Effects of ecological and anthropogenic factors on waterbird abundance at a Ramsar Site in the Yangtze River Floodplain

Ecological vulnerability evaluations can provide a scientific foundation for ecological environment management. Studies of ecological vulnerability have mainly focused on typical ecologically vulnerable regions with poor natural conditions or severe human interference, and such studies have rarely considered eco-provinces. Taking Jiangsu, an eco-province under construction in China, as the study area, we evaluated the spatiotemporal distributions of ecological vulnerability in 2005, 2010 and 2015 at the kilometer grid scale and analyzed the effects of natural and anthropogenic factors on ecological vulnerability. The pressure state response model (PSR), geographic information systems (GIS), spatial principal component analysis, spatial autocorrelation analysis, and correlation analysis methods were used. The results of the study are as follows: (i) the effects of anthropogenic factors on ecological vulnerability are greater than those of natural factors, and landscape evenness and the land resource utilization degree are the main factors that influence ecological vulnerability. (ii) Jiangsu Province is generally lightly to moderately vulnerable. Slight vulnerability is mainly observed in areas with water bodies. Light vulnerability is concentrated in paddy fields between the Main Irrigation Channel of North Jiangsu and the Yangtze River. Medium, heavy and extreme vulnerability areas are mainly composed of arable and built-up land. Medium vulnerability is mainly distributed to the north of the Main Irrigation Channel of North Jiangsu; heavy vulnerability is scattered to the south of the Yangtze River and in north-western hilly areas; and extreme vulnerability is concentrated in hilly areas; (iii) Ecological vulnerability displays a clustering characteristic. High-high (HH) regions are mainly distributed in heavy and extreme vulnerability regions, and low-low (LL) regions are located in slight vulnerability areas. (iv) Ecological vulnerability has gradually deteriorated. From 2005 to 2010, the vulnerability in hilly areas considerably increased, and from 2010 to 2015, the vulnerability in urban and north-eastern coastal built-up land areas significantly increased. Emphasis should be placed on the prevention and control of ecological vulnerability in high-altitude, urban and coastal areas.

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Multiscale effects of habitat and surrounding matrices on waterbird diversity in the Yangtze River Floodplain

Landscape Ecology ◽

10.1007/s10980-020-01131-4 ◽

2020 ◽

Author(s):

Boyu Gao ◽

Peng Gong ◽

Wenyuan Zhang ◽

Jun Yang ◽

Yali Si

Keyword(s):

Yangtze River ◽

Structural Features ◽

Ordinary Least Squares ◽

Habitat Connectivity ◽

The Yangtze River ◽

Least Squares Regression ◽

Spatial Error ◽

River Floodplain ◽

Surrounding Landscape ◽

Shape Complexity

Abstract Context With the expansion in urbanization, understanding how biodiversity responds to the altered landscape becomes a major concern. Most studies focus on habitat effects on biodiversity, yet much less attention has been paid to surrounding landscape matrices and their joint effects. Objective We investigated how habitat and landscape matrices affect waterbird diversity across scales in the Yangtze River Floodplain, a typical area with high biodiversity and severe human-wildlife conflict. Methods The compositional and structural features of the landscape were calculated at fine and coarse scales. The ordinary least squares regression model was adopted, following a test showing no significant spatial autocorrelation in the spatial lag and spatial error models, to estimate the relationship between landscape metrics and waterbird diversity. Results Well-connected grassland and shrub surrounded by isolated and regular-shaped developed area maintained higher waterbird diversity at fine scales. Regular-shaped developed area and cropland, irregular-shaped forest, and aggregated distribution of wetland and shrub positively affected waterbird diversity at coarse scales. Conclusions Habitat and landscape matrices jointly affected waterbird diversity. Regular-shaped developed area facilitated higher waterbird diversity and showed the most pronounced effect at coarse scales. The conservation efforts should not only focus on habitat quality and capacity, but also habitat connectivity and complexity when formulating development plans. We suggest planners minimize the expansion of the developed area into critical habitats and leave buffers to maintain habitat connectivity and shape complexity to reduce the disturbance to birds. Our findings provide important insights and practical measures to protect biodiversity in human-dominated landscapes.

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Distinguishing the impacts of climate change and anthropogenic factors on vegetation dynamics in the Yangtze River Basin, China

Ecological Indicators ◽

10.1016/j.ecolind.2019.105724 ◽

2020 ◽

Vol 108 ◽

pp. 105724 ◽

Cited By ~ 13

Author(s):

Sai Qu ◽

Lunche Wang ◽

Aiwen Lin ◽

Deqing Yu ◽

Moxi Yuan ◽

...

