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1.
Changes in the aboveground phytomass of a Geranium-Hedysarum meadow community and its constituent species after the removal of dominants, Geranium gymnocaulon and Hedysarum caucasicum, over ten years have been studied in the Northwestern Caucasus. Responses of individual species to this intervention have been revealed. It has been shown that the phytomass of nondominant species increases under such conditions, but this cannot fully counterbalance the loss of phytomass resulting from the removal of dominants. Dominant species of Geranium-Hedysarum meadows exert different influences on the community structure and also compete with each other. However, this competition is fairly weak, which is probably due to considerable divergence of these species with respect to resource consumption.  相似文献   

2.
采用GIS技术,根据高程、坡度、土壤类型等环境特征,将乌东德水库坝前段消落带分为18种生态类型,并完成了高程图、坡度图和土壤类型图,建立了环境特征和消落带类型的直观联系。然后根据不同的生态类型,提出了4种生态修复模式,并选择了10种植物作为生态修复物种。为其它水库消落带生态修复提供了参考依据。  相似文献   

3.
The results of studies on the biomorphological features of 22 plant species growing on the southern coast of the Russian Far East provide evidence for the diversity of pathways of their adaptation to stressful habitat conditions. An analysis of the anatomical and mesostructural characteristics of their leaves has revealed representatives of euhalophytes, crinohalophytes, and glycohalophytes among these plants. Adaptation is achieved by means of halomorphosis, haloxerophytism, and development of some heliophilic features accounted for by species-specific manifestations of succulence, the presence of salt excreting trichomes, and thick pubescence. The similarity of these adaptations to those of desert plants is discussed. Along with plants characterized by a high germination rate, species that counterbalance a low efficiency of seed reproduction by active vegetative propagation have also successfully established themselves on the coast. Adaptation to coastal habitats is also achieved due to the diversity of life forms characterized mainly by tap root systems with laterally extending branch roots, creeping shoots, and a high vegetative mobility.  相似文献   

4.
生态活度生态位--理论、方法及其应用   总被引:4,自引:0,他引:4  
“生态活度生态位(Eco-vigor Niche)”是对生态位概念和理论的发展.它描述区域生态系统中一个占据特定空间位置的复合生态系统单元(或景观斑块).在与其它单元相互作用过程中所形成的相对地位与作用。在由自然生态活度坐标和社会经济生态活度坐标构成的二维空间中.生态活度生态位可以用二维空间中的矢量表达。该矢量的“长度”意味着,生态系统单元的资源优势程度与提供生态服务的能力;矢量的“方向”则意味着该生态系统单元所具有的.由其社会经济生态活度和自然生态活度相比较而体现出来的属性.反映出该单元在区域复合生态系统中的性质和角色。“生态活度生态位”可以表达区域生态系统内的空间分异特征。反映各生态单元在区域内扮演的角色.判断各单元在区域生态系统中的功能定位.为生态区划、生态规划、土地利用规划等提供依据。  相似文献   

5.
城市生长管理与城市生态规划   总被引:3,自引:0,他引:3  
本文从城市生长机制着手 ,论述了生态位的竞争与演化以及导致城市结构和空间的变化 ;城市管理模式随着城市功能的转变而从后果导向转向原因导向的生长管理。并提出在生长机制研究的基础上进行城市生态规划 ,重点应突出生态评价、生态功能分区及定量模拟  相似文献   

6.
The current state of research on the biosphere is analyzed. Various approaches to determining the boundaries and estimating the chemical composition of the biosphere are reviewed. The concept of ecological space as a structural unit of the biosphere is proposed. It is shown that cartography as a methodological approach to biospheric research may be used for describing the specificity of terrestrial ecosystems in terms of ecological standardization.  相似文献   

7.
水生植物群落在湖泊生态修复过程中作用显著,但目前人工重建的水生植物群落抗外界干扰能力弱,群落稳定性差,这就需要我们对人工重建的水生植物群落结构及其演替的生态学过程进行研究,从而探索受损群落的修复途径。于2003年在富营养化水体中采用物理生态工程进行了水生植物群落的重建研究,对群落演替动态变化过程进行了持续3年的观测。结果表明:水生植物之间发生生态位重叠时,其结果往往是以一个物种取代另一个物种,随着生态位重叠程度下降,种间关系和群落结构趋于稳定;而当物种空间位置错开时,生长期相近的物种共存则变为可能,因此在群落的构建过程中应当避免同时引入生态位重叠较高的物种,应注意植物间时间序列及空间结构的分离;此外还通过物种间的竞争表现,对几种常见水生植物构建的群落稳定性做了初步探讨.  相似文献   

