Can urban forests provide acoustic refuges for birds?Investigating the influence of vegetation structure and anthropogenic noise on bird sound diversity

As a crucial component of terrestrial ecosystems,urban forests play a pivotal role in protecting urban biodiversity by providing suitable habitats for acoustic spaces.Previous studies note that vegetation structure is a key factor influencing bird sounds in urban forests;hence,adjusting the frequency composition may be a strategy for birds to avoid anthropogenic noise to mask their songs.However,it is unknown whether the response mechanisms of bird vocalizations to vegetation structure remain consistent despite being impacted by anthropogenic noise.It was hypothesized that anthropogenic noise in urban forests occupies the low-frequency space of bird songs,leading to a possible reshaping of the acoustic niches of forests,and the vegetation structure of urban forests is the critical factor that shapes the acoustic space for bird vocalization.Passive acoustic monitoring in various urban forests was used to monitor natural and anthropogenic noises,and sounds were classified into three acoustic scenes(bird sounds,human sounds,and bird-human sounds)to determine interconnections between bird sounds,anthropogenic noise,and vegetation structure.Anthropogenic noise altered the acoustic niche of urban forests by intruding into the low-frequency space used by birds,and vegetation structures related to volume(trunk volume and branch volume)and density(number of branches and leaf area index)significantly impact the diversity of bird sounds.Our findings indicate that the response to low and high frequency signals to vegetation structure is distinct.By clarifying this relationship,our results contribute to understanding of how vegetation structure influences bird sounds in urban forests impacted by anthropogenic noise.

Effects of vegetation strata and human disturbance on bird diversity in green areas in a city in southern Chile

Background: Urbanisation is a dominant geographical trend and an important component of global change, with unprecedented implications for socio?economic, cultural and environmental characteristics. However, green areas, including original fragments, can help to conserve native diversity, improving the functioning of these artificial systems in the long term. Urban areas can still provide habitats usable by wild birds, however the structural charac?teristics of the habitat formed by different types of green area differ, and therefore dissimilar bird diversities are to be expected. The object of this study was to characterise the α and β diversities of birds in different green areas and to analyse how diversity relates to ten variables that characterise the habitat.Methods: We studied the green areas in the city of Temuco, southern Chile(Park, Square and Median strips of main streets), evaluating the variables:(a) surface area,(b) vegetation,(c) estimated human impact as the proportions of vegetation and bare soil by area, and the vehicle traffic. The bird assemblage structures were characterised by α(intra?environment) diversity and β diversity(between environments) and the statistical analysis identified the environmen?tal variables related with the presence and abundance of birds. A statistical model was constructed to describe the contribution of the variables to bird diversity.Results: We found significant differences between the diversity of bird species in the three types of green area. The β showed medium to high similarity between the different study units. There was a negative correlation with bare soil areas; the correlations with vehicle flow, plant structure and tree and shrub cover were not significant, meaning that these variables did not explain the variation in the richness of bird species between the green areas. However the surface area did explain this variation presenting a positive potential relation. There was also a high correlation with the origin(native) of shrub species.Conclusions: The bird diversity varied significantly according to the type of urban green area. The environmental variables presenting significant correlations with bird diversity were: surface area, native species of shrub stratum, shrub cover, and bare soil area. The best multiple regression model showed that the three most important variables for bird diversity are the surface area of the green area, the cover of the shrub stratum and the presence of native shrub species.

Relationship between Vegetation Height and Species Richness of Birds in Some Wetlands of Sinnar State, Sudan

Objectives of this study were to: identify the relationship between vegetationhigheit and birds’ species at various wetlands of Sinnar State;This study was conducted in Sinnar state, central Sudan (Latitudes 05º -12º to 05º -14º N and longitudes 32.9º - 35.4º E), covering 12 wetlands(mayas) during the wet and the dry season duration 2011 - 2013;thewetlands are Ronga, Allahmaana, Gladeem, Elban, Rahad Kobri 45,Lawni, Kinnaf Tura 5, Rigaba, Shamiya, Wad elggack, Homrani andSinnar Dam reservoir. The study focused on abundance of herbaceousvegetation, Parameters of herbaceous vegetation were determined at50-m intervals along line transects;these parameters were plant countsand vegetation height in a 1-m circular quadrat. Birds were countedtwice a day (morning and evening) in all wetlands with the help of telescopesand binoculars, and species utilizing each site of the wetlandsare identified. Excel programme was used for data analysis. Vegetationheight is negatively correlated with birds’ species richness in wet seasonsof 2011 - 2012 and 2012 - 2013, positively correlated in the dryseason when herbaceous vegetation is tall, but negatively correlatedwhen it is short.

