The impact of earlier flood recession on metacommunity diversity of wintering waterbirds at shallow lakes in the middle and lower Yangtze River floodplain

The hydrological regime in wetlands plays an important role in the process of wintering waterbird metacommunity assemblage.However,increasing frequency of extreme climate and the intensification of human activities,such as the construction of sluices and dams,have resulted in frequently abnormal hydrological regime in the middle and lower Yangtze River floodplain.In recent years,earlier flood recession has become one of the main hydrological problems faced in the shallow lakes,having a great impact on wetland biodiversity.It is necessary to understand the impact of earlier flood recession on waterbirds,an indicator of wetland biodiversity,and the metacommunity concept is helpful to elucidate the underlying mechanism involved in the processes of assemblage by waterbird communities.In this study,we surveyed the wintering waterbirds at three sub-lakes of Caizi Lakes during 2019-2020 and 2020-2021 and compared the richness,abundance,alpha and beta diversity of waterbirds in and among local metacommunities under earlier flood recession and normal hydrological regime.The results showed that the earlier flood recession reduced the species richness in the early stage and abundance in the late stage,it also reduced the Shannon-Wiener index in the early stage and increased the dissimilarity between and within waterbird metacommunities in the late stage.The partition of beta diversity showed that the turnover component played a major role in the process of waterbird metacommunity assemblage.It was found that the earlier flood recession reduced the richness,abundance in different stages of flood recession,which also increased the turnover of waterbirds.Metacommunities with high habitat heterogeneity had better resistance to abnormal hydrological regime,which resulted in high dissimilarity between and within metacommunities.The results of this study provide important information for waterbird conservation and water level management at shallow lakes in the middle and lower Yangtze River floodplain.

Responses of breeding waterbird communities to environmental changes in subsidence wetlands in the North China Plain

In the context of global degradation and loss of natural wetlands,waterbirds have been increasingly using artificial wetlands as alternative habitats.However,waterbirds are facing various threats in these artificial wetlands,due to dramatic environmental changes induced by anthropogenic activities.Exploring the effects of these changes on the temporal dynamics of the waterbird communities can help understand how waterbirds adapt to environmental changes and thus formulate effective management and conservation plans.In this study,we carried out field surveys on waterbirds and environmental factors across 20 subsidence wetlands created by underground coal mining in the Huainan coal mining area in the breeding seasons of 2016 and 2021.We predicted that the waterbird assemblages(i.e.,number of individuals,species richness,Shannon-Wiener diversity,Pielou evenness and species composition) differed between the two years,and that these differences were correlated with the temporal changes in environmental factors.Across the surveyed wetlands,we recorded 26 waterbird species in 2016 and 23 in 2021.For individual wetlands,the number of waterbird individuals and species richness increased by 71.6% and 20.1%,respectively,over the five years,with no changes in Shannon-Wiener diversity and Pielou evenness.The overall increase in the number of bird individuals was mainly caused by an increase in vegetation gleaners and gulls that adapt well to anthropogenic activities.The species composition was significantly different between the two years,which was mainly caused by changes in the number of individuals of dominant species under influence of changes in human activities.For most wetlands,the temporal pairwiseβ-diversities could be explained by species turnover rather than nestedness,probably due to high mobility of waterbird species and dramatic changes in local environments.Our study suggests that waterbird communities could respond to environmental changes in subsidence wetlands,providing important implications for waterbird conservation in human-dominated artificial wetlands.

Waterbirds in the Wetlands of Casiguran, Aurora, Philippines

The wetlands of Casiguran, Aurora, Philippines are primarily the source of livelihood for most of the coastal communities of the area. However, this also serves as a feeding ground for many of the migratory and resident waterbirds. There are waterbird species occurring in the area that need protection but only a few studies of these species exist. This study was conducted from February to March 2019 to census and identify the water birds present in the study site, determine the conservation status and index of abundance of identified waterbirds, and describe their habitat association. Based on the result, 18 waterbird species in five families were present in the area. Family Ardeidae had six representative species, Family Charadriidae had five representative species, Family Scolopacidae had five representative species while only one species represents the Family Anatidae and Family Rallidae. Two waterbird species observed (Anas luzonica and Egretta eulophotes) were listed by the International Union for Conservation of Nature (IUCN) as vulnerable and another species (Numerius madagascariensis) was listed as endangered. In terms of abundance, Intermediate Egret (Egretta intermedia) was revealed as the most abundant (94.68%) among waterbirds. Different waterbird species prefer specific habitats. Some usually frequent freshwater and saltwater habitats, including mangroves, open sea, and watercourses inside forests while some were observed in mudflats, and rice fields during the survey.