8.
贵州赤水河流域生态红线区划分研究   总被引:4,自引:0,他引:4  
为保持生态系统平衡,维持社会健康、有序的发展,实现可持续发展的战略目标,在生态环境敏感脆弱区和重要生态功能区划定生态红线,确定生态红线区分布范围,科学指导开发活动,对生态环境进行有效管理,是我国当前在国务院政策指导和学界智力支持下的一项重要工作任务。以贵州赤水河流域为研究对象,选用水土流失敏感性、石漠化敏感性评估作为环境生态本底评估,综合土壤保持功能、水源涵养功能、生物多样性保护功能和禁止开发区,将生态需要和社会服务功能有机结合,通过空间综合叠加分析与处理等技术手段,共划分出9大类生态红线区,总面积为5 030.58 km2,占整个流域面积的44.16%。结合赤水河流域的生态环境现状,提出了相应的生态红线区管理建议,期望为赤水河流域生态环境保护和后续科学研究提供一定的科学基础。  相似文献   

9.
The role of ecotones with different (sharp or smooth) spatial boundaries between forest and meadow in ant biodiversity preservation was studied at the right-of-way of a power line in the Voronezh Reserve. The ecotone with a sharp boundary between forest and meadow (transitional zone 2 m wide) had higher species richness of ants compared to the ecotones (also 2 m wide) with smooth boundary between forest and meadow.  相似文献   

10.
With consideration of the data on soil temperature within the range of the Altai zokor Myospalax myospalax Laxmann (1773) published in the Handbook on the Climate of the Soviet Union, it has been shown that the actual temperature niche of this species is relatively narrow. Seasonal movements over the vertical profile of the burrow allow zokors to avoid exposure to subzero temperatures.  相似文献   

11.
嘉陵江干流鱼类群落生态结构分析   总被引:1,自引:0,他引:1  
鱼类群落生态结构是群落生态学研究的一个热点问题。通过野外调查和资料分析发现,嘉陵江干流分布鱼类有156种,隶属于7目18科85属。依据所摄取食物类型的不同,这些鱼类可以划分为浮游动物食性、浮游植物食性、着生藻类食性、水生植物食性、水生昆虫食性、软体动物食性、肉食性和杂食性等8种食性类型。使用相似性指数和相似性分析方法,对嘉陵江上、中和下游的鱼类组成及群落生态结构组成分析发现:(1)从上游到下游,鱼类物种逐渐增加;(2)整个嘉陵江干流中,水生昆虫食性的鱼类占3141%,肉食性占1923%,着生藻类食性占1859%,软体动物食性的占1154%,浮游动物食性占1026%,杂食性占641%,水生植物食性占192%,浮游植物食性占064%;(3)从上游到下游,肉食性鱼类所占比例逐渐增加,以水生昆虫和着生藻类为食的鱼类所占比例则逐渐减少,相似性分析表明,嘉陵江各江段鱼类群落生态结构组成的差异不显著。嘉陵江干流鱼类群落生态结构的组成和变化与水生态系统结构和功能的变化密切相关  相似文献   

12.
为了解三峡库区蓄水后小江流域鱼类群落现状及其历史变化,于2016年春季(5月)、秋季(9月)和冬季(12月)开展了小江鱼类调查。共调查到鱼类37种,隶属于6目11科;种类组成以鲤形目为主,占总数的64.86%,其中黑尾■Hemiculer tchangi和岩原鲤Procypris rabaudi为长江上游特有种类;草鱼Ctenopharyngodon idellus、赤眼鳟Squaliobarbus curriculus、■Elopichthys bambusa、鲫Carassius auratus、鲤Cyprinus carpio、鲢Hypophthalmichthys molitrix、鳙Aristichthys nobilis和黑尾■构成小江主要经济鱼类。对比历史资料分析显示:两次调查结果相似性指数为0.45(为中等不相似);特有种鱼类退化明显:主要经济鱼类组成发生了改变;土著鱼类物种多样性和资源量均呈明显下降趋势,而适应于静水或缓流水环境的鱼类呈上升趋势。推测水坝建设、过度捕捞及不合理的采砂活动等因素是导致变化的主要原因。结果建议,合理设置水坝(汉丰湖)调水机制,对于保护该水域土著鱼类资源具有重要意义。  相似文献   

