崇明东滩冬季水鸟的种类和生境偏好

20 0 2年 11月～ 2 0 0 3年 1月对崇明东滩自然保护区的越冬水鸟在 5种生境类型的分布、数量分别做了 2 0 0 0m× 10 0m的样带调查。共观察到水鸟 4 9种 ,整个群落个体总数 345 0 4只。其中低潮盐藻光滩带有鸟类37种 ,占水鸟个体总数的 39% ;海三棱草外带有 19种 ,占 6 % ;海三棱草内带有 10种 ,占 5 % ;堤外芦苇带有 4种 ,占 3% ;堤内鱼塘 -芦苇区有 37种 ,占 4 7%。这一结果证实了把围垦地转变为鱼塘 -芦苇湿地的生态恢复行动的合理性 ,因为最大的越冬水鸟物种多样性和个体多度出现在这种湿地中。     

崇明东滩越冬鸟类在养殖塘的空间分布

鸟类对空间的利用直接反映对栖息地的选择。通过对崇明东滩养殖塘越冬鸟类群落调查,运用空间自相关检验、空间插值分析和景观格局分析,研究越冬鸟类在养殖塘人工湿地的空间分布格局。结果显示:雁鸭类和鸻鹬类在养殖塘分布特征显著不同。雁鸭类呈现显著的空间自相关,为聚集分布,且丰富度和多度分布较为一致;而鸻鹬类在养殖塘以随机分布为主,丰富度显示一定的聚集分布。养殖塘已经成为崇明东滩越冬鸟类重要的栖息地,不同生态类群栖息地选择存在差异:芦苇植被发育好,水域面积较小且水深较深,不同斑块以聚集为特征的养殖塘是雁鸭类的适宜生境;鸻鹬类则偏好一定芦苇植被、水域面积大且水深较浅的养殖塘。因此在保护区土地利用和管理时应考虑不同生态类群对栖息地选择的差异。     

崇明东滩人工湿地春季水鸟群落结构及其生境分析

崇明东滩处于独特的地理位置,拥有辽阔的滩涂和丰富的湿地资源,是亚太地区候鸟迁徙路线上的重要驿站。然而崇明东滩也是上海促淤圈围重点区域之一,且围垦后滩涂用作多种农业、工业发展,导致当地植物群落和滩涂湿地结构的改变,从而直接造成了鸟类生物多样性的明显下降,因此东滩湿地保护人员采取了修复和优化的治理措施,但治理同时也将自然滩涂改造成人工湿地。本研究将改造后自然滩涂作为研究不同类型人工湿地的水鸟群落结构及其生境关系的研究区域,并把研究区域分为4种不同类型人工湿地,捕鱼港优化区即一期工程(已修复)、鸟类栖息地优化区即二期工程(修复中)、人工鱼蟹塘、耀全农场。本研究目的在于分析这4种不同类型人工湿地中鸟类群落特征并寻找影响鸟类对生境利用的主要因子,同时考虑修复优化工程的保育功能,对不同管理模式下的人工湿地进行研究,从而对湿地改造提出科学的建议。由于前期大量研究表明春季鸟类数量和种类较丰富,能够较好地反映崇明东滩湿地生态现状。因此从2013年3月下旬至5月上旬在大潮期和小潮期分别对上述4种不同类型人工湿地进行了鸟类及其生境因子调查。此次鸟类调查采用样点法,共统计到水鸟2357只,隶属于6目11科45种,其中斑嘴鸭(Anas poecilorhyncha)、红骨顶(Gallinula chloropus)、金眶鸻(Charadrius dubius)、环颈鸻(C.alexandrinus)、牛背鹭(Bubulcus ibis)、鹤鹬(Tringa erythropus)、林鹬(T.glareola)等25种鸟为优势种。非参数检验分析表明,春季这4类人工湿地水鸟种类、密度、多样性均有显著性差异,一期工程内水鸟的种类、密度、多样性指数、均匀度指数都为最大。对生境因子与鸟类群落特征进行相关分析,根据非参数检验的结果得出裸露浅滩面积、水域面积、生境小岛个数是影响水鸟分布的关键因子,为此对鸟类栖息地优化区的修复及其完善提出科学建议。     