Seasonal dynamics of wintering waterbirds in two shallow lakes along Yangtze River in Anhui Province

The shallow lake wetlands in the middle and lower Yangtze River floodplain are important wintering and stopover habitats for migratory waterbirds on the East Asia-Australia Flyway.With increasing fishery practices in recent years,however,the wetlands have deteriorated significantly and now threaten wintering waterbirds.To gain insight into the influence of deteriorating wetlands on waterbirds,we conducted a survey of wintering waterbird species,population size,and distribution across 11 belt transects in Caizi Lake and Shengjin Lake,two shallow lakes along the Yangtze River in Anhui Province from November 2007-April 2008 and from November 2008-April 2009,respectively.The impacts of different fishery patterns on the distribution of waterbirds were also analyzed.A total of 43 waterbirds species belong to 7 orders of 12 families were counted during the surveys,of which 38 were found in Caizi Lake with a density of 8.2 ind./hm2,and 42 in Shengjin Lake with a density of 3.5 ind./hm2.Geese（Anser cygnoides）,bean geese（Anser fabalis）,tundra swan（Cygnus columbianus）,and dunlin（Calidris alpina） were the dominant species in the two shallow lakes.Species number and individual assemble reached maximum at the end of December and in early January of the following year,without coincidence of the largest flock for different ecological groups.Based on waterbird diversity across the 11 belt transects and the fishery patterns,habitats could be divided into three groups.Gruiformes,Anseriformes and Charadriiformes had relatively higher densities in the natural fishery zones and lower densities in the cage fishery zones;whereas,the density of Ardeidae showed little change across all lake zones.It is important to develop sustainable fishery patterns in shallow lakes along the middle and lower Yangtze River floodplain to better protect resources of wintering waterbirds.

Species abundance and conservation of coastal wintering waterbirds in Hainan Island,China

Wintering waterbirds surveys were conducted throughout the coastal areas of Hainan,China,from 2003 to 2005,with the aim of further strengthening the conservation and management of wetlands in Hainan Island.A total of 68 species were recorded at 20 coastal wetlands.Three recently found wintering sites for the globally endangered Black-faced Spoonbill (Plataleaminor),i.e.Houshui Bay of Lingao,Beili Bay of Dongfang Counties and Sanya River in Sanya City were then extensively monitored during a period of 2003-2009.The largest number of birds were egrets and herons,followed by shorebirds,gulls and terns.On average,the total number of species and individuals at sites with mangrove forests were significantly greater than those of sites without mangrove forests.Some sites,important for conservation,were identified,such as Bopu Bay,Huanglonggang,Houshui Bay,Yangpugang,Beili Bay,Yinggehai,Sanya River,Qinlangang and Dongzhaigang.Thus,human disturbance at these important sites should be avoided.

Traditional fishing activities enhance the abundance of selected waterbird species in a wetland in India

Background:Waterbirds are globally declining as a result of habitat loss, alteration or degradation. Fishing activities may affect waterbird distribution, abundance and diversity, and traditional fishing activities often enhance waterbird abundance. We tested this hypothesis by studying the abundance and diversity of selected common waterbird species in the Kadalundi–Vallikkunnu Community Reserve, a globally significant wetland in southwestern India in relation to fishing activities.Methods:We monitored waterbird abundance four times a month from 2012 to 2015 using direct observation method during low tide. Traditional bamboo fish traps were deployed during the first and third weeks of each month. ANOVAs(one-way and multi-way) were used to examine how waterbird counts diversity varied in relation to years, seasons and period of fishing traps. Additionally we conducted a linear regression to examine the relationship between fish occurrence and waterbird counts and diversity.Results:Waterbird counts varied with years and seasons, with the maximum counts being recorded during the postmonsoon(winter). Individual species varied in their responses to trap deployment. Small waterbird species usually forage in shallow shorelines, increased during trap deployment whereas the larger waterbirds were not affected by trap deployment because they tend to hunt in deeper waters. The total fish captured was an important predictor of both waterbird abundance and diversity.Conclusion:In this study we documented a positive association between traditional fish trap deployment and waterbird counts and diversity. Providing high quality habitats for waterbirds as well as effective sustainable livelihoods through traditional fisheries is a critical management issue.

