Avian spatial segregation at edges and interiors of urban parks in Madrid, Spain

Few studies have investigated the effects of urban landscape composition on avian habitat selection at urban-park edges. I assessed how the number of species, density of guilds, and density of individual species varied between edge and interior habitats in six large wooded parks in Madrid (Spain), and analysed such patterns in relation to habitat structure, car traffic, and pedestrian traffic. Few differences in habitat structure were found; whereas car and pedestrian traffic were significantly higher at edges. Species foraging in trees and on the ground, and nesting in trees and in tree cavities had lower numbers and breeding densities at edges, probably as a result of the disturbance from traffic noise and pedestrians. Species highly habituated to human activities (House Sparrows Passer domesticus and Rock Doves Columba livia) displayed opposite patterns, with higher breeding densities at urban-park edges, probably due to their higher foraging opportunities (refuse, people leftovers, deliberate feeding) and nest site availability in adjacent buildings. Urbanisation sprawl may increase the prevalence of edge specialists and diminish the representation of species with specific habitat requirements.     

Spatial patterns in insect community composition in coldwater springs

The insects living in 27 coldwater springs in southern Ontario, Canada were analyzed using several permutation and ordination methods, in order to detect patterns in the composition of their communities. These patterns were compared against simulations using artificial landscapes. A Moving Window Mantel Correlogram indicated the presence of both a strong local spatial aggregation and a global trend toward higher dissimilarity of sites with increasing geographical distance, especially beyond 50 km. Ordination plots showed a clear global gradient from a southern group of springs to a northern group (likely related to temperature and pH), which dominated the global, total, and local plots in both a SCA (Spatial CA) and a SPCA (Spatial PCA) analysis. However, the results of the local analysis differed markedly between the two methods: while the local plot for the SCA analysis indicated considerable variation among sites belonging to the same spatial group (thought to be related to discharge and random colonization episodes) and showed a pattern that was different from both the global and total analysis plots, the local SPCA plot showed little within-group variation and resembled the global and total plots.     

Forest patch size and isolation as drivers of bird species richness in Maputaland,Mozambique

Aim To examine the response of forest‐dependent and generalist bird assemblages and feeding guilds to patch characteristics of forest fragments in the context of island biogeography and metapopulation theories in an area that supports high levels of species diversity and endemism. Location Dune, riverine, sand and swamp forest fragments in southern Mozambique’s Maputaland. Methods We recorded 20 forest‐dependent and 69 generalist bird species at 220 survey points in 30 forest fragments that ranged in size from 5 to 7432 ha and that were 100 to 5100 m apart. We used linear regressions to relate the number of species to forest fragment size, isolation, perimeter, fractal dimension, shape and core area for frugivores, insectivores, granivores, nectarivores, carnivores and omnivores separately for forest‐dependent and generalist bird assemblages. We tested for modality in occupancy frequency distributions of species in forest fragments and used the binary matrix temperature calculator to determine whether the assemblages had a nested structure separately for forest‐dependent and generalist bird species. Results The number of forest‐dependent and generalist bird species categorized into the feeding guilds varied independently from forest patch parameter values. Occupancy models showed a random distribution for forest‐dependent birds, and generalists had a unimodal distribution. Both the forest‐dependent and generalist bird assemblages had a non‐nested structure. The presence of eight rare forest‐dependent and four endemic bird species in 22 of the 30 fragments contributed to the non‐nested structure of these bird assemblages. Main conclusions Fragmented forests did not induce the expected responses of the forest bird assemblages in that the number of species was not explained by patch characteristics, nor could we find evidence for metapopulation dynamics. Non‐nestedness may be caused by the few rare and endemic species occupying forest fragments with a wide range of patch characteristics. Knowledge of the response of species to forest fragmentation can benefit conservation planning catering for rare and endemic species. Our study suggests that all forest fragments in the region may have to be included in a conservation network to complement existing landscape‐based plans to protect the region.     