上海崇明东滩湿地的栖息地重建对水鸟的作用

湿地快速丧失和退化是全球水鸟面临的严重威胁。位于长江口的上海崇明东滩鸟类自然保护区是亚太地区水鸟重要分布区,为了应对互花米草快速扩张所带来的水鸟栖息地丧失和质量下降,保护区于2011年开展互花米草治理和鸟类栖息地重建生态项目,为鸟类提供补偿栖息地。通过直接计数法调查了栖息地重建区域的水鸟种类和数量,以了解该区域对水鸟的支持作用并为湿地管理提供依据。2011年11月—2016年10月,在该区域共记录到水鸟7目13科69种,共计38 238只次。不同水鸟类群在不同年份和不同季节的变化较大,这可能与不同水鸟类群在栖息地需求方面存在较大差异,以及不同年份研究区域在植被、水文条件及人类活动干扰等方面发生的明显变化有关。建议根据水鸟的生态习性和时空分布特征,针对性地开展植被、水文特征等栖息地要素的管理,以达到为多种水鸟提供适宜栖息地的目标。     

澳门生态一区和二区水鸟谱系多样性的季节变化

季节变化是鸟类群落的重要特征之一,其引起的环境变化决定着鸟类群落构建过程中不同驱动因子的作用力。因此,了解鸟类群落结构的季节变化,对于全面认识生物群落结构具有重要意义,尤其利用谱系多样性来探讨鸟类的季节性变化和推断群落聚集规律越来越受到关注。2018年1—12月,采用样线法对澳门生态一区和二区2块湿地进行逐月调查,记录水鸟的物种丰富度和多度,并分析水鸟谱系多样性的季节动态。结果显示,1)共记录水鸟37种,隶属于6目9科,目、科、种中数量最多的依次为:鸻形目Charadriiformes物种数为15种,鹭科Ardeidae物种数为11种,白鹭Egretta garzetta多度为540只。2)生态一区和二区水鸟的物种丰富度在冬季最高,其次为秋季;生态一区和二区的物种多度分别在秋季和冬季最高;谱系多样性和平均成对谱系距离的季节变化规律与物种丰富度的相似。3)生态一区和二区的鸟类群落分别在春、秋、冬季和秋季趋向于谱系发散,而在其他时间大多呈现出谱系聚集。谱系发散可能表明了种间竞争在群落构建中作用更大,而谱系聚集则表明了环境过滤对繁殖季水鸟群落构建具有重要作用。结果表明,湿地水鸟群落的驱动因子存在季节变化,考虑这些变化是全面认识群落结构的前提。     

上海市崇明东滩湿地生态恢复与重建工程中社会经济价值分析

随着人类活动的增加,崇明东滩自然保护区内已被破坏或改变栖息地利用方式的湿地面积已达到8000hm^2,其逗留、栖息和越冬的鸟类逐年减少。因此,为了保护鸟类,并且提高上海在自然保护和维护物种多样性方面的国际地位,恢复和重建崇明东滩的湿地环境受到上海市政府的高度重视。崇明东旺沙B01号样地的恢复与重建是上海市崇明东滩湿地生态恢复与生态重建工程中的一期工程．结合野外调查,综合运用市场价值法、造林成本法和生态价值法等研究方法,对该样地现有功能价值,以及对样地在恢复和重建之后所产生的功能价值进行了估算,得到该示范区现有功能价值为72．27万元人民币,而初步预计恢复和重建之后的功能价值为7016.95万元人民币。     