Bird diversity and waterbird habitat preferences in relation to wetland restoration at Dianchi Lake, south-west China

Background:Restoration projects have been implemented worldwide to mitigate the adverse effects of the loss and degradation of wetland habitats.Much research has been carried out on the impacts on birds of wetland restoration and management projects in China. Studies have mainly investigated central or coastal wetlands,while inland wetlands in remote areas have been much less studied. We focused on examining the response of wild birds to wetland restoration in Dianchi Lake,south-west China. Methods: The line transect method was performed at 26 sampling plots.Three of these were in the city,and to acquire all wild bird data 23 plots were located every 2-8 km along the shore of Dianchi Lake, between December 2011 and November 2013.We collected all related bird records by searching the available literature, articles, newspapers and records of birdwatchers to compare species variation before and after implementation of wetland restoration.To measure the relationships between waterbird assemblages and habitat structures, we used canonical correspondence analysis (CCA) to pair the main matrix of bird assemblages with a second matrix of habitat variables. Results: We recorded 182 bird species belonging to 51 families and 17 orders. Of the species, 42 were new records for Kunming City and 20 were new records for Yunnan Province. Ten waterbird species were found to have disappeared from the shore of Dianchi Lake.CCA results indicated that waterbirds could be divided into four categories based on their habitat preference:synanthropic (wintering gulls), special habitat (shorebirds),semi-natural (wintering coots and ducks) and disturbance-tolerant (resident) species.Conclusions:Our study is the first to consider the entire wild bird community throughout the year and discuss the species variation before and after wetland restoration projects launched for Dianchi Lake.Distinct habitat requirements of different waterbird groups were detected in our study,suggesting different types of restoration and management should be implemented.

Identification of coastal wetlands of international importance for waterbirds:a review of China Coastal Waterbird Surveys 2005–2013

Background:China's coastal wetlands belong to some of the most threatened ecosystems worldwide.The loss and degradation of these wetlands seriously threaten waterbirds that depend on wetlands.Methods:The China Coastal Waterbird Census was organized by volunteer birdwatchers in China's coastal region.Waterbirds were surveyed synchronously once every month at 14 sites,as well as irregularly at a further 18 sites,between September 2005 and December 2013.Results:A total of 75 species of waterbirds met the 1 % population level Ramsar listing criterion at least once at one site.The number of birds of the following species accounted for over 20 % of the total flyway populations at a single site:Mute Swan(Cygnus olor),Siberia Crane(Grus leucogeranus),Far Eastern Oystercatcher(Haematopus osculans),Bar-tailed Godwit(Limosa lapponica),Spotted Greenshank(Tringa guttifer),Great Knot(Calidris tenuirostris),Spoon-billed Sandpiper(Calidris pygmeus),Saunders' s Gull(Larus saundersi),Relict Gull(Larus relictus),Great Cormorant(Phalacrocorax carbo),Eurasian Spoonbill(Platalea leucorodia),Black-faced Spoonbill(Platalea minor) and Dalmatian Pelican(Pelecanus crispus).A total of 26 sites supported at least one species of which their number met the1 % criterion.Forty-two species met the 1 % criterion in the Yellow River Delta,Shandong;29 at the Cangzhou coast,Hebei and 26 species at the Lianyungang coast,Jiangsu.Conclusions:The results highlight the international importance of China's coastal wetlands for waterbirds.This study also demonstrates that participation of local birdwatchers in waterbird surveys results in data that are invaluable not only for understanding the current status of waterbirds in China's coastal regions but also for waterbird conservation and management.