Carabid beetle community composition, body size, and fluctuating asymmetry along an urban-rural gradient

Within the goal of defining indicators (species or combinations of life history traits) for habitat quality in an urban environment we investigated effects of urbanization on the community composition and morphological characteristics of carabid beetles. Between May and July 2000 nine woodlots were sampled along three axes representing urban - rural gradients from the centre of the city of Hamburg to its rural borders. Species richness decreased towards the city centre and with increasing isolation of the sites but was uncorrelated with the size of the site. Species assemblages were highly nested making successive loss of species predictable. Responsivness towards urbanization could not be linked to specific life history traits. Body length of one species (Carabus nemoralis) declined towards the city centre. Four species were found at all sites. These four species showed differences in fluctuating asymmetry (FA) at the different sites that could not be interpreted as an indication of responses to habitat suitability. FA of the remaining species (species negatively affected by urbanization) increased towards the city centre and with increasing isolation of a site. This matched the prediction that FA indicates habitat quality. Thus, urban effects lead to changes of communities through a predictable loss of species, to a reduction in body size in one species, and to increased FA in species which are susceptible to urbanization. The results indicate that the different sites were islands in an urban matrix rather than parts of a green network which would allow free exchange of plants and animals within the city of Hamburg.Wir untersuchten den Einfluss von Verstädterung auf Laufkäfergemeinschaften in Hamburg, Deutschland. Zwischen Mai und Juli 2000 wurden neun Fangorte entlang städtischer Gradienten beprobt. die von relativ ländlichen Gebieten an den Stadtgrenzen, bis hin zu Flächen im Stadtzentrum reichten. Die Artenzahl korrelierte negativ mit dem Grad der Isolierung und der Entfernung des Gebietes von der Peripherie, aber nicht mit der Größe eines Gebietes. Die gefundenen Artengemeinschaften wiesen strenge Schachtelung auf. Der Verlust bestimmter Arten war daher vorhersagbar, konnte aber nicht auf bestimmte Charakteristika (“life history traits”) der Arten zurückgeführt werden. Die Körperlänge von Carabus nemoralis nahm entlang des Gradienten ab. Nur vier Arten kamen im gesamten Stadtgebiet vor. Fluktuierende Asymmetrien (FA) dieser Arten konnten nicht sinnvoll mit Habitatqualitäten oder Verstädterung in Beziehung gesetzt werden. Die anderen Arten, die nach den Ergebnissen der Analysen zu geschachtelten Strukturen durch “Verstädterung” negativ beeinflusst waren (d.h. nicht an allen Orten und vor allem nicht im Stadtzentrum gefunden worden waren) zeigten zunehmende FA zum Stadtzentrum. Verstädterung führte demnach zu vorhersagbaren Verlust an Arten, zu Reduktion der Körperlänge einer Art und zu erhöhten Asymmetrien bei Arten, die durch Verstädterung negativ beeinflusst wurden. Nach diesen Befunden kann das Ziel der offiziellen Politik, in Hamburg negative Effekte der Stadtentwicklung auf die Biodiversität durch einen Verbund von Grünflächen und geschützten Gebieten zu reduzieren, mit den heute noch verfügbaren Flächen nicht erreicht werden.     

北京城区花粉致敏植物种类、分布及物候特征

为了解北京城区花粉致敏植物的种类、分布格局和物候特征,结合文献调研及专家访问,对北京5环以内的花粉致敏植物进行了调查.结果表明:1)北京城区五环内共有致敏花粉植物19科32属99种,其中北京本地种52种,占总数的52.5%,国内其他地区引进种和国外引进种各占总数的26.3%和21.2%;2)北京城区32属花粉致敏植物以北温带成分为主,占40.6%,其次是世界性分布与泛热带分布;3)公园内的花粉致敏植物种数最多,行道树种中花粉致敏植物的比例最高.北京城区各功能区中花粉强致敏草本的盖度,从大到小的顺序是城市废弃地>体育中心及机关单位>道路绿地>公园>居民区>学校>广场;4)北京城区木本花粉致敏植物的花期主要集中在3—4月,草本在7—9月.     