崇明东滩自然保护区盐沼植被的时空动态

盐沼植被是滩涂湿地的重要组成部分,其动态变化直接影响着湿地的生态服务功能和价值。通过对1998~2005年间4景不同时相的LandsatTM遥感影像的解译分析,结合历史资料数据和近年来的现场调查,分析了崇明东滩鸟类自然保护区自建立以来,盐沼植被的时空演替动态过程。结果显示,随着滩涂的淤涨,东滩盐沼植被的面积从1998年的2478.32hm2增加到2005年的4687.74hm2,而互花米草(Spartina alterniflora)自人为引入至2005年,其面积已增加到1283.4hm2,其增加速率显著高于土著种芦苇(Phragmites australis)和海三棱藨草(Scirpus mariqueter),并且已在东滩保护区相当区域内形成单优势种群落。受1998年和2001年两次高滩围垦和互花米草入侵影响,崇明东滩的芦苇群落面积大大减少,虽随着滩涂的淤涨,芦苇群落的面积逐年有所增加,但增加的速度缓慢。互花米草有着更广的生态幅和竞争优势,是滩涂中扩散最快的植被,而淤涨型滩涂为其提供了可扩张的空生态位,如不加以控制和治理,其快速扩散将会对崇明东滩保护区的生态系统造成更大的威胁和影响。     

四川省东部和西南部冬季水鸟调查

2012年12月中旬至2013年1月中旬,对四川省东部8个中型水库和1条自然河段、西南部3个湖泊的冬季水鸟进行了调查,记录到水鸟41种,隶属7目10科。四川东部地区有23种,其中有国家Ⅱ级重点保护鸟类鸳鸯Aix galericulata 1种,东部冬季水鸟群落物种数不多,种群数量也不大,种群数量最多的是绿头鸭Anas platyrhynchos、绿翅鸭A.crecca和斑嘴鸭A.poecilorhyncha。四川西南部地区记录到33种,其中国家Ⅰ级重点保护鸟类中华秋沙鸭Mergus squamatus 1种,国家Ⅱ级重点保护鸟类鸳鸯1种,西南部冬季水鸟的群落物种数较多,种群数量也较大,种群数量最多的是骨顶鸡Fulica atra、凤头潜鸭A.fuligula和赤嘴潜鸭Netta rufina。天然湖泊和自然河段的冬季水鸟种类和数量都多于人工湖泊。除二滩水库外,湖泊(库塘)面积与水鸟种类和数量呈正相关。旅游、行船和偷猎是水鸟越冬地面临的主要干扰和威胁。需加强湿地保护和对偷猎行为的大力打击。     

崇明东滩抛荒鱼塘的自然演替过程对水鸟群落的影响

人工湿地抛荒的现象普遍存在,但针对抛荒后的自然演替过程对水鸟群落影响的研究较少.于2007、2008、2011年对崇明东滩自然抛荒的人工鱼塘水鸟群落展开调查,探究抛荒后的自然演替过程对水鸟群落结构及不同水鸟类群的影响.3a累计观察到水鸟59种12819只,隶属6目12科.其中抛荒前最多,共53种11001只;抛荒第1年22种1673只;抛荒第4年最少,9种145只.鱼塘抛荒后水鸟种类和数量下降剧烈,物种多样性先上升再下降,均匀度逐年上升,优势度先下降再上升.方差分析结果表明,5个群落特征都存在极显著年度差异(P1＜0.01;P2＜0.01;P3＜0.01;P4=0.003;P5＜0.01).非参数检验结果表明,不同类群水鸟的种类和数量逐年下降趋势明显,且年际差异极显著.即抛荒后的自然演替过程对水鸟群落产生了不利影响.建议采取人工管理措施防止旱化,增加环境异质性,恢复水鸟群落多样性.     

基于空间分带的崇明东滩水鸟适宜生境的时空动态分析

本文采用1990—2008年期间6期Landsat TM遥感影像的解译结果,基于ArcGIS空间分带方法并构建生境有利度指数,分析了崇明东滩水鸟适宜生境的时空动态。结果表明：（1）近20 a来,主要受自然湿地的围垦、堤内土地利用方式变化和堤外互花米草(Spartina alterniflora)入侵的影响,崇明东滩海三棱藨草(Scirpus mariqueter)群落（SMC）和养殖塘（AP）的数量特征变化较大,水鸟适宜生境的数量和结构经历了由自然生境到人工生境再到自然生境占支配地位的变化;（2）1990—2008年期间,SMC和AP生境有利度指数值的最高年份分别是1990和2003年,指数值的最低年份分别是2000和2008年;（3）1990s年代的大规模围垦以及互花米草的入侵,致使SMC生境的面积锐减,其主要分布范围从1990年的堤外1000—5000 m变为堤外0—3000 m处,导致SMC生境状况恶化;（4）大堤内AP生境是崇明东滩的重要水鸟生境类型,受堤内土地利用方式改变的影响,该生境2008年的生境有利度指数很低。崇明东滩鸟类生境的管理和保护不仅应重视自然湿地中的光滩与浅水区域,同时更应侧重于海三棱藨草群落和堤内养殖塘的管理和保护,其重点管理和保护范围可界定在堤外3000 m到堤内2000 m之间。崇明东滩水鸟生境的管理应实现多目标管理,维持各类适宜生境的足够面积和合理的空间布局,并在时间尺度上保持相对稳定,才能有效地保护各类水鸟种群及其生物多样性。     

