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植物物种多样性的垂直分布格局 总被引:75,自引:6,他引:75
生物多样性沿环境梯度的变化趋势是生物多样性研究的一个重要议题,而海拔梯度包含了多种环境因子的梯度效应,因此研究生物多样性的海拔梯度格局对于揭示生物多样性的环境梯度变化规律具有重要意义。在不同的研究尺度,植物多样性沿海拔梯度具有不同的分布格局,而形成这种格局的因素有很大差异。本文从α多样性,β多样性和γ多样性三个尺度总结了植物物种多样性沿海拔梯度分布格局及其环境解释。α多样性沿海拔梯度的分布格局在不同生活型的物种之间差异很大,但对于木本植物来说,虽然也存在其他格局,但α多样性随海拔升高而降低是被广泛接受的一种格局。在一般情况下,β多样性随着海拔的升高而降低,并且对于不同生活型的物种,β多样性沿海拔梯度具有相似的分布格局。γ多样性沿海拔梯度具有两种分布格局:偏峰分布格局和显著的负相关格局;特有物种数往往随着海拔的升高而减少,而特有度则随着海拔的升高而增加。 相似文献
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秦岭牛背梁植物物种多样性垂直分布格局 总被引:32,自引:0,他引:32
基于秦岭山脉中段牛背梁自然保护区南北坡垂直样带51个样方的调查资料,利用植被数量分析方法(TWINSPAN和DCA)对牛背梁植物群落进行了分类和排序,并分析了植物物种多样性沿海拔梯度的分布格局。结果表明,牛背梁的植被群落具有明显的海拔梯度格局,从低海拔到高海拔依次分布有:锐齿槲栎(Quercus aliena var.acuteserrata)林,桦木(Betula spp.)林.巴山冷杉(Abis Jargesii)林和亚高山灌丛。海拔梯度是牛背梁山区制约植物群落分布的主要因子,而坡向和坡度则起到次要作用。对物种多样性的分析表明,物种总数、木本植物物种多样性和草本植物物种多样性在南北坡具有不同的海拔梯度格局。物种总数在南坡呈现单峰分布格局,而在北坡分布趋势不明显;木本植物物种多样性在南北坡具有相似的分布格局:在低海拔沿海拔梯度变化不明显,而在高海拔则随海拔上升而急剧下降;草本植物物种多样性在南北坡沿海拔梯度变化的规律不明显。β多样性沿海拔梯度先减少后增加,形成两端高中间低的格局,说明中海拔地区生境条件较为均一,低海拔地区的人为活动增加了生境的异质性,而高海拔地区的生态过渡特性增加了物种的更替速率以及群落的相异性。 相似文献
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南岭东西段植物群落物种组成及其树种多样性垂直格局的比较 总被引:11,自引:0,他引:11
根据沿海拔梯度设置的样地的调查资料,对南岭东段的莽山和西段的猫儿山植物群落乔木层物种多样性的垂直分布格局进行了比较研究。莽山和猫儿山的植被类型差异不大,但相同植被类型的物种组成有比较明显的差异。随海拔的上升,两山体乔木的最大树高均呈现显著下降趋势。猫儿山乔木的最大胸径、胸高断面积之和以及立木密度在海拔梯度上呈单峰曲线变化趋势。莽山乔木的最大胸径、胸高断面积之和与海拔呈明显的负相关性,而立木密度的变化规律不明显。这种单峰曲线格局或负相关关系与中尺度上的海拔高度以及小尺度上的土壤特性、小地形以及人为干扰强度等因素有关。在海拔1000m以下的常绿阔叶林群落和1700m以上的山顶矮林群落,莽山乔木的物种丰富度均明显高于猫儿山。两山体的乔木种数与海拔之间都显示出负相关性,但莽山由于高海拔群落受人为干扰的影响,这种相关性不显著。乔木层α多样性沿海拔梯度没有表现出明显的变化规律,并且在两山体之间也看不出明显的差别。本文最后还对两山脉低海拔区段的常绿阔叶林群落的物种组成和多样性进行了对比分析,结果表明人为干扰导致猫儿山常绿阔叶林的物种丰富度(S)和α多样性(H’)明显低于莽山的原生性常绿阔叶林群落,而且落叶阔叶树种和毛竹(Phyllostachys pubescens)开始入侵到群落中。 相似文献
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物种多样性的梯度变化及原因 总被引:2,自引:0,他引:2
物种多样性在地球表层时空结构中的分布是不均匀的,存在梯度变化,包括物种多样性的空间梯度和时间梯度变化。本文在论述各种梯度变化及其特征的基础上,简要介绍了解释物种多样性梯度变化形成原因的几种学说。 相似文献
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长白山北坡植物群落组成、结构及物种多样性的垂直分布 总被引:45,自引:1,他引:45
通过沿海拔梯度的系统调查,运用TWINSPAN分类方法,划分出长白山北坡的主要植物群落类型,对这些群落的组成和结构进行了分析。利用物种丰富度、α多样性和β多样性等指标,研究了群落多样性随海拔梯度的变化趋势。结果表明,乔木层植物可分为4个群落类型:从低海拔到高海拔依次为红松(Pinus koraiensis)针阔混交林、红松针阔叶树种与云冷杉组成的过渡群落、云冷杉暗针叶林以及岳桦林(Betula ermanii)。乔木层优势种重要值的分析清楚地反映出长白山北坡植被垂直带谱的优势成分。径级频度分布的分析表明该区域主要群落的自我更新状况良好。植物物种多样性随海拔梯度的变化趋势为:随海拔升高,乔木层和灌木层的物种丰富度呈下降趋势,但草本层的变化趋势不明显;乔木层和灌木层的α多样性(Shannon-Wiener指数)呈下降趋势,草本层则变化不明显;无论是木本层还是草本层的Pielou均匀度指数均没有明显的变化;乔木层、灌木层和草本层植物的β多样性(Cody指数)均随着海拔的升高而下降。 相似文献
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为探明黔西北地区不同杜鹃灌丛群落特征和物种多样性变化,本研究以5个不同的杜鹃群落为研究对象,分析了物种组成、重要值和多样性指数。结果表明,5个群落共有33种植物,属16科23属,灌木层和草本层分别有27种和6种;优势种和共优势种植物分别为小果珍珠花、小果珍珠花+露珠杜鹃、小果珍珠花+露珠杜鹃、露珠杜鹃、露珠杜鹃+黄山杜鹃。5个杜鹃灌丛群落灌木层的α多样性指数差异明显,灌木层的Margalef丰富度指数、Simpson多样性指数均表现为露珠杜鹃+黄山杜鹃灌丛群落(V)最大,小果珍珠花灌丛群落(I)最小;Shannon-Wiener多样性指数和Pielou均匀度指数均表现为小果珍珠花+露珠杜鹃灌丛群落(II)最大,小果珍珠花灌丛群落(I)最小。露珠杜鹃+黄山杜鹃灌丛群落(V)有进一步演替为亚热带常绿阔叶林的趋势。杜鹃属植物覆盖度大的临近群落的Whittaker指数、Jaccard指数和Sorenson指数值均较覆盖度小的临近群落大。 相似文献