城市热岛效应与景观格局的关联:从城市规模、景观组分到空间构型

景观格局的改变被视为城市热岛形成的直接原因,但景观格局指标与热岛效应的关联机理仍未厘清。城市规模、景观组分、空间构型作为景观格局的重要表征指标,对热岛效应的影响体现了从整体到局部、从数量到空间的递进关系。其中,城市规模与热岛效应的关联存在地带性规律;景观组分与热岛效应的相关性受昼夜、季节控制;显著驱动热岛效应的关键空间构型指标仍有待遴选。景观格局与热岛效应的非线性关联可能存在拐点,拐点前后对应不一致的因子驱动强度。科学界定城市规模、景观组分、空间构型等景观格局要素显著影响热岛效应的阈值区间,有助于明晰缓解城市热岛效应的关键景观生态途径。     

贵州花溪大学城破碎化林地鸟类多样性与嵌套分布格局

为揭示城镇化进程中生境破碎化对鸟类多样性及分布格局的影响, 本研究于2017-2019年每年的4-8月使用样线法对贵州花溪大学城26块破碎化林地(面积介于0.3-290.4 ha)中的鸟类群落进行了10次调查。共记录到鸟类78种, 隶属于11目37科。其中, 东洋界物种数占56.4%, 古北界物种数占32.1%, 广布种占11.5%; 有中国特有种1种。剔除高空飞行、非森林鸟类及偶然出现物种后, 不同斑块中的鸟类物种数介于12-55之间, 平均每个斑块有23.2 ± 10.5种。线性回归分析显示, 鸟类物种丰富度与林地斑块的面积有显著相关性, 斑块面积越小, 鸟类物种丰富度越低; 斑块隔离度对物种丰富度没有显著影响。基于物种多度分布矩阵的WNODF (weighted nestedness metric based on overlap and decreasing fill)嵌套分析显示, 不同斑块中鸟类群落呈现出反嵌套结构。小斑块中鸟类物种丰富度较低可能与植物丰富度较低、食物资源稀缺和繁育条件不足有关, 但短距离的隔离对鸟类迁入或扩散影响有限。环境过滤效应、种间竞争或优先效应可能导致不同斑块间存在较大的物种组成差异, 从而导致反嵌套格局。因此, 本研究建议在城市规划建设中应注重维持栖息地的完整性, 对不同面积大小的破碎化斑块都应加以保护。     

Functional diversity of urban bird communities: effects of landscape composition,green space area and vegetation cover

In this study, we aim to gain a better insight on how habitat filtering due to urbanization shapes bird communities of Vienna city parks. This may help to derive implications for urban planning in order to promote and maintain high diversity and ecosystem function in an increasing urbanized environment. The structure of wintering bird communities of 36 Vienna city parks – surveyed once a month in January 2009, December 2009, December 2012, and January 2013 – was described by species richness and the functional diversity measurements FRic (functional richness), FEve (functional evenness), and FDiv (functional divergence). Environmental filtering was quantified by park size, canopy heterogeneity within the park, and the proportion of sealed area surrounding each park. Species richness, FRic, and FDiv increased with increasing park size. Sealed area had a strong negative effect on species richness and FDiv. Canopy heterogeneity played a minor role in explaining variance in FDiv data. FEve did not respond to any of these park parameters. Our results suggest a loss of species richness and functional diversity, hence most likely indicate a decline in ecosystem function, with decreasing park size and increasing sealed area of the surrounding urban landscape matrix.     

