The Experts below are selected from a list of 228 Experts worldwide ranked by ideXlab platform
Si Long Wang - One of the best experts on this subject based on the ideXlab platform.
-
Declines in the tuber-feeding waterbird guild at Shengjin Lake National Nature Reserve, China - a barometer of submerged macrophyte collapse
Aquatic Conservation: Marine and Freshwater Ecosystems, 2010Co-Authors: Anthony D Fox, Yong Zhang, Lei Cao, Mark Barter, Meijuan Zhao, Fanjuan Meng, Si Long WangAbstract:1. The Yangtze floodplain is globally unique for its extensive ephemeral wetlands, recharged by summer monsoon precipitation. The annual cycle of inundation and water table recession favours submerged macrophytes, including Vallisneria that overwinters in desiccated substrates as tubers, which provide high-energy winter food for tuber-feeding waterbirds that were formerly abundant in the region. 2. Large declines among the tuber-feeding waterbirds Swan goose Anser cygnoides (L.), Tundra Swan Cygnus columbianus (Ord) and hooded crane Grus monacha Temminck between 2004/2005 and 2009/2010 at Shengjin Lake, Anhui Province, suggest that major changes in food availability have occurred there. 3. Based on observations of feeding behaviour and energy budgets of these species, it was calculated that at least 5.0 and 8.9?km2 of Vallisneria beds in 2004 and 2005, respectively, would be needed to support observed numbers of these species, compared with less than 1.5?km2 found in 2009 and 2010. 4. An incomplete macrophyte survey in summer 2000 located at least 7.7?km2 of Vallisneria beds in the Upper Lake, where none was present during resurveys in 2008 and 2009. Declines in tuber-feeding waterbirds at Shengjin Lake coincide with the disappearance of their submerged macrophyte food plants, possibly as a result of eutrophication since the mid-2000s. 5. Widespread declines and concentration of tuber-eating wintering waterbirds at other sites elsewhere in the Yangtze floodplain may also reflect the local collapse of submerged macrophytes and of ecosystem services that these wetlands provide to the human communities.
-
Declines in the tuber‐feeding waterbird guild at Shengjin Lake National Nature Reserve, China – a barometer of submerged macrophyte collapse
Aquatic Conservation: Marine and Freshwater Ecosystems, 2010Co-Authors: Anthony D Fox, Yong Zhang, Lei Cao, Mark Barter, Meijuan Zhao, Fanjuan Meng, Si Long WangAbstract:1. The Yangtze floodplain is globally unique for its extensive ephemeral wetlands, recharged by summer monsoon precipitation. The annual cycle of inundation and water table recession favours submerged macrophytes, including Vallisneria that overwinters in desiccated substrates as tubers, which provide high-energy winter food for tuber-feeding waterbirds that were formerly abundant in the region. 2. Large declines among the tuber-feeding waterbirds Swan goose Anser cygnoides (L.), Tundra Swan Cygnus columbianus (Ord) and hooded crane Grus monacha Temminck between 2004/2005 and 2009/2010 at Shengjin Lake, Anhui Province, suggest that major changes in food availability have occurred there. 3. Based on observations of feeding behaviour and energy budgets of these species, it was calculated that at least 5.0 and 8.9?km2 of Vallisneria beds in 2004 and 2005, respectively, would be needed to support observed numbers of these species, compared with less than 1.5?km2 found in 2009 and 2010. 4. An incomplete macrophyte survey in summer 2000 located at least 7.7?km2 of Vallisneria beds in the Upper Lake, where none was present during resurveys in 2008 and 2009. Declines in tuber-feeding waterbirds at Shengjin Lake coincide with the disappearance of their submerged macrophyte food plants, possibly as a result of eutrophication since the mid-2000s. 5. Widespread declines and concentration of tuber-eating wintering waterbirds at other sites elsewhere in the Yangtze floodplain may also reflect the local collapse of submerged macrophytes and of ecosystem services that these wetlands provide to the human communities.
Lei Cao - One of the best experts on this subject based on the ideXlab platform.