On Identity Reconstruction of Black Woman in I Know Why the Caged Bird Sings

Maya Angelou(1928-2014)is a celebrated African American woman writer.She's not only an autobiographer,a poet,an educator,but also a politician,an actress and a director.Her first autobiographical novel I Know Why the Caged Bird Sings is a significant milestone of the African American literature of woman.The novel depicts Marguerite life experience from the age of 3 to the age of17,recording how she breaks through the bondage of racial discrimination and sex prejudice,and realizes self-consciousness.From the perspective of post-colonist criticism and feminism,this thesis analyses how the protagonist suffered from the"othering"under the colonial discourse and patriarchal ideology and how she got out of the bondage and reconstruct her identity.Finally,it is concluded that only if the black women break through the cage of race and gender,accept and reconstruct their identities,can they gain the real emancipation and respect.

Relationships between bird communities and vegetation structure in Honghuaerji, northern Inner Mongolia

The survey on bird communities was conducted by the belt-style method in six different sample plots in the Honghua抏rji Forests area in the northern Inner Mongolia in June 2001 and totally 28 bird species were recorded. Vegetation investigation was carried out in five 10 m×10 m quadrats at each plot. The asymptotic regression function formulae were adopted to identify the relationships between the vegetation coverage and the numbers of bird species and individuals. The analytical results showed that the changes of species number and density of bird as well as the formation of bird communities follow the changes of forest type and the total foliage. Both the number of bird species and their density decreased with the de-crease of total foliage. The similarity of bird community was very low at the breeding time. In the same classification of cluster, no similarity was higher than 0.65, which indicated that the composition of species had a great difference between all the bird communities. The bird breeding density was closely related to forest growth stage. From the bare grassland ecosystem to cli-max ecosystem, the density of bird species showed a gradually increasing trend.

Identification of habitat requirements of farmland birds based on a hierarchical structured monitoring scheme

Agricultural landscapes are essential for the conservation of biodiversity. Nevertheless, a negative trend continues to be observed in many rural areas for the most prominent indicator species group, the farmland birds. However, clear cause-effect relationships are rarely reported and sometimes difficult to deduce, especially from monitoring data which are based only on the detection of species and counts of the numbers of individuals. Because the identification of habitat preferences is a precondition for farmland bird biodiversity conservation efforts, a monitoring scheme for the simultaneous collection and analysis of bird and land use data was developed and tested. In order to assign the occurrence of bird species to land characteristics at various spatial scales and different land use and crop types, we applied a hierarchical structured sampling design. The spatial scales were ‘agricultural landscape', ‘agricultural landscape types', ‘field crops and other habitats' and ‘vegetation structures'. These scales were integrated with a novel concept, the ‘habitat matrix'(HM). This method was applied to farmland breeding bird abundances on 29 plots, each 1 km2 in size, by the use of the territory mapping method. The same plots were enlarged by a 100 m buffer and the sizes and location of habitats documented. Vegetation height, coverage and density were also recorded for all crop fields in the study area. We propose that this monitoring method facilitates the identification of scale dependent relationships between farmland bird habitat characteristics and bird abundance. This is demonstrated by the farmland bird species Corn Bunting(Emberiza calandra), Skylark(Alauda arvensis), and Whinchat(Saxicola rubetra). The breeding territories of these species reveal large differences within the various spatial scales ‘agricultural landscape', ‘agricultural landscape types' and ‘field crops'. Throughout the breeding season the abundances varied, dependent on the field crop and the development of vegetation structures(height, coverage, and density). HM-analysis led to the identification of specific habitat configurations preferred by individual bird species within the agricultural landscape. These findings indicate that the methodology has the potential to design monitoring schemes for the identification of cause-and-effects of landscape configuration, land use and land use changes on the habitat suitability and abundance of farmland birds.

Floristic, Structural, and Conservation Analysis of the Habitats Occupied by Dupont’s Lark, Chersophilus duponti, in the Northwest Edge of Its Distributional Range

This paper describes and analyzes floristic, structural and conservation features of the shrubland occupied by Chersophilus duponti in the northwest corner of its world distribution range. This study relates the coverage, floristic composition with estimated lark density in the area. We identified four types of shrublands, three of them varied significantly in floristic composition for the habitats of this species in contrast with those of their world distribution: Cistus ladanifer scrubs;heaths dominated by Ericaceae, and scrubs dominated by the genera Lavandula, Thymus and Cytisus. The fourth type, dominated by aromatic chamaephytes and grass, fits descriptions of the bird’s typical habitat. The areas sampled are subject to different categories of threats, the most significant being the natural succession process due to the cessation of grazing, reforestation measures and the use of flat areas for farmlands or other uses. The density of larks in this area was directly related to coverage-composition of plant community.

