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1.
什么样的生境更有利于外来植物入侵,一直是入侵生态学重点关注的问题。本研究以豚草为实验入侵植物,探讨生境与豚草入侵的关系。通过人工草地群落试验发现,豚草入侵物种多样性水平为1、4、9、16四个不同人工植物群落与入侵有土壤种子库的裸地生境相比,其生物量平均减少590 g·m-2、植株高度平均降低43.7 cm、成活率平均降低21.4%,其在群落中的优势度平均降低0.695。说明已有植物群落定居的生境对豚草的入侵有强烈的抵御作用。由此推断豚草入侵裸地时,生境中存在大量的空余生态位,豚草很容易成为单优势物种,而豚草入侵已有植物群落的生境时,现有植物物种已占据了大量的生态位空间,其入侵性明显降低。研究结果揭示,对外来入侵植物的管理和防控上应采取以预防为主的策略,营造多样化的本地植物群落,减少人为裸地存在时间,可阻挡或延缓外来植物的入侵。 相似文献
2.
Crimmins SM Dobrowski SZ Greenberg JA Abatzoglou JT Mynsberge AR 《Science (New York, N.Y.)》2011,331(6015):324-327
Uphill shifts of species' distributions in response to historical warming are well documented, which leads to widespread expectations of continued uphill shifts under future warming. Conversely, downhill shifts are often considered anomalous and unrelated to climate change. By comparing the altitudinal distributions of 64 plant species between the 1930s and the present day within California, we show that climate changes have resulted in a significant downward shift in species' optimum elevations. This downhill shift is counter to what would be expected given 20th-century warming but is readily explained by species' niche tracking of regional changes in climatic water balance rather than temperature. Similar downhill shifts can be expected to occur where future climate change scenarios project increases in water availability that outpace evaporative demand. 相似文献
3.
应用相似离度法预测红火蚁在中国适生区域及其入侵概率 总被引：4，自引：0，他引：4
【目的】依据气候相似理论,采用相似离度法预测红火蚁在中国的适生区域及其入侵概率。【方法】收集红火蚁在世界范围的分布数据和国内外气候站点的气候数据,建立红火蚁原产地和严重发生地气候站点集合,采用相似离度法找到与气候站点集合最相似的地区。在气候因素影响下,相似程度相对百分比认为是红火蚁入侵中国政区和气候区的概率值,并且建立了预警级别。【结果】预测结果表明,香港、澳门、广东、广西的入侵概率均大于80%,处于红色警报区;安徽、江苏、上海、江西、浙江、福建、台湾、贵州、云南、海南的入侵概率在50%～80%,处于橙色警报区,其它地区均处于黄色警戒区和绿色小风险区。【结论】红、橙警报区需要采取适当的防控措施,川渝地区和云南东南部的气候与原产地气候较为相似,尽管目前尚未发现有红火蚁入侵,但由于红火蚁对气候具有很强的适应性,因此也应该采取相应的预防措施。此外,相似离度法尽管多用于气象研究领域,但在预测外来物种分布范围时也起到了良好的辅助效果。 相似文献
4.
Changes in Soil Biota Resulting from Growth of the Invasive Weed,Ambrosia artemisiifolia L. (Compositae), Enhance Its Success and Reduce Growth of Co-Occurring Plants 
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下载免费PDF全文 Exotic plant invasion presents a serious threat to native ecosystem structure and function. Little is known about the role of soil microbial communities in facilitating or resisting the spread of invasive plants into native communities. The purpose of this research is to understand how the invasive annual plant Ambrosia artemisiifolia L. facilitates its competition capacity through changing the structure and function of soil microbial communities. The soil characteristics of different areas invaded by A. artemisiifolia were examined. Greenhouse experiments were designed to assess the effect of A. artemisiifolia invasion-induced changes of soil biota on co-occurring plant growth, and on the interactions between A. artemisiifolia and three co-occurring plant species. The results showed that the soil organic C content was the highest in heavily invaded sites, the lowest in native plant sites, and intermediate in newly invaded sites. Soil available N, P and K concentrations in heavily invaded site were 2.4, 1.9 and 1.7 times higher than those in native plant soil, respectively. Soil pH decreased as A. artemisiifolia invasion intensity increased, and was lower in invaded sites (heavily invaded and newly invaded) than in native plant sites. The soil microbial community structure was clearly separated in the three types of sites, and A. artemisiifolia invasion increased anaerobe, sulfate-reducing bacteria and actinomycete abundance. Soil biota of invaded sites inhibits growth of co-occurring plants (Galinsoga parviflora Cav., Medicago sativa L. and Setaria plicata (Lam.) T. Cooke.) compared to soil biota from un-invaded sites, but facilitates A. artemisiifolia growth and competition with co-occurring plants. A. artemisiifolia biomass was 50-130% greater when competing with three co-occurring plants, compared to single-species competition only (invasion by A. artemisiifolia alone), in heavily invaded soil. Results of the present study indicated that A. artemisiifolia invasion alters the soil microbial community in a way that favors itself while inhibiting native plant species, with measurable effects on performance of co-occurring plants. 相似文献
5.