Climatic patterns in the establishment of wintering areas by North American migratory birds

Long‐distance migration in birds is relatively well studied in nature; however, one aspect of this phenomenon that remains poorly understood is the pattern of distribution presented by species during arrival to and establishment of wintering areas. Some studies suggest that the selection of areas in winter is somehow determined by climate, given its influence on both the distribution of bird species and their resources. We analyzed whether different migrant passerine species of North America present climatic preferences during arrival to and departure from their wintering areas. We used ecological niche modeling to generate monthly potential climatic distributions for 13 migratory bird species during the winter season by combining the locations recorded per month with four environmental layers. We calculated monthly coefficients of climate variation and then compared two GLM (generalized linear models), evaluated with the AIC (Akaike information criterion), to describe how these coefficients varied over the course of the season, as a measure of the patterns of establishment in the wintering areas. For 11 species, the sites show nonlinear patterns of variation in climatic preferences, with low coefficients of variation at the beginning and end of the season and higher values found in the intermediate months. The remaining two species analyzed showed a different climatic pattern of selective establishment of wintering areas, probably due to taxonomic discrepancy, which would affect their modeled winter distribution. Patterns of establishment of wintering areas in the species showed a climatic preference at the macroscale, suggesting that individuals of several species actively select wintering areas that meet specific climatic conditions. This probably gives them an advantage over the winter and during the return to breeding areas. As these areas become full of migrants, alternative suboptimal sites are occupied. Nonrandom winter area selection may also have consequences for the conservation of migratory bird species, particularly under a scenario of climate change.     

Impacts of climate and land‐use change on wintering bird populations in Finland

Few studies have covered both the effects of climate and land‐use change on animal populations under a single framework. Besides, the scarce multi‐species studies conducted have focused on breeding data, and there is little information published on changes in wintering populations. Here, we relate the pattern of long‐term temporal trends of wintering bird populations in Finland, north Europe, to covariates associated with climate and land‐use change. Finnish wintering populations have been monitored using ca 10 km winter bird census routes (> 420 routes counted annually) during 1959–2012. Population trends of 63 species were related to migratory strategy, urbanity, and thermal niche measured as species‐specific centre of gravity of the wintering distribution. Waterbird trends have shown a marked increase compared to landbirds. Among landbirds, forest species have suffered severe declines, whereas urban species have considerably increased in their wintering numbers. To follow up these results, we produced three multi‐species indices (for waterbirds, forest and urban species, respectively), which can improve our ability to detect and monitor the specific consequences of climate change and changes in land‐use, but at the same time act as a feedback to track the conservation status of the species. Our results suggest that waterbirds are responding to climate change, given their dependence on open water and the correlation with early‐winter temperature over the last decades. On the other hand, we believe trends of landbirds have been mainly driven by human‐induced land‐use changes. While urban species have likely benefited from the increase of supplementary feeding, forest species have probably suffered from the loss of native habitats.     