烟草内生真菌多样性和种群结构

从云南“世界烟草品种园”10种烟草的根、茎、叶中分离得到199株内生真菌,根据rDNA-ITS系统发育分析鉴定为17属25种,其中格孢腔菌目Pleosporales内生真菌的种类和数量最多;茎点霉属Phoma、链格孢属Alternaria和镰孢菌属Fusarium为主要优势属,相对频率分别为25.1%、24.6%和11.6%,优势度Y值分别为0.251、0.172和0.104。烟草不同组织内生真菌的种群结构存在显著差异,分离自根的内生真菌的主要优势属为Fusarium和Phoma,Y值分别为0.235和0.123;分离自茎的内生真菌的主要优势属为Phoma和Alternaria,Y值分别为0.186和0.155;分离自叶片的内生真菌的主要优势属为Alternaria,Y值为0.286。Phoma从烟草根茎叶中均可分离得到,而Alternaria只分布在地上部茎叶中,Fusarium只分布在根茎中,表明这3个优势属真菌对根茎叶组织的专化性不同。     

Effects of habitat size and isolation on species immigration–extinction dynamics and community nestedness in a desert river system

相似文献   

Bird community patterns in response to the island features of urban woodlots in eastern China

Many studies have demonstrated the changes in the spatial patterns of plant and animal communities with respect to habitat fragmentation.Insular communities tend to exhibit some special patterns in connection with the characteristics of island habitats.In this paper,the relationships between richness,assemblage,and abundance of bird communities with respect to island features were analyzed in 20 urban woodlots in Hangzhou,China.Field investigations of bird communities,using the line transect method,were conducted from January to December,1997.Each woodlot was surveyed 16 times during the year.Results indicated that bird richness was higher,per unit area,in the smaller woodlots than the larger ones,and overall bird density decreased with the increase in the size of woodlot.However,the evenness of species abundance increased with the area,and small woodlots were usually dominated by higher density species and large woodlots by medium density species.Most species occurring in the small woodlots also occurred in larger woodlots.Also,bird communities among urban woodlots showed a nestedness pattern in assemblage.These patterns implied that the main impacts of woodland habitat fragmentation are:(1) species are constricted and thus species number will increase at a given sample size;(2) as surface area decreases,the proportion of forest edge species as to interior species will increase;(3)community abundance will therefore increase per unit area but most individuals will be from a few dominant species;and (4) overall species diversity will decrease at a habitat level as well as at a region level.These patterns of community in response to the island features were therefore summarized as "island effects in community".The underlying processes of such observations were also examined in this paper.Woodlot area,edge ratio,isolation,and habitat nestedness were considered as the important factors forming the island effects in community.High heterogeneity between habitats usually contributed most to the maintenance of regional biodiversity,especially in urban woodlots.     

园林鸟类群落的岛屿性格局

岛屿群落由于受岛屿栖息地特征结构的影响而产生一系列特殊的格局。通过对杭州市园林鸟类群落的研究,分析了园林鸟类群落的物种数、组成和多度与园林岛屿性状的关系,从而确定了园林鸟类群落存在如下与园林的岛屿性状有关的格局:(1)在物种数方面,在相同的取样面积下,园林的物种数随园林面积的增大而减少;(2 )在群落组成上,园林鸟类群落呈现出不完全的嵌套格局,分布于物种数较少的园林中的物种多数也分布在物种数较多的园林中;(3)在物种多度方面,园林鸟类的总密度随面积的增大而减少,园林鸟类多度的均匀度随着面积的增大而提高。群落的岛屿性格局反映了栖息地的岛屿化对群落的影响,总称之为群落的岛屿效应。通过比较全年、繁殖季节、越冬季节和迁徙季节群落岛屿性格局的显著性,分析群落的稳定性与群落岛屿效应之间的关系,认为两者之间没有必然的联系,相对非稳定的群落也可导致显著岛屿效应     