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为了解东北地区胡桃楸次生混交林乔木树种组成和多样性,在黑龙江、吉林和辽宁三省中东部23个胡桃楸典型分布区内,设置123块面积0.1 hm2圆形样地,对样地内DBH≥5 cm乔木树种的物种组成、区系特征、重要值、丰富度和多样性等进行调查与分析。结果表明:东北地区胡桃楸次生混交林内共调查到乔木物种48种,隶属于17科,31属,其中黑龙江省30种,隶属于14科,21属;吉林省37种,隶属于14科,25属;辽宁省35种,隶属于16科,25属。物种主要以北温带分布区类型为主,不同区域物种数量随纬度升高呈先增加后减少趋势,随海拔升高呈先增加后减少趋势,在海拔300~700 m物种数量最为丰富。3个地区调查样地内重要值排在前6的共有树种是胡桃楸(Juglans mandshurica)、春榆(Ulmus pumila)、色木槭(Acer mono)、蒙古栎(Quercus mongolica)和水曲柳(Fraxinus mandshurica),非共有树种为红松(Pinus koraiensis)(黑龙江)、紫椴(Tilia amurensis)(吉林)和花曲柳(Fraxinus rhynchoph... 相似文献
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在高黎贡山北段沿海拔梯度设置17个样地,采用数量分类,对高黎贡山北段植物群落类型、物种组成和多样性的垂直格局进行了研究.结果表明:(1)随着海拔的升高,森林群落类型由常绿阔叶林(2 000~2 300 m)依次过渡为以阔叶树为主的针阔混交林(2 300~2 600 m)、以针叶树为主的针阔混交林(2 600~3 000 m)和针叶林(3 000~3 100 m);(2)木本植物的物种丰富度随着海拔高度的增加显著下降,而草本植物的物种丰富度则随着海拔高度的增加先下降,然后在林线以上显著上升;(3)木本植物β多样性随着海拔的上升呈单调下降趋势,而草本植物β多样性在中海拔附近区域较低;(4)在植物区系方面,热带亚热带成分所占比例随海拔上升而下降,温带成分、世界分布成分则随着海拔的升高而增加.中国特有分布成分所占比重较小,主要分布在中海拔区域.总体上,温带成分占主导地位.区系平衡点在海拔2100~2200 m. 相似文献
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太白山南坡土壤种子库的物种组成与优势成分的垂直分布格局 总被引:15,自引:0,他引:15
本文通过野外植被调查和室内试验,采用物理方法从1220份土样中挑选种子,进行分类统计,研究了秦岭太白山南坡土壤种子库物种组成与优势成分的垂直格局。主要研究结果有:(1)从种子数量上看,在不同的海拔段,优势科不同;从物种数来看,海拔1600m和海拔2600m处的优势科数相对较多,有4个科;蔷薇科是种数最多的优势科。(2)桦木科的糙皮桦(Betula utilis)在16个海拔样地(海拔样地共有21个)中都是优势成分之一。糙皮桦和巴山冷杉(Abies fargesii)的种子储量在中等海拔呈现峰值;较高海拔处,糙皮桦作为优势成分之一所占的比例较大;而在低海拔则相对较小。(3)从种子库中种类组成上来看,草本种类占优势;从各样地土壤种子库的生活型组成并结合优势种类来看,乔木不仅在个体组成上占优势,大部分单优种类也是来自于乔木种类。灌木种类在土壤种子库中无论是种类组成,还是在个体组成上都没有表现出优势。本文为研究太白山南坡植物群落演替动态及其沿海拔梯度的变化提供了基础。 相似文献
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河北小五台山北坡植物物种多样性的垂直梯度变化 总被引:25,自引:0,他引:25
通过野外群落调查,分析了小五台山北坡植物物种多样性的垂直梯度变化。结果表明:(1)小五台山北坡的物种丰富度随海拔的升高逐渐减小,物种组成趋于简单,乔木树种渐少。d多样性指数变化较小,但呈现出随海拔升高先增大、后减小的趋势。(2)β多样性指数很好地反映了群落之问的变化。相异系数峰值出现在海拔1.400-1500m处灌丛向森林的过渡带和海拔2600—2700m处森林向亚高山草甸的过渡带。海拔1400-1500m处出现的Cody指数极大值反映了灌丛群落向森林群落的变化,而Cody指数在海拔2100—2200m的极大值反映了阔叶林和针叶林之间的过渡。(3)作为小五台山两种最为重要的阔叶树种,白桦(Betula platyphylla)和红桦(Betula albosinensis)沿海拔梯度出现明显的替代现象,随着海拔的升高,白桦逐渐为红桦所取代。 相似文献
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Ayako Shimono Huakun Zhou Haihua Shen Mitsuru Hirota Toshiyuki Ohtsuka Yanhong Tang 《Journal of Plant Ecology》2010,3(1):1
Aims To describe the biodiversity patterns of plants along an altitudinal gradient on the Qinghai-Tibetan Plateau and to clarify the bias in plant specimen records at high altitude.Methods We conducted a large-scale investigation of vegetation at a wide range of altitudes, focusing on a high-altitudinal range (3?200–5?200 m) at different locations on the Qinghai-Tibetan Plateau. We then compared the altitudinal distribution of plant species obtained from our field investigation with that in plant specimen records from published sources and an online