安徽沿江浅水湖泊越冬水鸟群落的集团结构

长江中下游湖泊是越冬水鸟的重要栖息地,随着湖泊渔业养殖强度的不断加大,湖泊湿地严重退化,水鸟的越冬生态受到影响。为揭示长江中下游浅水湖泊越冬水鸟对湿地资源的利用特征,2008年12月至2009年3月,通过扫描取样法采集安徽省长江沿江升金湖、菜子湖和武昌湖3个浅水湖泊30种越冬水鸟的取食行为百分比数据,利用聚类分析法对越冬水鸟进行集团划分,并采用无倾向对应法(DCA)分析越冬水鸟的取食特征。聚类分析结果表明,安庆沿江湖泊越冬水鸟群落可分为4个集团,即深水取食集团G1、挖掘和啄取集团G2、浅水取食集团G3和泥滩拾取集团G4。G2集团的鸟种最多,共有13种,优势种为鸿雁(Anser cygnoides)、豆雁(Anser fabalis);G3集团次之,共6种,优势种为小天鹅(Cygnus columbianus)、白琵鹭(Platalea leucorodia);G4集团共5种,优势种为黑腹滨鹬(Calidris alpina)、鹤鹬(Tringa erythropus)和红脚鹬(Tringa totanus);G1集团水鸟种类有6种。这些水鸟的觅食生境主要在湖泊滩涂和浅水区域,其食物资源的可利用性和觅食对策共同决定群落组成结构。DCA分析表明,取食方式及取食时运动方式组成的觅食对策决定了集团食物资源的分割,草滩中取食鸟类主要采用静止取食和啄取方式,泥滩取食集团主要采取拾取及奔-停取食,深水区取食集团则主要采用潜水方式取食,因此,维持湖泊不同区域的丰富食物资源对于保护湖泊丰富的水鸟资源具有重要意义。     

Macrophyte-associated macroinvertebrates as an important food source for wintering waterbirds at Lake Constance

In many lake ecosystems, waterbirds rate among the top consumers. Lake Constance is an important overwintering site for waterbirds in Central Europe because it provides sufficient food sources to meet energy demands during the winter months. In this study we focussed on the submerged vegetation and its associated macroinvertebrate fauna as a food source. We conducted experiments with exclosure cages which protected evergreen charophytes from bird grazing and compared the mass decline throughout the winter to unprotected grazed sites. Furthermore, we assessed the change in macrophyte-associated macroinvertebrates during the course of winter. We found that wintering waterbirds caused a significant decline of charophytes and their associated macroinvertebrates down to a depth of 4 m. We determined the taxa and abundance of macroinvertebrates associated with charophytes and predominantly found Dreissena polymorpha. At sites protected from bird grazing, the biomass of the macroinvertebrate fauna increased relative to the plant biomass during the course of winter. This might also have affected the foraging behaviour of diving waterbirds.     

Winter bird communities in the northern Negev: species dispersal patterns, habitat use and implications for habitat conservation

Bird habitat conservation may require different management strategies for different seasonal bird assemblages. We studied habitat use by winter birds in forest and scrubland habitat patches in the northern Negev, Israel. Our goal was to assess whether differences in responses to landscape and habitat structure between breeding and non-breeding seasons require changes in future conservation plans that have been suggested for the Negev breeding bird community. We evaluated habitat and area effects on bird abundance and distribution and tested whether species habitat use during winter involves niche shifts. Compared with breeding birds, a larger proportion of winter bird species occupied both scrubland and forest. As in summer, forest bird species responded to habitat structure, whereas scrubland species were associated with both habitat structure and area. Resident birds disperse into habitats in which they were not present during summer. Consequently, for several species, the correlation between bird densities and environmental factors showed a better fit at the landscape rather than at the habitat scale. In addition, rather than niche shift, birds actually extended their niche breadth. Nest site selection may constrain bird distribution into a realized niche, smaller than their fundamental niche. Despite the scale differences in habitat use, the similar species diversity patterns between seasons suggest that both winter and summer birds would benefit from conservation of scrub patches larger than 50 ha, and enrichment of foliage layers within the planted forests.     