-
Response of Anatidae Abundance to Environmental Factors in the Middle and Lower Yangtze River Floodplain, China
Sustainability, 2019Co-Authors: Qiang Jia, Yong Zhang, Lei CaoAbstract:Understanding and predicting animal distribution is one of the most elementary objectives in ecology and conservation biology. Various environmental factors, such as habitat area, habitat quality, and climatic factors, play important roles in shaping animal distribution. However, the mechanism underlying animal distribution remains unclear. Using generalized additive mixed models, we analyzed the effects of environmental factors and years on the population of five Anatidae species: Tundra Swan, Swan goose, bean goose, greater and lesser white-fronted goose, across their wintering grounds along the Middle and Lower Yangtze River floodplain (MLYRF) during 2001–2016. We found that: (1) All populations decreased except for that of the bean goose. (2) The patch area was not included in any of the best models. (3) NDVI was the most important factor in determining the abundance of grazing geese. (4) Climatic factors had no significant effect on the species in question. Our results suggest that, when compared to habitat area, habitat quality is better in predicting Anatidae distribution on the basin scale. Thus, to better conserve wintering Anatidae, we should keep a sufficiently large area at the single lake, as well as high quality habitat over the whole basin. This might be achieved by developing a more strategic water plan for the MLYRF.
-
Changes in Tundra Swan Cygnus columbianus bewickii distribution and abundance in the Yangtze River floodplain
Bird Conservation International, 2011Co-Authors: Peihao Cong, Lei Cao, Mark Barter, Anthony D Fox, Eileen C. Rees, Yong Jiang, Wenzhong Zhu, Guoxian SongAbstract:Approximately 75% of the East Asian Flyway Tundra Swan Cygnus columbianus bewickii population winters in the Yangtze River floodplain, China. Historically the species was more widely distributed throughout the floodplain but now most of the population is confined to five wetlands in Anhui Province and to Poyang Lake in Jiangxi Province, where the majority (up to 113,000 birds) occur. Within-winter counts suggest that Swans congregate at Poyang Lake before dispersing to other sites later in the winter. Counts show large between-year fluctuations, but suggest declines at Shengjin and Fengsha Lakes (both in Anhui) during the last five years. Declines at Shengjin Lake are likely due to decreases in submerged vegetation (particularly tuber-producing Vallisneria, a major food item) perhaps linked to eutrophication. Range contractions throughout the floodplain may also be linked to reductions in submerged vegetation coverage elsewhere. Changes in water quality and lake hydrology post-Three Gorges Dam may have adversely affected submerged vegetation productivity. Key information needs for the effective implementation of conservation measures for Tundra Swans include: (1) annual surveys of all major wintering sites throughout each winter to establish the importance of different sites during the non-breeding period; (2) more information on Swan diets at important sites; and (3) an assessment of adverse effects of water quality and lake water levels post-Three Gorges Dam on submerged vegetation productivity at Poyang Lake and other important sites.
-
Short communication Changes in Tundra Swan Cygnus columbianus bewickii distribution and abundance in the Yangtze River floodplain
2011Co-Authors: Peihao Cong, Lei Cao, Mark Barter, Anthony D Fox, Yong Jiang, Wenzhong Zhu, Guoxian SongAbstract:PEIHAO CONG, LEI CAO, ANTHONY D. FOX, MARK BARTER, EILEEN C.REES, YONG JIANG, WEITOU JI, WENZHONG ZHU and GUOXIAN SONGApproximately 75% of the East Asian Flyway Tundra Swan Cygnus columbianus bewickiipopulation winters in the Yangtze River floodplain, China. Historically the species was morewidely distributed throughout the floodplain but now most of the population is confined to fivewetlands in Anhui Province and to Poyang Lake in Jiangxi Province, where the majority (up to113,000 birds) occur. Within-winter counts suggest that Swans congregate at Poyang Lake beforedispersing to other sites later in the winter. Counts show large between-year fluctuations,but suggestdeclines at Shengjin and Fengsha La kes (both in Anhui) during the last five years. Declines atShengjin Lake are likely due to decreases in subme rged vegetation (particularly tuber-producingVallisneria, a major food item) perhaps linked to eutrophication. Range contractions throughout thefloodplain may also be linked to reductions in submerged vegetation coverage elsewhere. Changes inwater quality and lake hydrology post-Three Gorges Dam may have adversely affected submergedvegetation productivity. Key information needs for the effective implementation of conservationmeasures for Tundra Swans include: ( 1) annual surveys of all major wintering sites throughout eachwinter to establish the importance of different sites during the non-breeding period; ( 2)moreinformation on Swan diets at important sites; and ( 3) an assessment of adverse effects of water qualityand lake water levels post-Three Gorges Dam on submerged vegetation productivity at Poyang Lakeand other important sites.
