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1.
多年生草本, 高17~40cm;根状茎褐色, 具褐色细弱的细根。茎丛生, 直立, 圆柱形, 直径0.7~1.4mm, 表面有纵条纹。叶基生和茎生;低出叶1~2枚, 鞘状褐色, 长0.5~1.5cm, 顶端尖;基生叶(1~)2(~4)枚;叶鞘长1.3~8cm, 边缘膜质, 叶耳卵形, 长1~3mm, 顶端渐尖;叶片线形, 下面圆, 上面具沟槽, 长8~26cm, 宽1~1.7mm, 顶端钝;茎生叶2~3枚;叶鞘长1~5cm, 边缘膜质;叶耳明显, 卵形, 膜质, 长1~3mm, 顶端钝, 叶片线形, 上面具沟槽, 下面圆, 长2.5~27cm, 宽0.8~1.5mm, 顶端钝。  相似文献   

2.
滇东南岩溶山地3种人工林群落林下植物群落学特征比较   总被引:2,自引:0,他引:2  
通过样地法比较了川滇桤木(Alnusferdinandi-coburgii)、墨西哥柏(Cupressuslusitanica)、银荆(Acaciadealbata)3个人工林群落林下植物和次生灌丛的群落学特征。结果发现,3个群落都以高位芽植物为主,其次为地面芽植物;在高位芽植物中又都以小高位芽植物比例较高;其叶型谱以中型叶为主。生活型谱和叶型谱都与滇中亚热带常绿阔叶林的群落相似。从3种人工林的群落学特征看,以川滇桤木林的水热条件最好;川滇桤木林的物种多样性最高,说明川滇桤木林林下植物种类成分复杂,生境优越,群落破坏后恢复能力最强,最有利于向顶极演替发展。  相似文献   

3.
极危植物焕镛木的群落学特征及其保护   总被引:2,自引:1,他引:1  
对广西罗城大黄泥常绿阔叶林进行样方调查,分析了极危植物焕镛木(Woonyoungia septentrionalis (Dandy)taw)群落的组成结构特征.1200 m2样地内有维管植物129种,隶属57科103属,以热带属占绝对优势;优势科为樟科、壳斗科、茜草科等.群落中焕镛木为优势种,重要值最大,为35.06,其次为粗丝木、红锥,重要值分别为22.09和19.66,因此,本群落可命名为焕镛木-粗丝木-红锥群落(Woonyoungia septentrionalis+Gomphandra tetrandra+Castanopsis hickelii Community).群落成层现象明显,可分为乔木层(3亚层)、灌木层和草本层3个层次,层间植物丰富.生活型以中、小高位芽为主,占67.18%.叶型以中、小型革质单叶为主.种群频度分布规律为A>B>CE,属于A级的种类占优势,为总种数的41.09%.乔木径级以小径级为主.焕镛木是我国南亚热带常绿阔叶林中非常珍稀濒危的物种,希望有关部门尽快在此设立保护区,以保护焕镛木的种质基因资源.  相似文献   

4.
木论喀斯特林区翠柏群落学特征的初步研究   总被引:6,自引:0,他引:6  
广西木论喀斯特林区,位于我国中亚热带南缘。据600m2翠柏群落样方调查结果:有维管束植物76种,隶51科69属,其中单种的属占89.9%。植物区系以热带分布区类型为主,占总属数(不含世界分布)的71.0%,温带分布占25.8%,但群落的种类组成是以亚热带成分占优势,按Rarnkiaer生活型分类系统,高位芽植物占82.9%,地面芽植物占15.8%,一年生植物占1.3%,缺少地上芽和地下芽植物;从生理角度分析,叶级以小型叶(包括微型和鳞型叶)为主,占59.2%;叶型以单叶占的比例最大,为86.8%,群落结构可分为乔、灌、草三层,其中乔木层又可分出二个亚层。对该群落各乔木种群的大小结构分析,显示出翠柏群落是相对稳定性较大的群落。  相似文献   

