China are compiled with a resolution of 1 km in every grid and the indicative meanings of these soil indicators are discussed.By cluster analysis it is proved that these soil indicators are better than the soil types and soil regionalization in delineating eco-geographic regions.展开更多
基金This study is supported by major projects of Knowledge Innovation Program Chinese Academy of Sciences ( No. KZCX2-SW-320-3) and Institute of Applied Ecology (a grant SCXZD010-01)CAS
文摘The restoration of the riparian vegetation disturbed by human activities is one of the hotspots of watershed ecology. Through interpreting the images of Remote Sensing in 1985 and 1999, the basic information of forest resources of Lushuihe Forest Bureau, which is a typical forest area of Changbai Mountain, was obtained with support of GIS. By dividing Land covers of Lushuihe area into 10 types (water body, residential land, stump land, farming land, wetland, mature conifer forest, midlife conifer forest, mature broadleaf forest, midlife broadleaf forest, and man-made young forest) and dividing the riparian zone into four buffers (in turn, 1000, 2000, 3000, 4000 m away from the river), the changes of riparian forest resources during 1985-1999 were analyzed. The results showed that the deforestation intension has obviously decreased and the whole environment has been evidently improved, but the riparian ecosystem was still flimsy. In buffer 1, 2, 3, the area of midlife conifer forest increased largely, but the areas of other types of land covers all decreased. Midlife conifer forest had a comparatively good status in the three buffers. In buffer 4, midlife conifer forest, mature conifer forest, and mature broadleaf forest formed a forest-age rank that is helpful to stabilize the forest ecosystem and exert its functions. Area percentage of wetland decreased in buffer 1, buffer 2, and buffer 3, even in buffer 4 in which forest ecosystem rehabilitated comparatively well, so protecting and rehabilitating wetland is a very difficult task.
基金supported by the National Natural Science foundation of China (40971064)the Innovatioin Program of Chinese Academy of Sciences (No. kzcx2-yw-308)IGSNRR Youth Innovation Project,and the LREIS Self-determined Project
文摘This paper analyses the diversity and spatial pattern of the altitudinal belts in the Hengduan Mountains in China. A total of 7 types of base belts and 26 types of altitudinal belts are identified in the study region. The main altitudinal belt lines, such as forest line, the upper limit of dark coniferous forest and snow line, have similar latitudinal and longitudinal spatial patterns, namely, arched quadratic curve model with latitudes and concave quadratic curve model along longitudinal direction. These patterns can be together ealled as ＂Hyperbolic-paraboloid model＂, revealing the complexity and speciality of the environment and ecology in the study region. This result further validates the hypnosis of a common quadratic model for spatial pattern of mountain altitudinal belts proposed by the authors. The spatial pattern of altitudinal belts is closely related with moisture-related exposure effect in the Hengduan Mountains. Different combinations （spectra） of altitudinal belts and different base belt types appear in windward and leeward flanks and even in the same flanks of different ranges. This is closely related with the parallel mountain ranges of the Hengduan Mountains, which, at nearly right angle with the moving direction of prevailing moisture-laden air masses from west and east, hold up the warm and humid monsoon wind from moving into the core region and result in different moisture conditions in windward and leeward flanks. However, how to quantitatively describe the moisture-related exposure effect needs further study. In addition, the data quality and data accuracy at present also affect to some extent the result of quantitative modeling and should be improved with RS/GIS in the future.
文摘The suitability of constructed wetland （CW） in were developed. The first experiment focused on zinc and treating acid mine drainage （AMD） was investigated. Two experiments nutrients removals. Four units of horizontal subsurface flow CWs were used, two cells planted with Phragmites mauritianus, one cell with Typha domingensis and one cell unplanted （control cell）. Artificial high concentrated AMD was used. It was mixed with domestic wastewater from the anaerobic waste stabilization pond （WSP） to ensure nutrient supply to the plants in the CW cells. The second experiment tested the tolerance of locally available macrophytes to the harsh acidic environment, while providing required condition for treatment of AMD. To accomplish this, another set of four CW cells planted with different types of macrophytes, namely Typha domingensis, Phragmites mauritianus, Vetiver grass and Papyrus, were used thereby subjecting them to varying acid concentration ofpH of 3.5, 3.0, 2.9 and 2.7. The study demonstrated adequate zinc removal from AMD which is related to sulphide precipitation. A CW cell planted with Typha domingensis showed higher zinc removal （80%-84%） compared to other cells. Different macrophytes showed different nutrient removal efficiency, but overall, for the type of wetland plants studied, phosphorous removal increased with decreasing pH while nitrogen removal behaved quite opposite. On the other hand, Typha domingensis, Phragmites mauritianus and Papyrus were observed to tolerate high acidity as low pH as 2.7 and therefore are suitable macrophytes for AMD treatment with CW.