Keyword(s):

Climate Change ◽

River Basin ◽

Vegetation Dynamics ◽

Yangtze River ◽

Yangtze River Basin ◽

Anthropogenic Factors ◽

The Yangtze River ◽

The Yangtze River Basin ◽

Impacts Of Climate Change

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Changes in Tundra Swan Cygnus columbianus bewickii distribution and abundance in the Yangtze River floodplain

Bird Conservation International ◽

10.1017/s0959270911000098 ◽

2011 ◽

Vol 21 (3) ◽

pp. 260-265 ◽

Cited By ~ 11

Author(s):

PEIHAO CONG ◽

LEI CAO ◽

ANTHONY D. FOX ◽

MARK BARTER ◽

EILEEN C. REES ◽

...

Keyword(s):

Water Quality ◽

Yangtze River ◽

Poyang Lake ◽

Submerged Vegetation ◽

Three Gorges ◽

The Yangtze River ◽

Vegetation Productivity ◽

River Floodplain ◽

Cygnus Columbianus ◽

Tundra Swan

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.

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Biogeographic patterns of complete ammonia oxidizers (comammox) within the Yangtze River continuum

10.5194/egusphere-egu21-7121 ◽

2021 ◽

Author(s):

Shufeng Liu ◽

Haiying Wang ◽

Jinren Ni

Keyword(s):

Yangtze River ◽

Ammonia Oxidation ◽

Gene Clusters ◽

Anthropogenic Factors ◽

Ammonia Oxidizing Bacteria ◽

The Yangtze River ◽

Related Gene ◽

Biogeographic Patterns ◽

Environmental Selection ◽

Phylogenetic Resolution

The recent discovery of comammox Nitrospira performing complete ammonia oxidation to nitrate has fundamentally renewed the 120-year-held perspective of &#8220;two-step&#8221; nitrification. Rivers are known as the &#8220;Arteries&#8221; of the Earth, coupling the biogeochemical cycling of continents and oceans. Frequent human activities usually increase nitrogen load, and nitrifying microorganisms are crucial for the management of nitrogen load in rivers. The ecological roles of truncated nitrifiers, including canonical ammonia-oxidizing bacteria, ammonia-oxidizing archaea and nitrite-oxidizing bacteria in rivers have been fully understood, however, investigations of the newly discovered comammox Nitrospira are very scarce. To fill this gap, we used the metagenomic shotgun sequencing to provide the first biogeographic patterns of comammox Nitrospira in the Yangtze River over a 6030 km continuum.First, ten novel comammox genomes (71~96% completeness) were reconstructed with the metagenome assemblies from fluvial water in the upper reach and surface sediments from the middle reach to the estuary. Gene arrangements in ammonia oxidation-related gene clusters of these novel genomes were more complex and diverse than those of the previously discovered ones. For instance, multi-copy amoA or amoB genes, peptidases, cupredoxin and fkpA-cytochrome c-nirK gene sets were first found within the ammonia oxidation-related gene clusters of comammox Nitrospira, which might confer them advantages in adapting to the relatively oligotrophic environments and stabilizing the ammonia-oxidation process in rivers. Taxonomic analysis demonstrated that all riverine comammox genomes (constituting four new species) belonged to clade A. Based on the phylogenies of their 37 &#8220;elite&#8221; conserved marker genes, we further separated all reported comammox clade A into five sublineages, named clade A-Ia, A-Ib, A-Ic and A-IIa, A-IIb. The reclassified sublineages were sufficiently divergent to be meaningful in expanding the taxonomic/functional diversity and improving the phylogenetic resolution.Second, based on the improved phylogenetic resolution, we explored the biogeographic patterns of planktonic and benthic comammox Nitrospira subjected to natural and anthropogenic factors along the Yangtze River. Our study revealed the wide existence of comammox Nitrospira and their significant contributions to nitrifier abundances, constituting 30% and 46% of ammonia-oxidizing prokaryotes (AOPs) and displaying 30.4- and 17.9-fold greater abundances than canonical Nitrospira representatives in water and sediments, respectively. Comammox Nitrospira were found to contribute more to nitrifier abundances (34~87% of AOPs) in typical oligotrophic environments with a higher pH and lower temperature, particularly in the plateau (clade B), mountain and foothill (clade A-Ic) of the upper reach. Environmental selection determined the niche replacement of planktonic comammox Nitrospira by canonical ammonia-oxidizing bacteria and Nitrospira sublineages I/II from upstream to downstream, leading to a higher spatial turnover rate than observed for the benthic counterpart, while the dissimilarity of benthic comammox Nitrospira was moderately driven by geographic distance. A considerable decrease (83%) in benthic comammox Nitrospira abundance occurred immediately downstream of the Three Gorges Dam, which was consistent with a substantial decrease in the overall bacterial taxa in sediments.Together, this study highlights the previously unrecognized dominance of comammox Nitrospira in major river systems and underlines the importance of revisiting the distributions of and controls on nitrification processes within global freshwater environments.

