We investigated the weathering-pedogenesis of carbonate rocks and its environmental effects in subtropical regions of China. The investigation demonstrated that the weathering- pedogenesis of carbonate rocks is the pr...We investigated the weathering-pedogenesis of carbonate rocks and its environmental effects in subtropical regions of China. The investigation demonstrated that the weathering- pedogenesis of carbonate rocks is the process of a joint action of corrosion and illuviation and metasomatism in subtropical region. It is characterized by multi-stage, multi-path and multi-style. With the persisting development of weathering-pedogenesis of carbonate rocks, metasomatic pedogenesis progressively became the main process of the weathering-pedogenesis and the dominant style of formation of minerals. And it proceeds through the whole process of evolution of the weathering-pedogenesis of carbonate rocks. The stage evolution of weathering-pedogenesis of carbonate rocks and the fractionation evolution of newly produced minerals are characterized by obvious vertically zoning structures and the rules of gradation of elements geochemical characteristics in the carbonate rocks weathering profiles. The geochemical process of weathering-pedogenesis of carbonate rocks can be divided into three geochemical evolution stages, i.e., the Ca, Mg-depletion and Si, Al-enrichment stage; the Fe, Mn enrichment stage and the Si-depletion and Al-enrichment stage in the subtropical regions. Consistent with the three geochemical evolution stages, the sequence of formation and evolution of minerals can be divided into the clay mineral stage; the Fe, Mn oxide and the gibbsite stage. The influence of weathering-pedogenesis of carbonate rocks on the chemical forms of heavy elements is mainly affected via newly produced components and minerals in the process of weathering-pedogenesis, e.g., iron oxide minerals and organic matters. The important mechanism for the mobilization, transport and pollution of F and As is affected the selective adsorption and desorption of F and As on the surface of iron oxide minerals in the subtropical karst zones, i.e., the selective adsorption and desorption on mineral surfaces of newly produced minerals in the process of weathering-pedogenesis control the geochemical behavior of elements on the Earth's surface and environmental quality in subtropical regions.展开更多
There is a dearth of information on the effects of landscape and microhabitat variables on the distribution of anurans in areas of rapid urban development, in both tropical and subtropical regions. Therefore, we studi...There is a dearth of information on the effects of landscape and microhabitat variables on the distribution of anurans in areas of rapid urban development, in both tropical and subtropical regions. Therefore, we studied 24 Wetlands sites from the center of Shanghai city, China extending outward to rural areas. Sampling was performed from May through July 2014. Urbanization was categorized by the proportion of hard ground cover. Transect sampling and 'calling' surveys were used to investigated the richness and density of anurans; microhabitat factors were recorded simultaneously. One-way analysis of variance and Kruskal-Wallis tests were conducted to analyze differences of total density, species richness and density of individual anuran species in the three urbanization levels; redundancy analysis was carried out on the relationship between anuran density and environmental variables. Species richness was lowest in the areas where the proportion of hard ground cover was 〉 80%, and the total density of anurans was highest in the areas where coverage of the hard ground cover was 〈 30%. We recorded five species belonging to four genera and four families and an individual anuran species that had varied representations in urban environments. Beijing gold-striped pond frogs (Pelophylax plancyi) and Zhoushan toads (Bufo gargarizans) appeared to be well adapted to the Shanghai metropolis. Large water environments and aquatic vegetation (floating-leaves and emergent vegetation) were indicators of the presence of Beijing gold-striped pond frogs. The density of black-spotted pond frog (Pelophylax nigromaculatus) was at the lowest density in the areas where hard ground coverage was 〉 80%, and tended to prefer larger bodies of water. Hong Kong rice-paddy frogs (Fejervarya multistriata) and ornamented pygmy frogs (Microhyla achatina) both suffered severely from cropland loss due to urban development. Bare land around breeding grounds was important for Hong Kong rice-paddy frogs, since it usually chooses mud coast caves for hibernation.展开更多
