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Objective: To explore the application effect of virtual simulation teaching platform in the practical teaching of medical imaging. Methods: A total of 97 students majoring in medical imaging technology of class 2022 were selected and divided into two groups according to the random number method: control group (n = 48) and observation group (n = 49). The observation group was under the practical teaching mode based on the virtual simulation teaching platform, while the control group was under the traditional multimedia teaching mode. Questionnaire survey and teaching assessment were carried out after the teaching period, and the application effects of the two teaching modes were compared. Results: The reading and theoretical scores of the students in the observation group were significantly higher than those of the students in the control group (P < 0.01); there were statistically significant differences in the results of the questionnaire survey (improved learning interest, improved language expression, improved ability to comprehensively analyze problems, and improved teamwork awareness) between the two groups of students (P < 0.05); the students in the observation group were markedly more satisfied with the teaching content, teaching methods, and teaching quality than the students in the control group (P < 0.05). Conclusion: The medical imaging practical teaching mode based on virtual simulation platform not only helps improve students’ theoretical understanding and practical ability in medical imaging technology, but also improves students’ learning interest, language expression ability, ability to comprehensively analyze problems, communication skills, teamwork awareness, and satisfaction with the teaching content, teaching methods, and teaching quality. Therefore, it has wide application value in medical specialty education.

SummaryThe extent of intertidal flats in the Yellow Sea region has declined significantly in the past few decades, resulting in severe population declines in several waterbird species. The Yellow Sea region holds the primary stopover sites for many shorebirds during their migration to and from northern breeding grounds. However, the functional roles of these sites in shorebirds’ stopover ecology remain poorly understood. Through field surveys between July and November 2015, we investigated the stopover and moult schedules of migratory shorebirds along the southern Jiangsu coast, eastern China during their southbound migration, with a focus on the ‘Critically Endangered’ Spoon-billed Sandpiper Calidris pygmaea and ‘Endangered’ Nordmann’s Greenshank Tringa guttifer. Long-term count data indicate that both species regularly occur in globally important number in southern Jiangsu coast, constituting 16.67–49.34% and 64.0–80.67% of their global population estimates respectively, and it is highly likely that most adults undergo their primary moult during this southbound migration stopover. Our results show that Spoon-billed Sandpiper and Nordmann’s Greenshank staged for an extended period of time (66 and 84 days, respectively) to complete their primary moult. On average, Spoon-billed Sandpipers and Nordmann’s Greenshanks started moulting primary feathers on 8 August ± 4.52 and 27 July ± 1.56 days respectively, and their moult durations were 72.58 ± 9.08 and 65.09 ± 2.40 days. In addition, some individuals of several other shorebird species including the ‘Endangered’ Great Knot Calidris tenuirostris, ‘Near Threatened’ Bar-tailed Godwit Limosa lapponica, ‘Near Threatened’ Eurasian Curlew Numenius arquata and Greater Sand Plover Charadrius leschenaultii also underwent primary moult. Our work highlights the importance of the southern Jiangsu region as the primary moulting ground for these species, reinforcing that conservation of shorebird habitat including both intertidal flats and supratidal roosting sites in this region is critical to safeguard the future of some highly threatened shorebird species.

