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

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.

scholarly journals Priority sites and conservation gaps of wintering waterbirds in the Yangtze River floodplain

2020 ◽  
Vol 30 (10) ◽  
pp. 1617-1632
Author(s):  
Shaoxia Xia ◽  
Xiubo Yu ◽  
Jinyu Lei ◽  
Richard Hearn ◽  
Bena Smith ◽  
...  
Keyword(s):  
Yangtze River ◽  
The Yangtze River ◽  
River Floodplain

Structural features of Phalaris arundinacea in the Jianghan Floodplain of the Yangtze River, China

Flora ◽  
2017 ◽  
Vol 229 ◽  
pp. 100-106 ◽  
Author(s):  
Xia Zhang ◽  
Lujie Hu ◽  
Chaodong Yang ◽  
Cunyu Zhou ◽  
Longyi Yuan ◽  
...  
Keyword(s):  
Yangtze River ◽  
Structural Features ◽  
Phalaris Arundinacea ◽  
The Yangtze River

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

2011 ◽  
Vol 21 (3) ◽  
pp. 260-265 ◽  
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.

Applying a Home-Based Approach to the Understanding Distribution of Economic Impacts of Traffic Crashes

2020 ◽  
Vol 2674 (12) ◽  
pp. 360-371
Author(s):  
Amin Mohamadi Hezaveh ◽  
Christopher R. Cherry
Keyword(s):  
Travel Behavior ◽  
Positive Association ◽  
Economic Cost ◽  
Ordinary Least Squares ◽  
Least Squares Regression ◽  
Significant Positive Association ◽  
Traffic Crashes ◽  
Spatial Error ◽  
Home Address ◽  
Spatial Autoregressive

The current practice of road safety attributes traffic crash costs to the location of traffic crashes. Therefore it is challenging to estimate the economic cost of traffic crashes and individuals who are more prone to the burden of traffic crashes. To address this limitation, this study used the home address of individuals who were involved in traffic crashes in the Knoxville Regional Travel Model (KRTM) region between 2015 and 2016. After geocoding the home addresses, 110,312 individuals were assigned to the Traffic Analysis Zone (TAZ) corresponding to their home address and the economic cost of traffic crashes per capita (ECCPC) was calculated for each TAZ. The average ECCPC in the study area was $1,250. The KRTM output was used for extracting travel behavior data elements for modeling ECCPC at the zonal level. This study also established an index to measure average zonal activity in the transportation system for each TAZ. Analysis indicates that the burden of traffic crashes was more tangible in the TAZs with lower-income households and higher average zonal activities. To account for spatial autocorrelation, a Spatial Autoregressive model (SAR) and a spatial error model (SEM) were used. The SAR model was more suitable compared with SEM and ordinary least squares regression. Findings indicate that average zonal activity and traffic exposure have a significant positive association with ECCPC. The ECCPC could be used as an index for allocating proper countermeasures and interventions to groups and areas where the burden of traffic crashes is more tangible.

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

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.

scholarly journals Spatiotemporal Dynamics and Driving Forces of Urban Land-Use Expansion: A Case Study of the Yangtze River Economic Belt, China

2020 ◽  
Vol 12 (2) ◽  
pp. 287 ◽  
Author(s):  
Yang Zhong ◽  
Aiwen Lin ◽  
Lijie He ◽  
Zhigao Zhou ◽  
Moxi Yuan
Keyword(s):  
Standard Deviation ◽  
Correlation Analysis ◽  
Landscape Pattern ◽  
Yangtze River ◽  
Partial Least Squares Regression ◽  
Urban Land ◽  
Spatial Expansion ◽  
The Yangtze River ◽  
Least Squares Regression ◽  
Urban Land Expansion

It is important to analyze the expansion of an urban area and the factors that drive its expansion. Therefore, this study is based on Defense Meteorological Satellite Program Operational Linescan System (DMSP/OLS) night lighting data, using the landscape index, spatial expansion strength index, compactness index, urban land fractal index, elasticity coefficient, the standard deviation ellipse, spatial correlation analysis, and partial least squares regression to analyze the spatial and temporal evolution of urban land expansion and its driving factors in the Yangtze River Economic Belt (YREB) over a long period of time. The results show the following: Through the calculation of the eight landscape pattern indicators, we found that during the study period, the number of cities and towns and the area of urban built-up areas in the YREB are generally increasing. Furthermore, the variations in these landscape pattern indicators not only show more frequent exchanges and interactions between the cities and towns of the YREB, but also reflect significant instability and irregularity of the urbanization development in the YREB. The spatial expansion intensity indices of 1992–1999, 1999–2006, and 2006–2013 were 0.03, 0.16, and 0.34, respectively. On the whole, the urban compactness of the YREB decreased with time, and the fractal dimension increased slowly with time. Moreover, the long axis and the short axis of the standard deviation ellipse of the YREB underwent a small change during the inspection period. The spatial distribution generally showed the pattern of “southwest-north”. In terms of gravity shift, during the study period, the center of gravity moved from northeast to southwest. In addition, the Moran's I values for the four years of 1992, 1999, 2006, and 2013 were 0.451, 0.495, 0.506, and 0.424, respectively. Furthermore, by using correlation analysis, we find that the correlation coefficients between these four driving indicators and the urban expansion of the YREB were: 0.963, 0.998, 0.990 and 0.994, respectively. Through the use of partial least squares regression, we found that in 1992-2013, the four drivers of urban land expansion in the YREB were ranked as follows: gross domestic product (GDP), total fixed asset investment, urban population, total retail sales of consumer goods.

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