Fall armyworm(FAW),Spodoptera frugiperda(J.E.Smith),has become an important pest in Chinese agricultural systems since its invasion on 11 December 2018.After its establishment,FAW months in the year-round breeding reg...Fall armyworm(FAW),Spodoptera frugiperda(J.E.Smith),has become an important pest in Chinese agricultural systems since its invasion on 11 December 2018.After its establishment,FAW months in the year-round breeding region have become the main source population migrating to other areas in China.Field investigations were conducted in tropical and subtropical regions to improve understanding of its year-round breeding area in China.The results showed that FAW larval density was significantly correlated with the seasonal temperature of the location surveyed.The FAW larvae maintained a high density in the tropical area and were frequently found in sites of the south subtropical region,but were absent from the north subtropical region and the northern part of the central subtropical region.These results indicated that FAW can reproduce annually in the tropical and south subtropical regions of China,including Hainan,Taiwan and the southern area of Fujian,Guangdong,Guangxi,Guizhou,and Yunnan.Hence,great effort should be made to monitor and control FAW in the year-round breeding region to suppress the population density of this area and to reduce migration of moths into northern parts of China.This study clarifies the occurrence area of the pest in winter in China and provides much valuable information for its population forecasting and management.展开更多
Soil phosphorus (P) plays a vital role in both ecological and agricultural ecosystems, where total P (TP) in soil serves as a crucial indicator of soil fertility and quality. Most of the studies covered in the literat...Soil phosphorus (P) plays a vital role in both ecological and agricultural ecosystems, where total P (TP) in soil serves as a crucial indicator of soil fertility and quality. Most of the studies covered in the literature employ a single or narrow range of soil databases, which largely overlooks the impact of utilizing multiple mapping scales in estimating soil TP, especially in hilly topographies. In this study, Fujian Province, a subtropical hilly region along China’s southeast coast covered by a complex topographic environment, was taken as a case study. The influence of the mapping scale on soil TP storage (TPS)estimation was analyzed using six digital soil databases that were derived from 3 082 unique soil profiles at different mapping scales, i.e., 1:50 000 (S5),1:200 000 (S20), 1:500 000 (S50), 1:1 000 000 (S100), 1:4 000 000 (S400), and 1:10 000 000 (S1000). The regional TPS in the surface soil (0–20 cm) based on the S5, S20, S50, S100, S400, and S1000 soil maps was 20.72, 22.17, 23.06, 23.05, 22.04, and 23.48 Tg, respectively, and the corresponding TPS at0–100 cm soil depth was 80.98, 80.71, 85.00, 84.03, 82.96, and 86.72 Tg, respectively. By comparing soil TPS in the S20 to S1000 maps to that in the S5map, the relative deviations were 6.37%–13.32%for 0–20 cm and 0.33%–7.09%for 0–100 cm. Moreover, since the S20 map had the lowest relative deviation among different mapping scales as compared to S5, it could provide additional soil information and a richer soil environment than other smaller mapping scales. Our results also revealed that many uncertainties in soil TPS estimation originated from the lack of detailed soil information, i.e., representation and spatial variations among different soil types. From the time and labor perspectives, our work provides useful guidelines to identify the appropriate mapping scale for estimating regional soil TPS in areas like Fujian Province in subtropical China or other places with similar complex topographies. Moreover, it is of tremendous importance to accurately estimate soil TPS to ensure ecosystem stability and sustainable agricultural development, especially for regional decision-making and management of phosphate fertilizer application amounts.展开更多
Previous study comes to the conclusion: based on the anomalies of the South Asian high (SAH), 100-hPa geopotential height, and 100-hPa circulation over tropical and subtropical regions, we can predict precipitation...Previous study comes to the conclusion: based on the anomalies of the South Asian high (SAH), 100-hPa geopotential height, and 100-hPa circulation over tropical and subtropical regions, we can predict precipitation anomaly in the Yangtze River Valley and North China. To test its validity, a series of experiments have been designed and operated, which include controlled experiment, sensitivity experiment (which has added anomalies into 100-hPa geopotential height and wind field), and four-composite experiments. Experiments based on the composed initial field such as EPR-CF, EPR-CD, EPR-HF, and EPR-HD, can reproduce the floods or droughts in the Yangtze River Valley and North China. It suggests that anomalies of the SAH, 100- hPa geopotential height, and circulation over tropical and subtropical regions may probably imply summer precipitation anomalies in the two regions. Sensitivity experiment results show that anomalies of the SAH, 100-hPa geopotential height, and southwest flow in the previous period is a signal of droughts or floods for the following summer in the Yangtze River Valley and North China. And it is also one of the factors that have impact on summer precipitation anomaly in the two regions. Positive anomaly of 100-hPa geopotential height and the anomalous intensifying of the SAH and southwest flow will induce floods in the Yangtze River Valley and droughts in North China; while negative anomaly of 100-hPa geopotential height and anomalous weakening of the SAH and southwest flow will induce droughts in the Yangtze River Valley and floods in North China.展开更多