Background Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer and has an extremely poor prognosis. We aimed to determine the latent relationships between TRIM36 regulation of apoptosis and the Wnt/β-catenin pathway in HCC. Methods Immunohistochemistry and western blotting were used to characterize the aberrant expression of TRIM36 in HCC and adjacent tissues. Clinical information was analyzed using Kaplan–Meier and Cox methods. RNA-seq of potential targets was conducted to detect the regulation of TRIM36. Apoptosis assays and cellular proliferation, invasion and migration were conducted in a loss- and gain-of-function manner in cultured cells to determine the biological functions of TRIM36. A rescue experiment was conducted to confirm the role of Wnt/β-catenin signaling in TRIM36 regulation. Finally, in vivo experiments were conducted using cell line-derived xenografts in nude mice to validate the central role of TRIM36 in HCC. Results TRIM36 expression was significantly downregulated in HCC tissues compared to adjacent non-tumor tissues. TRIM36 repressed the proliferation, migration, and invasion of Huh7 and HCCLM3 cells, whereas it stimulated apoptosis. Wnt/β-catenin signaling was inhibited by TRIM36, and rescue experiments highlighted its importance in HCC proliferation, migration, and invasion. In vivo experiments further confirmed the effects of sh-TRIM36 on HCC tumorigenesis, inhibition of apoptosis, and promotion of Wnt/β-catenin signaling. Conclusion Our study is the first to indicate that TRIM36 acts as a tumor suppressor in HCC. TRIM36 activates apoptosis and inhibits cellular proliferation, invasion, and migration via the Wnt/β-catenin pathway, which may serve as an important biomarker and promising therapeutic target for HCC.

Protected areas (PAs) are a cornerstone of modern conservation. For PAs that are established to conserve mobile species, it is important to cover all the key areas regularly used by these species. However, zonation and boundaries of PAs have often been established with limited knowledge of animal movements, leaving the effectiveness of some PAs doubtful. We used radio tracking data to evaluate the extent to which two coastal PAs in mainland China encompassed the full range of habitats used by migratory shorebirds during non-breedingseasons. The core zone (highest restriction on human activities) of the Yalu Jiang Estuary National Nature Reserve (Liaoning) incorporated only 22 ± 6% (n=34) of the diurnal home range (95% kernel density) of the endangered great knots Calidris tenuirostris. In contrast, the core zone of Chongming Dongtan (Shanghai) incorporated 73 ± 24% (n=25) of the home range of dunlins Calidris alpine. During high tide, great knots in Yalu Jiang mostly occurred in the experimental zone (least restriction on human activities) or sometimes outside the PA boundary altogether, where the birds could face substantial threats. By investigating satellite tracking records, consulting published literature, interviewing local experts and mapping habitat composition in different coastal PAs in China, we found that wet artificial supratidal habitats were frequently used by migratory shorebirds but the coverage of these habitats in coastal PAs was low. These PA boundaries and/or zonations should be revised to conserve mobile species more effectively. With the increasing number of tracking studies, analysing the spatial relationships between PAs and the movement ranges of mobile species can increasingly inform the development of a representative, comprehensive PA network.

Recent increases in ivory poaching have depressed African elephant populations. Successful enforcement has led to ivory being stockpiled. Stockpile destruction is becoming increasingly popular, and most destruction has occurred in the last five years. Ivory destruction is intended to send a strong message against ivory consumption, both in promoting a taboo on ivory use and catalyzing policy change. However, there has been no effort to establish the distribution and extent of media reporting on ivory destruction events globally. We analyze media coverage across eleven important nation states of the largest ivory destruction event in history (Kenya, 30 April 2016). We used a well-accepted online media crawling tool and key language translations to search online and print newspapers. We found most online news on the ivory burn came from the US (81% of articles), while print news was dominated by Kenya (61% of articles). We subjected online articles from five key countries and territories to content analysis and found 86-97% of all online articles reported the burn as a positive conservation action, while between 4-50% discussed ivory burning as having a negative impact on elephant conservation. Most articles discussed law enforcement and trade bans as effective for elephant conservation. There was more relative search interest globally on the 2016 Kenyan ivory burn than any other in five years. Our study is the first attempt to track the spread of media around an ivory burn and is a case study in tracking the effects of a conservation-marketing event. This article is protected by copyright. All rights reserved.