Parker et al. (Reports, 10 March 2006, p. 1459) showed that native herbivores suppress exotic plants more than native plants. Further analysis reveals that the effect of native herbivores is reduced on exotic plant species that are closely related to native species in the invaded region. Exotic plants may share traits with native congeners that confer similar resistance to resident herbivores. 相似文献
6.
研究了水生外来植物水盾草(Cabomba carolimana)入侵沉水植物群落的不同种群生态位特征和种间联结性.选择了其扩散区域内的24个样地进行群落学调查,测定了群落中13个种群的生态位宽度、生态位重叠、多物种间总体关联性及成对物种间联结性,结果表明:①水盾草入侵沉水植物群落13个种群中,水盾草的生态位宽度最大,金鱼藻(Ceratophyllum demersum)、黑藻(Hydrilla verticillata)和苦草(Vallisneria natans)次之.②水盾草与金鱼藻、黑藻、苦草和黄花狸藻(Utricularia aurea)间生态位重叠较大,与其他物种间的生态位重叠较小.③水盾草和金鱼藻、苦草、黑藻之间具有一定的正联结,而与其他物种间的联结性不显著,基本上趋于独立出现.由此可见,水盾草在中国急剧扩散,对常见的乡土种有很大的负面影响,导致群落物种多样性下降,应加强防控研究. 相似文献
7.
刺槐对乡土植被的入侵与影响 总被引：1，自引：0，他引：1
通过样带法和小样方法于2005年在山东泰山调查刺槐繁殖扩散和对乡土植被的入侵状况。结果表明,刺槐主要以根蘖繁殖进行扩散入侵,并且根蘖繁殖能力与根系是否受伤或是否被砍伐有密切关系;刺槐通过根蘖扩散进入已有高大乔木的林内,如油松人工林和侧柏人工林;在密闭均匀的林分内,刺槐只是伴生下木,很难形成优势群体,但在林隙处可以迅速生长而成为上层木,与乡土树种形成混交林;刺槐能扩散进入灌木丛,说明耐瘠薄能力很强。调查还发现有6种乡土木本植物能在刺槐林下天然更新并且正常生长。分析比较发现,刺槐目前能与泰山低山分布的许多乡土树种形成混交林,不会侵占掉乡土树种。由于刺槐寿命短,推测刺槐混交林会被乡土植被群落替代。刺槐是荒山造林的先锋树种,只要造林前合理设计树种配置,造林后加强管理,可以减少对自然、半自然的森林生态系统产生危害。该文研究结果可为刺槐的引种栽培管理提供理论依据。 相似文献
8.
[目的]调查两种入侵植物黄花刺茄和刺苍耳对新疆当地植物群落物种种类组成及物种多样性的影响.[方法]采用样方法选取两种入侵植物黄花刺茄和刺苍耳分布较多的样地,分别作20个有黄花刺茄和刺苍耳入侵的样方,并在与之相距5 m处没有其入侵的区域,作20个对照样方,应用重要值、物种丰富度指数和均匀度指数分析两种入侵植物入侵区域与未入侵区域当地群落的组成及植物多样性的变化.[结果]黄花刺茄的试验样方中共有植物6科14种,而对照样方中有7科29种;刺苍耳的对照样方中植物有11科31种,而试验样方中植物仅有9科23种.两种入侵植物验样方中多数土著物种的重要值均比对照样方中的物种重要值低,黄花刺茄样方中只有萹蓄和蒺藜的重要值相差较小;刺苍耳样方中只有狗尾草的重要值高于试验样方.两种入侵植物的试验样方和对照样方相比,物种丰富度和Pielou均匀度指数J均差异显著或极显著.[结论]黄花刺茄和刺苍耳的入侵影响了当地植物群落的结构和组成,导致物种数量减少,使物种多样性降低. 相似文献
9.
