道路生态研究进展

道路广泛分布在各种景观中,其密度和交通量都不断增加,随之带来多方面的生态影响：道路建设导致动植物死亡和生境丧失、物理化学环境变化、路旁植被改变。对动物种群产生的生态影响包括道路致死、道路回避和巢区转移、移动格局改变、障碍作用导致生境和种群的破碎化。道路还强烈地改变景观格局和过程。道路生态影响的定量化测度指数包括道路密度、道路位置和道路影响域,道路生态研究在道路规划和野生动物保护中有很广阔的应用前景,成为生态学的一个重要领域。     

道路网络对景观生态风险的影响——以云南省红河流域为例

道路网络扩展既影响周围的景观格局,也对生态过程造成直接或间接的影响。以云南省红河流域为研究区域,利用GIS和RS技术,进行格网划分,从空间上分析道路对景观格局和土壤侵蚀的影响,并通过基于景观格局和过程的景观生态风险指数计算,分析道路网络扩展影响下的景观生态风险规律。结果表明:红河流域道路周围景观类型以耕地、林地和草地为主,其中林地和草地的格局风险指数随着距离道路的增加而减少,受道路影响显著;一级路、三级路和四级路缓冲区内土壤侵蚀量随着距离道路的增加而减少,三四级路分布广泛,更容易发生土壤侵蚀;道路密度和基于景观格局和过程的景观生态风险指数在空间分布上具有一定的相关性。     

道路对景观的影响及其生态风险评价--以澜沧江流域为例

道路贯穿于各类景观。道路网络的发展也产生了许多生态效应。道路的生态风险分析是基于生态效应,通过格局和过程的研究,综合评估各类潜在生态影响及其累积性后果。从景观生态学理论入手．分析了道路对景观的影响,将道路对景观的影响区分为建设期和运营期2个阶段,并提出了基于格局和过程的生态环境指数,进而得出道路综合生态风险评价的方法。以澜沧江流域上中下游的3个典型区为例,研究道路对景观的影响。结果表明,虽然不同案例区道路影响的景观类型和格局不同,其风险的分布也不同．但综合风险指数和道路密度具有很高的一致性。     

道路对两栖类种群的生态学影响

随着道路密度和交通量的不断增加,道路对两栖类种群产生的负面影响也在不断的加深和扩大,其影响主要有:1)直接作用:道路致死、廊道效应、生境破碎、回避效应等:2)间接作用:即边缘效应,包括非生物环境(土、水、气、声、热等)和生物环境(植被和其他动物等)的影响.这些因素的综合作用,将会威胁物种长期的存活,从而导致种群数量的严重下降.文章系统论述了道路对两栖类种群的生态学影响,以期引起人们的关注,并采取相应的措施,使人类在追求经济利益的同时最大限度的减少道路对动物的影响和危害.     

多尺度空间下害虫生态调控理论与应用

不同尺度空间下农田生态系统具有不同的生境斑块组成结构,尺度性也是生态系统的重要特征之一.近年来,北美和欧洲等地区用农田生境管理与区域性景观设计相结合的研究方法实施多尺度空间下害虫生态调控,实现复合生态系统服务.其核心思想是以大区域景观设计和农田作物布局与农事管理的有机结合,通过农业景观格局的空间配置,调节种植模式、管理技术、乃至改变农业景观格局的空间配置等以切断害虫种群的生活史,建立和恢复天敌种群库与转移通道,从而最大程度地提高农业生态系统自身的控害功能.近年来,北美和欧洲对多尺度空间下农业复合生态系统服务功能都做了大量工作,尤其是田间尺度与景观尺度相结合的研究方法更是当前生境管理研究的重要内容.本文总结了多尺度空间下生态系统环境条件与天敌种群间的作用机制及假说,包括田间尺度上主要通过轮作与间套作、覆盖作物、减免耕及发展有机农业等方式提高天敌种群,景观尺度上通过生境斑块的空间配置来改变植物资源布局,最终提高天敌的控害作用.以期为深入地解析景观格局及复杂性对生物多样性的影响,揭示农业景观变化对昆虫种间关系的作用机制,在实践上为利用农田景观格局控制害虫种群发生提供新的途径与方法.     

