基于物种分布的北京平原生态网络构建

高强度的城市化活动导致了生物栖息地破碎化、退化和消失,是生物多样性减少的主要原因。建立城市地区生态网络是保护生物多样性的重要途径。因其他物种数据可获得性差,以观测的典型鸟类群落为指示物种,探讨构建生态网络,可为城市生物多样性保护提供新思路。以北京市平原区为研究范围,重点基于86种鸟类分布大数据,通过Maxent模型掩膜生成栖息地源地并进行分级,在GIS技术的支撑下,以土地利用数据建立鸟类活动阻力面,采用最小累积阻力模型算法,模拟并形成了平原地区分级的生物多样性保护网络。研究结果表明,河湖湿地和城市公园组成了北京平原地区生态网络的优势景观类型,占平原区生态空间的81%。基于景观类型大小与物种数量的线性关系筛选出分级生物栖息地,其中一级生物栖息地58个,二级生物栖息地146个,通过模型模拟形成了平原地区生物多样性保护的一二级生态网络,共948条网络,长3760km。筛选出重要生态节点12处,关键生态廊道6条,是保护平原地区生物多样性的重要生态设施。该生态网络的实施对于提升首都平原区的生物多样性具有重要价值,研究结果可为国土生态空间优化提供重要科学依据和参考。     

互花米草入侵对鸟类的生态影响

生物入侵威胁本地物种生存,破坏生态系统的结构和功能,是导致全球生物多样性丧失的重要原因之一。外来植物是入侵生物中的重要一类,可以显著改变本地植被群落,并影响其他生物类群。鸟类作为生态系统中的较高营养级,对由入侵植物引起的栖息地变化十分敏感。互花米草自引入中国沿海以来,其分布区域不断扩散,多数研究认为互花米草入侵造成本地生物多样性降低和生态系统退化。系统梳理了互花米草入侵对鸟类栖息地、食物资源、繁殖、群落等方面的生态影响。主要负面影响有:(1)植被群落结构不利于鸟类栖息、筑巢、觅食;(2)鸟类食物资源丰度和多样性下降;(3)本地鸟类种群数量和物种多样性显著下降。在我国东部沿海湿地,互花米草入侵已经显著改变了植被与鸟类分布格局。但随着入侵历史的增长,少数小型雀形目鸟类却可以逐渐适应互花米草生境。互花米草入侵为某些非本地鸟类提供了空白生态位,在一定程度上丰富了本地物种多样性,对互花米草的快速清除反而可能不利于已适应并依赖互花米草生境的鸟类。综上,认为互花米草入侵对鸟类群落甚至整个生态系统的影响可能需要更多研究进行综合评价,应开展长期、大尺度、多因子的监测研究和多物种比较研究,建立生态评价模型并制定科学有效的互花米草管理对策。     

北京城市及近郊区环境结构对鸟类的影响

本文研究了北京市区及近郊环境结构与四季鸟类群落的关系,用相对数量路线调查法估计了鸟类的实际分布。环境结构分为面积和空间异质性两个主要因素,后者又包括自然度和环境多样性两个方面。结果表明,空间异质性对鸟类物种数及多样性有显著的影响,其中自然度的作用较环境多样性的作用更为显著。“边缘效应”是由于环境多样造成的。当空间异质性较高时,面积对鸟类物种数的影响是明显的。由于城市环境的空间异质性较低,由少数优势种决定了鸟类群落特征。为改善城市环境结构,建议增加绿化面积,丰富植被层次及物种组成,同时在北京城市环境中适当增加各种形式的水体。     