<i>Acinetobacter baumannii</i>in Birds’ Feces: A Public Health Threat to Vegetables and Irrigation Farmers

The rising trend of resistance in Acintobacter baumannii had in recent days become a public health care concern with most literature reported from samples collected from hospital environment. This research therefore, wishes to determine the occurrence of multidrug-resistant A. baumannii in birds’ droppings, associated with irrigated farms vegetables, for epidemiological update and future clinical forecast. Forty eight birds fecal samples were collected and processed for isolation and identification of A. baumannii on MacConkey agar and Microbact 24E (Oxoid), and tested against 10 commonly used antibiotics (quinolones, fluoroquinolones, aminoglycosides, sulfonamides). A. baumannii was isolated from 31.25% of samples and had shown more resistant to ceporex (100.00%) and to streptomycin with 80.00% and 90.00% for Jakara and Sharada farms’ fecal samples respectively;isolates were however sensitive to co-trimoxazole. Forty eight (46.67%) of the isolates were resistant to at least 6 drugs, with strong correlation between some drugs. By this result, wild birds’ fecal materials demonstrate high potential of A. baumannii carrying capacity and dissemination, and thus pose risk of contaminating vegetables, infecting human and transmitting resistance phenotype to other non-multidrug-resistant bacteria—a situation quite challenging to health care management and public health. And thus it further suggests for screening of additional probable contributing factors, so as to develop possible detailed transmission pathway and control strategies.

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。

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。

机场植被管理与鸟击灾害防范的研究

鸟击灾害是航空"A"类灾难,机场鸟击灾害的根源在于机场生境对鸟类的吸引,减少机场生境中吸引鸟类的生态因子是解决机场鸟击威胁的根本方法。本文通过对南充高坪机场植被和鸟类进行调查,统计分析两者之间的关系,以寻找最适宜的机场植被管理措施。结果显示:植被为鸟类提供食物和栖息场所,植食性鸟类数量与植被的种类和季节变动规律基本吻合,同时植物的繁茂滋生大量昆虫,使肉食性鸟类数量增多。对飞行区植被进行处理,设法控制机场内鸟类的食物来源,对于减少飞行区鸟类的数量非常重要。建议采取的措施有碾压、割草和农药喷洒、挖除高草丛、使用除草剂、草坪植物种类的调控。

奔牛机场植被现状调查及鸟类适宜指数评估

对常州奔牛机场内部及周边地区的植被进行了详细调查,在此基础上从植物对鸟类活动的贡献的大小出发,就植物在群落中的地位、高度、生活型及提供鸟类食物能力4个方面对机场内分布植物的鸟类适宜指数进行评估.结果显示机场内鸟类适宜指数最高的植物共有7种,它们对鸟类有着强烈的吸引作用,应清除机场内的这些植物;另有19种植物适宜指数较高,应在机场内严格控制其高度和种群大小.

南大港湿地保护研究

笔者根据对南大港湿地的考察和调研 ,阐述南大港湿地的变迁和现状植被及鸟类资源状况 ,提出了保护南大港湿地的措施。

北京绿化隔离地区鸟类群落与环境因子关系研究

于2003年7月至2005年7月采用样线或样方法对北京市绿化隔离地区3种绿地体系中21个样地内鸟类群落、节肢动物种类多样性与绿地植被组成进行了调查,共记录到鸟类131种、节肢动物278种、植物269种.通过对不同绿地体系内鸟类群落与节肢动物种类多样性、植被结构关系的分析,探讨了城市绿地植被与节肢动物群落对城市鸟类群落结构及多样性的影响.结果表明,鸟类种类及其多样性与栖息地多样性、植物种类、绿化面积或绿化宽度以及节肢动物种类之间均呈正相关关系.鸟类密度与公园水域面积之间呈负相关关系.由于植被组成、绿化面积等方面的差异,不同功能的绿地体系内鸟类群落与栖息地环境因子的相互关系有所不同.