文摘Based on comparative studies on four regional floras from northwest, west, south and southeast of Yunnan respectively, the formerly suggested two biogeographical lines, i.e. the “Tanaka Line" and the “Ecogeographical Diagonal Line", both going from northwest to southeast of Yunnan, and their significance are discussed. In family and generic levels, similarity coefficients among the four compared floras are more than 93% and 60% separately, which indicate the close floristic affinities among them. The highest similarity coefficient, i.e. 98.7% in family level and 78.6% in generic level separately, is found between the regional flora of northwest Yunnan and the flora of southeast Yunnan although these two regions are the most distant away each other among the compared regional floras. The flora of northwest Yunnan is also the most similar to the flora of southeast Yunnan in floristic composition. These support the idea of “Ecogeographical Diagonal Line". In specific level, the relatively high similarity coefficient is between the regional flora of west Yunnan and the one of south Yunnan. The floristic affinities among these regional floras and some distribution patterns could be explained by the geological history and tectonic theory of Yunnan.
文摘The features of physical geography in the transitional region between Qinling Mountains and Huanghuai Plain possess transitional characters evidently in two directions: one is from the western mountain to the eastern plain and the other is from southern subtropical zone to northern temperate zone. Torrential rain, especially strong torrential rain is frequent in the transitional region, and there are many torrential rain centers. A majority of torrential rain is distributed among 100-200 m asl. The winter temperature at 100-400 m asl is higher than that in Huanghuai Plain whose altitude is lower than that of the transitional region, and the highest temperature in January appears at 350-400 m asl.The thickness of warm slope belt in the transitional region varies from 100 m to 250 m asl. The formation of torrential rain and warm slope belt is the result of joint action of atmospheric circulation and local terrain. Frequent torrential rains and warm slope belt had tremendous influences on the soil properties, plant distribution and local climate in the transitional region.
基金Supported by Earmarked Fund for China Agriculture Research System(CARS-11-cssy)
文摘Cassava is vulnerable to frost and snow, so it is suitable for planting in tropical and subtropical region. Low temperature is an important environment factor affecting the growth and development and production of cassava, and the region with annual average temperature below 15 ℃ is not conducive to its normal growth and development. The improvement of cold resistance of cassava can increase the planting area and improve the yield and quality of cassava. In this study, morphological,physiological and biochemical and molecular researches on cold resistance of cassava, as well as the latest research progress,were reviewed in this paper. At the same time, some potential difficulties in the research on cold resistance of cassava were put forward, and the future work focus was also discussed.
基金National Natural Science Foundation of China,No.40771016
文摘Eco-geographic regional system is formed by division or combination of natural features based on geographic relativity and comparison of major ecosystem factors(including biological and non-biological) and geographic zonality.In previous studies, soil types were often taken as a basis for soil regionalization.However, the quantitative characteristics of soil indicators are fitter than the qualitative ones of soil types for modern regionalization researches.Based on the second China's national soil survey data and the provincial soil resource information, by principal analysis and discriminant analysis, this paper discusses the appropriate soil indicators as the complement of eco-geographic region indicator systems and the relationships between these soil indicators and soil types in regionalization.The results show that five indicators are used in eco-geographic zonality in mid-temperate zone of eastern China which are organic matter content, cation exchange capacity, pH, clay content and bulk density in topsoils.With a regression-kriging approach, the maps of soil indicators in mid-temperate zone of eastern China are compiled with a resolution of 1 km in every grid and the indicative meanings of these soil indicators are discussed.By cluster analysis it is proved that these soil indicators are better than the soil types and soil regionalization in delineating eco-geographic regions.