城市公园生境类型对鸟类群落的影响

2011年12月—2012年11月,在上海世纪公园和滨江森林公园对鸟类群落和植物群落进行调查,通过对12个植被变量进行主成分分析,将两个公园分为8种不同的生境类型。结果表明:2个公园生境构成存在显著差异,滨江森林公园灌木层植物发达的生境(Habitat with developed shrub layer,S型)以及灌木层和地被层植物都发达的生境(Habitat with developed tree layer and shrub layer,T+S型)数量显著多于世纪公园,世纪公园地被层发达的生境(Habitat with developed ground cover layer,G型)以及乔木层和地被层植物都发达的生境(Habitat with developed tree layer and ground cover layer,T+G型)数量显著多于滨江森林公园。世纪公园不同生境中鸟种数差异显著,而滨江森林公园中差异不显著。2个公园有24种共有鸟种,对共有鸟种生境利用率的配对t检验结果表明,滨江森林公园鸟类生境利用率显著高于世纪公园。对2个公园共有生境类型中鸟种数进行分析,发现滨江森林公园鹟科(Muscicapidae)鸟类种数显著大于世纪公园。根据以上结果,上海城市公园不同生境类型对鸟类群落结构存在显著影响。因此,建议在规划和建设大型城市公园时,应构建植被分层结构复杂的生境,多样化种植各类乔木,林下多样化搭配灌木。在保留供游客休憩草坪区域的同时种植各类草本植物,以此提高鸟类生境利用率,增加城市公园的鸟类多样性。     

北京城市公园常见乔木土壤真菌群落特征及影响因素

快速城市化引起的城市环境污染问题日趋严重,由城市中心到城郊往往呈规律性递变趋势。北京城市公园作为城市绿地主体,不仅是城市居民重要的休闲游憩场所,也能在一定程度上反应环境污染,如土壤重金属污染的作用规律。以北京市这一典型大城市为研究区域,根据不同城市公园的建成时间、所处位置和距离市中心的远近选择六个公园作为研究样点,选取公园常见6种乔木下土壤,通过对土壤重金属含量、土壤理化性质以及土壤真菌群落测定和测序,旨在探讨城市公园植被下土壤真菌群落特征（多样性和群落结构组成）以及影响因素。研究结果表明：北京城市公园乔木下的土壤真菌群落多样性、群落组成以及优势类群受到土壤pH值、土壤养分和水分以及重金属铅的调控。其中公园土壤重金属铅含量增加会降低土壤真菌多样性、显著影响优势类群子囊真菌（占真菌群落73%）以及土壤真菌功能类群病原真菌群落组成。研究揭示了北京城市公园土壤真菌群落特征及调控因素,特别是重金属铅对土壤真菌群落的影响,这对提高城市公园科学管理和环境健康具有积极的应用价值。     

Bird community patterns in response to the island features of urban woodlots in eastern China

Many studies have demonstrated the changes in the spatial patterns of plant and animal communities with respect to habitat fragmentation. Insular communities tend to exhibit some special patterns in connection with the characteristics of island habitats. In this paper, the relationships between richness, assemblage, and abundance of bird communities with respect to island features were analyzed in 20 urban woodlots in Hangzhou, China. Field investigations of bird communities, using the line transect method, were conducted from January to December, 1997. Each woodlot was surveyed 16 times during the year. Results indicated that bird richness was higher, per unit area, in the smaller woodlots than the larger ones, and overall bird density decreased with the increase in the size of woodlot. However, the evenness of species abundance increased with the area, and small woodlots were usually dominated by higher density species and large woodlots by medium density species. Most species occurring in the small woodlots also occurred in larger woodlots. Also, bird communities among urban woodlots showed a nestedness pattern in assemblage. These patterns implied that the main impacts of woodland habitat fragmentation are: (1) species are constricted and thus species number will increase at a given sample size; (2) as surface area decreases, the proportion of forest edge species as to interior species will increase; (3) community abundance will therefore increase per unit area but most individuals will be from a few dominant species; and (4) overall species diversity will decrease at a habitat level as well as at a region level. These patterns of community in response to the island features were therefore summarized as “island effects in community”. The underlying processes of such observations were also examined in this paper. Woodlot area, edge ratio, isolation, and habitat nestedness were considered as the important factors forming the island effects in community. High heterogeneity between habitats usually contributed most to the maintenance of regional biodiversity, especially in urban woodlots. __________ Translated from Acta Ecologica Sinica, 2005, 25(4): 657–663 [译自: 生态学报, 2005, 25(4): 657–663]     