Alsos IG Eidesen PB Ehrich D Skrede I Westergaard K Jacobsen GH Landvik JY Taberlet P Brochmann C 《Science (New York, N.Y.)》2007,316(5831):1606-1609
The ability of species to track their ecological niche after climate change is a major source of uncertainty in predicting their future distribution. By analyzing DNA fingerprinting (amplified fragment-length polymorphism) of nine plant species, we show that long-distance colonization of a remote arctic archipelago, Svalbard, has occurred repeatedly and from several source regions. Propagules are likely carried by wind and drifting sea ice. The genetic effect of restricted colonization was strongly correlated with the temperature requirements of the species, indicating that establishment limits distribution more than dispersal. Thus, it may be appropriate to assume unlimited dispersal when predicting long-term range shifts in the Arctic. 相似文献
10.
若尔盖高原不同退化程度草地植物种群生态位特征 总被引：1，自引：0，他引：1
为探索高寒脆弱生态区不同退化程度草地生态系统中各植物种群资源利用能力,通过草地群落学调查结合物种重要值、Shannon-Wiener生态位宽度指数、Pianka生态位重叠指数等对若尔盖高原轻度退化、中度退化、重度退化和极重度退化草地植物群落特征及主要种的生态位进行了研究。结果表明:①在轻度、中度退化群落中,建群种为莎草科Cyperaceae植物线叶嵩草Kobresia capillifolia,已侵入不可食性杂类草,且具有较高的重要值;在重度、极重度群落中,建群种更替为禾本科Poaceae植物垂穗披碱草Elymus nutans和赖草Leymus secalinus,群落中不可食性杂类草的重要值高于轻度和中度退化群落。②随着退化程度加剧,除建群种具有较高的生态位宽度以外,退化草地指示种也在群落中占较大的生态位宽度,增加了草地优良牧草的生长压力。③群落中主要种之间的所有生态位重叠指数平均值随退化程度加剧而降低,依次为轻度退化（0.59）,中度退退化（0.58）,重度退化（0.42）和极重度退化（0.40）,主要种群之间对资源的利用随退化程度加剧在整体上逐渐趋向于离散。轻度退化群落中的线叶嵩草、黄帚橐吾Ligularia virgaurea,中度退化中的线叶嵩草、乳白香青Anaphalis lactea,重度退化中的垂穗披碱草以及极重度退化中的赖草,与群落中的其他种群之间的生态位重叠值较高。综上,若尔盖高原草地在退化过程中,伴随具有不同资源利用策略的植物种群替代的过程。 相似文献
11.
为探索河流生态修复的理论和技术,该文采用生态工程原理与技术研究了亚热带城市水源地受损河岸植物群落的修复方法,以植物种类组成、盖度、生物多样性为指标对修复效果进行了验证．结果表明,构建后的实验河段经过2年(亚热带生长季远长于温带或寒温带)的恢复后,成功地恢复了河岸乡土植物群落,优化了植物群落的结构．上游植物群落修复区(A-1区)通过乡土种的自然侵入,恢复了河岸植物群落;中游植物群落修复区(A-2区)通过建群种与自然侵入植物种间的竞争机制,构建了以茭白为优势种的河岸植物带;下游植物群落修复区(A-3区)增加芦苇和茭白的栽植密度以促使其不断扩张,形成了具有净化水质能力的河流湿地植物群落区．与对照区(B区)相比,A-1区、A-2区、A-3区的物种数和生物多样性都有了很大的提高,3个区河岸近水区的物种数到2006年分别增加到24、26、23种,河岸远水区增加到16、17、14种,而B区河岸近水区2006年仅为14种,河岸远水区12种;3个区的植物群落总盖度都达到了95%以上,对照区仅为55%左右．该研究变革了传统水利工程的设计理念,使治河不仅考虑到传统的工程安全和经济性,还应基于生态学原理进行水利工程设计,为治河理念提供了一个新的视点 相似文献
12.