Ecological traits influence the phylogenetic structure of bird species co‐occurrences worldwide

The extent to which species’ ecological and phylogenetic relatedness shape their co‐occurrence patterns at large spatial scales remains poorly understood. By quantifying phylogenetic assemblage structure within geographic ranges of >8000 bird species, we show that global co‐occurrence patterns are linked – after accounting for regional effects – to key ecological traits reflecting diet, mobility, body size and climatic preference. We found that co‐occurrences of carnivorous, migratory and cold‐climate species are phylogenetically clustered, whereas nectarivores, herbivores, frugivores and invertebrate eaters tend to be more phylogenetically overdispersed. Preference for open or forested habitats appeared to be independent from the level of phylogenetic clustering. Our results advocate for an extension of the tropical niche conservatism hypothesis to incorporate ecological and life‐history traits beyond the climatic niche. They further offer a novel species‐oriented perspective on how biogeographic and evolutionary legacies interact with ecological traits to shape global patterns of species coexistence in birds.     

菜子湖冬季水鸟空间分布与环境因子的关系研究

水鸟空间分布与环境因子的关系是生态研究的重要内容,环境因子的变化可以通过改变栖息地的生境特征、食物资源从而直接或间接影响水鸟的种类、数量和分布.利用网格单元对2019—2020年菜子湖冬季水鸟及其环境因子进行调查,共记录到水鸟6目12科41种,其优势种为豆雁(Anser fabalis)和黑腹滨鹬(Calidris a...     

Meta‐barcoding insights into the spatial and temporal dietary patterns of the threatened Asian Great Bustard (Otis tarda dybowskii) with potential implications for diverging migratory strategies

Food resources are often not sufficient to satisfy the nutritional and energetic requirements during winter conditions at high latitudes. Dietary analysis is a prerequisite to fully understanding the feeding ecology of a species and the nature of trophic interactions. Previous dietary studies of Asian Great Bustard (Otis tarda dybowskii) relied on behavioral observations, resulting in categorization of diet limited to broad taxonomic groupings. Here, we applied a high‐throughput sequencing meta‐barcoding approach to quantify the diet of resident and migratory Asian Great Bustard in three wintering sites during early winter and late winter. We detected 57 unique plant taxa in the bustard diet, among which 15 species were confirmed by a local plant database we generated. Both agricultural and natural foods were detected, indicating a relatively broad dietary niche. Spatiotemporal dietary changes were discovered, revealing diet differences among wintering sites and a general shift toward lower plant diversity later in winter. For the nonmigratory population, we detected a significantly more diverse array of plant species in their diet. We hypothesize that dietary variation between resident and migratory populations could be involved in the recent transition to partial migration in this species, although climate change can not be excluded. Collectively, these results support protecting unharvested grain fields and naturally unplowed lands to help conserve and promote population growth of Asian Great Bustard.     

Evolution of seasonal ecological niches in the Passerina buntings (Aves: Cardinalidae)

The evolution of migration has long been considered complex and recent work has demonstrated additional complexity: some species follow the same ecological conditions throughout the year, whereas others 'switch niches' between breeding and wintering ranges. Hypotheses regarding the evolution of migration would generally predict niche-following as primitive, and niche-switching as derived. However, no test has, to our knowledge, yet determined the directionality of evolution of these states within a lineage. We present an analysis of phylogenetic dimensions of seasonal niches in the Passerina buntings that indicates greater evolutionary change in the niches of breeding populations than among those of wintering populations. These results are consistent with hypotheses of (i) niche conservatism (in winter, at least) across a recently speciated lineage; and (ii) the derived state of the breeding (rather than winter) ecological niches of each species.     

Niche congruency of aquatic macrophytes in central North America with respect to 5 water chemistry parameters

The occurrences of aquatic macrophytes were studied at 430 sites in central North America with respect to total alkalinity, chloride, sulphate, molybdenum reactive phosphorus and dissolved organic matter. Mean niche positions were calculated for the combination of 5 parameters by comparing mean values for each species using agglomerative hierarchical cluster analysis. Overall niche relations were examined by calculating and summing the amount of overlap in the observed ecological tolerance ranges for the 5 parameters for each species pair, and applying cluster and principal component analysis. The results showed that the macrophytes occupied a broad spectrum of niches, ranging from species found at low inorganic concentrations and narrow tolerance ranges, to species occupying broad ranges in the study area. Species with similar overall niches differed with respect to their mean niche positions, and vice versa. Macrophytes with similar niche positions may use a number of strategies to reduce interspecific competition.