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1.
北京山区栎林的群落结构与物种组成 总被引：24，自引：0，他引：24
在北京东灵山、喇叭沟门和大海陀山地区的辽东栎(Quercus liaotungensis)林以及白龙潭地区的槲树(Q.dentata)-麻栎(Q.acutissima)混交林中共调查了43个样方,利用这些样方资料,对群落进行TWINSPAN聚类和CCA排序,以研究北京地区栎林的群落结构、物种组成以及各群落之间的关系。结果表明：本地区栎林群落结构简单,不同栎林群落的结构差异很大。利用TWINSPAN对乔木层物种进行了分类,按不同指示种划分为7类。CCA排序结果显示第一轴与海拔关系显著,主要反映了温度因子的作用;第二轴与坡向关系显著,反映了水分因子的作用。排序结果与分类结果吻合,显示了不同生境条件对群落结构和物种分布的影响。结果还显示,本地区物种丰富度低,这可能与本地区植被受人为干扰强烈有一定关系。 相似文献
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Olivier J. Hardy Pierre Couteron François Munoz B. R. Ramesh Raphaël Pélissier 《Global Ecology and Biogeography》2012,21(10):1007-1016
Aim We addressed the roles of environmental filtering, historical biogeography and evolutionary niche conservatism on the phylogenetic structure of tropical tree communities with the following questions. (1) What is the impact of mesoclimatic gradients and dispersal limitation on phylogenetic turnover and species turnover? (2) How does phylogenetic turnover between continents compare in intensity with the turnover driven by climatic gradients at a regional scale? (3) Are independent phylogenetic reconstructions of the mesoclimatic niche of clades congruent between continents? Location Panama Canal Watershed and Western Ghats (India), two anciently divergent biogeographic contexts but with comparable rainfall gradients. Methods Using floristic data for 50 1‐ha plots in each region, independent measures of phylogenetic turnover (ΠST) and species turnover (Jaccard) between plots were regressed on geographic and ecological distances. Mesoclimatic niches were reconstructed for each node of the phylogeny and compared between the two continents. Results (1) The phylogenetic turnover within each region is best explained by mesoclimatic differences (environmental filtering), while species turnover depends both on mesoclimatic differences and geographic distances (dispersal limitation). (2) The phylogenetic turnover between continents (ΠST = 0.009) is comparable to that caused by mesoclimatic gradients within regions (ΠST = 0.010) and both effects seem cumulative. (3) Independent phylogenetic reconstructions of the mesoclimatic niches were strongly correlated between the two continents (r = 0.61), despite the absence of shared species. Main conclusions Our results demonstrate a world‐wide deep phylogenetic signal for mesoclimatic niche within a biome, indicating that positive phylogenetic turnover at a regional scale reflects environmental filtering in plant communities. 相似文献
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揭示区域物种组成随环境梯度的变化规律, 掌握物种多样性的周转过程及其与环境的耦合关系, 是理解物种多样性形成的生态过程的核心, 也是生物多样性保护和保护地网络构建的科学基础。神农架是众多古老、孑遗和特有植物的关键栖息地, 也是全球落叶木本植物最丰富的地区之一。然而, 我们对影响神农架植物物种周转并形成镶嵌格局的驱动因素知之甚少。本研究基于对神农架长期系统的植物群落物种调查数据, 通过广义相异模型(GDM)和偏回归分析等方法, 分析了气候差异、地理距离、人为干扰等因素对神农架植物物种周转的驱动效应。结果表明, 随着年均温(MAT)、≥ 0℃积温、≥ 10℃积温差异和地理距离增大, 植物β多样性显著增加, 而年均降水量(MAP)、距离道路距离及森林破碎化等人为干扰因素对植物β多样性无显著影响。地理距离、气候差异和人为干扰分别解释了物种相异性变异的28.75%、34.56%和12.55%, 其交互作用解释了变异的8.52%。地理距离、气候差异和人为干扰共同解释了物种相异性变异的43.47%。综上, 地理距离和温度分异是驱动神农架植物物种空间周转过程的关键因素。保护海拔梯度上植被的垂直带谱及复杂多样的地貌异质性, 是维持神农架物种周转生态过程的关键, 也是神农架国家公园建设乃至鄂西北保护地网络构建应关注的重点。 相似文献
