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.     

Common European birds are declining rapidly while less abundant species' numbers are rising

Biodiversity is undergoing unprecedented global decline. Efforts to slow this rate have focused foremost on rarer species, which are at most risk of extinction. Less interest has been paid to more common species, despite their greater importance in terms of ecosystem function and service provision. How rates of decline are partitioned between common and less abundant species remains unclear. Using a 30‐year data set of 144 bird species, we examined Europe‐wide trends in avian abundance and biomass. Overall, avian abundance and biomass are both declining with most of this decline being attributed to more common species, while less abundant species showed an overall increase in both abundance and biomass. If overall avian declines are mainly due to reductions in a small number of common species, conservation efforts targeted at rarer species must be better matched with efforts to increase overall bird numbers, if ecological impacts of birds are to be maintained.     

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。     

中国城市鸟类学研究进展

我国的城市鸟类学起步于20世纪80年代,随着城市化过程的加速,城市鸟类学也有了较快发展。为了全面系统地了解中国城市鸟类学研究的历史、现状与发展趋势,在中国期刊全文数据库中以"城市"和"鸟类"为主题词检索了1950—2015年间发表的文章,筛选获得128篇文章,并对检索结果进行综述。结果显示,城市鸟类学发表文章数量自20世纪80年代起逐渐增加,由1981—1990的年均0.7篇跃升至2011—2015年的年均11.6篇。研究地涉及全国29个省级行政区的57个城市。研究的主要议题包括:城市鸟类的群落结构和分布、影响城市鸟类的主要环境因素和城市鸟类的保护实践。综述发现,不同城市环带位置,城市中不同生境组合会影响城市的鸟类群落结构;不同尺度上的环境因素会对鸟类的分布、繁殖、觅食和生理情况产生多种影响,而城市化是影响这些环境因素的主要驱动力;鸟类栖息地规划以保护城市中自然栖息地,增加其景观连通性促进鸟类保护,鸟类招引技术主要通过补充巢资源和食物资源促进鸟类保护。然而,由于资源限制,有关城市鸟类的长期研究相对较少。并且,已有研究中城市鸟类的生态系统服务也鲜有涉及。为此,对我国城市鸟类学的发展提出了三点展望,城市鸟类学研究应加强城市绿地鸟类招引措施的生态影响研究,进一步发掘城市鸟类的自然体验与环境教育价值,并促进民间爱好者参与长期系统性城市鸟类学调查。     

Avian conservation practices strengthen ecosystem services in California vineyards

Insectivorous Western Bluebirds (Sialia mexicana) occupy vineyard nest boxes established by California winegrape growers who want to encourage avian conservation. Experimentally, the provision of available nest sites serves as an alternative to exclosure methods for isolating the potential ecosystem services provided by foraging birds. We compared the abundance and species richness of avian foragers and removal rates of sentinel prey in treatments with songbird nest boxes and controls without nest boxes. The average species richness of avian insectivores increased by over 50 percent compared to controls. Insectivorous bird density nearly quadrupled, primarily due to a tenfold increase in Western Bluebird abundance. In contrast, there was no significant difference in the abundance of omnivorous or granivorous bird species some of which opportunistically forage on grapes. In a sentinel prey experiment, 2.4 times more live beet armyworms (Spodoptera exigua) were removed in the nest box treatment than in the control. As an estimate of the maximum foraging services provided by insectivorous birds, we found that larval removal rates measured immediately below occupied boxes averaged 3.5 times greater than in the control. Consequently the presence of Western Bluebirds in vineyard nest boxes strengthened ecosystem services to winegrape growers, illustrating a benefit of agroecological conservation practices. Predator addition and sentinel prey experiments lack some disadvantages of predator exclusion experiments and were robust methodologies for detecting ecosystem services.     

