Background:China's coastal wetlands belong to some of the most threatened ecosystems worldwide.The loss and degradation of these wetlands seriously threaten waterbirds that depend on wetlands.Methods:The China Coa...Background:China's coastal wetlands belong to some of the most threatened ecosystems worldwide.The loss and degradation of these wetlands seriously threaten waterbirds that depend on wetlands.Methods:The China Coastal Waterbird Census was organized by volunteer birdwatchers in China's coastal region.Waterbirds were surveyed synchronously once every month at 14 sites,as well as irregularly at a further 18 sites,between September 2005 and December 2013.Results:A total of 75 species of waterbirds met the 1 % population level Ramsar listing criterion at least once at one site.The number of birds of the following species accounted for over 20 % of the total flyway populations at a single site:Mute Swan(Cygnus olor),Siberia Crane(Grus leucogeranus),Far Eastern Oystercatcher(Haematopus osculans),Bar-tailed Godwit(Limosa lapponica),Spotted Greenshank(Tringa guttifer),Great Knot(Calidris tenuirostris),Spoon-billed Sandpiper(Calidris pygmeus),Saunders' s Gull(Larus saundersi),Relict Gull(Larus relictus),Great Cormorant(Phalacrocorax carbo),Eurasian Spoonbill(Platalea leucorodia),Black-faced Spoonbill(Platalea minor) and Dalmatian Pelican(Pelecanus crispus).A total of 26 sites supported at least one species of which their number met the1 % criterion.Forty-two species met the 1 % criterion in the Yellow River Delta,Shandong;29 at the Cangzhou coast,Hebei and 26 species at the Lianyungang coast,Jiangsu.Conclusions:The results highlight the international importance of China's coastal wetlands for waterbirds.This study also demonstrates that participation of local birdwatchers in waterbird surveys results in data that are invaluable not only for understanding the current status of waterbirds in China's coastal regions but also for waterbird conservation and management.展开更多
Background:Despite an increasing number of surveys and a growing interest in birdwatching,the population and distribution of Asian Dowitcher(Limnodromus semipalmatus),a species endemic to the East Asian-Australasian a...Background:Despite an increasing number of surveys and a growing interest in birdwatching,the population and distribution of Asian Dowitcher(Limnodromus semipalmatus),a species endemic to the East Asian-Australasian and Central Asian Flyways,remains poorly understood,and published information about the species is largely outdated.In boreal spring 2019,over 22,432 Asian Dowitchers were recorded in a coastal wetland at Lianyungang,Jiangsu Prov-ince,China,constituting 97.5%of its estimated global population.Methods:In 2019 and 2020,we conducted field surveys at Lianyungang to determine the numbers of Asian Dow-itchers using the area during both southward and northward migrations.We also assessed the distribution and abun-dance of Asian Dowitchers elsewhere along the China coast by searching literature and consulting expert opinion.Results:The coastal wetlands of Lianyungang are the most important stopover site for Asian Dowitchers during both northward and southward migrations;they supported over 90%of the estimated global population during north-ward migration in two consecutive years(May 2019 and 2020).This area also supported at least 15.83%and 28.42%(or 30.74%and 53.51%using modelled estimates)of the global population during southward migration in 2019 and 2020 respectively.Coastal wetlands in the west and north of Bohai Bay also have been important stopover sites for the species since the 1990s.Although comprehensive,long-term monitoring data are lacking,available evidence sug-gests that the population of the species may have declined.Conclusions:The high concentration of Asian Dowitchers at Lianyungang during migration means the species is highly susceptible to human disturbances and natural stochastic events.The coastal wetlands of Lianyungang should be protected and potentially qualify for inclusion in China’s forthcoming nomination for World Heritage listing of Migratory Bird Sanctuaries along the Coast of Yellow Sea-Bohai Gulf of China(Phase II)in 2023.Additional research is needed to understand Asian Dowitchers’distribution and ecology,as well as why such a high proportion of their population rely on the Lianyungang coast.展开更多
The vertical distribution of aerosols was directly observed under various atmospheric conditions in the free troposphere using surface micro-pulse lidar （MPL4） at the Zhangye Station （39.08°N, 100.27°E） ...The vertical distribution of aerosols was directly observed under various atmospheric conditions in the free troposphere using surface micro-pulse lidar （MPL4） at the Zhangye Station （39.08°N, 100.27°E） in western China in the spring of 2008. The study shows that the aerosol distribution over Zhangye can be vertically classified into upper, middle and lower layers with altitudes of 4.5 to 9 km, 2.5 to 4.5 kin, and less than 2.5 km, respectively. The aerosol in the upper layer originated from the external sources at higher altitude regions, from far desert regions upwind of Zhangye or transported from higher atmospheric layers by free convection, and the altitude of this aerosol layer decreased with time; the aerosols in the middle and lower layers originated from both external and local sources. The aerosol extinction coefficients in the upper and lower layers decreased with altitude, whereas the coefficient in the middle layer changed only slightly, which suggests that aerosol mixing occurs in the middle layer. The distribution of aerosols with altitude has three features： a single peak that forms under stable atmospheric conditions, an exponential decrease with altitude that occurs under unstable atmospheric conditions, and slight change in the mixed layer. Due to the impact of the top of the atmospheric boundary layer, the diurnal variation in the aerosol extinction coefficient has a single peak, which is higher in the afternoon and lower in the morning.展开更多