近自然社区公园的生物多样性特征——以北京市中心城区为例

城市绿地为城市动植物提供了重要栖息地，对城市生物多样性保护具有重要意义。然而，传统社区公园绿地（"传统绿地"）主要围绕安全、景观和游憩功能，植物种类偏少，群落结构单一，为城市野生动物提供食源和栖息地的资源有限。北京市以2035规划"留白增绿"为政策背景，在中心城区建设一系列小型近自然社区公园绿地（"近自然绿地"），在植物物种组成、群落结构和管理方式上有别于以往的传统绿地。一般认为生物多样性在一定范围内随面积的增大而提高，那么对于受到高度干扰的小型绿地，"近自然"特征是否能够显著提高其包括昆虫、鸟类在内的生物多样性？为探究这类近自然绿地的生物多样性特征，在2020年8月至2021年3月，综合采用样方法、样线法，对北京市西城区2个近自然绿地及4个传统绿地的植物、昆虫和鸟类进行调查，分析比较其多样性特征。结果表明，近自然绿地的灌木和草本层丰富度和多样性显著高于传统绿地，均匀度则无显著差异；近自然绿地的昆虫和鸟类的丰富度、多样性显著高于传统绿地，均匀度则无显著差异。与传统绿地相比，近自然绿地具有更丰富的鸟类食源、蜜源植物，以及更为复杂的植被垂直结构。根据以上结果，近自然绿地具有比传统绿地更为显著的生物多样性优势，建议在进行城市绿地建设时，应增加植被结构复杂的近自然绿地的比例，增加绿地的灌木和草本层多样性。研究成果不仅丰富了小面积绿地的生物多样性内涵，且可为大都市近自然绿地营建提供理论依据。本研究还将为今后公园设计、改造和管理提供新的思路，引导绿地向基于生物多样性保护的方向可持续发展。     

岛屿栖息地鸟类群落的丰富度及其影响因子

1997年1月至1997年12月间,以杭州市的园林鸟类群落为研究对象,对岛屿栖息地鸟类群落的丰富度与面积,人为干扰,内部结构和周围景观结构等多种因素的关系进行了系统的分析和检验。在杭州市各园林中共观察到82种鸟类。园林单次调查的鸟类物种数（S）与园林全年总物种数（Sy)与园林面积（A）的最佳回归拟合方程分别为;S＝ 2.7432A^0.3846,Sy=10.6574A^0.3669。杭州市园林鸟类群落物种－面积关系的成因不支持平衡假说,随机取样假说,栖息地多样性假说和干扰假说,岛屿栖息地鸟类群落的丰富度是多因素综合作用的结果,包括取样面积效应（排除了取样面积效应之后,小园林具有更高的物种密度）,栖息地结构的多样性（其中树种多样性是最主要的影响因子）,干扰因素,物种因素和研究尺度等几个方面。     

千岛湖雀形目鸟类群落嵌套结构分析

2006年4月至2007年11月, 采用截线法对千岛湖20个岛屿上的雀形目鸟类种类组成进行调查, 检验其群落是否符合嵌套式分布的格局。此外通过野外直接记录与辨认法对岛屿上的植物种类组成进行调查, 同时通过查阅文献资料和野外调查获得鸟类体长、分布宽度和生境专属性等生活史特征参数, 以及采用GIS分析测定岛屿面积和隔离度参数, 进而分析和探讨雀形目鸟类群落嵌套格局的影响因素。结果显示, 千岛湖岛屿雀形目鸟类群落呈现显著的嵌套结构, 岛屿面积、植物物种丰富度和生境专属性对其嵌套结构具显著性的影响。千岛湖岛屿雀形目鸟类存在着选择性灭绝过程; 植物物种丰富度和鸟类生境专属性则通过影响鸟类在不同生境下的分布对鸟类群落嵌套结构产生影响。上述结果表明千岛湖岛屿雀形目鸟类群落嵌套格局同时受到栖息地和物种两方面因素的影响, 为此我们认为应更多地关注那些面积较大和植物物种丰富度较高的岛屿, 以及生境专属性较高的种类等鸟类多样性及其栖息地的保护策略。     