-
Declines in the tuber-feeding waterbird guild at Shengjin Lake National Nature Reserve, China - a barometer of submerged macrophyte collapse
Aquatic Conservation: Marine and Freshwater Ecosystems, 2010Co-Authors: Anthony D Fox, Yong Zhang, Lei Cao, Mark Barter, Meijuan Zhao, Fanjuan Meng, Si Long WangAbstract:1. The Yangtze floodplain is globally unique for its extensive ephemeral wetlands, recharged by summer monsoon precipitation. The annual cycle of inundation and water table recession favours submerged macrophytes, including Vallisneria that overwinters in desiccated substrates as tubers, which provide high-energy winter food for tuber-feeding waterbirds that were formerly abundant in the region. 2. Large declines among the tuber-feeding waterbirds Swan goose Anser cygnoides (L.), Tundra Swan Cygnus columbianus (Ord) and hooded crane Grus monacha Temminck between 2004/2005 and 2009/2010 at Shengjin Lake, Anhui Province, suggest that major changes in food availability have occurred there. 3. Based on observations of feeding behaviour and energy budgets of these species, it was calculated that at least 5.0 and 8.9?km2 of Vallisneria beds in 2004 and 2005, respectively, would be needed to support observed numbers of these species, compared with less than 1.5?km2 found in 2009 and 2010. 4. An incomplete macrophyte survey in summer 2000 located at least 7.7?km2 of Vallisneria beds in the Upper Lake, where none was present during resurveys in 2008 and 2009. Declines in tuber-feeding waterbirds at Shengjin Lake coincide with the disappearance of their submerged macrophyte food plants, possibly as a result of eutrophication since the mid-2000s. 5. Widespread declines and concentration of tuber-eating wintering waterbirds at other sites elsewhere in the Yangtze floodplain may also reflect the local collapse of submerged macrophytes and of ecosystem services that these wetlands provide to the human communities.
-
Declines in the tuber‐feeding waterbird guild at Shengjin Lake National Nature Reserve, China – a barometer of submerged macrophyte collapse
Aquatic Conservation: Marine and Freshwater Ecosystems, 2010Co-Authors: Anthony D Fox, Yong Zhang, Lei Cao, Mark Barter, Meijuan Zhao, Fanjuan Meng, Si Long WangAbstract:1. The Yangtze floodplain is globally unique for its extensive ephemeral wetlands, recharged by summer monsoon precipitation. The annual cycle of inundation and water table recession favours submerged macrophytes, including Vallisneria that overwinters in desiccated substrates as tubers, which provide high-energy winter food for tuber-feeding waterbirds that were formerly abundant in the region. 2. Large declines among the tuber-feeding waterbirds Swan goose Anser cygnoides (L.), Tundra Swan Cygnus columbianus (Ord) and hooded crane Grus monacha Temminck between 2004/2005 and 2009/2010 at Shengjin Lake, Anhui Province, suggest that major changes in food availability have occurred there. 3. Based on observations of feeding behaviour and energy budgets of these species, it was calculated that at least 5.0 and 8.9?km2 of Vallisneria beds in 2004 and 2005, respectively, would be needed to support observed numbers of these species, compared with less than 1.5?km2 found in 2009 and 2010. 4. An incomplete macrophyte survey in summer 2000 located at least 7.7?km2 of Vallisneria beds in the Upper Lake, where none was present during resurveys in 2008 and 2009. Declines in tuber-feeding waterbirds at Shengjin Lake coincide with the disappearance of their submerged macrophyte food plants, possibly as a result of eutrophication since the mid-2000s. 5. Widespread declines and concentration of tuber-eating wintering waterbirds at other sites elsewhere in the Yangtze floodplain may also reflect the local collapse of submerged macrophytes and of ecosystem services that these wetlands provide to the human communities.
Anthony D Fox - One of the best experts on this subject based on the ideXlab platform.