5.
封面说明     
大花杓兰(Cypripedium macranthum Sw.),隶属于兰科、杓兰属,为国家二级重点保护野生植物,北京市一级重点保护野生植物。多年生草本,植株高25。50cm。茎直立。基部叶鞘状;茎生叶互生,3—5枚,叶片椭圆形或卵状椭圆形,长10—16cm,宽6-8cm。花常单生,极罕2朵,紫红色,通常有暗色脉纹。外轮中萼片卵状椭圆形,合萼片卵形;  相似文献   

6.
锡林河河漫滩草甸群落的结构与生产力及其排序   总被引:1,自引:0,他引:1       下载免费PDF全文
 锡林河河漫滩主要草甸群落的植物组成、群落构成规律、地上植物量、群落间生态关系的研究表明:1)踏头草甸以中间型荸荠(Eleocharis intersita)、无脉苔草(Carex enervis)、巨序剪股颖(Agrostis gigantea)和湿中生杂类草共同建群,其地上植物量为445.64gDM·m-2,是该区草原群落的2—4倍;密花凤毛菊(Saussurea acuminata)杂类草草甸的地上植物量为3584.50gFM·m-2(鲜重);马蔺(Iris lactea)杂类草草甸的地上现存量为1444.02gFM·m-2(鲜重)。2)与该区草原群落相比,草甸群落或没有单种建群植物,或单种建群植物的作用不很突出。说明了草甸优越的生境可满足多种植物共同充分生长。3)河漫滩不同草甸群落的排序表明:在积水生境中沼泽植被的外围、较为湿润的地段上分布着以莎草科植物为主的莎草(苔草)草甸;中度湿润的地段分布着以禾本科植物为主的禾草草甸;而相对较干的地段分布着以双子叶植物为主的杂类草草甸。  相似文献   

7.
林芝云杉群落特征的研究   总被引:3,自引:1,他引:3  
析了林芝云杉( Picea likiangensis var. linzhiensis )群落的种类组成、区系特征、群落外貌、垂直结构和水平结构等特性。结果表明:调查样地共有维管植物144种,隶属于53科116属,其中只含1种的属占81.03%。林芝云杉群落的区系组成、植物生活型谱、叶片性质等特征反映了群落的温带性质。群落垂直结构明显,可分为乔木层、灌木层、草本层及层间植物,乔木层郁闭度为0.4~0.8,林芝云杉大多为乔木层的单一优势种,有时与急尖长苞冷杉(Abies georgei var. smithii)、华山松(Pinus armandii)等混生,而群落植物的水平分布不均匀。优势种种群的年龄结构分析表明,该种群处于稳定状态;群落的物种丰富度为32.6364,其Shannon-Wiener指数为3.0926,Simpson指数为0.9366,均匀度指数为0.8942,且均为草本层>灌木层>乔木层。  相似文献   

8.
大盘山自然保护区香果树群落结构特征   总被引:5,自引:0,他引:5  
对浙江省大盘山国家级自然保护区香果树群落结构特征以及香果树种群结构进行了调查研究。研究表明,香果树主要伴生种为具有热带性质的樟科和山茶科的一些物种;该群落乔木层、灌木层、草本层的物种丰富度、多样性、均匀度都偏低,优势度相对较高;其生活型以包括藤本在内的高位芽植物占绝对优势,达75.90%;叶级以中型叶为主,占53.97%,小型叶次之,占36.51%;叶型以单叶占有较大的优势,达74.70%;叶质以纸质叶为主,占63.86%。香果树在群落水平结构上整体成聚集分布状态,垂直结构上明显分成3个亚层;种群更新不良,具有明显的衰退趋势。  相似文献   

9.
新疆的短命植物(三)群落学意义和资源价值   总被引:3,自引:0,他引:3  
在中亚西部荒漠亚区,短命植物种类丰富(乌兹别克斯坦即有250种之多),且发育繁茂。由其所形成的草群,外貌状若草甸、草原或荒漠,曾被一些早期的地植物学家描述为不同的植物群落类型。我国的植物学工作者,对局部地段或小生境中群集生长的短命植物草被现象,常称之为“小群落”或“群聚现象”,在文献中也从不使用短命荒漠、短命草甸、萨旺纳或半萨旺纳等植物群落类型的名称。新疆的短命植物总是或多或少地出现在某些植物群落之中,所以我们更加强调它的群落学意义。在新疆北部的莫索湾沙区,短命植物种类占白梭梭群落全部种类组成的…  相似文献   