滇西山地核桃林与天然林的春季鸟类群落比较研究

人工种植林正在发展中国家快速发展,但目前这些人造景观对生物多样性保护的价值却未被深入理解。2015年春季,对云南省大理白族自治州云龙县和永平县内的核桃种植林,及其邻近保护区内的天然林进行了鸟类和植被结构调查。所有60个样点鸟类调查共记录到鸟类88种,仅在天然林中出现的物种有54种,仅在核桃林中出现的有14种,2种林型中共有的物种有20种。2个核桃林研究地点中的鸟类物种丰富度和多度均低于相应天然林的;群落相似性系数比较显示核桃林与天然林的鸟类群落组成也明显不同,永平县的核桃林和天然林之间鸟类群落组成差异更大。与天然林相比,利用核桃林的物种多为普通物种、森林边缘和开阔地活动物种,3种国家Ⅱ级重点保护物种和食果鸟、啄木鸟类、多数画眉科等特殊鸟类仅在天然林中出现。典型对应分析表明鸟类群落分布与天然乔木盖度、藤本植物盖度密切相关,天然乔木及其附属的林下植被对鸟类栖息地的保护具有重要作用。研究认为即使在非落叶季节邻近天然林的核桃林中,其中的鸟类多样性仍远低于天然林。与天然林相比,核桃林这一人工林的生物多样性保护价值有限。本研究从保护鸟类的角度出发,为云南省核桃林的发展和管理提出了保护建议。     

如何在北京充分实现受胁鸟类栖息地保护?

实现有效生物多样性保护的关键在于提升生物多样性丰富的人口密集区的保护效率。北京人口密集且生物多样性丰富, 存在3类具有生态保护功能的区划——自然保护区、生态保护红线和限制建设线。上述区域可视为生态保护潜力区。本文以在北京有分布的30种受胁鸟类为主要对象, 探讨现有生态保护潜力区对这些物种栖息地的覆盖程度, 并对如何改善上述受胁鸟类栖息地的保护状况进行了建议。根据物种对栖息地的选择, 基于高分辨率卫星解译的土地利用类型图, 利用最大熵模型(MaxEnt)掩膜栖息地分布图, 得到各受胁鸟类的预测空间分布。叠加这些分布获得北京受胁鸟类丰富度分布格局并进行验证。依据物种丰富度高低, 将受胁鸟类栖息地划分为一至四级(最重要的栖息地是一级栖息地, 以此类推)。同时, 依据地表覆盖类型和人类活动强度高低将北京市域划分为城市建成区、乡村生境区和自然生境区。分别计算3类保护潜力区对上述3类区域以及四级栖息地的覆盖面积比例。结果表明: (1) 95.64%的一级关键栖息地和86.32%的二级关键栖息地分布在乡村生境区, 但仅有0.69%和15.15%的乡村生境区分别被自然保护区和生态保护红线覆盖; (2)未受到自然保护区和生态保护红线覆盖的一、二级关键栖息地主要为水域和沼泽地等湿地、高覆盖度草地和部分耕地, 以及含有较高比例水体的大型城市绿地。基于以上结果, 我们建议至少在一定区域内试行如下保护措施: (1)严格保护湿地及其周边的高覆盖度草地, 确保面积不减少; (2)维持基本农田规模和粮食种植模式; (3)将乡村生境区位于河道附近的水域、沼泽地、高覆盖草地和灌木林纳入生态保护红线范围; (4)在公园绿地中划定生物多样性保护区; (5)优化平原地区林地结构。以上措施将使北京的受胁鸟类栖息地得到更好保护, 为中国东部人口密集区生物多样性保护提供示范。     

滇西北地区优先保护的植物群落类型

确定优先保护的地区和群落类型对生物多样性保护尤为重要.为评价滇西北地区优先保护的植物群落类型,针对植物群落在维持栖息地稳定及生物多样性保护方面的功能,依据科学性、层次性及可操作性等原则,构建了由3个层次6个指标构成的评价指标体系.6个与群落相关的指标分别是:物种多样性、珍稀濒危植物物种种数、保护植物级别、群落稀有性、特有植物物种种数和群落特有性.通过对滇西北地区现有资料的收集整理,共选出有样地数据的群落61个,归入13个植被亚型.根据数据的分布特征,利用等级赋值的方法制定了各个指标的评分标准.运用层次分析法与专家咨询法相结合确定权重,采用综合指数法对各群落及植被亚型进行评价,再进行重分类,划分出一级、二级、三级和一般保护类型.利用ArcGIS9.3软件制作不同保护级别的植被亚型的分布图,划分出优先保护的区域.综合评价划分出一级保护群落4类,二级31类,三级23类,一般3类;一级保护植被亚型1类,二级6类,三级6类.这些优先保护类型中,一级保护类型少量,分布在贡山县西南部和泸水县西南部的高黎贡山;二级保护类型较为集中地分布在研究区西北部高海拔地区各大山系及东南部高山地区;三级保护类型主要分布在研究区东南部海拔较低的区域以及独龙江、怒江、澜沧江和金沙江流域的河谷地段.     