区域农田景观格局对麦田天敌瓢虫群落的影响

【目的】明确农田景观格局对麦田天敌瓢虫种群的影响,为开展区域性害虫生态调控提供理论依据。【方法】以山东省22个县市区域的小麦种植区为研究对象,基于遥感影像与土地覆盖分类数据以及田间调查的瓢虫种群数据,计算景观格局指数,使用负二项分布的广义线性模型从农田景观、非作物生境景观和区域景观3个方面分析区域农田景观格局对麦田天敌瓢虫群落的影响。【结果】麦田瓢虫种群数量与草地的平均斑块面积(mean patch area,AREA_MN)和面积加权平均斑块分维数(area-weighted mean patch fractal dimension,FRAC_AM)、区域景观的斑块丰富度密度(patch richness density,PRD)呈正相关,与非作物生境的面积加权平均几何最邻近距离(areaweighted mean Euclidean nearest neighbor distance,ENN_AM)呈负相关。草地、聚集的非作物生境以及多样性的区域景观有利于天敌瓢虫种群数量的增加。使用草地的平均斑块面积和非作物生境的面积加权平均几何最邻近距离可以预测瓢虫的发生量。【结论】作为非作物生境的草地、非作物生境的空间分布及区域景观的多样性是影响麦田天敌瓢虫发生的重要因素。     

区域农田景观格局对麦蚜种群数量的影响

明确农田景观格局对麦田蚜虫种群的影响,是开展区域性害虫生态调控的重要理论依据之一。以区域性小麦种植区为研究对象,基于遥感影像与土地覆盖分类数据以及田间调查的蚜虫种群数据,计算景观格局指数,使用负二项分布的广义线性模型从农田景观、非作物生境景观和区域景观3个方面分析了区域农田景观格局对麦田蚜虫种群的影响。结果表明,蚜虫种群的数量与草地的平均斑块面积和最大斑块指数显著正相关,与县域的平均几何最邻近距离和面积加权平均斑块面积显著负相关,与耕地的面积加权平均斑块面积显著负相关,与耕地的斑块密度显著正相关。草地斑块面积的增大、区域景观与耕地的破碎化、区域景观的聚集会促进蚜虫种群数量的增加。使用草地的斑块面积和最大斑块指数、区域景观的平均几何最邻近距离可以预测蚜虫种群的发生量。非作物生境草地的斑块面积、耕地的破碎化、区域景观的空间分布及破碎化是影响麦田蚜虫种群发生的重要景观因素。     

秦岭中段南坡景观格局与大熊猫栖息地的关系

景观格局是各种生态过程在不同尺度上作用的结果 ,同时景观格局强烈影响着生境内种群的生物学过程 ;种群的结构和分布状况同栖息地景观格局之间存在一定的联系。借助遥感和地理信息系统软件 ,对秦岭中段南坡地区 3个保护区 (佛坪、长青和观音山 )大熊猫栖息地的景观格局及其与大熊猫活动痕迹密度之间的关系进行了研究。该研究首先绘制了景观类型格局图并进行总体斑块格局分析 ,其次分别从保护区尺度和 1km2 尺度分析平均斑块分维数、破碎度指数和香农多样性指数 ,以进行比较 ;最后在 1km2尺度上统计分析大熊猫活动密度同景观格局指数分布的相关性。研究结果表明 :(1)各自然保护区内的景观格局存在着差异性 ,佛坪保护区景观多样性水平较高 ,长青保护区居中 ,观音山保护区最低 ;(2 )各保护区内部受人为干扰和生境恢复程度不同 ,使得景观破碎化程度在佛坪保护区最低 ,长青保护区居中 ,观音山保护区最高 ;(3)大熊猫活动密度有集中分布的趋势 ,高密度区域主要分布在佛坪中部和长青北部 ;(4 )在 1km2尺度 ,3个保护区大熊猫活动痕迹密度同景观指数格局之间存在不同的相关性 ,说明不同的景观格局会影响到大熊猫的活动和生境利用。     