10.
海南铜铁岭热带低地雨林群落特征研究   总被引:8,自引:3,他引:5  
根据样方调查的结果,分析了海南岛铜铁岭热带低地雨林群落的种类组成、区系成分、外貌特征和年龄结构.结果表明,在2600m2样方中,有维管束植物88科186属258种;优势科为番荔枝科、大戟科、茜草科、樟科、芸香科、桃金娘科等.区系地理成分可分为10种类型,热带分布的属占绝对优势,达94.89%.群落的生活型以高位芽为主,群落外貌主要由革质、单叶和中型叶为主的常绿阔叶林高位芽植物决定.群落成层现象明显,可分为乔木层、灌木层、草本层,乔木层可再划分为2~3个亚层.种群频度分布规律为A>B>C>D>E 按Raunkiaer将频度指数划分 ,属于A级的种类占优势,为总种数的70.54%,大部分种类具有10个以下个体.乔木径级分布呈金字塔形,小径级占优势.  相似文献   

11.
A key issue in evolutionary biology is whether selection acting at levels higher than the individual can cause evolutionary change. If it can, then conceptual and empirical studies must consider how selection operates at multiple levels of biological organization. Here, we test the hypothesis that estimates of broad‐sense community heritability, HC2, can be used to predict the evolutionary response by community‐level phenotypes when community‐level selection is imposed. Using an approach informed by classic quantitative genetics, we made three predictions. First, when we imposed community‐level selection, we expected a significant change in the average phenotype of arthropod communities associated with individual tree genotypes [we imposed selection by favoring high and low NMDS (nonmetric multidimensional scaling) scores that reflected differences in arthropod species richness, abundance and composition]. Second, we expected HC2 to predict the magnitude of the community‐level response. Third, we expected no significant change in average NMDS scores with community‐level selection imposed at random. We tested these hypotheses using three years of common garden data for 102 species comprising the arthropod communities, associated with nine clonally replicated Populus angustifolia genotypes. Each of our predictions were met. We conclude that estimates of HC2 account for the resemblance among communities sharing common ancestry, the persistence of community composition over time, and the outcome of selection when it occurs at the community level. Our results provide a means for exploring how this process leads to large‐scale community evolutionary change, and they identify the circumstances in which selection may routinely act at the community level.  相似文献   

12.
Soil degradation has been found in urban forests in Shanghai, especially in the pure plantations. Mixed plantations are considered to improve soil quality because they can stimulate organic matter cycling and increase soil carbon and nutrient content. Although soil microbes play crucial roles in regulating soil biogeochemical processes, little is known about how mixed plantations affect soil microbial communities, including bacteria, archaea, and fungi. Here, we evaluated soil chemical properties, abundances and compositions of soil bacterial, archaeal, and fungal communities, and enzyme activities in pure and mixed Metasequoia glyptostroboides and Bischofia polycarpa plantations, located in Shanghai, China. The results showed that soil available phosphorus content in the mixed plantation of M. glyptostroboides and B. polycarpa was significantly higher than that in pure plantations, while no significant difference was observed in the content of soil organic carbon, total and available nitrogen, total and available potassium among the three studied plantations. We found higher fungal abundance in the mixed plantation, when compared to both pure plantations. Moreover, fungal abundance was positively correlated with the content of soil available phosphorus. No significant difference was found in the abundance and diversity of bacterial and archaeal community among the three studied plantations. A similarity analysis (ANOSIM) showed that mixed plantation significantly altered the community composition of archaea and fungi, accompanied with an increase of alkaline phosphatase activity. However, ANOSIM analysis of bacterial communities showed that there was no significant group separation among different plantations. Overall, results from this study indicated that fungal and archaeal communities were more sensitive to aboveground tree species than bacterial community. Moreover, mixed plantations significantly increased the activity of alkaline phosphatase and the content of soil available phosphorus, suggesting that afforestation with M. glyptostroboides and B. polycarpa is an effective way to alleviate phosphorus deficiency in urban forests in Shanghai, China.  相似文献   