上海城市绿地冬季鸟类群落特征与生境的关系

2005年11月至2006年2月对上海市区绿地鸟类进行了调查,共记录到鸟类34种,隶属5目16科。研究发现冬季鸟类群落结构相对稳定,优势种为麻雀(Passer montanus)和白头鹎(Pycnonotus sinensis)。冬季鸟类群落多样性受多种因素的影响,其中绿地面积、乔木盖度和栖息地类型多样性是影响鸟类多样性的关键因子。聚类结果表明,面积大、生境类型丰富及人为干扰相对较少的绿地,鸟类多样性高。因此提出如下建议:(1)增加城市中植物种类,特别是乡土物种,适当提高冬季常绿乔木以及乔、灌、草的比例;(2)在绿地中尽可能多地保留自然生境;(3)在城市绿地中适当开辟湿地生境,以吸引水鸟栖息。     

A green design of city squares increases abundance and diversity of birds

Cities are designed for humans but are also highly dynamic ecosystems that provide habitats for wild animals. These habitats depend on a city's green infrastructure which is increasingly threatened by urban densification. A commonly studied model taxon for wild animals in cities are birds, and the importance of large green spaces for the diversity of birds in cities has been shown. However, how small-scale green spaces affect bird communities, which local characteristics are important, and whether there are seasonal differences remains unclear. We asked how and to what extent the characteristics of city squares in Munich affect the diversity and abundance of birds and if there are differences between bird communities in spring, autumn, and winter. We monitored birds on 103 city squares in Munich using a search-route method. Sampled squares spanned a spatial gradient from the center to the periphery of the city and differed in sealed surface proportion and vegetation structures, such as trees, shrubs, and lawns. The diversity and abundance of birds increased with a higher proportion of green characteristics on the square. Especially the proportion of grass cover and the density of trees had strong positive effects. Old trees had additional effects on birds beyond the effects of trees in general, while the mean number of people on a square negatively influenced bird abundance and diversity. Despite seasonal changes in bird composition, square characteristics showed consistent effects on bird abundance and diversity over seasons. These results underline that the green characteristics of city squares, and therefore of small-scale green spaces, affect their suitability as habitat for wildlife in cities. Integrating this knowledge into city planning can help to maintain or even increase urban biodiversity in the future.     

基于提高鸟类多样性的北京城市线性公园绿地植物景观探析

植被覆盖率高的线性公园,可作为鸟类的迁徙途径和栖息之所,并猜测其可作为生态廊道的一部分,适宜的营造植物景观、提升植物种类的多样性对保护鸟类多样性有促进作用。因此,采用标准取样法对北京城市线性公园绿地进行研究,提取可能影响鸟类多样性的植物群落因素、植物生境因素,对提高鸟类多样性提出建设性的意见。研究结果主要表明,在线性公园绿地宽度30~200m内,随着宽度的增加,鸟类的数量有所提高;含有不同类型植物生境的线性公园绿地,对鸟类目标种的吸引力不同,植物生境类型数较多样的线性公园绿地具有较高的鸟类目标种吸引力;不同的鸟类目标种偏好在不同的树种上进行活动。     