Global warming has exerted a significant influence on the water cycle in global drainage basins, involving various aspects associated with ecology, society, economy and human activity. Therefore, accurate forecast and analysis of climatic change trends are the prerequisite to disaster alleviation and prevention. This paper selects a large-scale climate predictor by modeling steps and evaluation indicators for a statistical downscaling (SD) model and establishes a statistical relation between atmospheric circulation factor and precipitation and air temperature at eight stations in Wei River basin in Shaanxi Province for a global climate model output based on hydrological data for Wei River basin in Shaanxi Province. A study was made of the simulated precipitation and air temperature in Wei River basin by principal component analysis and multiple linear regression and achieved favorable results. The approach is better in physical significance and is characterized by accurate climate simulation, simple calculation for statistical downscaling and is convenient for application in various climate models.

Coastal armouring and the reclamation of intertidal areas through the use of seawalls and other artificial structures has been practiced for thousands of years, but its recent expansion in China and elsewhere in Asia has been unprecedented in its rate and intensity. One result has been the recent loss of nearly two-thirds of tidal flats in the Yellow Sea, a globally unique ecosystem of high ecological value. The severe effects on biodiversity of the recent large-scale coastal land claim activities in China are well documented, yet some recent studies have emphasized the ecological opportunities provided by such artificial coastal infrastructure in China, in some cases suggesting that the ecological impacts of coastal infrastructure should be reconsidered due to benefits to some rocky shore species in a changing climate. This is cause for concern because, while studying the “new ecology” arising from coastal modification is useful, broad conclusions around the ecological role or conservation gains from seawall construction without adequate contextualization underplays the ecological consequences of large-scale coastal land claim, and could potentially undermine efforts to achieve biodiversity conservation. Here, we clarify the characteristics of seawall construction in China and summarize the environmental damage and some broadscale impacts caused by this type of infrastructure expansion on the endangered Yellow Sea tidal flats ecosystem. We also highlight the urgent need for all coastal development plans to consider how coastal wetlands and ecosystem functionality can be maximally retained within the development precinct.

SummaryThe Yellow Sea region is of high global importance for waterbird populations, but recent systematic bird count data enabling identification of the most important sites are relatively sparse for some areas. Surveys of waterbirds at three sites on the coast of southern Jiangsu Province, China, in 2014 and 2015 produced peak counts of international importance for 24 species, including seven globally threatened and six Near Threatened species. The area is of particular global importance for the ‘Critically Endangered’ Spoon-billed Sandpiper Calidris pygmaea (peak count across all three study sites: 62 in spring [2015] and 225 in autumn [2014] and ‘Endangered’ Spotted Greenshank Tringa guttifer (peak count across all three study sites: 210 in spring [2014] and 1,110 in autumn [2015]). The southern Jiangsu coast is therefore currently the most important migratory stopover area in the world, in both spring and autumn, for both species. Several serious and acute threats to waterbirds were recorded at these study sites. Paramount is the threat of large-scale land claim which would completely destroy intertidal mudflats of critical importance to waterbirds. Degradation of intertidal mudflat habitats through the spread of invasive Spartina, and mortality of waterbirds by entrapment in nets or deliberate poisoning are also real and present serious threats here. Collisions with, and displacement by, wind turbines and other structures, and industrial chemical pollution may represent additional potential threats. We recommend the rapid establishment of effective protected areas for waterbirds in the study area, maintaining large areas of open intertidal mudflat, and the urgent removal of all serious threats currently faced by waterbirds here.