13.
1. Three floods (July 2000, August 2002, September 2003) and a hurricane (October 2001) that occurred in a lowland forest in the southern Maya Mountains of Belize presented an opportunity to evaluate the influence of these disturbances on the structure of a small mammal assemblage. 2. Four terrestrial and four primarily scansorial/arboreal species were trapped July 2000-March 2005 in six grids over 14 irregularly spaced trapping periods. 3. Community dynamics were characterized more by changes in species composition than changes in diversity. The dynamics were driven by species-specific variation in abundance, with changes in composition generally, but not exclusively, due to the occurrence or disappearance of species at low abundance. Despite the disturbances, species richness remained relatively constant. Evenness within the assemblage was consistently low, primarily as a result of dominance by one species, Heteromys desmarestianus. 4. Effects of flooding on community structure were direct but relatively brief (< 1 year), and varied with the duration and intensity of flooding. Effects from the hurricane were indirect but long-lasting and strongly related to severely reduced food resources. 5. This study suggests that long-term dynamics in the structure of many animal communities in the tropics often results from interactions between direct and indirect effects of disturbance. It also suggests that community resistance will depend on variation in disturbance type and regime, but resilience will be determined by the life-history characteristics of each species.  相似文献   

14.
应用中性理论分析局域群落中的物种多样性及稳定性   总被引:5,自引:2,他引:5  
张立敏  陈斌  李正跃 《生态学报》2010,30(6):1556-1563
如何解释群落中物种的丰富与稀少,并对物种多样性和群落稳定性进行合理的量化评价是群落生态学研究中的一个热点问题。20世纪中期,MacArthur将影响自然群落稳定性的因素归结为物种数量多少以及物种间相互作用的大小,20世纪末Doak等学者提出群落的容纳能力和物种间的维持机制是决定群落稳定性的关键因素。同时对群落结构及物种间维持机制的研究也有了新的突破,Hubbell提出"生物多样性与生物地理学统一的中性理论(Unified Neutral Theory of Biodiversity and Biogeography)"为群落生态学研究提供了新的思路和方法。从群落中性理论的基本假设出发,对Hubbell中性理论中局域群落的物种多度动态模型进行分析,归纳得出群落中性理论中物种多样性与群落稳定性之间的量化关系。封闭的局域群落中,出现物种灭绝或单物种独占的时间与群落大小及物种相对多度成正比,物种多样性程度的增加可延长物种灭绝或独占的时间;开放的局域群落中,物种多度期望值与局域群落大小、物种在集合群落中的物种相对多度成正比,周围群落中物种的灭绝会引起局域群落中相应物种的灭绝,最终导致整个生态群落物种多样性的降低;群落中物种多度的方差与局域群落大小、迁移率、物种在集合群落中的物种相对多度相关,局域群落物种多度的波动幅度随着群落间生态隔离的减弱或物种多样性程度的增加而减小。由此,集合群落物种多样性是影响局域群落物种多样性的重要因素,生态隔离程度的减弱及物种多样性的增加都将增强群落的稳定性。  相似文献   

15.
The mechanisms that determine the spatial structure of macroscopic and microbial communities and how they respond to environmental changes are central themes that have been explored in ecological research. However, little is known about the relative roles and importance of neutral and niche-related factors in the assemblage of bacterial, fungal, and plant communities. Here partial Mantel, null model, and variation partitioning analysis were used to compare mechanisms driving the beta diversity of bacteria, fungi and plant communities at the regional scale in arid and semi-arid areas. Denaturing gradient gel electrophoresis (PCR-DGGE) was used to evaluate the distribution pattern of microbial communities, and vegetation survey were conducted to evaluate the characteristics of plant communities. We found that bacterial, fungal, and plant communities were strongly influenced by niche processes at the regional scale in arid and semi-arid areas. Bacteria had a stronger habitat association, indicating community assembly is strongly affected by niche processes. Fungi, with their body size between plants and bacteria, had moderate environment correlation, and plants had less environment association than fungi or bacteria, which suggests that body size may determine the association between organism and environment. We concluded that the pivotal niche process, environmental filtering, weakened with increasing body size, and it should be considered when we evaluate the relative roles of deterministic and stochastic processes in community assemblage.  相似文献   