Hooded Vultures Necrosyrtes monachus nearly extirpated from Edo State,Nigeria: a report on the avian scavenger community

Avian scavengers, by feeding on carrion and other organic matter, provide critical ecosystem services. Vultures, the only obligate avian scavengers, have reportedly experienced massive population declines in Africa yet current knowledge regarding their status in most West African countries is unknown. This study set out to ascertain the status of the avian scavenger community in Edo State, southern Nigeria. We made total counts of all scavenging birds at foraging and roosting sites in 13 urban areas. We recorded three species of avian scavenger which were, in order of decreasing relative abundance, Pied Crow Corvus albus, Yellow-billed Kite Milvus migrans and Hooded Vulture Necrosyrtes monachus. There was a positive correlation between relative abundance of avian scavengers and human population size, such that more populous urban centres had larger populations of scavengers. We counted more scavenging birds at roosting sites than at foraging sites. While the Pied Crow and Yellow-billed Kite appear to be thriving in Edo State, the Hooded Vulture appears to have experienced a massive population decline. Our results suggest that without immediate conservation effort such as protection, education and advocacy, the Hooded Vulture will be extirpated from this region in the near future. We suggest that these conservation efforts be focused on the largest urban areas. Furthermore, we recommend that other states in southern Nigeria be urgently surveyed in order for more general conclusions to be drawn about the fate of avian scavengers in this region.     

Understanding relationships among multiple ecosystem services

Ecosystem management that attempts to maximize the production of one ecosystem service often results in substantial declines in the provision of other ecosystem services. For this reason, recent studies have called for increased attention to development of a theoretical understanding behind the relationships among ecosystem services. Here, we review the literature on ecosystem services and propose a typology of relationships between ecosystem services based on the role of drivers and the interactions between services. We use this typology to develop three propositions to help drive ecological science towards a better understanding of the relationships among multiple ecosystem services. Research which aims to understand the relationships among multiple ecosystem services and the mechanisms behind these relationships will improve our ability to sustainably manage landscapes to provide multiple ecosystem services.     

Noise pollution alters ecological services: enhanced pollination and disrupted seed dispersal

Noise pollution is a novel, widespread environmental force that has recently been shown to alter the behaviour and distribution of birds and other vertebrates, yet whether noise has cumulative, community-level consequences by changing critical ecological services is unknown. Herein, we examined the effects of noise pollution on pollination and seed dispersal and seedling establishment within a study system that isolated the effects of noise from confounding stimuli common to human-altered landscapes. Using observations, vegetation surveys and pollen transfer and seed removal experiments, we found that effects of noise pollution can reverberate through communities by disrupting or enhancing these ecological services. Specifically, noise pollution indirectly increased artificial flower pollination by hummingbirds, but altered the community of animals that prey upon and disperse Pinus edulis seeds, potentially explaining reduced P. edulis seedling recruitment in noisy areas. Despite evidence that some ecological services, such as pollination, may benefit indirectly owing to noise, declines in seedling recruitment for key-dominant species such as P. edulis may have dramatic long-term effects on ecosystem structure and diversity. Because the extent of noise pollution is growing, this study emphasizes that investigators should evaluate the ecological consequences of noise alongside other human-induced environmental changes that are reshaping human-altered landscapes worldwide.     

生态系统服务功能体系框架整合的探讨

有关生态系统服务功能的价值估算的文献越来越多。然而,这些数据特别分散,且缺乏统一的尺度与估算标准,从而导致生态经济分析不具有可比性。鉴于这种情况,本文试图建立生态系统服务功能综合集成体系框架,对生态系统功能、服务和商品及其价值估算严谨一致地提出了基本概念框架,将生态系统服务功能划分为4大类23亚类,分别对应于经济、生态和社会文化价值,并以矩阵和清单的形式在这些生态系统服务功能与各种估算方法之间建立了对应关系。     

Integrating trait‐based empirical and modeling research to improve ecological restoration

A global ecological restoration agenda has led to ambitious programs in environmental policy to mitigate declines in biodiversity and ecosystem services. Current restoration programs can incompletely return desired ecosystem service levels, while resilience of restored ecosystems to future threats is unknown. It is therefore essential to advance understanding and better utilize knowledge from ecological literature in restoration approaches. We identified an incomplete linkage between global change ecology, ecosystem function research, and restoration ecology. This gap impedes a full understanding of the interactive effects of changing environmental factors on the long‐term provision of ecosystem functions and a quantification of trade‐offs and synergies among multiple services. Approaches that account for the effects of multiple changing factors on the composition of plant traits and their direct and indirect impact on the provision of ecosystem functions and services can close this gap. However, studies on this multilayered relationship are currently missing. We therefore propose an integrated restoration agenda complementing trait‐based empirical studies with simulation modeling. We introduce an ongoing case study to demonstrate how this framework could allow systematic assessment of the impacts of interacting environmental factors on long‐term service provisioning. Our proposed agenda will benefit restoration programs by suggesting plant species compositions with specific traits that maximize the supply of multiple ecosystem services in the long term. Once the suggested compositions have been implemented in actual restoration projects, these assemblages should be monitored to assess whether they are resilient as well as to improve model parameterization. Additionally, the integration of empirical and simulation modeling research can improve global outcomes by raising the awareness of which restoration goals can be achieved, due to the quantification of trade‐offs and synergies among ecosystem services under a wide range of environmental conditions.     