The Pearl River Delta,where Aedes albopictus(Ae.albopictus)is the only vector for dengue transmission,has exhibited one of the highest dengue burdens in southern China in recent decades.However,whether dengue virus(DE...The Pearl River Delta,where Aedes albopictus(Ae.albopictus)is the only vector for dengue transmission,has exhibited one of the highest dengue burdens in southern China in recent decades.However,whether dengue virus(DENV)can overwinter in Ae.albopictus in the Pearl River Delta has not been determined to date.In this study,300 field-derived Ae.albopictus mosquitoes from Guangzhou that were infected with the predominant endemic DENV-1 strain were investigated under simulated urban balcony environment from October 16,2016,to June 16,2017.The vertical transmission of DENV in the infected overwintering Ae.albopictus was analyzed.The DENV infected overwintering mosquitoes were evaluated for viral load at nine-time points using reverse transcription-quantitative PCR.The vector competence of the infected overwintering Ae.albopictus was also investigated by using suckling mice.Adult mosquitoes and larvae were found during the observation period.The vertical transmission of DENV-1 was documented.The DENV-1-positive rates between overwintering males and females had no difference.The proportion of DENV-1-positive overwintering mosquitoes decreased over time and had no difference beyond three months after the experiment.Overwintering mosquitoes can spread DENV-1 to hosts.No engorged mosquitoes at an ambient temperature below 15℃were observed.The ratio of engorged mosquitoes was positively correlated with the ambient temperature ranging from 15 to 30℃.Our results demonstrated that DENV can overwinter in Ae.albopictus in the Pearl River Delta,Ae.albopictus is the competent vector for DENV,and maintain autochthonous dengue outbreaks in the Pearl River Delta through vertical transmission.展开更多
基金the Ministry of Science and Technology of China(Grant No.2006CB403200)National Natural Science Foundation of China(Grant No.49463011,49833002 and 49962002)+2 种基金the open foundation projects of the State Key Laboratory of Environmental Geochemistry(in the years of 1993 and 1995)Engineering Project for Cross-century Qualified Scientific and Technological Personnel of Guizhou Province (2000-2004)Science Foundation of Guizhou Province.
文摘We investigated the weathering-pedogenesis of carbonate rocks and its environmental effects in subtropical regions of China. The investigation demonstrated that the weathering- pedogenesis of carbonate rocks is the process of a joint action of corrosion and illuviation and metasomatism in subtropical region. It is characterized by multi-stage, multi-path and multi-style. With the persisting development of weathering-pedogenesis of carbonate rocks, metasomatic pedogenesis progressively became the main process of the weathering-pedogenesis and the dominant style of formation of minerals. And it proceeds through the whole process of evolution of the weathering-pedogenesis of carbonate rocks. The stage evolution of weathering-pedogenesis of carbonate rocks and the fractionation evolution of newly produced minerals are characterized by obvious vertically zoning structures and the rules of gradation of elements geochemical characteristics in the carbonate rocks weathering profiles. The geochemical process of weathering-pedogenesis of carbonate rocks can be divided into three geochemical evolution stages, i.e., the Ca, Mg-depletion and Si, Al-enrichment stage; the Fe, Mn enrichment stage and the Si-depletion and Al-enrichment stage in the subtropical regions. Consistent with the three geochemical evolution stages, the sequence of formation and evolution of minerals can be divided into the clay mineral stage; the Fe, Mn oxide and the gibbsite stage. The influence of weathering-pedogenesis of carbonate rocks on the chemical forms of heavy elements is mainly affected via newly produced components and minerals in the process of weathering-pedogenesis, e.g., iron oxide minerals and organic matters. The important mechanism for the mobilization, transport and pollution of F and As is affected the selective adsorption and desorption of F and As on the surface of iron oxide minerals in the subtropical karst zones, i.e., the selective adsorption and desorption on mineral surfaces of newly produced minerals in the process of weathering-pedogenesis control the geochemical behavior of elements on the Earth's surface and environmental quality in subtropical regions.