16.
何云川  杨贵军  王新谱 《昆虫学报》2018,61(12):1439-1452
【目的】调查和分析银川不同湿地陆生昆虫群落结构组成、功能多样性及其稳定性变化。【方法】2016年5-10月选取银川黄河湿地(HH)、鸣翠湖湿地(MCH)、芦花台湿地(LHT)、水洞沟湿地(SDG)4种湿地生境,采用棋盘式扫网和陷阱捕捉的方法进行昆虫采集。根据调查数据进行昆虫群落结构多样性分析、主成分分析和聚类分析。【结果】4种湿地生境共采集昆虫38 668头,隶属13目97科370种。双翅目、同翅目、膜翅目在4种生境中均为优势类群。植食性(Ph)昆虫功能团的科数和种数在4种生境昆虫群落中占比均最大。植食性-中性昆虫(Ph-Ne)间个体数在4种生境下均存在显著负相关(P<0.01);植食性-捕食性昆虫(Ph-Pr)间个体数在MCH生境下存在显著正相关(P<0.05);中性-捕食性昆虫(Ne-Pr)间个体数在MCH生境下存在显著负相关(P<0.01),在LHT生境下存在显著负相关(P<0.05);4种功能团结构的其他组合的个体数在4种生境下均不存在显著相关性。主成分分析结果表明,捕食性类群是4个类群中影响构成昆虫群落组成的主要成分。同种功能团在4种生境下的多样性分析结果表明,捕食性功能团(Pr)与寄生性功能团(Pa)在4种生境群落中的群落丰富度、均匀程度[辛普森指数(Simpson index)]差异性显著(P<0.05),而植食性功能团(Ph)与中性功能团(Ne)的群落丰富度、均匀程度的差异性不显著(P>0.05);中性功能团(Ne)在4种生境群落中个体出现的不确定程度[香农-维纳指数(Shannon-Wiener index)]差异性不显著(P>0.05),在4种生境的均匀度指数(Pielou evenness index)差异性显著(P<0.05),其余3个功能团在4种生境下的香农-维纳指数均差异性显著(P<0.05),在4种生境下的均匀度指数均差异性不显著(P>0.05)。4种生境昆虫群落特征指数的聚类分析分为2类,永久性湿地HH和MCH为第1类,季节性湿地LHT和SDG为第2类。Ss/SiSa/Sp两个稳定性指标均显示MCH昆虫群落稳定性最高,4种生境昆虫群落最稳定的时期是5和9月。【结论】双翅目和膜翅目昆虫在银川不同湿地生境中均为优势类群,可作为环境指示参考;昆虫群落稳定性最好的湿地类型为永久性湖泊湿地;不同生境昆虫群落多样性随季节时序变化,在银川最稳定的时期是5和9月。气候因子、环境因素如何驱动各湿地昆虫群落多样性及稳定性的变化因素还有待开展研究。  相似文献   

17.
拉鲁湿地主要植物群落结构及物种多样性   总被引:2,自引:0,他引:2  
李春  周刊社  李晖 《西北植物学报》2008,28(12):2514-2520
2002年6~9月对拉鲁湿地植物种类、群落结构、生物量以及物种多样性进行了调查研究.结果表明:(1)拉鲁湿地共有植物30科52属85种,主要有芦苇[Phragmites australis(Cav.)Trin.ex Steud.](A)、尼伯尔酸模(RumexnepalensisSpreng)(B)、水葱(Scirpus validusVahl)(C)、穗状狐尾藻(MyriophyllumspicatumL.)(D)、灯芯草(Juncus effususL.)(E)、针叶苔草(CarexonoeiFranch.et Sav.)和黑褐苔草(CarexatrofuscaSchkuhr)(F)、藏北嵩草(KobresialittledaleiC.B.Clarke)(G)、藏蓟[Cirsiumlanatum(Roxb.ex Willd.)Spreng.](H)等8个主要植物群落.(2)在8个主要植物群落中,嵩草群落所含物种数最多,为44种,穗状狐尾藻群落最少,仅8种;芦苇群落生物量最高,为124.5~1 027.0 g/m2,藏蓟群落生物量最低,为124.5~220.5 g/m2;优势种芦苇的生物量最高,为183.5~660.0 g/m2,藏蓟生物量最低,为43.1~76.3 g/m2.(3)各群落的垂直结构特点是:芦苇群落、水葱群落、穗状狐尾藻群落具有挺水层、浮叶层和沉水层,其他群落只具有可分为高、低两层的草本层.(4)在各群落的相似性方面,嵩草群落与藏蓟群落、水葱群落与芦苇群落和尼伯尔酸模群落的相似性要明显高于其他群落,其Jaccard系数分别为0.549 0、0.538 5、0.500 0;芦苇群落、尼伯尔酸模群落、水葱群落、穗状狐尾藻群落与藏蓟群落以及芦苇群落、穗状狐尾藻群落与嵩草群落在建群种上没有相似之处,Jaccard系数为0.  相似文献   