文摘Background:China's coastal wetlands belong to some of the most threatened ecosystems worldwide.The loss and degradation of these wetlands seriously threaten waterbirds that depend on wetlands.Methods:The China Coastal Waterbird Census was organized by volunteer birdwatchers in China's coastal region.Waterbirds were surveyed synchronously once every month at 14 sites,as well as irregularly at a further 18 sites,between September 2005 and December 2013.Results:A total of 75 species of waterbirds met the 1 % population level Ramsar listing criterion at least once at one site.The number of birds of the following species accounted for over 20 % of the total flyway populations at a single site:Mute Swan(Cygnus olor),Siberia Crane(Grus leucogeranus),Far Eastern Oystercatcher(Haematopus osculans),Bar-tailed Godwit(Limosa lapponica),Spotted Greenshank(Tringa guttifer),Great Knot(Calidris tenuirostris),Spoon-billed Sandpiper(Calidris pygmeus),Saunders' s Gull(Larus saundersi),Relict Gull(Larus relictus),Great Cormorant(Phalacrocorax carbo),Eurasian Spoonbill(Platalea leucorodia),Black-faced Spoonbill(Platalea minor) and Dalmatian Pelican(Pelecanus crispus).A total of 26 sites supported at least one species of which their number met the1 % criterion.Forty-two species met the 1 % criterion in the Yellow River Delta,Shandong;29 at the Cangzhou coast,Hebei and 26 species at the Lianyungang coast,Jiangsu.Conclusions:The results highlight the international importance of China's coastal wetlands for waterbirds.This study also demonstrates that participation of local birdwatchers in waterbird surveys results in data that are invaluable not only for understanding the current status of waterbirds in China's coastal regions but also for waterbird conservation and management.
基金supported by the Science and Technology Innovation Committee of Shenzhen Municipality(JCYJ20190809115207397).
文摘Background:Despite an increasing number of surveys and a growing interest in birdwatching,the population and distribution of Asian Dowitcher(Limnodromus semipalmatus),a species endemic to the East Asian-Australasian and Central Asian Flyways,remains poorly understood,and published information about the species is largely outdated.In boreal spring 2019,over 22,432 Asian Dowitchers were recorded in a coastal wetland at Lianyungang,Jiangsu Prov-ince,China,constituting 97.5%of its estimated global population.Methods:In 2019 and 2020,we conducted field surveys at Lianyungang to determine the numbers of Asian Dow-itchers using the area during both southward and northward migrations.We also assessed the distribution and abun-dance of Asian Dowitchers elsewhere along the China coast by searching literature and consulting expert opinion.Results:The coastal wetlands of Lianyungang are the most important stopover site for Asian Dowitchers during both northward and southward migrations;they supported over 90%of the estimated global population during north-ward migration in two consecutive years(May 2019 and 2020).This area also supported at least 15.83%and 28.42%(or 30.74%and 53.51%using modelled estimates)of the global population during southward migration in 2019 and 2020 respectively.Coastal wetlands in the west and north of Bohai Bay also have been important stopover sites for the species since the 1990s.Although comprehensive,long-term monitoring data are lacking,available evidence sug-gests that the population of the species may have declined.Conclusions:The high concentration of Asian Dowitchers at Lianyungang during migration means the species is highly susceptible to human disturbances and natural stochastic events.The coastal wetlands of Lianyungang should be protected and potentially qualify for inclusion in China’s forthcoming nomination for World Heritage listing of Migratory Bird Sanctuaries along the Coast of Yellow Sea-Bohai Gulf of China(Phase II)in 2023.Additional research is needed to understand Asian Dowitchers’distribution and ecology,as well as why such a high proportion of their population rely on the Lianyungang coast.
基金supported by the National Natural Science Foundation of China (No. 40805009)a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)the SACOL stations (Lanzhou University Semi-Arid Climate & Environment Observatory of Lanzhou University),OMI and the NCEP database
文摘The vertical distribution of aerosols was directly observed under various atmospheric conditions in the free troposphere using surface micro-pulse lidar （MPL4） at the Zhangye Station （39.08°N, 100.27°E） in western China in the spring of 2008. The study shows that the aerosol distribution over Zhangye can be vertically classified into upper, middle and lower layers with altitudes of 4.5 to 9 km, 2.5 to 4.5 kin, and less than 2.5 km, respectively. The aerosol in the upper layer originated from the external sources at higher altitude regions, from far desert regions upwind of Zhangye or transported from higher atmospheric layers by free convection, and the altitude of this aerosol layer decreased with time; the aerosols in the middle and lower layers originated from both external and local sources. The aerosol extinction coefficients in the upper and lower layers decreased with altitude, whereas the coefficient in the middle layer changed only slightly, which suggests that aerosol mixing occurs in the middle layer. The distribution of aerosols with altitude has three features： a single peak that forms under stable atmospheric conditions, an exponential decrease with altitude that occurs under unstable atmospheric conditions, and slight change in the mixed layer. Due to the impact of the top of the atmospheric boundary layer, the diurnal variation in the aerosol extinction coefficient has a single peak, which is higher in the afternoon and lower in the morning.