森林所有制对景观格局和动物生境的影响研究进展

在欧美等地区的林业发达国家,多种森林所有制长期并存,至今,多种所有制影响下森林景观和生境格局的变化以及与动物保护之间的关系成为研究热点和重点.本文首先阐述了森林所有制对森林景观格局和动物生境的影响,以及林权分散和林权流转的加剧带来的生态后果,包括提供多样化的生境和导致原有大面积生境的破碎化;其次,总结了林业发达国家解决林权分散与生物保护之间矛盾的两个理论途径--改变所有制格局和相对统一各所有制的管理行为,分析现多采用后一种途径的原因,并指出目前森林所有制研究中模拟方法的局限;最后,论述我国的研究现状以及面临的机遇和挑战,提出近期发展建议.     

缙云山不同生境蝴蝶花(Iris japonica Thumb.)分株种群格局及对草本多样性的影响

运用空间格局、生态位及多样性分析,探讨了重庆缙云山自然保护区林缘旷地(OAFE)、竹林(BF)及常绿阔叶林(EBF)3类生境蝴蝶花(Iris japonica Thumb.)自然种群分株格局特征及对草本多样性的影响机制.结果表明:方差均值比(V/m)和Moristia指数(Iδ)的格局判别分析表明,3类生境中蝴蝶花分株种群从0.5 m×0.5 m至2 m×2 m尺度均为聚集分布;从林缘旷地-竹林-常绿阔叶林,种群分株密度逐渐降低,总体格局规模与格局强度(PI)在各尺度均呈下降趋势.林缘旷地与竹林生境中,蝴蝶花的分布,降低了原优势种的优势度,并显著降低草本层物种多样性(p<0.05),但在常绿阔叶林生境中对原优势种的优势度及草本物种多样性的影响很小.不同生境中蝴蝶花种群格局对草本多样性的影响机制各不相同:林缘旷地生境,通过强的更新生态位(地上空间与根生态位)与营养生态位(获取水分与养分资源)竞争,降低草本物种丰富度尤其是偶见种丰富度;竹林生境,通过更新生态位(根生态位)与营养生态位(获取光与养分资源)竞争,降低了草本偶见种丰富度;常绿阔叶林生境,物种间生态位重叠较低,表现一定的资源竞争,但对草本多样性影响很小.林冠决定蝴蝶花分株种群格局强度、克隆生长的强弱及林下土壤状况,从而影响蝴蝶花与草本层其它物种之间生态位竞争的强弱是决定蝴蝶花种群对草本层物种多样性影响机制的重要因素.     

Constructing China's greenways naturally

Roads are a prominent feature of many landscapes, and high road densities create correspondingly high ecological impacts by altering landscape patterns, interrupting ecological flows, increasing erosion, fragmenting habitat, and facilitating the spread of invasive species. Here, we describe the construction of “near-natural greenways” that produce environmentally and socially harmonious road systems that meet the needs of both the environment and the socioeconomic development in China and that satisfy environmental, ecological, educational, traffic safety, economic, and sustainable developmental goals. In the last decade, China has embarked upon the implementation of a network of near-natural greenways with the vision of linking economic development with nature conservation by means of improved rehabilitation of existing road systems and improved construction of new roads. Ecological science, and especially landscape ecology, will play an important role in the planning and implementation of future near-natural greenways in China and around the world.     