城市公园植被特征对陆生鸟类集团的影响

城市公共绿地是城市生态系统中重要的鸟类栖息地,其植被特征对鸟类集团存在显著影响。在通过分析植被特征对陆生鸟类集团的作用,从而为公园合理配置植被来提高其作为野生动物栖息地的生态服务功能提供理论基础。2009年10月至2011年10月,采用样线法对上海滨江森林公园进行鸟类调查,利用主成分分析划分鸟类集团,用高度定义植被层次,用卡方检验分析鸟类行为在植被层次上的差异。结果表明,滨江森林公园陆生鸟类群落在乔木层的栖息行为和运动行为频次显著多于其在灌木层和地被层的行为频次,在地被层的取食行为频次显著多于其在乔木层和灌木层的行为频次。陆生鸟类可划分为8个鸟类集团,鸟类集团之间存在栖息、运动和取食空间生态位的重叠。食虫拾取集团、杂食拾取集团、食肉飞取集团和植食拾取集团在栖息、运动和取食空间生态位上均存在较高的重叠度,其通过食性分离各自空间生态位。食虫探取集团和食虫飞取集团互为栖息空间生态位重叠度最高集团,其通过取食方式的不同来实现生态位的分离。根据公园植被特征对鸟类集团的影响结果对上海市公园绿地植被配置提出了建议。     

Increase in size and shrub cover improves bird functional diversity in Neotropical urban green spaces

Latin American cityscapes are growing fast, posing risks to many bird communities and ecosystem services (e.g. seed dispersal and arthropod population control), but few studies have addressed how bird functional diversity respond to urbanization in Neotropical cities. In this study, we tested which biotic (i.e. vegetation characteristics and human and pet disturbances) and abiotic variables (i.e. area size, number of vehicles, and glass panes) influence functional diversity indices of insectivores, frugivores-nectarivores, migrants, residents, and total bird community at urban green spaces in São Paulo megacity, southeastern Brazil. A rich avian community (235 species) from 25 studied sites was recorded. Generalized linear models (GLM) analyses showed that large-sized areas of urban green spaces and shrub cover are the main characteristics that drive high bird functional diversity. Small-sized sites were less favourable for preserving bird functional diversity. We showed that these areas were related to some negative impacts for bird species (e.g. absence of shrub layer, heavy traffic and massive presence of glass panes, and domestic animals), thus causing declines in avian functional diversity. Off-leash and homeless dogs and cats may cause declines in bird ecological functions (e.g. insect control, seed dispersal and pollination), which are essential to sustain biodiversity. Therefore, as management actions to improve bird diversity and better provisioning of ecosystem functions, we recommend that urban planners and managers should prioritize large-sized areas with high shrub cover. Additionally, we highlight the need to mitigate the negative impact on birds caused by glass panes, traffic of vehicles, and off-leash and homeless dogs and cats.     

海口和三亚两城市破碎化林地中鸟类群落多样性与嵌套分布格局

城市化是生物多样性快速丧失的主要原因之一。鸟类作为城市生态系统的重要组成部分, 其生物多样性格局和物种保护已成为城市生态学研究的热点。为揭示城市化过程中城区和郊区破碎化林地中鸟类群落的多样性差异和嵌套格局, 本研究于2021年春、夏季鸟类繁殖期采用样线法对海口和三亚市的城区、郊区共13个林地斑块中的鸟类群落进行调查。使用NODF (nestedness metric based on overlap and decreasing fill)和WNODF (weighted nestedness metric based on overlap and decreasing fill)方法进行嵌套格局分析。研究发现: (1)共记录到林鸟100种, 隶属于11目39科, 其中三亚郊区的鸟类丰富度最高, 共8目29科68种。记录到国家重点保护鸟类共18种, 其中两城市郊区的国家重点保护鸟类物种数均多于城区, 海口郊区还记录到国家I级重点保护鸟类黄胸鹀(Emberiza aureola)。(2)鸟类群落多度、物种丰富度、Pielou均匀度指数和Shannon-Wiener多样性指数在不同区域中均存在差异。海口城区的鸟类群落多度显著高于海口郊区(P < 0.05), 三亚郊区的鸟类群落物种丰富度、Pielou均匀度指数和Shannon-Wiener多样性指数均显著高于三亚城区和海口郊区(P < 0.05)。(3)嵌套分析结果表明, 海口和三亚市的城区、郊区林地鸟类群落均呈现反嵌套分布格局。线性回归分析显示, 三亚市城区和郊区的斑块面积与鸟类物种丰富度呈显著正相关, 而物种丰富度与斑块距最近大面积林地的距离之间无显著相关性。研究表明, 两城市鸟类群落多样性都表现出郊区高于城区的特点, 少数优势种(如白头鹎 Pycnonotus sinensis)占据了城市中的主要生态位。受城市化的影响, 海口郊区与城区鸟类群落有同质化的趋势。鸟类在城区和郊区斑块间的高流动性、种间竞争和斑块中资源的可利用性等因素可能导致斑块间鸟类群落的反嵌套分布格局。我们建议应加强城区和郊区鸟类的保护, 减少对林地的破坏, 提高城市鸟类多样性。     