Population trends, threats, and conservation recommendations for waterbirds in China

Background: China is one of the countries with abundant waterbird diversity. Over the past decades, China's waterbirds have suffered increasing threats from direct and indirect human activities. It is important to clarify the population trends of and threats to waterbirds as well as to put forward conservation recommendations.Methods: We collected data of population trends of a total of 260 waterbird species in China from Wetlands International database. We calculated the number of species with increasing, declining, stable, and unknown trends. We collected threatened levels of waterbirds from the Red List of China's Vertebrates(2016), which was compiled according to the IUCN criteria of threatened species. Based on literature review, we refined the major threats to the threatened waterbird species in China.Results: Of the total 260 waterbird species in China, 84 species(32.3%) exhibited declining, 35 species(13.5%) kept stable, and 16 species(6.2%) showed increasing trends. Population trends were unknown for 125 species(48.1%). There was no significant difference in population trends between the migratory(32.4% decline) and resident(31.8% decline) species or among waterbirds distributed exclusively along coasts(28.6% decline), inland(36.6% decline), and both coasts and inland(32.5% decline). A total of 38 species(15.1% of the total) were listed as threatened species and 27 species(10.8% of the total) Near Threatened species. Habitat loss was the major threat to waterbirds, with 32 of the total 38(84.2%) threatened species being affected. In addition, 73.7%(28 species), 71.1%(27 species), and 57.9%(22 species) of the threatened species were affected by human disturbance, environmental pollution, and illegal hunting, respectively.Conclusions: We propose recommendations for waterbird conservation, including(1) strengthening conservation of nature wetlands and restoration of degraded wetlands,(2) enhancing public awareness on waterbird conservation,(3) improving the enforcement of Wildlife Protection Law and cracking down on illegal hunting,(4) carrying out longterm waterbird surveys to clarify population dynamics,(5) restoring populations of highly-threatened species through artificial intervention, and(6) promoting international and regional exchanges and cooperation to share information in waterbirds and their conservation.

Spatiotemporal dynamics of ecological variation of waterbird habitats in Dongtan area of Chongming Island

Based on Landsat TM images, we explored the pattern of variation of suitable waterbird habitats from 1990 to 2008 in the Dongtan area of Chongming Island at the Changjiang (Yangtze) River mouth. By applying our highly accurate indicator model (R=0.999, P<0.01), we quantified the variations of fluctuation intensity for local waterbird habitats during 1990-2008, and for the main waterbird groups (Anatidae, Charadriidae, Ardeidae and Laridae) from 2006 to 2008, to evaluate the impact of habitat quantity change on the waterbird habitat status and the population dynamics of the different waterbird groups. The results show that the aquaculture ponds (AP) and the Scirpus mariqueter zone (SMZ) underwent drastic habitat changes during certain periods (AP: 1997-2000, 2000-2003, 2005-2008; SMZ: 1997-2000), and the fluctuation intensity differed among habitat types in the order AP>SMZ>TSH (total suitable habitat)>BSA (bare mud flat and shallow water area). The abandonment of tracts of aquaculture ponds in Dongtan in mid-2006 brought about an intensive population fluctuation, caused by rapidly changing habitat with the population expanding to adjacent areas. At present, Anatidae and Ardeidae are threatened in the Dongtan area with declining populations because of their very "picky" habitat requirements (i.e., high reliance on AP). The Charadriidae experienced enormous population declines in the late 1990s, however, they have since recovered to normal levels as habitat change has stabilized. Our findings suggest that the current challenges for habitat management are the protection and stabilization of AP and SMZ habitats.

Waterbird use of farm dams in south-eastern Australia:abundance and influence of biophysical and landscape characteristics