China's coastal wetlands are critically important to shorebirds. Substantial loss of tidal flats, shorebirds' primary foraging grounds, has occurred from land claim and other processes, and is driving population declines in multiple species. Smooth cordgrass Spartina alterniflora was intentionally introduced to the coast of China in 1979 to promote conversion of tidal flats into dry land and has since spread rapidly. The occurrence of S. alterniflora reduces the availability of foraging and roosting habitat for shorebirds, and may be particularly detrimental in places that have experienced other tidal flat loss. However, the extent to which S. alterniflora is encroaching upon important shorebird habitat throughout coastal mainland China, and its intersection with tidal flat loss, has not been quantified. Here, we i) estimate change in the spatial extent of tidal flats between 2000 and 2015 in coastal mainland China where internationally important numbers of shorebirds have been recorded; ii) map the extent of S. alterniflora coverage in 2015 at the same set of sites; and, iii) investigate where these two threats to important shorebird habitat intersect. Our analysis of remote sensing data indicated a 15% net loss in tidal flat area between 2000 and 2015 across all sites, including a net loss in tidal flat area in 39 of 53 individual sites (74%). Spartina alterniflora occurred at 28 of 53 sites (53%) in 2015, of which 22 sites (79%) also had a net loss in tidal flat area between 2000 and 2015. Combined pressures from tidal flat loss and S. alterniflora invasion were most severe in eastern coastal China. Species highly dependent on migrating through this region, which include the Critically Endangered Spoon-billed Sandpiper and Endangered Nordmann's Greenshank and Far Eastern Curlew, may be particularly impacted. Our results underscore the urgent need to arrest tidal flat declines and develop a comprehensive control program for S. alterniflora in coastal areas of mainland China that are important for shorebirds.

The southward migration strategies of shorebirds remain poorly understood in the East Asian–Australasian Flyway, yet understanding such strategies is critical to shorebird conservation. We estimate passage dates of 28 species of shorebird from count data at 15 sites to infer their migration strategies, using Thompson’s modelling approach. Our estimates of passage dates were consistent with available tracking data, giving us confidence that the modelled estimates were accurate. For large-bodied shorebirds, modelled departure dates from the northern Yellow Sea were similar to arrival dates throughout Australia, and their arrival dates in different regions in Australia were also similar, suggesting they flew directly from Asian staging areas to Australian non-breeding areas, or stopped only very briefly on the way. In contrast, small-bodied species apparently made multiple stops, especially in northern Australia, during their migration to their final non-breeding destinations. These differing patterns suggest that larger species in this Flyway depend on a small number of staging sites, whereas smaller species migrate in shorter steps and require additional staging sites between the northern Yellow Sea and Australasia. It is likely that some of these sites have not as yet been discovered, and that conservation of small shorebird species requires a more complete accounting of unknown and understudied staging sites.

Recent increases in ivory poaching have depressed African elephant populations. Successful enforcement has led to ivory stockpiling. Stockpile destruction is becoming increasingly popular, and most destruction has occurred in the last 5 years. Ivory destruction is intended to send a strong message against ivory consumption, both in promoting a taboo on ivory use and catalyzing policy change. However, there has been no effort to establish the distribution and extent of media reporting on ivory destruction events globally. We analyzed media coverage of the largest ivory destruction event in history (Kenya, 30 April 2016) across 11 nation states connected to ivory trade. We used an online-media crawling tool to search online media outlets and subjected 5 of the largest print newspapers (by circulation) in 5 nations of interest to content analysis. Most online news on the ivory burn came from the United States (81% of 1944 articles), whereas most of the print news articles came from Kenya (61% of 157 articles). Eighty-six to 97% of all online articles reported the burn as a positive conservation action, whereas 4-50% discussed ivory burning as having a negative impact on elephant conservation. Most articles discussed law enforcement and trade bans as effective for elephant conservation. There was more relative search interest globally in the 2016 Kenyan ivory burn than any other burn in 5 years. Ours is the first attempt to track the reach of media coverage relative to an ivory burn and provides a case study in tracking the effects of a conservation-marketing event.

China has numerous and various protected areas (PAs). By one count, at the end of 2010 more than 8,000 PAs existed and covered more than 18 percent of the land area of the country. The 2,669 nature...