-
Changes in Tundra Swan Cygnus columbianus bewickii distribution and abundance in the Yangtze River floodplain
Bird Conservation International, 2011Co-Authors: Peihao Cong, Lei Cao, Mark Barter, Anthony D Fox, Eileen C. Rees, Yong Jiang, Wenzhong Zhu, Guoxian SongAbstract:Approximately 75% of the East Asian Flyway Tundra Swan Cygnus columbianus bewickii population winters in the Yangtze River floodplain, China. Historically the species was more widely distributed throughout the floodplain but now most of the population is confined to five wetlands in Anhui Province and to Poyang Lake in Jiangxi Province, where the majority (up to 113,000 birds) occur. Within-winter counts suggest that Swans congregate at Poyang Lake before dispersing to other sites later in the winter. Counts show large between-year fluctuations, but suggest declines at Shengjin and Fengsha Lakes (both in Anhui) during the last five years. Declines at Shengjin Lake are likely due to decreases in submerged vegetation (particularly tuber-producing Vallisneria, a major food item) perhaps linked to eutrophication. Range contractions throughout the floodplain may also be linked to reductions in submerged vegetation coverage elsewhere. Changes in water quality and lake hydrology post-Three Gorges Dam may have adversely affected submerged vegetation productivity. Key information needs for the effective implementation of conservation measures for Tundra Swans include: (1) annual surveys of all major wintering sites throughout each winter to establish the importance of different sites during the non-breeding period; (2) more information on Swan diets at important sites; and (3) an assessment of adverse effects of water quality and lake water levels post-Three Gorges Dam on submerged vegetation productivity at Poyang Lake and other important sites.
-
Short communication Changes in Tundra Swan Cygnus columbianus bewickii distribution and abundance in the Yangtze River floodplain
2011Co-Authors: Peihao Cong, Lei Cao, Mark Barter, Anthony D Fox, Yong Jiang, Wenzhong Zhu, Guoxian SongAbstract:PEIHAO CONG, LEI CAO, ANTHONY D. FOX, MARK BARTER, EILEEN C.REES, YONG JIANG, WEITOU JI, WENZHONG ZHU and GUOXIAN SONGApproximately 75% of the East Asian Flyway Tundra Swan Cygnus columbianus bewickiipopulation winters in the Yangtze River floodplain, China. Historically the species was morewidely distributed throughout the floodplain but now most of the population is confined to fivewetlands in Anhui Province and to Poyang Lake in Jiangxi Province, where the majority (up to113,000 birds) occur. Within-winter counts suggest that Swans congregate at Poyang Lake beforedispersing to other sites later in the winter. Counts show large between-year fluctuations,but suggestdeclines at Shengjin and Fengsha La kes (both in Anhui) during the last five years. Declines atShengjin Lake are likely due to decreases in subme rged vegetation (particularly tuber-producingVallisneria, a major food item) perhaps linked to eutrophication. Range contractions throughout thefloodplain may also be linked to reductions in submerged vegetation coverage elsewhere. Changes inwater quality and lake hydrology post-Three Gorges Dam may have adversely affected submergedvegetation productivity. Key information needs for the effective implementation of conservationmeasures for Tundra Swans include: ( 1) annual surveys of all major wintering sites throughout eachwinter to establish the importance of different sites during the non-breeding period; ( 2)moreinformation on Swan diets at important sites; and ( 3) an assessment of adverse effects of water qualityand lake water levels post-Three Gorges Dam on submerged vegetation productivity at Poyang Lakeand other important sites.
-
Declines in the tuber-feeding waterbird guild at Shengjin Lake National Nature Reserve, China - a barometer of submerged macrophyte collapse
Aquatic Conservation: Marine and Freshwater Ecosystems, 2010Co-Authors: Anthony D Fox, Yong Zhang, Lei Cao, Mark Barter, Meijuan Zhao, Fanjuan Meng, Si Long WangAbstract:1. The Yangtze floodplain is globally unique for its extensive ephemeral wetlands, recharged by summer monsoon precipitation. The annual cycle of inundation and water table recession favours submerged macrophytes, including Vallisneria that overwinters in desiccated substrates as tubers, which provide high-energy winter food for tuber-feeding waterbirds that were formerly abundant in the region. 2. Large declines among the tuber-feeding waterbirds Swan goose Anser cygnoides (L.), Tundra Swan Cygnus columbianus (Ord) and hooded crane Grus monacha Temminck between 2004/2005 and 2009/2010 at Shengjin Lake, Anhui Province, suggest that major changes in food availability have occurred there. 3. Based on observations of feeding behaviour and energy budgets of these species, it was calculated that at least 5.0 and 8.9?km2 of Vallisneria beds in 2004 and 2005, respectively, would be needed to support observed numbers of these species, compared with less than 1.5?km2 found in 2009 and 2010. 4. An incomplete macrophyte survey in summer 2000 located at least 7.7?km2 of Vallisneria beds in the Upper Lake, where none was present during resurveys in 2008 and 2009. Declines in tuber-feeding waterbirds at Shengjin Lake coincide with the disappearance of their submerged macrophyte food plants, possibly as a result of eutrophication since the mid-2000s. 5. Widespread declines and concentration of tuber-eating wintering waterbirds at other sites elsewhere in the Yangtze floodplain may also reflect the local collapse of submerged macrophytes and of ecosystem services that these wetlands provide to the human communities.