城市花粉致敏植物种类构成、分布与潜在危害评估——以深圳市为例

气传致敏花粉会引发过敏症,且可通过每年在花粉季的反复接触逐渐加重,危害人体健康,严重时甚至危害生命。花粉致敏植物在城市中被广泛引种栽培,导致城市花粉症患者数量激增。以深圳市为案例,基于建成区600个样地的实地调查数据,分析花粉致敏植物的种类构成与时空分布,通过构建花粉浓度及花粉致敏危害潜力计算公式,评估花粉致敏危害潜力及其分布特点。结果显示：①调查记录到深圳市建成区花粉致敏植物46科92属186种,其中外来种占43.37%,其中美洲、亚洲和大洋洲来源占国外外来种的81.00%。花粉致敏植物种数以公园绿地最多,达126种。植物花粉致敏等级以Ⅰ级为主,达154种。②花粉致敏植物的盛花期为春夏季,占全年累计开花种数的65.02%。最高峰出现在8月,开花种数达92种。 ③花粉浓度潜力最高值也出现在8月,占全年总值的12.13%。豆科和禾本科植物贡献比例较大,分别占乔木和草本总值的40.86%和64.13%。龙岗区花粉浓度潜力占比较高,占各季花粉量的26.06%-29.42%。④冬春两季各样地花粉致敏危害等级均不高,但夏秋季有些样地达到二级重度危害。罗湖区调查样地全年花粉致敏危害等级均较低,光明区在春夏秋季致敏危害等级皆较高。高危害等级样地主要出现在附属绿地及公园绿地。⑤花粉致敏植物防控措施情景模拟结果,去除主要花粉致敏植物种类比降低所有花粉致敏植物的花粉浓度潜力更有效。本研究为城市花粉致敏植物的管理、规划、养护和研究提供参考。     

长江河口浮游动物的种类组成、群落结构及多样性

于1999年枯水期(2—3月份)、丰水期(8月份)、2000年枯水期(2—3月份)对长江河口浮游动物采样调查,研究了长江河口浮游动物的种类组成、群落结构及多样性并初步探讨了三峡工程对长江河口浮游动物的影响及长江河口水环境的生物监测。调查共发现浮游动物87种,甲壳动物占绝对优势,共59种。在所有浮游动物中挠足类31种。其次为水母类,有9种,此外,枝角类、毛颚类各8种。3次采样浮游动物的优势种主要有河口半咸水种和近岸低盐种类如华哲水蚤(Sinocalanus sinensis)、火腿许水蚤(Schmackeria poplesia)、虫肢歪水蚤(Tortanus vermiculus),真刺唇角水蚤(Labidocera euchaeta)等,还有长江径流带到河口的淡水种如近领剑水蚤（Cyclops vicinus vicinus)、英勇剑水蚤（Cyclops strenuus）、透明溞（Daphnia hyalina)等。一些浮游动物可作为水系指示种,其分布、数量反映了不同水系分布变化,长江河口浮游动物有;类水系指示种。通过对长江河口浮游动物群落聚类分析发现。1999、2000年枯水期浮游动物群落结构相似。可分为河口类群、近岸类群和近外海类群。1999年丰水期只形成近岸和近外海类群。浮游动物种类数由口门内向口门外方向有逐渐增加的趋势。浮游动物种类数由北向南变化趋势一致。大潮与小潮、涨憩与落强等潮汐作用对浮游动物影响往往因采样时间与区域等的不同而不同。对长江河口3次采样的物种多样性指数和均匀度指数进行了计算,结果表明：浮游动物多样性指数1999年枯水期最低,1999年丰水期最高。     

Floral resources,body size,and surrounding landscape influence bee community assemblages in oak‐savannah fragments

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