database.Important findings Our data provide evidence that altitude plays a large role in regulating species composition on the Qinghai-Tibetan Plateau. We could not, however, detect a clear relationship between altitude and species richness, although a weak monotonically increasing trend of richness was detected with increasing altitude. According to specimen records, most species have been sampled at a wide range of altitudes, and the average range of 145 species is>2?000 m. Despite this wide range, more than half of the species we observed were at higher altitudes than the specimen records indicate. High-altitude areas have probably been so poorly sampled that only a small fraction of the resident species has been recorded. This study clearly shows the regional bias of specimen records in the Qinghai-Tibetan Plateau. 相似文献
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Chang-Ming ZHAO Wei-Lie CHEN Zi-Qiang TIAN Zong-Qiang XIE 《植物学报(英文版)》2005,47(12):1431-1449
One hundred and sixty plots, approximately every 100 m above sea level (a.s.1.) along an altitudinal gradient from 470 to 3 080 m a.s.1, at the southern and northern watershed of Mt. Shennongjia, China, were examined to determine the altitudinal pattern of plant species diversity. Mt. Shennongjia was found to have high plant species diversity, with 3 479 higher plants recorded. Partial correlation analysis and detrended canonical correspondence analysis (DCCA) based on plant species diversity revealed that altitude was the main factor affecting the spatial pattern of plant species diversity on Mt. Shennongjia and that canopy coverage of the arbor layer also had a considerable effect on plant species diversity. The DCCA based on species data of importance value further revealed that altitude gradient was the primary factor shaping the spatial pattern of plant species. In addition, the rule of the “mid-altitude bulge” was supported on Mt. Shennongjia. Plant species diversity was closely related to vegetation type and the transition zone usually had a higher diversity. Higher plant species diversity appeared in the mixed evergreen and deciduous broadleaved forest zone (900-1500 m a.s.1.) and its transition down to evergreen broadleaved forest zone or up to deciduous broadleaved forest zone. The largest plant species diversity in whole communities on Mt. Shennongjia lay at approximately 1 200 m a.s.1. Greatest tree diversity, shrub diversity, and grass diversity was found at approximately 1 500, 1 100, and 1 200 m a.s.l., respectively. The southern watershed showed higher plant species diversity than the northern watershed, with maximum plant species diversity at a higher altitude in the southern watershed than the northern watershed. These results indicate that Mt. Shennongjia shows characteristics of a transition region. The relationship between the altitudinal pattern of plant species diversity and the vegetation type in eastern China are also discussed and a hypothesis about the altitudinal pattern of plant species diversity in eastern China is proposed. 相似文献