Background: While agriculture has taken much environmental water in Australia's Murray-Darling Basin, agricultural expansion has resulted in a vast number of farm dams, almost three-quarters of a million in the Murray-Darling Basin alone.Methods: Over a summer we studied(1) waterbird abundance and species richness and(2) the influence of biophysical and landscape characteristics across 49 farm dams at a large mixed-enterprise farm in northern Victoria on the southern reach of the Murray-Darling Basin.Results: On average, dams were found to host 27.1 ± 71.1 individuals/ha and 1.8 ± 2.9 species per pond. Such densities are comparable to those on natural wetlands. Dam surface area and perimeter and amount of vegetation were positively and strongly correlated with the Rallidae density(birds/ha), but no other parameters were strongly correlated with any other functional group. The landscape in which the dams were embedded had a highly significant effect(p < 0.001) on the number of birds found on a dam.Conclusions: Our research needs to be complemented with further studies in other parts of the Basin and on other taxa, but given at our site they supported similar densities of individuals and species to natural wetlands, and given the fact that there are 710,539 farm dams in the Murray-Darling Basin, which hosts much of Australia's waterbird fauna, it is reasonable to suggest that farm dams are overlooked, and possibly very important, avian biodiversity hotspots. It also highlights the importance of a landscape setting, in which dams are situated, on the number of birds using the dams.

Seasonal waterbird population changes in Lashihai Lake in northwest Yunnan, China

We studied the waterbird population at Lashihai Lake, Yunnan Province, China, which is a Ramsar Site(Wetland of International Importance), to determine seasonal variation in the species composition and size of the waterbird population. The study was conducted at five selected spots along Lashihai Lake at the same time each week from August 2011 to September 2013. In total, 62 waterbird species were recorded, of which 38.71%, 35.48%, 16.13%, and 9.68% were winter migrants, passage visitors, residents, and summer migrants, respectively. We found important seasonal changes in waterbird species composition and population size. Waterbird species richness was highest from September to the following April, with the total species numbers peaking in December. Total individual numbers peaked twice from late November to early December and mid-to-late February. However, waterbird species and individual numbers were comparatively lower from May to August. The change in species composition was determined by the arrival and departure dynamics of winter migrants and passage visitors. Winter migrants primarily caused the periodic changes in population size. Of concern,species and overall waterbird numbers seemed to be lower than the numbers in historical records. The decline of waterbird numbers implies that environmental changes caused by the implementation of the dam upstream of Lashihai Lake may have had adverse effects on this waterbird population. This study confirms the existence of major seasonal changes in species composition and size of the waterbird population at Lashihai Lake. Furthermore, the findings demonstrate that this wetland is of high conservation importance for waterbirds using the Central Asian–Indian and Asian–Pacific migratory routes.

Influence of land use change on the waterbird community of Sihwa Lake,Republic of Korea

Background:Land use and development alter mudflat and wetland habitat availability,although mudflats and wetlands provide important stopover habitats for shorebirds during the spring and autumn migrations and support communities of ducks and geese during the winter months in the Republic of Korea.This study investigated land use changes around Sihwa Lake(Republic of Korea)and evaluated the effect of these changes on waterbird community characteristics.Methods:We conducted a land-use-change analysis at the medium-resolution level using land cover maps for 2001,2007,2009,and 2014.Also,a tidal stream survey was conducted in Sihwa Lake and the surrounding reclaimed mudflats every season for 10 years(2003-2012)to identify the seasonal and interannual variations in waterbird species composition.To determine the total annual waterbird species and population counts,species diversity index,and interspecies variations,a TRIM(trends and indices for monitoring data)analysis was used.Results:Wetland area decreased more than 10%while agricultural land,barren land,and grassland area increased more than 10%due to continuous reclamation activities around Sihwa Lake.Barren land later turned into agricultural land or other land use.Sixty-three species and 566,623 individuals were recorded.The number of species,population size,and species diversity index by year and by species showed decreasing trends that were more marked in spring and summer.Furthermore,seasonal and annual variations in waterbird species composition showed decreasing trends in dabbling ducks,herons,grebes,and shorebirds but diving ducks displayed increasing trends.In particular,shorebirds were reduced to a greater extent than other waterbird species because of the reduction and simplification of the intertidal zone,and shallow waters caused by reclamation and road construction.Conclusions:Increased development and construction around Sihwa Lake has altered migratory shorebird populations with a general decline in species diversity and population size.The greatest decline was observed in wading birds,while diving duck populations showed increasing trends.