18.
凋萎病是制约杨梅产业发展的严重病害。为了有效防控凋萎病,本研究分析了杨梅健康和感染凋萎病树体各部位及根表土和根围土中细菌和真菌群落的丰富度与多样性的差异。结果表明: 与健康树相比,病树根围土、根表土、根、枝干、枝皮和叶片的细菌和真菌丰富度均发生了显著变化,其中,根表土细菌和枝皮内真菌的丰富度和多样性均显著降低,而枝皮内细菌和根表土的真菌丰富度和多样性均显著升高。病树各部位及根表、根围土细菌和真菌的优势菌相对丰度在门、纲和属水平上发生了明显的变化,在病树枝干、根和根表土中的假单胞菌属及根表土、根围土中的镰刀菌属的相对丰度明显降低,病树根表土及根围土中青霉菌属的相对丰度明显增加。与凋萎病菌同属的拟盘多毛孢菌在病树根内显著减少,而在其他位置均大量增殖,其相对丰度与多数相对丰度较高的真菌呈正相关。本研究结果将为开发杨梅凋萎病的生态改良、培育健康树体和生物防治技术提供有效的理论依据。  相似文献   

19.
蒙古扁桃(Amygdalus mongolica)是中国珍稀濒危保护植物, 对植物区系进化、维持荒漠生态系统多样性与稳定性具有较高的学术价值和诊断意义。在宁夏境内设置14个样地, 利用样地调查法对蒙古扁桃群落组成进行了研究。结果表明: 蒙古扁桃群落记录到物种有74种, 隶属于28科53属; 生长型统计显示乔木2种, 灌木21种, 半灌木11种, 多年生草本36种, 一年生草本4种。依据TWINSPAN等级分类将14个蒙古扁桃样地划分为蒙古扁桃-草本荒漠、蒙古扁桃-半灌木荒漠2个群丛组和蒙古扁桃-戈壁针茅(Amygdalus mongolica - Stipa tianschanica var. gobica)、蒙古扁桃-猫头刺(Amygdalus mongolica - Oxytropis aciphylla)、蒙古扁桃-短花针茅(Amygdalus mongolica - Stipa breviflora)、蒙古扁桃-蓍状亚菊(Amygdalus mongolica - Ajania achilleoides)、蒙古扁桃-阿拉善披碱草(Amygdalus mongolica - Elymus alashanicus)、蒙古扁桃-蓍状亚菊+短花针茅(Amygdalus mongolica - Ajania achilleoides + Stipa breviflora) 6个群丛。该研究结果将为蒙古扁桃的保护和利用以及该群系植被志的编纂提供基础数据。  相似文献   

20.
The discrepancy between high primary production and poor fish yields in some tropical reservoirs, especially in Souht East Asia, is apparently due to the fact that not all available trophic levels are utilized. Data analysis has shown that this is due to the riverline origin of fish communities which are not well adapted to lacustrine habitats in such lakes and reservoirs. These fishes are able to inhabit only a relatively narrow belt of the shallow inshore area. It has been shown that fish are rare in the deep water and pelagial area of geologically young lakes and reservoirs. Although most riverine fish are also able to inhabit the lacustrine habitat, only a few are preadapted to take advantage of deep or open water environments. In the tropics, Cichlidae and freshwater Clupeidae thrive in lakes and reservoirs. It is apparent that within these families suitable species can be chosen as potential candidates for introduction into young lakes and reservoirs. However, any fish introductions must be scientifically evaluated for desirability. Data from other lakes in the world have indicated that the present theory can be expanded to other than tropical lakes.  相似文献   

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