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内蒙古阿拉善地区分布着超过20万km2的典型戈壁生态系统, 且这些戈壁生态系统正遭受着持续性气候变暖与极端天气的影响。然而, 土壤、气候、空间变量等因子对阿拉善戈壁大尺度植物β多样性及其关键组分的相对影响还没有得到系统研究。本文通过对阿拉善典型戈壁生境的276个样方进行植物群落组成调查, 并结合气候、土壤等数据, 探讨了地理距离和环境因子对阿拉善戈壁区植物群落β多样性及其组分的影响。研究表明: (1)在阿拉善戈壁区, 随着地理距离的增加, 植物群落β多样性及物种周转组分显著增加, 而且β多样性主要源于物种周转组分, 物种嵌套组分的贡献非常有限; (2)偏Mantel分析显示环境因子和地理距离对β多样性及其物种周转组分均有显著的单独作用; 方差分解结果进一步表明, 环境因子和地理距离共同解释了植物β多样性及其物种周转组分10.84%-17.67% (Bray-Curtis)和15.47%-24.81% (Sørensen)的变异, 但环境因子可以单独解释更多的变异(6.62%-9.97% (Bray-Curtis)和8.98%-14.51% (Sørensen))。在众多环境因子中, 气温日较差、土壤含水量和地表砾石盖度对植物群落β多样性和物种周转组分的贡献更大。以上结果表明, 环境过滤、扩散限制以及其他未知过程可能共同影响阿拉善戈壁区植物群落β多样性格局, 其中环境过滤可能具有更大的影响。 相似文献
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Brandon Hendrickson; 《Ecology and evolution》2024,14(6):e11583
Phylogenetic diversity offers critical insights into the ecological dynamics shaping species composition and ecosystem function, thereby informing conservation strategies. Despite its recognized importance in ecosystem management, the assessment of phylogenetic diversity in endangered habitats, such as vernal pools, remains limited. Vernal pools, characterized by cyclical inundation and unique plant communities, present an ideal system for investigating the interplay between ecological factors and phylogenetic structure. This study aims to characterize the phylogenetic patterns of vernal pools and their associated vegetation zones, addressing questions about taxonomic and phylogenetic community discreteness, the role of flooding as a habitat filter, the influence of invasive species on phylogenetic structure, and the impact of seasonal variation on phylogenetic diversity. I find that zones-of-vegetation exhibit high between zone taxonomic and phylogenetic beta diversity whereas each zone forms a unique cluster, suggesting that zones are taxonomically and phylogenetically discrete units. Regions of high-inundation pressure exhibit phylogenetic clustering, indicating that flooding is a habitat filter in vernal pool habitats. Competition between native species conform to the ‘competitive relatedness hypothesis’ and, conversely, communities dominated by invasive Eurasian grass species are phylogenetically clustered. In addition, I find that phylogenetic diversity within zones fluctuates across the spring season in response to changing water levels, precipitation, and temperature. By analyzing three pools within the Merced Vernal Pool and Grassland Reserve, this research elucidates the phylogenetic dynamics of vernal pools. The findings underscore the need for tailored conservation strategies that account for the unique ecological characteristics of each vegetation zone within vernal pool habitats. 相似文献
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为深入了解岩溶石山森林植被物种多样性和功能多样性及其与环境因子的关系,该研究通过群落学调查、功能性状和环境因子的测定,结合方差分析、多重比较和冗余分析等统计方法,对桂林岩溶石山落叶阔叶林、常绿落叶阔叶混交林和常绿阔叶林的物种多样性和功能多样性进行对比分析,探究环境因子对不同植被类型物种多样性与功能多样性的影响机制.结果表明:(1)常绿阔叶林的Patrick丰富度指数显著高于落叶阔叶林和常绿落叶阔叶混交林;Pielou均匀度指数在常绿落叶阔叶混交林最高,落叶阔叶林次之,常绿阔叶林最低.(2)常绿阔叶林的功能丰富度指数显著高于常绿落叶阔叶混交林和落叶阔叶林;功能均匀度指数在常绿落叶阔叶混交林中最高,落叶阔叶林次之,常绿阔叶林最低.(3)冗余分析结合蒙特卡洛随机置换检验结果显示,落叶阔叶林物种多样性主要受林冠开阔度和土壤水溶钙影响;功能多样性则受到土壤水溶钙和岩石裸露率的影响;岩石裸露率和土壤厚度是影响常绿落叶阔叶混交林物种多样性和功能多样性的主要制约因子.此外,物种多样性还受到土壤速效氮的显著影响;常绿阔叶林物种多样性和功能多样性主要受岩石裸露率、土壤含水量和土壤厚度的显著影响.该研究结果揭示了不同森林植被物种多样性和功能多样性对非生物环境变化的响应,拓展了对岩溶石山物种多样性和功能多样性的认识,为岩溶石山生物多样性保护提供了进一步的参考依据. 相似文献