Comparative analysis of the microbiome of sympatric wintering Bean Geese,Domestic Ducks,humans,and soil at Shengjin Lake of China reveals potential public risk to human health

The gut microbiota of migratory waterbirds is affected by various complex factors,including cross-species transmission,which increases the risk of pathogen spreading among sympatric animals and poses a potential public health risk to humans.In this study,we investigated the microbial communities of wintering Bean Geese(Anser fabalis),Domestic Ducks(A.platyrhynchos domesticus),humans,and soil using high-throughput sequencing of the 16S rRNA gene region in Shengjin Lake,China.In total,6,046,677 clean reads were obtained,representing 41,119 operational taxonomic units(OTUs)across the four groups.The dominant microbial phyla were the Proteobacteria,Firmicutes,Bacteroidota,and Actinobacteriota.The Sorensen similarity index and alpha and beta diversity results showed that the gut microbial communities of Bean Geese and Domestic Ducks were more similar to those of the other pairs.Network analysis revealed that Faecalibacterium prausnitzii,Pseudomonas fragi,and Bradyrhizobium elkanii were hubs of the three major modules.Fourteen common microbiomes were iden-tified in Bean Geese,Domestic Ducks,humans,and soil in Shengjin Lake.A total of 96 potential pathogens were identified among the four groups,with 20 specific potentially pathogenic microbiomes found in the gut of Bean Geese.Some of these pathogens are responsible for significant financial losses in the poultry industry and pose risks to human health.Klebsiella pneumoniae,Morganella morganii,Escherichia coli,and Ralstonia insidiosa are potential core pathogens found in the four groups at Shengjin Lake that can cause diseases in humans and an-imals and facilitate cross-species transmission through various media.Therefore,humans are at risk of con-tracting these pathogens from migratory birds because of their frequent contact with domestic poultry.However,further studies are required to explore the potential pathogenic species and transmission pathways among sympatric wintering Bean Geese,Domestic Ducks,humans,and soil.

河北阳原桑干河国家湿地公园水鸟多样性

河北省阳原县桑干河国家湿地公园是鸟类迁徙的重要驿站。为掌握该湿地的鸟类状况,于2020年10月—2021年9月,采用样线法和样点法调查桑干河国家湿地公园的鸟类组成。结果表明:桑干河湿地公园共记录鸟类7目13科63种,其中,国家Ⅰ级保护鸟类2种,国家Ⅱ级保护鸟类7种,河北省重点保护鸟类23种,列入《世界自然保护联盟濒危物种红色名录(IUCN)》受胁物种的鸟类8种。居留型以旅鸟为主,有41种(65.08%),其余为夏候鸟22种(34.92%)。区系组成以古北界为主,共46种(73.02%),东洋界5种(7.94%)、广布种12种(19.05%)。优势种为赤麻鸭(Tadornaferruginea)和绿头鸭(Anasplatyrhynchos)。各月水鸟群落Shannon-Wiener多样性指数与Pielou均匀度指数差异较大,5月多样性指数与均匀度指数均最高,分别为2.732和0.860;11月均最低,为1.377和0.460。研究结果可为桑干河国家湿地的管理、该区域未来鸟类监测以及水鸟保护策略的制定提供依据。

长江中下游湖泊植食性水鸟栖息地适宜性变化

长江中下游湿地是东亚-澳大利西亚迁徙路线水鸟重要的越冬地,也是全球生物多样性保护的热点区域。近年来,气候变化和人类活动改变了长江中下游湖泊湿地的水文情况和自然生境,湿地变化对水鸟产生的影响尚未得到有效评估。了解湿地水鸟的分布动态,分析模拟湿地水鸟栖息地的分布变化至关重要。基于长江中下游植食性水鸟公民科学数据,结合MaxEnt模型,模拟了2012—2021年长江中下游25个湖泊植食性水鸟栖息地的适宜性及变化趋势,并探究湖泊洪泛区面积对植食性水鸟栖息地适宜性的影响。研究评估的长江中下游湖泊中,鄱阳湖2012—2021年栖息地适宜性呈现下降趋势,长湖和武湖呈上升趋势,其他湖泊并无显著上升或下降的趋势。湖泊洪泛区面积与湖泊植食性水鸟栖息地适宜性呈现显著相关关系,可作为水鸟栖息地适宜性的预测指标,研究可为湿地水鸟栖息地预测及湿地生态系统管理提供科学方法和结果参考。