海洋生态系统服务的产生与实现

在阐述海洋生态系统服务内涵的基础上,分析了海洋生态系统服务的产生过程和实现途径,将海洋生态系统每一组分和(或)功能与其所提供的服务联系起来,给出了从每种组分和(或)功能到相应的服务所经过的生理生态过程.结果表明,海洋生态系统的服务一部分是生物组分和(或)系统整体直接提供,另一部分是通过系统功能产生.系统内的各种生理生态过程不直接产生服务.服务的实现包括海洋生态系统途径和海洋生态经济系统途径两种.     

Review of the ecosystem service implications of mangrove encroachment into salt marshes

Salt marsh and mangrove have been recognized as being among the most valuable ecosystem types globally in terms of their supply of ecosystem services and support for human livelihoods. These coastal ecosystems are also susceptible to the impacts of climate change and rising sea levels, with evidence of global shifts in the distribution of mangroves, including encroachment into salt marshes. The encroachment of woody mangrove shrubs and trees into herbaceous salt marshes may represent a substantial change in ecosystem structure, although resulting impacts on ecosystem functions and service provisions are largely unknown. In this review, we assess changes in ecosystem services associated with mangrove encroachment. While there is quantitative evidence to suggest that mangrove encroachment may enhance carbon storage and the capacity of a wetland to increase surface elevation in response to sea‐level rise, for most services there has been no direct assessment of encroachment impact. On the basis of current understanding of ecosystem structure and function, we theorize that mangrove encroachment may increase nutrient storage and improve storm protection, but cause declines in habitat availability for fauna requiring open vegetation structure (such as migratory birds and foraging bats) as well as the recreational and cultural activities associated with this fauna (e.g., birdwatching and/or hunting). Changes to provisional services such as fisheries productivity and cultural services are likely to be site specific and dependent on the species involved. We discuss the need for explicit experimental testing of the effects of encroachment on ecosystem services in order to address key knowledge gaps, and present an overview of the options available to coastal resource managers during a time of environmental change.     

Frugivore diversity increases frugivory rates along a large elevational gradient

The effect of biodiversity on ecosystem functioning is increasingly well understood, but it has mainly been studied in small‐scale experiments of plant‐based ecosystem functions. In contrast, the relevance of biodiversity for animal‐mediated ecosystem functions like seed dispersal still poses an important gap in ecological knowledge. In particular, it is little understood how avian diversity affects frugivory rates, one of the most important parameters of seed dispersal rates, along large environmental gradients. Even less is known about the environmental context dependence of the frugivore–frugivory relationship. We used artificial fruits to analyze experimentally how the abundance and richness of three avian frugivore guilds (with incrementally more stringent classifications of frugivory) contributed to frugivory rates across 13 different habitat types along an elevational gradient from 870 to 4550 m a.s.l. at Mt Kilimanjaro, Tanzania. We further investigated how environmental context, in terms of local vegetation structure and natural fruit availability, modified the relationship between frugivores and frugivory rates. Our results demonstrate that the positive effect of avian diversity on frugivory rates holds along a large elevational gradient. We found marked differences in frugivory rates among the 13 habitat types, which were strongly related to the abundance and richness of obligate frugivorous birds. Vegetation structure had no significant effect on frugivory rates. An intermediate abundance of natural fruits enhanced frugivory rates, but this effect did not alter the positive frugivore–frugivory relationship. These results emphasize the fundamental importance of obligate frugivore diversity for frugivory rates and suggest that the positive effect of biodiversity on ecosystem functioning holds along large environmental gradients.     