基金supported by research funding and permits from Shanghai Landscaping and City Appearance Administrative Bureau (Grant No.F131508)
文摘There is a dearth of information on the effects of landscape and microhabitat variables on the distribution of anurans in areas of rapid urban development, in both tropical and subtropical regions. Therefore, we studied 24 Wetlands sites from the center of Shanghai city, China extending outward to rural areas. Sampling was performed from May through July 2014. Urbanization was categorized by the proportion of hard ground cover. Transect sampling and 'calling' surveys were used to investigated the richness and density of anurans; microhabitat factors were recorded simultaneously. One-way analysis of variance and Kruskal-Wallis tests were conducted to analyze differences of total density, species richness and density of individual anuran species in the three urbanization levels; redundancy analysis was carried out on the relationship between anuran density and environmental variables. Species richness was lowest in the areas where the proportion of hard ground cover was 〉 80%, and the total density of anurans was highest in the areas where coverage of the hard ground cover was 〈 30%. We recorded five species belonging to four genera and four families and an individual anuran species that had varied representations in urban environments. Beijing gold-striped pond frogs (Pelophylax plancyi) and Zhoushan toads (Bufo gargarizans) appeared to be well adapted to the Shanghai metropolis. Large water environments and aquatic vegetation (floating-leaves and emergent vegetation) were indicators of the presence of Beijing gold-striped pond frogs. The density of black-spotted pond frog (Pelophylax nigromaculatus) was at the lowest density in the areas where hard ground coverage was 〉 80%, and tended to prefer larger bodies of water. Hong Kong rice-paddy frogs (Fejervarya multistriata) and ornamented pygmy frogs (Microhyla achatina) both suffered severely from cropland loss due to urban development. Bare land around breeding grounds was important for Hong Kong rice-paddy frogs, since it usually chooses mud coast caves for hibernation.
基金supported by the National Key R&D Program of China(2017YFB0403905)the Central Publicinterest Scientific Institution Basal Research Fund,China(CAAS-ZDRW202007)the earmarked fund for China Agriculture Research System(CARS-15-19).
文摘Fall armyworm(FAW),Spodoptera frugiperda(J.E.Smith),has become an important pest in Chinese agricultural systems since its invasion on 11 December 2018.After its establishment,FAW months in the year-round breeding region have become the main source population migrating to other areas in China.Field investigations were conducted in tropical and subtropical regions to improve understanding of its year-round breeding area in China.The results showed that FAW larval density was significantly correlated with the seasonal temperature of the location surveyed.The FAW larvae maintained a high density in the tropical area and were frequently found in sites of the south subtropical region,but were absent from the north subtropical region and the northern part of the central subtropical region.These results indicated that FAW can reproduce annually in the tropical and south subtropical regions of China,including Hainan,Taiwan and the southern area of Fujian,Guangdong,Guangxi,Guizhou,and Yunnan.Hence,great effort should be made to monitor and control FAW in the year-round breeding region to suppress the population density of this area and to reduce migration of moths into northern parts of China.This study clarifies the occurrence area of the pest in winter in China and provides much valuable information for its population forecasting and management.
基金supported by the National Natural Science Foundation of China(Nos.41971050 and 42207271)the Provincial Natural Science Foundation of Fujian,China(No.2022J05036)the Open Project Program of the State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry,Institute of Atmospheric Physics,Chinese Academy of Sciences(No.LAPC-KF-2022-08)。
文摘Soil phosphorus (P) plays a vital role in both ecological and agricultural ecosystems, where total P (TP) in soil serves as a crucial indicator of soil fertility and quality. Most of the studies covered in the literature employ a single or narrow range of soil databases, which largely overlooks the impact of utilizing multiple mapping scales in estimating soil TP, especially in hilly topographies. In this study, Fujian Province, a subtropical hilly region along China’s southeast coast covered by a complex topographic environment, was taken as a case study. The influence of the mapping scale on soil TP storage (TPS)estimation was analyzed using six digital soil databases that were derived from 3 082 unique soil profiles at different mapping scales, i.e., 1:50 000 (S5),1:200 000 (S20), 1:500 000 (S50), 1:1 000 000 (S100), 1:4 000 000 (S400), and 1:10 000 000 (S1000). The regional TPS in the surface soil (0–20 cm) based on the S5, S20, S50, S100, S400, and S1000 soil maps was 20.72, 22.17, 23.06, 23.05, 22.04, and 23.48 Tg, respectively, and the corresponding TPS at0–100 cm soil depth was 80.98, 80.71, 85.00, 84.03, 82.96, and 86.72 Tg, respectively. By comparing soil TPS in the S20 to S1000 maps to that in the S5map, the relative deviations were 6.37%–13.32%for 0–20 cm and 0.33%–7.09%for 0–100 cm. Moreover, since the S20 map had the lowest relative deviation among different mapping scales as compared to S5, it could provide additional soil information and a richer soil environment than other smaller mapping scales. Our results also revealed that many uncertainties in soil TPS estimation originated from the lack of detailed soil information, i.e., representation and spatial variations among different soil types. From the time and labor perspectives, our work provides useful guidelines to identify the appropriate mapping scale for estimating regional soil TPS in areas like Fujian Province in subtropical China or other places with similar complex topographies. Moreover, it is of tremendous importance to accurately estimate soil TPS to ensure ecosystem stability and sustainable agricultural development, especially for regional decision-making and management of phosphate fertilizer application amounts.