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AimAnticipating and mitigating the impacts of climate change on species diversity in montane ecosystems requires a mechanistic understanding of drivers of current patterns of diversity. We documented the shape of elevational gradients in avian species richness in North America and tested a suite of a priori predictions for each of five mechanistic hypotheses to explain those patterns.LocationUnited StatesMethodsWe used predicted occupancy maps generated from species distribution models for each of 646 breeding birds to document elevational patterns in avian species richness across the six largest U.S. mountain ranges. We used spatially explicit biotic and abiotic data to test five mechanistic hypotheses proposed to explain geographic variation in species richness.ResultsElevational gradients in avian species richness followed a consistent pattern of low elevation plateau‐mid‐elevation peak (as per McCain, 2009). We found support for three of the five hypotheses to explain the underlying cause of this pattern: the habitat heterogeneity, temperature, and primary productivity hypotheses.Main ConclusionsSpecies richness typically decreases with elevation, but the primary cause and precise shape of the relationship remain topics of debate. We used a novel approach to study the richness‐elevation relationship and our results are unique in that they show a consistent relationship between species richness and elevation among 6 mountain ranges, and universal support for three hypotheses proposed to explain the underlying cause of the observed relationship. Taken together, these results suggest that elevational variation in food availability may be the ecological process that best explains elevational gradients in avian species richness in North America. Although much attention has focused on the role of abiotic factors, particularly temperature, in limiting species’ ranges, our results offer compelling evidence that other processes also influence (and may better explain) elevational gradients in species richness. 相似文献
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通过样线法调查并综合有关文献,录得珠峰保护区鸟类342种,并对其鸟类群落结构与多样性进行了分析。其中留鸟218种,夏候鸟67种,冬候鸟43种,旅鸟及迷鸟14种;国家一级保护鸟类8种,二级保护鸟类31种;东洋界132种,古北界156种,广布种54种,特有种19种。多样性指数2.4340,均匀性指数0.4371。研究表明,喜马拉雅山脉将保护区明显阻隔为南坡和北坡两种不同的生态景观。南坡鸟类群落以森林鸟类为主,东洋界成分占67%,垂直分带明显,多样性系数3.3983,均匀度指数0.6396;北坡鸟类群落以湿地和荒漠鸟类为主,古北界成分占77%。呈斑块状分布,多样性指数1.8751,均匀度指数0.4199,南、北坡鸟类群落的相似百分率为15.70,差异显著。 相似文献