13.
长江上游玉龙雪山植物物种多样性形成的探讨   总被引:5,自引:0,他引:5  
玉龙雪山位于云南省西北部的丽江市,是界于澜沧江和金沙江之间云岭山脉的主峰。南临丽江坝,东、西、北三面均为金沙江环绕,处于中国三大植物多样性中心之一的横断山区的核心地带,具有很高的植物物种多样性。该区有藻类植物31科72属196种,地衣植物17科20余种,在苔藓植物中有苔类45种、藓类130种,蕨类植物约有220 多种,种子植物有171科804属2 646种(不含栽培种及种下等级),其中中国特有种1 631种,占本区种子植物总数的61.46%。对玉龙雪山植物物种多样性的形成进行了探讨,认为玉龙雪山丰富的植物物种多样性主要来源于3个第三纪古植物区系成分即古北大陆、古地中海以及古南大陆成分,其中以古北大陆成分为主。之后的新构造运动及第四纪冰期冰川的反复作用,形成了玉龙雪山复杂多样的生态环境。来源于以上3个古植物区系成分的植物物种在以后的进化过程中经过不断分化、发展以及与临近区域的交流,形成了现在丰富的植物物种多样性格局。  相似文献   

14.
岷江上游山区聚落生态位地理特征与驱动因子间关系研究   总被引:1,自引:0,他引:1  
山区聚落生态位反映聚落在山地垂直方向上所处的空间位置及人类生活所能利用的资源空间,是当地居民长期适应山地自然环境的结果。基于岷江上游各民族山区聚落生态位和气象、社会、地形驱动因子的空间分布,借助冗余分析,构建山区聚落生态位地理特征与驱动因子间的多水平贝叶斯模型,定量刻画聚落生态位的民族属性对山区聚落生态位地理特征与驱动因子间关系的影响。结果表明:(1)影响研究区域内1 667个与各民族聚落生态位地理特征的驱动因子有显著差异,海拔和坡度对前者影响较大,海拔、坡度、干季和湿季湿度、距河流距离对后者影响较大,且海拔对两者的影响程度都最大,海拔和坡度地形驱动因子与干、湿季湿度和距河流距离间的相关性较弱。(2)干、湿季湿度气象驱动因子对藏-羌聚落生态位地理特征影响较大,距河流距离和距县城距离社会驱动因子、海拔和坡度地形驱动因子对藏族聚落生态位地理特征影响较大,这与藏族聚落生态位的分布面积和个数有关。(3)民族类型对聚落生态位地理特征指标与气象因子干季湿度间关系的影响最大,对聚落生态位地理特征指标与地形因子坡度间关系的影响最小。岷江上游山区聚落生态位地理特征与驱动因子间关系的研究,为量化山区聚落生态位与山地环境的关系提供了有效的数据支撑。  相似文献   

15.
With consideration of the data on soil temperature within the range and over the burrow depth of the greater mole rat Spalax microphthalmus Güld. (1770) published in the Handbook on the Climate of the Soviet Union, it has been shown that the fundamental temperature niche of this species is relatively narrow. The seasonal activity of the greater mole rat in the vertical plane of the burrow depends on the vertical distribution of soil temperature.  相似文献   

16.
一个国家或地区的作物生产是通过轮作进行的,某些地区存在耕地的弃耕现象。Wackernagel生态足迹方法没有考虑复种的影响,耕地类生态足迹核算结果实际是播种面积,而生态承载力核算得到的是耕地面积,因此,二者不具有可比性,生态足迹盈余核算存在逻辑性错误。从理论角度采用复种指数修正耕地类生态足迹,使核算结果为耕地面积,增强了生态足迹和生态承载力的可比性。用改进的生态足迹核算方法,分析了阜宁县区域生态经济系统1995~2003年的生态供需状况及发展能力变动趋势,采用生态足迹盈余强度评价区域可持续发展能力。1995~2003年,阜宁县人均生态足迹从1.120 7 hm2增加到2.434 0 hm2,人均生态承载力变化较小,人均生态赤字从0.815 3 hm2增加为2.017 2 hm2,发展能力由1.226 5增加为3.140 7,生态足迹盈余强度由-1.226 5增强为-0.495 7 hm2。基于改进的生态足迹核算方法得到的发展能力和人均GDP之间的相关系数大于Wackernagel方法所得结果,表明改进的生态足迹方法能更好地反映区域社会经济状况。  相似文献   