桂西南喀斯特山地木本植物群落种间关系及CCA排序 总被引：2，自引：1，他引：2
基于桂西南喀斯特山地木本植物群落11个样方(20 m×20 m)取样调查,运用生态位理论、种间关系原理、双向指示种分析(TWINSPAN)和典范对应分析(CCA)方法,探讨主要木本植物间的种间联结性和相关性及其与环境因子之间的关系。结果表明:桂西南喀斯特山地木本植物群落中麻栎、枫香、蚬木占优势地位,罗伞树-鹅掌柴、九节-琴叶榕、澄广花-鱼骨木的生态位重叠度分别在3种木本植物群落中最大。麻栎次生林群落总体种间关系表现为不显著正关联,χ2检验统计显示正关联种对数有50对,负关联种对数有52对,无关联种对数有3对,正负关联比为0.96,检验显著率为6.67%。枫香次生林群落总体种间关系表现为不显著负关联,χ2检验统计显示正关联种对数有96对,负关联种对数有113对,无关联种对数有1对,正负关联比为0.85,检验显著率为8.10%。蚬木次生林群落总体种间关系表现为显著正关联,正关联种对数有19对,负关联种对数有17对,正负关联比为1.12,检验显著率为8.33%。CCA前瞻选择显示土壤pH值、全磷、坡向、土壤全钾、海拔是影响桂西南喀斯特山地木本植物群落物种组成与分布最重要的因子,总体上可以对76.95%的环境因子进行解释。物种间的正联结性越显著,其生态位重叠程度越高,反之,物种间的负联结性越显著,其生态位重叠程度则越低。 相似文献
13.
在广东省增城市次生林区和马尾松林、南洋楹林和湿地松林等主要人工林群落中设置了76个100矗的样方，开展这些群落优势种群的生态位研究．结果显示，变叶榕(Ficus variolosa、山乌桕(Sapium discolor)、罗浮柿(Diospyros morrisiana)和山苍子(Listea cubeba)等阳性、鸟播树种具有较高的生态位宽度，大多数次生林种类均具有较小的生态位宽度和生态位重叠。南洋楹与较多植物种类有较大的生态位重叠，反映南洋楹能与较多的乡土种类共存。建议根据植物生态位特点，采用相应的方法促进天然林树种的恢复和发展。 相似文献
14.
YIRu-han MASAEShiyomi SHIGEOTakahashi TADAKATSUOkubo 《东北农业大学学报(英文版)》2004,11(1):47-51
In order to understand the temporal changes of botanical composition in grassland ecosystem, and to clarify the relation between these changes and environmental impacts, such as climatic factors and artificial disturbance, a grazing trail was carried out during a 21-year period from 1974 at a sown grassland of the National Grassland Research Institute, located in Nishinasuno, the central area of Japan. The data sets of biomass for each mouth(from April to November)of the 21-year period were analyzed in this paper. The botanical composition of aboveground biomass varied greatly with both season and year. The biomass ratio of improved herbage species to invaded native plants gradually decreased each year. This may have been owing to meteorological factors, such as low air-temperature in winter, dry and hot summers, grassland management(including grazing intensity and fertilizer application), and inter-specific competition between native and introduced herbage plants. 相似文献
15.
Recent plant diversity changes on Europe's mountain summits 总被引：2，自引：0，他引：2
Pauli H Gottfried M Dullinger S Abdaladze O Akhalkatsi M Benito Alonso JL Coldea G Dick J Erschbamer B Fernández Calzado R Ghosn D Holten JI Kanka R Kazakis G Kollár J Larsson P Moiseev P Moiseev D Molau U Molero Mesa J Nagy L Pelino G Puşcaş M Rossi G Stanisci A Syverhuset AO Theurillat JP Tomaselli M Unterluggauer P Villar L Vittoz P Grabherr G 《Science (New York, N.Y.)》2012,336(6079):353-355
In mountainous regions, climate warming is expected to shift species' ranges to higher altitudes. Evidence for such shifts is still mostly from revisitations of historical sites. We present recent (2001 to 2008) changes in vascular plant species richness observed in a standardized monitoring network across Europe's major mountain ranges. Species have moved upslope on average. However, these shifts had opposite effects on the summit floras' species richness in boreal-temperate mountain regions (+3.9 species on average) and Mediterranean mountain regions (-1.4 species), probably because recent climatic trends have decreased the availability of water in the European south. Because Mediterranean mountains are particularly rich in endemic species, a continuation of these trends might shrink the European mountain flora, despite an average increase in summit species richness across the region. 相似文献
16.