Spatial similarity of urban bird communities: a multiscale approach

Aim Human land use, especially urbanization, might homogenize the world's biota. The objective of this study is to find out if urbanization homogenizes wintering bird communities, and if habitat type affects the spatial variation of urban bird communities across spatial scales. Location We compared the quantitative similarity of winter bird communities between town centres, apartment block areas and single‐family house areas across regional and local scales in five towns in northern Finland. Methods The wintering birds were surveyed using a single‐visit study plot (30 ha) method in January and February 2001. The validity of single‐visit and single‐year data was confirmed by using data from several‐visit surveys and multi‐year data set. The level of urbanization was measured according to the number of inhabitants and general structure of the habitat. Results Temporal variability in species richness and total number of individuals was low, both between winters and within winter. Bird community similarity between different habitat types within a single town was about the same as that in similar habitats in different towns. At the regional scale, bird community similarity between town centres (30%) was lower than between areas of apartment blocks (54%) or between areas of single‐family houses (54%). We detected a threshold point between towns of 35,000 and 105,000 inhabitants and between town sizes of 5.0–8.5 km in diameter where human impact causes marked changes in bird community structure. At the local scale, bird community similarity level between apartment block areas (49%) and single‐family house areas (62%) were about the same. Passer domesticus, Parus major and Pica pica dominated the bird communities in residential areas. Different habitat factors affected bird species abundances on the local and regional scales. Conclusions Urbanization cannot be seen as a process that monotonically increases the similarity of bird communities. Our results indicate that the similarity between urban bird communities is dependent on the size of the town, location of the study site within the town and especially the local habitat structure. Because different habitat factors affected bird species abundances, it is difficult to extrapolate bird–habitat relationships derived from one scale to other scales. In wintertime, single‐family house areas are important biodiversity hotspots in cities. Therefore, it is especially important to understand the factors affecting the occurrence of birds in the single‐family house area in order to maintain or even increase diversity on winter birds in other urban habitats.     

A habitat island approach to conserving birds in urban landscapes: case studies from southern and northern Europe

Wildlife conservation in urban habitats is increasingly important due to current urbanization trends. We review the different approaches to studying birds in urban landscapes, and point out the importance of the habitat island ecological theory as a research framework for the management and conservation of urban birds. Based on two comprehensive research projects conducted at urban parks in Spain (Madrid) and Finland (Oulu and Rovaniemi), several different issues related to bird conservation in cities are discussed, main findings of these projects are presented, and future research needs are suggested. Urban parks are important biodiversity hotspots in cities. Fragmentation conditions have the same deleterious effects to urban birds as in other fragmented landscapes. Park size accounts for species accumulation in urban parks; this pattern being highly nested. Urban parks of 10–35 ha would contain most of the species recorded in cities, but other indicators related to the probabilities of persistence of the target species should be obtained. Wooded streets can increase urban landscape connectivity by providing alternative habitat for feeding and nesting during the breeding season. Because increasing the size of parks is difficult in cities, enhancement of habitat diversity and resource availability for birds within parks (e.g. nest boxes, winter feeding tables, etc.) appears to be a straightforward way of increasing urban bird diversity. However, human disturbance (pedestrians) should be controlled since it can negatively influence many urban birds. We present a conceptual model for urban bird conservation, which includes three aspects (management, environmental education and research) and new alternatives to promote the involvement of different sectors of the society.     