-
Declines in the tuber‐feeding waterbird guild at Shengjin Lake National Nature Reserve, China – a barometer of submerged macrophyte collapse
Aquatic Conservation: Marine and Freshwater Ecosystems, 2010Co-Authors: Anthony D Fox, Yong Zhang, Lei Cao, Mark Barter, Meijuan Zhao, Fanjuan Meng, Si Long WangAbstract:1. The Yangtze floodplain is globally unique for its extensive ephemeral wetlands, recharged by summer monsoon precipitation. The annual cycle of inundation and water table recession favours submerged macrophytes, including Vallisneria that overwinters in desiccated substrates as tubers, which provide high-energy winter food for tuber-feeding waterbirds that were formerly abundant in the region. 2. Large declines among the tuber-feeding waterbirds Swan goose Anser cygnoides (L.), Tundra Swan Cygnus columbianus (Ord) and hooded crane Grus monacha Temminck between 2004/2005 and 2009/2010 at Shengjin Lake, Anhui Province, suggest that major changes in food availability have occurred there. 3. Based on observations of feeding behaviour and energy budgets of these species, it was calculated that at least 5.0 and 8.9?km2 of Vallisneria beds in 2004 and 2005, respectively, would be needed to support observed numbers of these species, compared with less than 1.5?km2 found in 2009 and 2010. 4. An incomplete macrophyte survey in summer 2000 located at least 7.7?km2 of Vallisneria beds in the Upper Lake, where none was present during resurveys in 2008 and 2009. Declines in tuber-feeding waterbirds at Shengjin Lake coincide with the disappearance of their submerged macrophyte food plants, possibly as a result of eutrophication since the mid-2000s. 5. Widespread declines and concentration of tuber-eating wintering waterbirds at other sites elsewhere in the Yangtze floodplain may also reflect the local collapse of submerged macrophytes and of ecosystem services that these wetlands provide to the human communities.
Yong Zhang - One of the best experts on this subject based on the ideXlab platform.
-
Response of Anatidae Abundance to Environmental Factors in the Middle and Lower Yangtze River Floodplain, China
Sustainability, 2019Co-Authors: Qiang Jia, Yong Zhang, Lei CaoAbstract:Understanding and predicting animal distribution is one of the most elementary objectives in ecology and conservation biology. Various environmental factors, such as habitat area, habitat quality, and climatic factors, play important roles in shaping animal distribution. However, the mechanism underlying animal distribution remains unclear. Using generalized additive mixed models, we analyzed the effects of environmental factors and years on the population of five Anatidae species: Tundra Swan, Swan goose, bean goose, greater and lesser white-fronted goose, across their wintering grounds along the Middle and Lower Yangtze River floodplain (MLYRF) during 2001–2016. We found that: (1) All populations decreased except for that of the bean goose. (2) The patch area was not included in any of the best models. (3) NDVI was the most important factor in determining the abundance of grazing geese. (4) Climatic factors had no significant effect on the species in question. Our results suggest that, when compared to habitat area, habitat quality is better in predicting Anatidae distribution on the basin scale. Thus, to better conserve wintering Anatidae, we should keep a sufficiently large area at the single lake, as well as high quality habitat over the whole basin. This might be achieved by developing a more strategic water plan for the MLYRF.