鸟类对山黄麻种子的传播及其生态作用

在云南西双版纳的勐宋和勐仑地区观察和研究了传播山黄麻种子的鸟类。在野外挂网捕获摄食山黄麻果实的鸟类 ,称量后分别放在布袋内 ,让其自然排泄 ,然后标志释放。观察和网捕共记录到摄食山黄麻果实的鸟类 36种 ,其中 2 6种挂网捕获并从排泄物得到种子。用鸟类排泄物中的山黄麻种子、山黄麻树上采摘的成熟果实及人工分离山黄麻种子播种 ,进行萌发对比实验。实验结果表明 ,直接播种成熟果实 ,在阳光充足的空旷地、林冠下或用树叶覆盖遮光等条件下都未萌发 ,种子容易霉烂或被虫蚀 ;从山黄麻果肉中分离出来的种子具有萌发能力 ;而经鸟类摄食、消化后从果肉中分离的种子 ,具有较好的萌发活力。在不同条件下山黄麻种子萌发情况差异明显 ,林冠下条件对种子有抑制作用 ,阳光作用下种子显示出很好的萌发及成活率。鸟类排泄物种子放在林冠下或用树叶覆盖遮光 ,经过较长时间便可萌发 ,而人工分离种子不能萌发。鸟类摄食及消化过程对山黄麻种子的处理表现出很好的生态互惠关系。观察萌发后的山黄麻幼苗的生长情况还表明 ,幼苗生长也需要光照和较开阔的生境条件 ,鸟类取食山黄麻果实及其将种子远距离传播到适宜生境 ,正好具有这样的生态作用。

北京东灵山地区鸟类群落与栖息环境的关系研究

于 1999 0 3— 2 0 0 1 0 6对北京东灵山地区鸟类群落进行了研究 ,共发现鸟类 84种 ,依据营巢位置和取食部位的不同可以划分为 6个集团 .对鸟类种群密度、集团丰富度、物种多样性等群落指标与植被结构关系的研究发现 ,地面取食集团的物种数、种群密度与灌木丛的高度和盖度成正比 .影响鸟类密度的栖息地参数对于不同物种存在较大差别 .对地面营巢集团鸟类而言 ,随着灌木高度和盖度的增加 ,鸟类数量明显上升 ;而林冠营巢集团鸟类的数量却随着灌木高度和树种多样性的增加而下降 .鸟类种群密度和均匀度受到灌丛高度异质性和乔木高度的显著影响 。

基于AdaBoost的高分辨率遥感影像城市绿地提取算法

针对高分辨率遥感影像中城市绿地的光谱、纹理及NDVI等特征,提出了一种基于多特征、多检测器组合的高分辨率遥感影像绿地提取算法。该算法分别以城市绿地的光谱信息、纹理及NDVI来构造提取绿地的弱检测器,并通过AdaBoost算法进行训练,将弱检测器加权组合构成提取绿地的强检测器。对武汉地区QuickBird影像进行了绿地提取实验,实验结果表明该方法可以高效并准确地提取出绿地信息,优于传统的单一采用光谱信息或纹理信息的绿地提取算法。

青海湖鸟岛盐碱地植被演替的初步研究

利用聚类分析和演替度分析方法,研究青海湖鸟岛地区湖水退缩形成的盐碱地植物群落类型及其演替过程.结果表明,青海湖鸟岛湖水退缩形成的盐碱地植被有四大主要群落类型为碱蓬单优群落,碱蓬+西伯利亚蓼群落,西伯利亚蓼+碱茅+碱蓬群落和碱茅+西伯利亚蓼+碱蓬群落;青海湖鸟岛盐碱地植被有两条演替线路,为盐碱沙地群落演替线路 碱蓬单优群落经碱蓬+西伯利亚蓼群落,向西伯利亚蓼+碱茅+碱蓬群落演替 和盐碱草地演替线路 碱蓬单一优势种群落,经碱蓬+西伯利亚蓼群落,向碱茅+西伯利亚蓼+碱蓬群落演替 ;随着植物群落的演替,物种多样性增加,均匀度提高,而丰富度在不同的演替线路表现不同的规律.

沟谷地形下路侧生物多样性特征

路侧生物多样性特征受其背景环境条件与公路建设运营的综合影响,对其研究可为公路建设工艺优化提供参考依据。为了研究沟谷地形条件下路侧生物多样性的特征,选择了G214线德钦段公路穿越沟谷地形路段,在不同坡面进行植被样方调查,研究不同坡向植物多样性特征;并通过沿公路等距设置样地观测沟谷与非沟谷地带的鸟类多样性特征差异。调查结果表明:沟谷西南向坡(SW)、东北向坡(NE)及北向坡(N)物种总数、小区平均物种数、木本Shannon-wieners指数、Pielou指数、Simpson指数均大于西北向坡(NW)与南向坡(S);南向坡草本多样性指数小于其他坡向;S-SW、SW-NE、SW-NW Jaccard指数值低于0.15,NE-N Jaccard指数值小于0.4,沟谷地带坡向间木本与草本层α多样性差异大,并有着相对较高的β多样性;沟谷地形下鸟类种数、鸟类平均数量均高于非沟谷地形条件。调查结果初步揭示了沟谷是植物多样性丰富且富于变化之处,也是动物物种多样性较丰富之处。建议在这些路段加强公路桥梁与动物通道、植被生境连通性的协同建设,以缓解公路建设对景观的切割阻断效应。