道路对陆栖野生动物的生态学影响

道路网络为大多数景观所共同具有的空间特征,在增进社会财富、方便人们生活的同时。也会产生严重的生态学后果。就道路对陆栖野生动物的生态学影响进行了综述。道路交通导致动物死亡。已成为野生脊椎动物死亡的首要原因;阻碍动物个体在同种种群问的交流以及在互补性资源间的周期性迁移;迫使森林内部种、边缘敏感种主动回避道路栖息地;导致道路区域栖息鸟类繁殖下降;有利于小型物种沿道路边缘扩散,造成生物入侵。道路区域为一种特殊的边缘。对一些边缘物种以及其它被吸引过来的动物来说是一种死亡陷阱。这些影响的综合作用会导致孤立的小种群问题。从而严重威胁到渐危濒危物种的长期存活。     

Where to invest in road mitigation? A comparison of multiscale wildlife data to inform roadway prioritization

Roads and associated traffic have significant impacts on wildlife, from direct mortality caused by vehicle collisions to indirect effects when wildlife avoid roads, restricting access to important resources. Road mitigation measures such as constructing wildlife passages over or under the road with directional fencing have proven effective at reducing wildlife vehicle collisions while also enabling wildlife to safely cross the road. Highway mitigation projects are led by transportation agencies with a primary purpose of improving motorist safety. More recently, through the discipline of road ecology, considerations have included safe wildlife passage through transportation corridors. To prioritize road sections for mitigation, data sources include animal vehicle collision data collected by transportation agencies and connectivity models generated by wildlife professionals. We used a third data source, pronghorn observations collected by citizen scientists, and demonstrated its value to prioritize potential wildlife mitigation sites. Our results clearly demonstrate a misalignment of road mitigation sites using animal-vehicle collision data and those of rarer species of interest.     

Measures to reduce population fragmentation by roads: what has worked and how do we know?

Roads impede animal movement, which decreases habitat accessibility and reduces gene flow. Ecopassages have been built to mitigate this but there is little research with which to evaluate their effectiveness, owing to the difficulty in accessing results of existing research; the lack of scientific rigor in these studies; and the low priority of connectivity planning in road projects. In this article, we suggest that the imperative for improving studies of ecopassage effectiveness is that road ecology research should be included from the earliest stages of road projects onwards. This would enable before-after-control-impact (BACI) design research, producing useful information for the particular road project as well as rigorous results for use in future road mitigation. Well-designed studies on ecopassage effectiveness could help improve landscape connectivity even with the increasing number and use by traffic of roads.     

Mitigating the impacts of rainforest roads in Queensland’s Wet Tropics: Effective or are further evaluations and new mitigation strategies required?

Summary Research into mitigation of the ecological impacts of rainforest roads in North Queensland has a long history, commencing during the formative years of Australian road ecology. In Queensland’s Wet Tropics and throughout Australia, installation of engineered structures to ameliorate ecological road impacts is now common during larger construction projects, but unusual in smaller road projects. Retro‐fitting of engineering solutions to roads that are causing obvious impacts is also uncommon. Currently, Australian mitigation measures concentrate on two important impacts: road mortality and terrestrial habitat fragmentation. Unfortunately, other important ecological impacts of roads are seldom addressed. These include edge effects, traffic disturbance, exotic invasions and fragmentation of stream habitats. In North Queensland, faunal underpasses and canopy bridges across rainforest roads have been monitored over long periods. These structures are used frequently by multiple individuals of various species, implying effectiveness for movements and dispersal of many generalist and specialised rainforest animals. However, without addressing population and genetic implications, assessment of effectiveness of these connectivity structures is not holistic. These aspects need sufficient long‐term funding to allow similar systematic monitoring before and after construction. Throughout Australia, more holistic approaches to mitigation of road impacts would routinely examine population and genetic connectivity, consider mitigation against more ecological impacts where appropriate and include landscape‐scale replication.     