生物入侵已成为世界性的生态、经济问题,是人类当前面临的巨大挑战.作为入侵生物中一个重要组分的外来入侵植物,其入侵不仅改变了入侵地地上植物群落的多样性,而且对入侵地的地下生态系统也产生了深刻影响.国内外的生态学家对于外来植物的入侵虽已提出多个机制假说,但真正机理还未明确.近年来兴起的外来入侵植物与入侵地土壤生态过程相互影响的研究为外来植物入侵机理的揭示提供了新思路.从两个方面综述了近年来对外来入侵植物与入侵地地下生态系统相互作用的研究结果:(1)入侵植物与入侵地土壤微生物的相互影响:外来入侵植物可通过破坏土著植物与土壤微生物问的共生关系、分泌化感物质影响入侵地微生物群落结构和功能、逃避原产地土传天敌、改变入侵地的微生物群落结构进而间接改变土壤养分循环等途径实现入侵;(2)入侵植物与入侵地土壤养分的相互影响:主要是入侵植物与入侵地土壤氮、磷、钾等几种大量元素及其他元素之间的相互作用.在综述国内外研究的基础上,探讨了外来入侵植物入侵机理研究中存在的问题及未来的研究方向,以期为外来植物入侵的预防、控制与生境恢复提供依据. 相似文献
17.
Bondevik S Mangerud J Birks HH Gulliksen S Reimer P 《Science (New York, N.Y.)》2006,312(5779):1514-1517
Estimates of the radiocarbon age of seawater are required in correlations between marine and terrestrial records of the late Quaternary climate. We radiocarbon-dated marine shells and terrestrial plant remains deposited in two bays on Norway's west coast between 11,000 and 14,000 years ago, a time of large and abrupt climatic changes that included the Younger Dryas (YD) cold episode. The radiocarbon age difference between the shells and the plants showed that sea surface reservoir ages increased from 400 to 600 years in the early YD, stabilized for 900 years, and dropped by 300 years within a century across the YD-Holocene transition. 相似文献
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以湖南省凤凰县刺楸(Kalopanax septemlobus)天然种群分布相对集中的9个样地作为资源位,按重要值总和排序确定主要植物种,应用Levins、Shannon–Wiener、Pianka和Schoener公式分析群落乔木层和灌木层总计29个主要植物种的生态位。结果表明:在乔木层中,刺楸的重要值总和最高(1.345),杉木、柞木、刺楸的生态位宽度较大;乔木层多数种对间的生态位重叠程度较高,对环境需求存在较高的相似性,高重叠种对的相似度为69.23%,高相似种对的相似度为52.75%;刺楸和其他物种的生态位重叠与其他物种的生态位宽度呈正相关;灌木层种间生态位分化不明显,在资源不足时极易产生竞争;生态位宽度值与生态位重叠值、生态位相似比例值关系复杂;刺楸生态位宽度较宽,当资源不足时,刺楸在竞争中不占优势,其种群更新会受到其他物种的影响。 相似文献
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澜沧江上游森林珍稀草本植物生态位研究 总被引：14，自引：1，他引：14
20 0 2年和 2 0 0 3年 7— 8月 ,笔者采用常规调查方法对三江源自然保护区内澜沧江上游物种进行了调查研究 .以不同群落类型和海拔高度作为资源位 ,分别以物种重要值和个体多度为生态位计测的状态指标 ,对澜沧江上游桃儿七、星叶草和角盘兰及选取的几种对照草本植物进行生态位的计测和分析 .结果表明 :桃儿七、星叶草、角盘兰生态位宽度值小 ,充分显示了它们的稀有性 ,在该地区应优先保护 .桃儿七种群在海拔 36 0 0～ 36 5 0m分布最多 ,并且种群数量随海拔高度的增加逐渐减少 ;星叶草种群在海拔 36 5 0～ 375 0m分布最多 ,但种群数量不随海拔高度变化呈现规律性变化 .草本植物物种的生态位相似性比例值大于 0 5的占 5 0 % ,桃儿七、星叶草、角盘兰的生态位相似性比例大 ,说明它们在该地区的生态位相似程度大 .草本植物的生态位重叠值较小 ,大于 0 0 1的占 2 1 4 3% .桃儿七、星叶草、角盘兰之间生态位重叠程度小 ,它们分布的群落类型相似程度小 . 相似文献