Natural coastal wetlands are important habitats for shorebirds while flooded agricultural croplands, may also be useful habitats. Shorebirds in East Asia utilize an often highly developed coastal landscape, which may be dissected by seawalls with intertidal flats on the seaward side, and aquaculture ponds and agricultural croplands on the landward side. Little is known about the value of aquaculture ponds to shorebirds. We investigated the habitat use, preference and home range of wintering Dunlin (Calidris alpina) in Chongming Dongtan, east China, through radio tracking and field observations in 2006–2007. Our results indicated that Dunlins preferred tidal flats, avoided agricultural croplands, and used aquaculture ponds in proportion to their availability. The probability of Dunlin usage of aquacultural ponds decreased with increasing size of unflooded area in the aquaculture ponds. Dunlins foraging in aquaculture ponds had lower feeding success rate than those in tidal flats. Thus, tidal flats may provide important foraging habitats for wintering Dunlins, while aquaculture ponds may provide alternative roosting and supplemental foraging habitat. Conserving the natural wetlands on tidal flats is vital for shorebird conservation in East Asia but at the same time, the aquaculture ponds also could play an important role if managed properly.

Smooth cordgrass (Spartina alterniflora) is one of the most invasive exotic plants of saltmarshes worldwide. To understand the effects of smooth cordgrass invasion on the habitat use and selection by breeding saltmarsh birds, we compared species number and abundance of breeding birds in native reed (Phragmites australis) and smooth cordgrass-invaded habitats (reed-cordgrass mixed habitats and cordgrass monocultures) at Chongming Dongtan in the Yangtze River estuary, China. We further examined the similarity of bird communities in different habitats and habitat selection by dominant bird species. For saltmarsh generalists, species number and abundance did not differ among the habitats. For saltmarsh specialists, species number and abundance did not differ in reed monocultures and reed-cordgrass mixed habitats but were significantly lower in cordgrass monocultures than in reed monocultures and reed-cordgrass mixed habitats. ANOSIM indicated that the difference in bird communities was larger between cordgrass monocultures and the habitats with reed than between the habitats with reed. The saltmarsh specialists preferred reed monocultures, while saltmarsh generalists avoided reed monocultures. Most species indicated no selection (neither preferred nor avoided) on reed-cordgrass mixed habitats, and no species preferred the cordgrass monocultures. The use of cordgrass monocultures by the common saltmarsh birds was negatively related to their body size. This study suggests that the spread of exotic smooth cordgrass has greatly affected the species composition and structure of local bird communities and has been especially disadvantageous to the saltmarsh specialists.

The exotic Smooth Cordgrass (Spartina alterniflora) has spread rapidly on the east coast of China over the past three decades and has greatly changed the native saltmarsh vegetation. We conducted bird surveys using mist nets in the exotic Spartina and native Common Reed (Phragmites australis) habitats at Chongming Dongtan of eastern China in the winters of 2004 and 2005. We related bird capture rates to habitat type (Phragmites or Spartina habitat), habitat structure (plant height and density), and food availability (densities of seeds and arthropods). The Spartina habitat was composed of shorter and denser vegetation and provided fewer food resources for birds than the Phragmites habitat. Bird capture rate was lower in Spartina, negatively related to plant density in the Spartina habitat, and positively correlated with overall arthropod abundance and plant height. Food resources consumed by birds were similar to those found in Phragmites habitat, irrespective of capture location. Our results su...

Invasive smooth cordgrass (Spartina alterniflora, hereafter Spartina) has been expanding rapidly in the estuarine wetlands at Chongming Dongtan (East China) at the expense of native sea-bulrush (Scirpus mariqueter, hereafter Scirpus) and common reed (Phragmites australis, hereafter Phragmites). To examine the potential impacts of the Spartina invasion on bird diversity, we compared the abundance and species richness of birds in habitats created by Spartina, Phragmites, Spartina mixed with Phragmites, Scirpus, and the bare intertidal zone at Chongming Dongtan in spring 2008. Most birds were recorded in the native habitats, with songbirds and breeding birds being most abundant in the Phragmites habitats, and waterbirds and migrants being most abundant in the Scirpus habitats and bare intertidal zone. Both species number and population densities of birds were lower in the exotic Spartina habitats than in the other four habitats. Although some songbirds and breeding birds used the Spartina-invaded habitats, and even preferred Spartina-invaded habitats to Scirpus habitats and bare intertidal zone, their densities were lower in the Spartina-invaded habitats than in the native Phragmites habitats. This might have resulted from the dense Spartina stands restricting bird movement and providing insufficient useable food for most birds. We conclude that the spread of exotic Spartina has negative impacts on local bird communities. Because Chongming Dongtan is an important stopover site for energy replenishment of shorebirds in the East Asian-Australasian Flyway, urgent measures are needed to control further spread of Spartina and to restore the native habitats for birds.