生境破碎化对动物种群存活的影响

生境破碎是生物多样性下降的主要原因之一。通常以岛屿生物地理学、异质种群生物学和景观生态学的理论来解释不同空间尺度中生境破碎化的生态学效应。生境破碎化引起面积效应、隔离效应和边缘效应。这些效应通过影响动物种群的绝灭阈值、分布和多度、种间关系以及生态系统过程,最终影响动物种群的存活。野外研究表明,破碎化对动物的影响,因物种、生境类型和地理区域不同而有所变化,因此,预测物种在破碎生境中的存活比较困难。研究热点集中于：确定生境面积损失和生境斑块的空间格局对破碎景观中物种绝灭的相对影响,破碎景观中物种的适宜生境比例和绝灭阈值,异质种群动态以及生态系统的生态过程。随着3S技术的发展,生境破碎化模型趋于复杂,而发展有效的模型和验证模型将成为一项富有挑战性的任务。     

Molecular road ecology: exploring the potential of genetics for investigating transportation impacts on wildlife

Transportation infrastructures such as roads, railroads and canals can have major environmental impacts. Ecological road effects include the destruction and fragmentation of habitat, the interruption of ecological processes and increased erosion and pollution. Growing concern about these ecological road effects has led to the emergence of a new scientific discipline called road ecology. The goal of road ecology is to provide planners with scientific advice on how to avoid, minimize or mitigate negative environmental impacts of transportation. In this review, we explore the potential of molecular genetics to contribute to road ecology. First, we summarize general findings from road ecology and review studies that investigate road effects using genetic data. These studies generally focus only on barrier effects of roads on local genetic diversity and structure and only use a fraction of available molecular approaches. Thus, we propose additional molecular applications that can be used to evaluate road effects across multiple scales and dimensions of the biodiversity hierarchy. Finally, we make recommendations for future research questions and study designs that would advance molecular road ecology. Our review demonstrates that molecular approaches can substantially contribute to road ecology research and that interdisciplinary, long-term collaborations will be particularly important for realizing the full potential of molecular road ecology.     

湿地克隆植物的繁殖对策与生态适应性

湿地是地球上独特的生态系统,它是水陆交替的过渡带,而湿地植物为了适应这种特殊的环境,必须有其相应的生长格局（ｇｒｏｗｔｈｐａｔｔｅｒｎ）和繁殖对策（ｒｅｐｒｏｄｕｃｔｉｖｅｓｔｒａｔｅｇｙ）。有些湿地植物具有密丛型的生态特点,这是对过湿的土壤和氧气供给不足环境的一种适应方式。随着有机质的不断积累,每年从分蘖节向上长出新枝,向下生长不定根,其分蘖节不断上移,以便从地表面上获得氧气,并使植物体免遭埋没,这样年复一年的生长,在地表面上形成了草丘。生殖是生物繁衍后代延续种族最基本的行为和过程,它不仅是…     

Population Genetic Analysis of Streptomyces albidoflavus Reveals Habitat Barriers to Homologous Recombination in the Diversification of Streptomycetes

Examining the population structure and the influence of recombination and ecology on microbial populations makes great sense for understanding microbial evolution and speciation. Streptomycetes are a diverse group of bacteria that are widely distributed in nature and a rich source of useful bioactive compounds; however, they are rarely subjected to population genetic investigations. In this study, we applied a five-gene-based multilocus sequence analysis (MLSA) scheme to 41 strains of Streptomyces albidoflavus derived from diverse sources, mainly insects, sea, and soil. Frequent recombination was detected in S. albidoflavus, supported by multiple lines of evidence from the pairwise homoplasy index (Φ_w) test, phylogenetic discordance, the Shimodaira-Hasegawa (SH) test, and network analysis, underpinning the predominance of homologous recombination within Streptomyces species. A strong habitat signal was also observed in both phylogenetic and Structure 2.3.3 analyses, indicating the importance of ecological difference in shaping the population structure. Moreover, all three habitat-associated groups, particularly the entomic group, demonstrated significantly reduced levels of gene flow with one another, generally revealing habitat barriers to recombination. Therefore, a combined effect of homologous recombination and ecology is inferred for S. albidoflavus, where dynamic evolution is at least partly balanced by the extent that differential distributions of strains among habitats limit genetic exchange. Our study stresses the significance of ecology in microbial speciation and reveals the coexistence of homologous recombination and ecological divergence in the evolution of streptomycetes.