-
Declines in the tuber-feeding waterbird guild at Shengjin Lake National Nature Reserve, China - a barometer of submerged macrophyte collapse
Aquatic Conservation: Marine and Freshwater Ecosystems, 2010Co-Authors: Anthony D Fox, Yong Zhang, Lei Cao, Mark Barter, Meijuan Zhao, Fanjuan Meng, Si Long WangAbstract:1. The Yangtze floodplain is globally unique for its extensive ephemeral wetlands, recharged by summer monsoon precipitation. The annual cycle of inundation and water table recession favours submerged macrophytes, including Vallisneria that overwinters in desiccated substrates as tubers, which provide high-energy winter food for tuber-feeding waterbirds that were formerly abundant in the region. 2. Large declines among the tuber-feeding waterbirds Swan goose Anser cygnoides (L.), Tundra Swan Cygnus columbianus (Ord) and hooded crane Grus monacha Temminck between 2004/2005 and 2009/2010 at Shengjin Lake, Anhui Province, suggest that major changes in food availability have occurred there. 3. Based on observations of feeding behaviour and energy budgets of these species, it was calculated that at least 5.0 and 8.9?km2 of Vallisneria beds in 2004 and 2005, respectively, would be needed to support observed numbers of these species, compared with less than 1.5?km2 found in 2009 and 2010. 4. An incomplete macrophyte survey in summer 2000 located at least 7.7?km2 of Vallisneria beds in the Upper Lake, where none was present during resurveys in 2008 and 2009. Declines in tuber-feeding waterbirds at Shengjin Lake coincide with the disappearance of their submerged macrophyte food plants, possibly as a result of eutrophication since the mid-2000s. 5. Widespread declines and concentration of tuber-eating wintering waterbirds at other sites elsewhere in the Yangtze floodplain may also reflect the local collapse of submerged macrophytes and of ecosystem services that these wetlands provide to the human communities.
-
Declines in the tuber‐feeding waterbird guild at Shengjin Lake National Nature Reserve, China – a barometer of submerged macrophyte collapse
Aquatic Conservation: Marine and Freshwater Ecosystems, 2010Co-Authors: Anthony D Fox, Yong Zhang, Lei Cao, Mark Barter, Meijuan Zhao, Fanjuan Meng, Si Long WangAbstract:1. The Yangtze floodplain is globally unique for its extensive ephemeral wetlands, recharged by summer monsoon precipitation. The annual cycle of inundation and water table recession favours submerged macrophytes, including Vallisneria that overwinters in desiccated substrates as tubers, which provide high-energy winter food for tuber-feeding waterbirds that were formerly abundant in the region. 2. Large declines among the tuber-feeding waterbirds Swan goose Anser cygnoides (L.), Tundra Swan Cygnus columbianus (Ord) and hooded crane Grus monacha Temminck between 2004/2005 and 2009/2010 at Shengjin Lake, Anhui Province, suggest that major changes in food availability have occurred there. 3. Based on observations of feeding behaviour and energy budgets of these species, it was calculated that at least 5.0 and 8.9?km2 of Vallisneria beds in 2004 and 2005, respectively, would be needed to support observed numbers of these species, compared with less than 1.5?km2 found in 2009 and 2010. 4. An incomplete macrophyte survey in summer 2000 located at least 7.7?km2 of Vallisneria beds in the Upper Lake, where none was present during resurveys in 2008 and 2009. Declines in tuber-feeding waterbirds at Shengjin Lake coincide with the disappearance of their submerged macrophyte food plants, possibly as a result of eutrophication since the mid-2000s. 5. Widespread declines and concentration of tuber-eating wintering waterbirds at other sites elsewhere in the Yangtze floodplain may also reflect the local collapse of submerged macrophytes and of ecosystem services that these wetlands provide to the human communities.
Mark Barter - One of the best experts on this subject based on the ideXlab platform.
-
Changes in Tundra Swan Cygnus columbianus bewickii distribution and abundance in the Yangtze River floodplain
Bird Conservation International, 2011Co-Authors: Peihao Cong, Lei Cao, Mark Barter, Anthony D Fox, Eileen C. Rees, Yong Jiang, Wenzhong Zhu, Guoxian SongAbstract:Approximately 75% of the East Asian Flyway Tundra Swan Cygnus columbianus bewickii population winters in the Yangtze River floodplain, China. Historically the species was more widely distributed throughout the floodplain but now most of the population is confined to five wetlands in Anhui Province and to Poyang Lake in Jiangxi Province, where the majority (up to 113,000 birds) occur. Within-winter counts suggest that Swans congregate at Poyang Lake before dispersing to other sites later in the winter. Counts show large between-year fluctuations, but suggest declines at Shengjin and Fengsha Lakes (both in Anhui) during the last five years. Declines at Shengjin Lake are likely due to decreases in submerged vegetation (particularly tuber-producing Vallisneria, a major food item) perhaps linked to eutrophication. Range contractions throughout the floodplain may also be linked to reductions in submerged vegetation coverage elsewhere. Changes in water quality and lake hydrology post-Three Gorges Dam may have adversely affected submerged vegetation productivity. Key information needs for the effective implementation of conservation measures for Tundra Swans include: (1) annual surveys of all major wintering sites throughout each winter to establish the importance of different sites during the non-breeding period; (2) more information on Swan diets at important sites; and (3) an assessment of adverse effects of water quality and lake water levels post-Three Gorges Dam on submerged vegetation productivity at Poyang Lake and other important sites.