We compared seasonal variations in body condition and fuel deposition patterns of five calidrid sandpipers at Chongming Dongtan (eastern China), a stopover site in the East Asian—Australasian Flyway. We tested the hypothesis that long-distance migrants show different body condition and fuel deposition patterns relative to those undertaking short-distance flights. Results indicated that the body condition and fuel deposition patterns of the sandpipers varied between the northward and southward migration seasons and between age-classes. Great Knots Calidris tenuirostris and Red Knots Calidris canutus migrate southwards on a long-distance nonstop flight from Chongming Dongtan to northwest Australia, while covering on the return flight a relatively short-distance between Chongming Dongtan and the north Yellow Sea region. Both species attained a significantly higher body condition at Chongming Dongtan during the southward than northward migration. Moreover, they showed a significant increase in body condition ...

The Yangtze River estuary is an important ecoregion. However, Spartina alterniflora, native to North America, was introduced to the estuary in the 1990s through both natural dispersal and humans and now it is a dominant species in the estuarine ecosystems, with its invasions leading to multiple consequences to the estuary. S. alterniflora had great competitive effects on native species, including Scirpus mariqueter and Phragmites australis, and could potentially exclude the natives locally. The presence of S. alterniflora had little influence on the total density of soil nematodes and macrobenthonic invertebrates, but significantly altered the structure of trophic functional groups of nematode and macrobenthonic invertebrate communities. The conversion of mudflats to Spartina meadows had significant effects on birds of Charadriidae and Scolopacidae, which might be attributable to the reduction of food resources and the physical alterations of habitats for shorebirds. S. alterniflora invasions increased the primary productivity of the invaded ecosystems, and altered carbon and nitrogen cycling processes. Our studies focused mainly on the effects of S. alterniflora invasions on the structure of native ecosystems; thus further studies are clearly needed to investigate how ecosystem functioning is affected by the modification of the structure of estuarine ecosystems by S. alterniflora invasions.

We compared wintering bird communities and their habitats among three shoals at Jiuduansha, a newly-formed wetland in the Yangtze River estuary. The highest species richness and diversity were recorded in Shangsha, which is the highest shoal, and the highest abundance and lowest species diversity were recorded in Xiasha, which is the lowest shoal. Shangsha had the largest abundance of perching birds whereas Xiasha was the most abundant in waterbirds. Bird assemblages showed different associations with the different habitat types-perching birds were favored by reed (Phragmites australis) communities, shallow water foragers and dabbling ducks preferred sea-bulrush (Scirpus mariqueter) communities, and moist-soil foragers and gulls showed a preference for bare intertidal zones. All bird assemblages, however, avoided the smooth cordgrass (Spartina alterniflora) communities, which are dominated by an alien invasive plant. The composition of avian communities was related to habitat types at the three shoals. Our results suggest that the newly-formed tidelands can provide suitable habitats for waterbirds and that the lower tidelands can attract more waterfowl than the higher tidelands. Because the shoal with low species diversity could have exclusive bird species, conservation efforts should not concentrate only on the area with high species diversity. The estuarine wetlands should be considered as a whole when conservation strategies are designed. The alien invasive plant should, moreover, be effectively controlled, to provide suitable habitats for birds.