越冬期水位变化下菜子湖水鸟取食集团结构及多样性分析

2018—2023年越冬期,对菜子湖的水鸟资源进行调查,共记录到水鸟7目12科59种,其中,国家一级保护动物5种,国家二级保护动物9种。对水鸟取食集团群落结构进行分析,结果表明,不同取食集团水鸟群落多样性指数存在显著差异,不同类型多样性指数变化幅度是Shannon-Wiener多样性指数>Margalef丰富度指数>Simpson优势度指数>Pielou均匀度指数。不同取食集团水鸟的数量对水位变化响应存在一定差异,其中,食鱼组、食草组、食底栖动物组的数量与水位之间存在显著负相关关系,水位变化对水域、草本沼泽、泥滩等3种生境的面积具有显著影响。未来应从水位优化调控入手,维持越冬期水鸟丰富食物资源,对提高菜子湖水鸟群落多样性具有重要意义。

Nestedness of waterbird assemblages in the subsidence wetlands recently created by underground coal mining

Nestedness has been a research focus in fields of island biogeography and community ecology in recent decades. Although nestedness of faunal assemblages has been investigated in natural wetlands, it remains largely unknown whether and why waterbird communities in artificial wetlands follow n ested patter ns. We exami ned the existence of n ested ness and un derlyi ng drivers in waterbird comm un ities in subside nee wetlands that are recently created by large-scale un derground coal mining in the North China Plain. Twelve point-count surveys for waterbirds were undertaken approximately every 2 weeks in 55 subside nee wetla nds from September 2016 to April 2017. We used the metric WNODF to estimate nestedness of the assemblages. Partial Spearman rank correlations were performed to examine the association between the nestedness and habitat variables (wetland area, landscape connectivity, wetland age, and habitat diversity) as well as life-history traits (body size, clutch size, dispersal ratio, geographical range size, and migrant status) related to species exti notion risk and colon izati on rate. Waterbird assemblages in the subside nee wetla nds were significantly nested. After controlling for other independent variables, the magnitude of nestedness was significantly and negatively correlated with wetland area and species trait linked to extinction risk (i.e., geographical range size). Our results indicate that selective extinction may be the main driver of the nestedness of waterbird assemblages in our study system. However, the nestedness was not due to passive sampling, selective colonization, or habitat diversity. From a conservation viewpoint, both large wetlands and waterbirds with a small geographic range should be protected to maximize the preserved species richness.

滇池湖滨湿地水鸟栖息地重要性评估及其影响因子分析

评估水鸟栖息地重要性及其与生境因子间的关系,可为制定栖息地保护规划提供科学依据,对水鸟的保护具有重要意义。2021年5月—2022年4月,对滇池27个湖滨湿地开展水鸟调查,采用模糊综合评价法对各湿地(水鸟栖息地)重要性进行评估,并通过差异性和相关性分析探讨生境因子对栖息地重要性的影响。结果显示:滇池共有水鸟7目14科64种56640只,重要性较高的湿地分别为东大河湿地(0.68)、鸽子窝(0.63)、余家沟(0.57)、海东湿地(0.52),建议优先将以上湿地规划为水鸟栖息地保护地。自然湿地重要性显著高于人工湿地,所有湿地重要性均随湿地面积、周长和水域面积比例的增加而升高,基于此类生境因子提出水鸟栖息地生境营造策略,以期为滇池水鸟栖息地保护规划的制定和栖息地生境管理提供科学指导。

基于两种生态位模型对苏州市湿地水鸟潜在适生区预测

以苏州市为例,利用42种水鸟的分布数据和气候因子、地理因子及遥感影像因子相结合,使用Maxent模型和GARP模型对水鸟适生区进行预测。通过对42种水鸟适生区的预测和叠加,获得4幅水鸟适生区预测图。结果表明:引入地理因子可以有效预测水鸟的适生区,4个预测结果中Maxent水鸟种群适生区分布预测图精度最高。预测结果显示,水鸟高适生区分布在张家港沿江、太湖周边、阳澄湖周边。研究结果为水鸟适生区预测提供了新思路,对保护苏州市水鸟多样性、维持苏州市湿地生态系统安全和稳定具有参考价值。