17.
一个国家或地区的作物生产是通过轮作进行的,某些地区存在耕地的弃耕现象。Wackernagel生态足迹方法没有考虑复种的影响,耕地类生态足迹核算结果实际是播种面积,而生态承载力核算得到的是耕地面积,因此,二者不具有可比性,生态足迹盈余核算存在逻辑性错误。从理论角度采用复种指数修正耕地类生态足迹,使核算结果为耕地面积,增强了生态足迹和生态承载力的可比性。用改进的生态足迹核算方法,分析了阜宁县区域生态经济系统1995~2003年的生态供需状况及发展能力变动趋势,采用生态足迹盈余强度评价区域可持续发展能力。1995~2003年,阜宁县人均生态足迹从1.120 7 hm2增加到2.434 0 hm2,人均生态承载力变化较小,人均生态赤字从0.815 3 hm2增加为2.017 2 hm2,发展能力由1.226 5增加为3.140 7,生态足迹盈余强度由-1.226 5增强为-0.495 7 hm2。基于改进的生态足迹核算方法得到的发展能力和人均GDP之间的相关系数大于Wackernagel方法所得结果,表明改进的生态足迹方法能更好地反映区域社会经济状况。  相似文献   

18.
Rockström et al. (2009a, 2009b) have warned that humanity must reduce anthropogenic impacts defined by nine planetary boundaries if “unacceptable global change” is to be avoided. Chemical pollution was identified as one of those boundaries for which continued impacts could erode the resilience of ecosystems and humanity. The central concept of the planetary boundary (or boundaries) for chemical pollution (PBCP or PBCPs) is that the Earth has a finite assimilative capacity for chemical pollution, which includes persistent, as well as readily degradable chemicals released at local to regional scales, which in aggregate threaten ecosystem and human viability. The PBCP allows humanity to explicitly address the increasingly global aspects of chemical pollution throughout a chemical's life cycle and the need for a global response of internationally coordinated control measures. We submit that sufficient evidence shows stresses on ecosystem and human health at local to global scales, suggesting that conditions are transgressing the safe operating space delimited by a PBCP. As such, current local to global pollution control measures are insufficient. However, while the PBCP is an important conceptual step forward, at this point single or multiple PBCPs are challenging to operationalize due to the extremely large number of commercial chemicals or mixtures of chemicals that cause myriad adverse effects to innumerable species and ecosystems, and the complex linkages between emissions, environmental concentrations, exposures and adverse effects. As well, the normative nature of a PBCP presents challenges of negotiating pollution limits amongst societal groups with differing viewpoints. Thus, a combination of approaches is recommended as follows: develop indicators of chemical pollution, for both control and response variables, that will aid in quantifying a PBCP(s) and gauging progress towards reducing chemical pollution; develop new technologies and technical and social approaches to mitigate global chemical pollution that emphasize a preventative approach; coordinate pollution control and sustainability efforts; and facilitate implementation of multiple (and potentially decentralized) control efforts involving scientists, civil society, government, non-governmental organizations and international bodies.  相似文献   

19.
The spatial structure of the total bird population at the level of communities has been studied in a definite area at the boundary between northern open forests and forest-tundra. The boundaries of communities have been delimited by mapping out areas with a homogeneous species composition. The pattern of communities is shown to be as follows: the species-richest part of a local species assemblage (characteristic of a given landscape type) forms the basic community, which is surrounded by poorer communities of increasingly variable composition and configuration, depending on distance from the basic community. The most distant communities consist almost exclusively of abundant and widespread species. A group of borderline communities of mixed composition is located at the boundary between two landscape complexes. Mechanisms accounting for such a pattern are discussed.  相似文献   

20.
四川省西北部地区是以藏羌民族集居为主的民族地区,也是四川省的生态资源中心。区域内自然保护区数量多、密度大,民族文化浓郁,经济发展落后,居民城市化率低。由于早期建立保护区指导思想的制约,现已建立的多数保护区的规划缺乏系统科学性,依然存在来自区域内部居民和外部经济活动对其的破坏。研究认为,要实现为区域社会经济可持续发展创造条件的保护区设立终极目的,必须对现有的保护区管理系统实施调整与完善,建立具有政府管理职能的资源保护特区,选择以城镇化为主要方式的保护区内就近生态移民,构建科学的自然保护区层次,形成政府(资源保护特区)与民族居民的资源保护利益共同体。  相似文献   

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