黄淮平原农业景观不同生境鸟类多样性特征及年际动态

鸟类是地球生物多样性中的重要组成部分,在生态系统功能和服务中发挥着重要作用,是生态环境变化的重要指示物种。农业景观中的食虫鸟类提供了重要的虫害控制服务。当前,农业景观中鸟类多样性丧失加剧,为探讨鸟类多样性在各生境以及年际间的变化,以黄淮平原为研究区,在河流、湖泊、农田、村庄等生境中共设置20个样点。于2016-2019年连续4年在繁殖期采用样线法对鸟类进行多样性调查。调查结果显示：（1）共发现22922只个体,分属14目,38科,53属。从区系分布来看,各生境各年间均以广布种为主;从生态类群来看,鸣禽占绝对优势;从居留型来看,留鸟所占比例最高。（2）在食性组成上,从物种丰富度看,食虫鸟类有57种,约占总物种数的77%;从个体数来看,杂食性鸟类占比超52%。（3）物种丰富度、多样性和均匀度指数最高值均出现在湖泊或河流生境中。（4）鸟类群落相似性分析显示,各生境间鸟类群落均为中等相似程度;鸟类物种丰富度波动幅度在农田和村庄中呈逐年上升趋势。（5）物种多样性加性拆分分析显示,在生境尺度上,局地的α多样性是生物多样性的最重要组成,而从整个研究区来看,生境间的差异则更为重要。造成鸟类多样性时空差异的原因复杂多样,而生境异质性的增加和水域的存在对提高鸟类多样性是具有积极作用的。调查中超过77%的物种和40%的个体均为食虫鸟类,应当充分重视鸟类为区域农业景观提供的虫害控制服务。本研究可为区域鸟类多样性保护及鸟类提供的生态系统服务的提升管理提供理论基础和科学依据。     

基于生态系统服务供求评价的空间分异特征与生态格局划分——以长三角城市群为例

生态系统服务供给与需求能力存在显著的空间异质性与空间失衡,对区域经济发展与环境保护产生巨大影响。以长三角城市群区县为研究单元,分别核算其生态系统服务供给与需求值,引入梯度分析,分析生态系统服务供给与需求的空间特征,并基于供求分析提出长三角城市群生态格局分区方案,且针对性地提出相应片区的发展策略,为长三角城市群土地利用规划、区域协调发展提供科学依据。研究结果表明:(1)长三角城市群生态系统服务供给能力与土地利用类型密切相关,呈现从北到南逐渐升高趋势;(2)长三角城市群生态系统服务需求能力与社会经济发展联系紧密,在长江入海口附近形成生态系统服务需求高值区,然后向外围递减;(3)沪宁杭庐发展梯度带上,生态系统服务供需大致呈现负相关趋势;(4)基于生态系统服务供需关系构建,得到长三角城市群生态格局四大分区:生态保育区(高供给-高需求),生态修复区(低供给-高需求),生态重塑区(低供给-低需求),生态开发区(高供给-低需求)。     

Feather function and the evolution of birds

The ability of feathers to perform many functions either simultaneously or at different times throughout the year or life of a bird is integral to the evolutionary history of birds. Many studies focus on single functions of feathers, but any given feather performs many functions over its lifetime. These functions necessarily interact with each other throughout the evolution and development of birds, so our knowledge of avian evolution is incomplete without understanding the multifunctionality of feathers, and how different functions may act synergistically or antagonistically during natural selection. Here, we review how feather functions interact with avian evolution, with a focus on recent technological and discovery-based advances. By synthesising research into feather functions over hierarchical scales (pattern, arrangement, macrostructure, microstructure, nanostructure, molecules), we aim to provide a broad context for how the adaptability and multifunctionality of feathers have allowed birds to diversify into an astounding array of environments and life-history strategies. We suggest that future research into avian evolution involving feather function should consider multiple aspects of a feather, including multiple functions, seasonal wear and renewal, and ecological or mechanical interactions. With this more holistic view, processes such as the evolution of avian coloration and flight can be understood in a broader and more nuanced context.     