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Long-Term Effects of Anthropogenic Factors on Nonpoint Source Pollution in the Upper Reaches of the Yangtze River

Sustainability ◽

10.3390/su11082246 ◽

2019 ◽

Vol 11 (8) ◽

pp. 2246 ◽

Cited By ~ 3

Author(s):

Xiaowen Ding ◽

Lin Liu

Keyword(s):

Point Source ◽

Pollution Control ◽

Yangtze River ◽

Agricultural Land ◽

Anthropogenic Factors ◽

The Yangtze River ◽

Long Term Effects ◽

Point Source Pollution ◽

Non Point Source Pollution

With the continuous enhancement of point source pollution control, non-point source (NPS) pollution has become an important factor in the deterioration of surface water quality. Meanwhile, due to the soaring global population, long-term effects of anthropogenic factors on non-point source pollution in large river basins have increasingly attracted worldwide attention. The Yangtze river is the largest river basin of China, and protecting its ecological environment has great significance on protecting the lifeline of the entire Yangtze river. In this study, the improved output coefficient and nutrient losses empirical model were used to conduct space–time simulations of non-point source pollution in the upper reaches of the Yangtze river (URYR) based on GIS during 1960–2003. This method reveals the anthropogenic effects of non-point source pollution in the upper reaches of the Yangtze river. The results indicate that the impacts of anthropogenic factors on dissolved pollutants increased significantly, while those on sediment and adsorbed pollutants increased first and then decreased during the simulation year. Agricultural land use and atmospheric deposition, as well as rural life, were the main sources of dissolved pollutants. In addition, dry land and paddy fields were the major sources of sediment and adsorbed pollutants. For the load intensities, the long-term effects of anthropogenic factors on dissolved pollutants increased rapidly, and those on the load intensity of sediment and adsorbed pollutants increased first and then decreased. Therefore, the study would propose some corresponding environmental management measures to strengthen environmental protection and non-point source pollution control in the upper reaches of the Yangtze river.

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The benefits of being big: effects of body size on energy budgets of three wintering goose species grazing Carex beds in the Yangtze River floodplain, China

Journal of Ornithology ◽

10.1007/s10336-013-0979-7 ◽

2013 ◽

Vol 154 (4) ◽

pp. 1095-1103 ◽

Cited By ~ 8

Author(s):

Xin Wang ◽

Yong Zhang ◽

Meijuan Zhao ◽

Lei Cao ◽

Anthony D. Fox

Keyword(s):

Body Size ◽

Yangtze River ◽

Energy Budgets ◽

The Yangtze River ◽

River Floodplain ◽

Goose Species

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Migration routes, population status and important sites used by the globally threatened Black-faced Spoonbill (Platalea minor): a synthesis of surveys and tracking studies

Avian Research ◽

10.1186/s40657-021-00307-z ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Yiwen Chen ◽

Yat-tung Yu ◽

Fanjuan Meng ◽

Xueqin Deng ◽

Lei Cao ◽

...

Keyword(s):

Yangtze River ◽

Conservation Status ◽

Far East ◽

Satellite Tracking ◽

Coastal Areas ◽

Liaoning Province ◽

Population Abundance ◽

The Yangtze River ◽

Term Survival ◽

River Floodplain

Abstract Background The Black-faced Spoonbill (Platalea minor) is a globally threatened species, nesting mainly in western Korea with smaller numbers breeding in Liaoning Province, China, and Far East Russia. Recent winter field surveys to estimate the species’ population size were almost totally conducted in coastal areas, but tracking studies showed that some individuals now winter inland. To ensure its long-term survival, we need a more comprehensive assessment of the current distribution and abundance of the species. Methods We combined the most recent count data and satellite tracking information to update existing information about the population abundance and distribution of the Black-faced Spoonbill at all stages of its annual life cycle, and how these have changed during 2004–2020. Results Black-faced Spoonbills mainly breed on the west coast of the Korean peninsula, while immature birds show a wider summer distribution throughout Yellow Sea coastal areas, when a few remain on wintering sites in the south. Combined tracking results and mid-winter counts confirmed known wintering sites on the east and south coasts of China, but showed that the species also winters on wetlands in the Yangtze River floodplain and in Southeast Asia. During 2004–2020, counts of wintering birds in coastal habitats increased from 1198 to 4864, with numbers wintering on the island of Taiwan contributing most to the overall increase. Latest counts found 5222 in 2021. We also identify key wintering and stopover sites as well as their current conservation status. Conclusions This study revised the known summering and wintering ranges of the Black-faced Spoonbill and assessed the conservation status of key sites based on a combination of field survey and satellite tracking data. We recommend prioritisation of further field research to identify and survey inland wintering areas in the Yangtze River floodplain and summering areas of immature birds. More tracking of adult individuals and birds during spring migration is necessary to fill these information gaps. We also suggest establishing a Black-faced Spoonbill monitoring platform to store, share and show real-time distribution range and population abundance data.

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