The threatened Marsh Grassbird (Locustella pryeri) first appeared in the salt marsh in east China after the salt marsh was invaded by cordgrass (Spartina alterniflora), a non-native invasive species. To understand the dependence of non-native Marsh Grassbird on the non-native cordgrass, we quantified habitat use, food source, and reproductive success of the Marsh Grassbird at the Chongming Dongtan (CMDT) salt marsh. In the breeding season, we used point counts and radio-tracking to determine habitat use by Marsh Grassbirds. We analyzed basal food sources of the Marsh Grassbirds by comparing the δ(13) C isotope signatures of feather and fecal samples of birds with those of local plants. We monitored the nests through the breeding season and determined the breeding success of the Marsh Grassbirds at CMDT. Density of Marsh Grassbirds was higher where cordgrass occurred than in areas of native reed (Phragmites australis) monoculture. The breeding territory of the Marsh Grassbird was composed mainly of cordgrass stands, and nests were built exclusively against cordgrass stems. Cordgrass was the major primary producer at the base of the Marsh Grassbird food chain. Breeding success of the Marsh Grassbird at CMDT was similar to breeding success within its native range. Our results suggest non-native cordgrass provides essential habitat and food for breeding Marsh Grassbirds at CMDT and that the increase in Marsh Grassbird abundance may reflect the rapid spread of cordgrass in the coastal regions of east China. Our study provides an example of how a primary invader (i.e., cordgrass) can alter an ecosystem and thus facilitate colonization by a second non-native species.

We studied the changes in wetland habitats and waterbird communities between the 1980s and the 2000s at Chongming Dongtan, a Ramsar site in the Yangtze River estuary, an ecologically important region. This region is an important stopover site for shorebirds along the East Asian–Australasian flyway and is extensively used by waterfowl. A net loss of 11% of the wetland area was estimated during study periods at Chongming Dongtan. The change was dependent on wetland types: while the area of artificial habitats such as paddy fields and aquacultural ponds more than doubled, more than 65% of natural habitats including sea bulrush (Scirpus mariqueter) and common reed (Phragmites australis) marshes were lost over the two decades. An exotic plant species introduced from North America, smooth cordgrass (Spartina alterniflora), occupied 30% of the vegetated intertidal zone by the 2000s. Although waterbird species richness did not change between the 1980s (110) and the 2000s (111), 13 species found in 1980s were replaced by 14 newly recorded species. Moreover, there were more species with declining trends (58) than with increasing trends (19). The population trends of species were affected by residential status and habitat types. Transients, wintering migrants, and habitat specialists were more likely to show declining trends compared to those breeding at Dongtan (including year-round and summer residents) and habitat generalists. Furthermore, species associated mainly with natural wetlands were more likely to decline than those associated mainly with artificial wetlands. These patterns suggest that the loss and change of wetland habitats at Chongming Dongtan adversely affected local population dynamics and might have contributed to the global decline of some waterbird species. Because Chongming Dongtan provides stopover and wintering habitats for many migratory waterbirds, protection and restoration of natural wetlands at Chongming Dongtan are urgently needed.

Biological invasion is recognized as one of the greatest threats to the global biodiversity because invasive exotic species not only alter the local environments but also have serious ecological effects on native species. Birds are positioned at high trophic level within the food web in the ecosystem, and thus any changes within the system can affect the birds in one way or another. The ecological effects of different exotic taxa like mammals, birds, invertebrates and plants on native birds are reviewed in this paper. In summary, the ex-otic species can affect native bird species in four main ways, 1) predation of birds or eggs by the exotic mammals; 2) competition for habitats and foods with exotic birds, and loss of genetic diversity by hybridiza-tion with the closely-related exotic species; 3) direct and indirect alterations of native habitats and food re-sources, and predation by the exotic invertebrates; and 4) loss and fragmentation of habitats for native birds through altering species composition and structure of native plant communities by exotic plants. The un-solved questions and future research directions in this field are also addressed.