Assessing the impact of revegetation and weed control on urban sensitive bird species

Nature in cities is concentrated in urban green spaces, which are key areas for urban biodiversity and also important areas to connect people with nature. To conserve urban biodiversity within these natural refugia, habitat restoration such as weed control and revegetation is often implemented. These actions are expected to benefit biodiversity, although species known to be affected by urbanization may not be interacting with restoration in the ways we anticipate. In this study, we use a case study to explore how urban restoration activities impact different bird species. Birds were grouped into urban sensitivity categories and species abundance, and richness was then calculated using a hierarchical species community model for individual species responses, with “urban class” used as the hierarchical parameter. We highlight variable responses of birds to revegetation and weed control based on their level of urban sensitivity. Revegetation of open grassy areas delivers significant bird conservation outcomes, but the effects of weed control are neutral or in some cases negative. Specifically, the species most reliant on remnant vegetation in cities seem to remain stable or decline in abundance in areas with weed control, which we suspect is the result of a simplification of the understorey. The literature reports mixed benefits of weed control between taxa and between locations. We recommend, in our case study site, that weed control be implemented in concert with replanting of native vegetation to provide the understory structure preferred by urban sensitive birds. Understanding the impacts of revegetation and weed control on different bird species is important information for practitioners to make restoration decisions about the allocation of funds for conservation action. This new knowledge can be used both for threatened species and invasive species management.     

合肥市小微湿地鸟类多样性的时空格局及其影响因素

小微湿地是城市生态系统的重要组成部分, 也是生物多样性的重要庇护场所。鸟类作为城市小微湿地生态系统的指示类群, 其多样性时空格局受多种环境因子影响。本研究于2020年8月至2021年7月采用样点法对合肥市45个小微湿地鸟类的种类、数量分布和生境因子进行了调查, 并获取湿地面积、湿地形状、建筑面积比例、植被面积比例、环境噪声、人为干扰和城市化指数等生境变量。通过α多样性和β多样性分析, 研究城市小微湿地鸟类多样性的时空特征及其决定因素。采用信息论模型选择和模型平均法以及基于距离矩阵的多重回归模型进行计算, 确定影响鸟类群落α多样性和β多样性及其组分的主要环境因子。结果显示, 研究区域共有鸟类13目39科102种, 其中水鸟31种, 国家二级重点保护鸟类2种, 安徽省重点保护鸟类17种, IUCN濒危物种红色名录中的易危(VU)物种1种。湿地面积和城市化指数对小微湿地陆地鸟类和水鸟的α多样性、β多样性及其组分均具有显著影响, 其中陆地鸟类物种丰富度在中度和低度城市化之间的小微湿地中达到最高值, 面积超过4 ha的小微湿地能维持较多的水鸟物种。植被面积比例对陆地鸟类多样性具有重要的影响, 而建筑面积比例对水鸟多样性具有显著影响。此外, 总体β多样性及其组分计算结果显示物种周转组分占明显优势, 表明城市小微湿地群作为城市复合生态系统的重要组成部分, 加强整体保护更为必要。研究结果对于加强城市鸟类保护和提高城市生态环境质量具有指导意义。     

Assessing the role of invasive weeds in the impact of successional habitats on the bird assemblage in overgrowing agriculture

Agricultural habitats are assumed to be biodiversity refuges. However, some studies treat agricultural land management as a cause of the biodiversity decline, to which habitat loss and heterogeneity may contribute. Between the crops, the successional habitats appear – ruderal plant communities and bush areas. Their influence on farmland biodiversity is unknown. This research assessed the impact of spatial relationships between agricultural areas, semi-natural meadows and successional habitats on the bird species richness, Shannon diversity index, and Faith’s phylogenetic diversity index. An additional habitat variable was the presence of weeds, i.e., invasive Caucasian hogweeds Heracleum sp., treated as crops in the past. The birds and habitats research was on 74 sites set in pairs (invaded vs control) in south-eastern Poland. Results showed that birds assembling in agricultural and semi-natural areas were more diverse and contained protected farmland species, while birds appearing in overgrown habitats (i.e., successional and invaded) were clumped with their habitat requirements. In the presence of plant invaders, ruderal habitats negatively affected the bird phylogenetic diversity index. In invaded sites, bush areas had no positive effects on the Shannon diversity index and species richness of birds, in contrast with control sites. The presented research suggests the need to re-evaluate the importance of successional non-crop habitats considered positive in agricultural landscapes if those habitats develop in areas with plant invasion.