-
Short communication Changes in Tundra Swan Cygnus columbianus bewickii distribution and abundance in the Yangtze River floodplain
2011Co-Authors: Peihao Cong, Lei Cao, Mark Barter, Anthony D Fox, Yong Jiang, Wenzhong Zhu, Guoxian SongAbstract:PEIHAO CONG, LEI CAO, ANTHONY D. FOX, MARK BARTER, EILEEN C.REES, YONG JIANG, WEITOU JI, WENZHONG ZHU and GUOXIAN SONGApproximately 75% of the East Asian Flyway Tundra Swan Cygnus columbianus bewickiipopulation winters in the Yangtze River floodplain, China. Historically the species was morewidely distributed throughout the floodplain but now most of the population is confined to fivewetlands in Anhui Province and to Poyang Lake in Jiangxi Province, where the majority (up to113,000 birds) occur. Within-winter counts suggest that Swans congregate at Poyang Lake beforedispersing to other sites later in the winter. Counts show large between-year fluctuations,but suggestdeclines at Shengjin and Fengsha La kes (both in Anhui) during the last five years. Declines atShengjin Lake are likely due to decreases in subme rged vegetation (particularly tuber-producingVallisneria, a major food item) perhaps linked to eutrophication. Range contractions throughout thefloodplain may also be linked to reductions in submerged vegetation coverage elsewhere. Changes inwater quality and lake hydrology post-Three Gorges Dam may have adversely affected submergedvegetation productivity. Key information needs for the effective implementation of conservationmeasures for Tundra Swans include: ( 1) annual surveys of all major wintering sites throughout eachwinter to establish the importance of different sites during the non-breeding period; ( 2)moreinformation on Swan diets at important sites; and ( 3) an assessment of adverse effects of water qualityand lake water levels post-Three Gorges Dam on submerged vegetation productivity at Poyang Lakeand other important sites.
-
Declines in the tuber-feeding waterbird guild at Shengjin Lake National Nature Reserve, China - a barometer of submerged macrophyte collapse
Aquatic Conservation: Marine and Freshwater Ecosystems, 2010Co-Authors: Anthony D Fox, Yong Zhang, Lei Cao, Mark Barter, Meijuan Zhao, Fanjuan Meng, Si Long WangAbstract:1. The Yangtze floodplain is globally unique for its extensive ephemeral wetlands, recharged by summer monsoon precipitation. The annual cycle of inundation and water table recession favours submerged macrophytes, including Vallisneria that overwinters in desiccated substrates as tubers, which provide high-energy winter food for tuber-feeding waterbirds that were formerly abundant in the region. 2. Large declines among the tuber-feeding waterbirds Swan goose Anser cygnoides (L.), Tundra Swan Cygnus columbianus (Ord) and hooded crane Grus monacha Temminck between 2004/2005 and 2009/2010 at Shengjin Lake, Anhui Province, suggest that major changes in food availability have occurred there. 3. Based on observations of feeding behaviour and energy budgets of these species, it was calculated that at least 5.0 and 8.9?km2 of Vallisneria beds in 2004 and 2005, respectively, would be needed to support observed numbers of these species, compared with less than 1.5?km2 found in 2009 and 2010. 4. An incomplete macrophyte survey in summer 2000 located at least 7.7?km2 of Vallisneria beds in the Upper Lake, where none was present during resurveys in 2008 and 2009. Declines in tuber-feeding waterbirds at Shengjin Lake coincide with the disappearance of their submerged macrophyte food plants, possibly as a result of eutrophication since the mid-2000s. 5. Widespread declines and concentration of tuber-eating wintering waterbirds at other sites elsewhere in the Yangtze floodplain may also reflect the local collapse of submerged macrophytes and of ecosystem services that these wetlands provide to the human communities.