湖泊生态服务受益者分析及生态生产函数构建

生态系统服务管理作为生态系统管理的优化方式,是生态学研究的前沿方向。湖泊生态系统服务管理是指综合利用生态学、经济学、社会学和管理学等学科知识,对影响湖泊生态系统结构、过程、功能的关键因子进行调控,提高湖泊生态系统服务供给水平和供给能力的过程。近年来国内外学者针对湖泊生态系统服务内涵、分类、经济价值评估等方面开展了大量研究,极大地促进了湖泊生态系统服务从认知走向管理实践。然而,现有研究在开展湖泊生态系统服务价值评估时多忽略生态系统服务受益者和生态系统特征对生态系统服务的边际影响分析,无法揭示生态系统服务空间流动和转移特征及生态系统服务时空权衡关系,制约了生态系统服务研究与管理决策和政策设计结合。在综述湖泊生态系统服务定量评估方法的基础上,认为通过生态系统服务受益者分析确定湖泊生态系统最终服务,并通过构建生态生产函数确定湖泊生态系统服务权衡关系及湖泊生态系统特征对生态系统最终服务的边际影响,是生态系统服务走向管理实践和政策设计的科学依据,可以确保生态、社会、经济可持续发展。     

基于生态系统服务的生态安全研究进展

生态安全是全球环境变化背景下人类可持续发展面临的重要问题之一。生态系统服务作为自然环境中人类赖以生存的环境条件与效用,成为人们感知和评价生态系统结构或功能变化的重要指标,同时为研究自然生态与社会-经济两大系统之间的交互作用提供了连接路径。目前,国内外对基于生态系统服务的生态安全研究尚处于起步阶段。在大量查阅国内外相关文献的基础上,总结了生态安全的理论内涵及方法体系,并从基于生态系统服务内在关系和基于生态系统服务拓展的生态安全研究,以及将生态系统服务与生态安全结合应用的综合研究等3个方面系统性梳理了目前国内外基于生态系统服务的生态安全研究进展。结果表明,发展初期的生态安全研究主要基于各种生态系统服务之间的供需关系、权衡/协同关系和服务重要性等内在关系,二者的结合效果能通过耦合生态系统服与生态系统状态指标和相关模型得到改善,近年来将生态系统服务与生态安全结合应用的综合研究在区域规划管理等领域已呈现良好的发展趋势。在此基础上,本文指出了目前研究过程中所存在的一些不足与未来发展的方向,为进一步深入开展生态系统服务与生态安全的耦合研究提供理论依据。     

湖泊湿地生态系统服务研究进展

湖泊湿地生态系统服务可持续供给对维持区域、国家乃至全球生态安全格局具有重要意义。近20年,国内外学者在生态系统服务内涵、评估模型、影响机制、权衡与优化等领域的研究不断深入,但与管理决策和政策设计的结合仍面临多方面严峻挑战。系统分析湖泊湿地生态系统服务研究进展与存在的不足,对于今后一段时间内湖泊湿地生态系统服务研究的全方位拓展具有重要指导意义。以湖泊湿地生态系统服务概念与内涵为切入点,对湖泊湿地生态系统服务评估内容与方法、影响机理、生态系统服务权衡与优化等几个重要方面的研究进展进行了梳理,并结合管理决策和政策设计的需求,评述其研究中存在的不足。本研究以生态系统服务监测、模型不确定性、风险评估、优化与调控等四个重点研究方向为切入点,对湖泊湿地生态系统服务的研究方向进行了展望,以期深化湖泊湿地生态系统服务研究的理论与方法,并实现其与管理决策和政策设计的高度结合。     

生态系统服务研究：进展、局限和基本范式

 生态系统服务是生态学研究的热点问题。该文首先从概念、分类、价值评估理论、评估案例等方面总结了目前国内外生态系统服务的研究现状。然后评述了目前生态系统服务研究存在的局限性,包括：评估结果的准确性问题、生态资产与生态系统服务的混淆、物理量评估方法的不确定性、价值量评估的不确定性以及生态系统功能与服务的复杂性。针对这些研究的局限,文章提出了生态系统服务研究的基本范式,包括：严格区分生态资产和生态系统服务、生态系统服务评估必须基于生态观测或生态模型以及区域生态系统服务评估应区分不同样元。最后,文章展望了今后生态系统服务研究的课题：生态系统服务与生态系统结构及生态过程的关联性和复杂关系的研究,人类干扰下生态系统服务的响应与反馈研究,生态系统服务变化对人类福利的影响研究,政策机制对生态系统服务的影响研究以及不同生态系统类型的各种生态服务价值研究等方面。