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根据2021年3‒12月浅水II型浮游生物网在长岛南部海域10个航次调查结果, 研究了该海域浮游动物种类组成、群落结构的周年变化规律。共鉴定浮游动物53种(类), 其中浮游幼虫17类, 桡足类16种, 刺胞动物8种, 端足类3种, 枝角类、涟虫类、尾索动物各2种, 栉板动物、十足类、毛颚动物各1种。浮游动物种类数自3月起逐月升高, 并在7月达到最高值, 而后逐渐降低, 变化幅度是19‒38。受采样网具影响, 长岛南部海域浮游动物优势种以小型桡足类和浮游幼虫为主, 在排名前五位的优势种中, 小型桡足类拟长腹剑水蚤(Oithona similis)、小拟哲水蚤(Paracalanus parvus)、洪氏纺锤水蚤(Acartia hongi)出现在所有调查月份, 而大型桡足类中华哲水蚤(Calanus sinicus)出现2次, 浮游幼虫仅出现在夏季和秋季。在浮游动物各类群中, 桡足类丰度最高, 其次是浮游幼虫。多元统计分析结果显示, 不同月份间浮游动物群落结构总体差异达极显著水平(P < 0.01), 其中仅3月和4月差异不显著。与莱州湾、崂山湾、胶州湾对比, 长岛南部海域浮游动物物种数最少, 但物种多样性指数平均水平最高, 且周年变化幅度最小(2.73‒3.15), 可能与其水体流通性强、初级生产力较高有关。 相似文献
19.
Felicitas Hoppeler Ram Devi Tachamo Shah Deep Narayan Shah Sonja C. Jähnig Jonathan D. Tonkin Subodh Sharma Steffen U. Pauls 《Freshwater Biology》2016,61(11):1905-1920
- Ecological studies of freshwater biota in understudied regions are often obstructed by poor taxonomic knowledge. We posit that molecular tools can help alleviate this issue and present an example where we combined molecular tools, environmental data and ecological statistics to investigate the distribution and community ecology of an unknown fauna of hydropsychid caddisflies along altitudinal gradients in four Himalayan river systems of Central and Eastern Nepal.
- A total of 484 larval specimens from 34 tributaries were examined. Phylogenetic analysis of the mitochondrial cytochrome c oxidase I (COI) and the nuclear ribosomal RNA 28S were used to delineate molecular operational taxonomic units (MOTUs) applying three analytical methods: general mixed Yule‐coalescent (GMYC) model, Automatic Barcode Gap Discovery (ABGD) and Bayesian Phylogenetics and Phylogeography (BPP). Spatial distributional patterns and potential differences in ecological niches among MOTUs were statistically tested using regression and correlation approaches. Further, we examined the data for signs of non‐random structure in MOTU communities.
- MOTU diversity within the family of Hydropsychidae was generally high but varied across evaluated gene fragments and slightly among delineation methods. Yet, the subsequent evaluation of environmental and spatial drivers and resulting distributional patterns were highly consistent among the different MOTU estimates.
- Within each river system, we found community composition varied greatly along the altitudinal gradients, with many MOTUs associated with specific altitudinal ranges. Prevalent MOTU turnover at the river system scale indicated high β‐diversity in the hydropsychid community leading to high degrees of regional endemism. In the Langtang river system, we found fewer MOTU co‐occurrences than expected by chance.
- These results highlight the utility of DNA‐based approaches using variable genetic markers (mitochondrial or ribosomal nuclear) for primary biodiversity assessment of poorly studied groups or regions. Our study further shows that DNA‐based biodiversity measures are suitable for downstream applications, such as exploring fundamental questions in stream ecology.