基金Supported by the National Key Developing Programme for Basic Science Project under No.1998040900 amd the Key Project of National Natural Science Foundation of China under No.40175021.
文摘Previous study comes to the conclusion: based on the anomalies of the South Asian high (SAH), 100-hPa geopotential height, and 100-hPa circulation over tropical and subtropical regions, we can predict precipitation anomaly in the Yangtze River Valley and North China. To test its validity, a series of experiments have been designed and operated, which include controlled experiment, sensitivity experiment (which has added anomalies into 100-hPa geopotential height and wind field), and four-composite experiments. Experiments based on the composed initial field such as EPR-CF, EPR-CD, EPR-HF, and EPR-HD, can reproduce the floods or droughts in the Yangtze River Valley and North China. It suggests that anomalies of the SAH, 100- hPa geopotential height, and circulation over tropical and subtropical regions may probably imply summer precipitation anomalies in the two regions. Sensitivity experiment results show that anomalies of the SAH, 100-hPa geopotential height, and southwest flow in the previous period is a signal of droughts or floods for the following summer in the Yangtze River Valley and North China. And it is also one of the factors that have impact on summer precipitation anomaly in the two regions. Positive anomaly of 100-hPa geopotential height and the anomalous intensifying of the SAH and southwest flow will induce floods in the Yangtze River Valley and droughts in North China; while negative anomaly of 100-hPa geopotential height and anomalous weakening of the SAH and southwest flow will induce droughts in the Yangtze River Valley and floods in North China.
基金This project was supported by the Provincial Science and Technology Projects of Guangdong Province,China(Grant numbers:2014A020219007,2015A020218003,2016A020219006 and 2017A020215101)the Medical Scientific Research Foundation of Guangdong Province,China(Grant numbers:A2018167).
文摘The Pearl River Delta,where Aedes albopictus(Ae.albopictus)is the only vector for dengue transmission,has exhibited one of the highest dengue burdens in southern China in recent decades.However,whether dengue virus(DENV)can overwinter in Ae.albopictus in the Pearl River Delta has not been determined to date.In this study,300 field-derived Ae.albopictus mosquitoes from Guangzhou that were infected with the predominant endemic DENV-1 strain were investigated under simulated urban balcony environment from October 16,2016,to June 16,2017.The vertical transmission of DENV in the infected overwintering Ae.albopictus was analyzed.The DENV infected overwintering mosquitoes were evaluated for viral load at nine-time points using reverse transcription-quantitative PCR.The vector competence of the infected overwintering Ae.albopictus was also investigated by using suckling mice.Adult mosquitoes and larvae were found during the observation period.The vertical transmission of DENV-1 was documented.The DENV-1-positive rates between overwintering males and females had no difference.The proportion of DENV-1-positive overwintering mosquitoes decreased over time and had no difference beyond three months after the experiment.Overwintering mosquitoes can spread DENV-1 to hosts.No engorged mosquitoes at an ambient temperature below 15℃were observed.The ratio of engorged mosquitoes was positively correlated with the ambient temperature ranging from 15 to 30℃.Our results demonstrated that DENV can overwinter in Ae.albopictus in the Pearl River Delta,Ae.albopictus is the competent vector for DENV,and maintain autochthonous dengue outbreaks in the Pearl River Delta through vertical transmission.