-
Declines in the tuber‐feeding waterbird guild at Shengjin Lake National Nature Reserve, China – a barometer of submerged macrophyte collapse
Aquatic Conservation: Marine and Freshwater Ecosystems, 2010Co-Authors: Anthony D Fox, Yong Zhang, Lei Cao, Mark Barter, Meijuan Zhao, Fanjuan Meng, Si Long WangAbstract:1. The Yangtze floodplain is globally unique for its extensive ephemeral wetlands, recharged by summer monsoon precipitation. The annual cycle of inundation and water table recession favours submerged macrophytes, including Vallisneria that overwinters in desiccated substrates as tubers, which provide high-energy winter food for tuber-feeding waterbirds that were formerly abundant in the region. 2. Large declines among the tuber-feeding waterbirds Swan goose Anser cygnoides (L.), Tundra Swan Cygnus columbianus (Ord) and hooded crane Grus monacha Temminck between 2004/2005 and 2009/2010 at Shengjin Lake, Anhui Province, suggest that major changes in food availability have occurred there. 3. Based on observations of feeding behaviour and energy budgets of these species, it was calculated that at least 5.0 and 8.9?km2 of Vallisneria beds in 2004 and 2005, respectively, would be needed to support observed numbers of these species, compared with less than 1.5?km2 found in 2009 and 2010. 4. An incomplete macrophyte survey in summer 2000 located at least 7.7?km2 of Vallisneria beds in the Upper Lake, where none was present during resurveys in 2008 and 2009. Declines in tuber-feeding waterbirds at Shengjin Lake coincide with the disappearance of their submerged macrophyte food plants, possibly as a result of eutrophication since the mid-2000s. 5. Widespread declines and concentration of tuber-eating wintering waterbirds at other sites elsewhere in the Yangtze floodplain may also reflect the local collapse of submerged macrophytes and of ecosystem services that these wetlands provide to the human communities.
-
Results of a survey for waterbirds in the lower Yangtze floodplain, China, in January-February 2004
2005Co-Authors: Mark Barter, Lei Cao, Liwei Chen, Gang LeiAbstract:A total of 515,896 waterbirds of 82 species was counted during a comprehensive, simultaneous count in the lower Yangtze River floodplain, conducted during late January to early February 2004. Most of the important wetlands between the Three Gorges Dam and the Yangtze estuary, a distance of 1,850 km, were visited. Ducks, geese and Swans were most abundant, comprising 66% of waterbirds counted, followed by shorebirds (17%), gulls (7%), and egrets and herons (5%). The ten commonest species were Bean Goose Anser fabalis (79,758 individuals), Swan Goose Anser cygnoides (60,886), Dunlin Calidris alpina (40,709), Common Teal Anas crecca (36,483), Black-headed Gull Larus ridibundus (32,114), Tundra Swan Cygnus columbianus (30,925), Greater White-fronted Goose Anser albifrons (25,241), Spot-billed Duck Anas poecilorhyncha (22,562), Falcated Duck Anas falcata (18,364) and Lesser Whitefronted Goose Anser erythropus (16,937). These ten species comprised 70% of the total waterbird count. Twenty-three species were found in internationally important numbers at one or more sites. Very high proportions of the estimated world populations of six globally threatened species were found (Oriental Stork Ciconia boyciana, Swan Goose, Lesser White-fronted Goose, Siberian Crane Grus leucogeranus,White-naped Crane G. vipio and Hooded Crane G. monacha).The numbers of Swan Geese and Lesser White-fronted Geese counted exceeded the current global population estimates for these species. High proportions of the estimated flyway populations were found for Black Stork Ciconia nigra, Eurasian Spoonbill Platalea leucorodia and Tundra Swan, and for the global population of the Falcated Duck. A total of 33 sites were identified at which at least one waterbird species was recorded in internationally important numbers. Nineteen sites supported at least one species in numbers exceeding 5% of the global or flyway population, and some sites supported several, with Poyang Hu NNR (eight species >5%), Shengjin Hu (five), East Dongting Hu (four), Nanjishan (three) and Cai Zi Hu (three) holding the most.Three important regions within the lower Yangtze River floodplain were identified: (1) Poyang Hu; (2) Dongting Hu; and (3) Shengjin Hu and the lakes of the Anqing Yangtze River Wetland Provincial Nature Reserve. Waterbird populations are reported to have declined in recent decades owing to hunting pressure. It is very important to establish a programme to monitor waterbird numbers within the lower Yangtze River floodplain.