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Ya‐Huang Luo Marc W. Cadotte Kevin S. Burgess Jie Liu Shao‐Lin Tan Kun Xu De‐Zhu Li Lian‐Ming Gao 《Journal of Biogeography》2019,46(10):2174-2187
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理解沿环境或空间梯度的群落组成变化(即beta多样性)一直是生态学和保护生物学的中心问题, 且beta多样性的形成机制及其对环境的响应已成为当前生物多样性研究的热点问题。本文以西藏横断山区怒江和澜沧江两个流域入江溪流中的细菌为研究对象, 使用Baselga的beta多样性分解方法, 基于Sørensen相异性指数将细菌的beta多样性分解为周转(turnover)和嵌套(nestedness)两个组分, 探究了细菌beta多样性及其分解组分随海拔距离的分布模式, 并且衡量了环境、气候和空间因子的相对重要性。结果表明, 两个流域中细菌的群落结构显著不同。两个流域的细菌总beta多样性和周转组分随海拔距离的增加而增加, 周转组分占总beta多样性的比例较大。气候和环境因子是两个流域中细菌总beta多样性及周转过程的重要预测因子, 并且所有的显著因子均为正相关, 其中环境因子中相关性最高的为海拔距离(R 2= 0.408, P < 0.001), 而气候因子中相关性最高的为年均温差(R 2= 0.417, P < 0.001)。方差分解结果暗示嵌套组分主要受空间扩散的影响; 总beta多样性和周转组分在环境较恶劣的澜沧江主要受环境过滤的影响, 而在环境较温和的怒江主要受空间扩散和环境过滤的共同影响。此外, 较为恶劣的环境条件会增加细菌的总beta多样性和周转率, 并且会形成更强的环境筛选作用去影响细菌群落的物种组成。我们的研究表明对西藏横断山区水体细菌多样性的保护需要从整个流域入手, 而非少量的生物多样性热点地区。 相似文献
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Abstract Vegetation samples from either spontaneously revegetated or technically reclaimed spoil heaps of different ages in one of the largest active brown coal mining districts in Europe were analyzed and compared. The spoil heaps are located in the northwestern part of the Czech Republic and represent ages between 0 and 45 years. Ordination analysis (detrended correspondence analysis) showed that vegetation on technically reclaimed spoil heaps developed in a different way than that on spontaneously revegetated ones. The latter exhibited much higher species diversity in the oldest stages with the number of species doubled that of technically reclaimed sites. The oldest stages were also more advanced along an expected successional gradient as indicated by the ordination. Accelerating the vegetation development by technical reclamation was only of temporal character, whereas spontaneous succession proceeded further over the longer time scale. Spontaneous succession is advocated as an inexpensive and easy alternative to technical reclamation, because it leads to a more natural and rich vegetation cover. Unfortunately, technical reclamation is still the only approach considered in the present reclamation activities for this region. 相似文献
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Aim To analyse the structure of pteridophyte assemblages, based on phylogenetic relatedness and trait properties, along an elevational gradient. Ecological theory predicts that co‐occurring species may be: randomly selected from a regional pool; ecologically sorted so that they are functionally different hence resulting in reduced competition (overdispersion); or functionally similar as an adaptation to specific ecological conditions (clustering). Location Braulio Carrillo National Park and Cerro de la Muerte, Costa Rica, Central America. Methods We used an empirical dataset of the quantitative pattern of species occurrences and individual numbers of ferns within 156 plots along a tropical elevational gradient to test whether directed ecological sorting might cause deviations in patterns of trait and phylogenetic diversity. Mean pairwise distances of species based on phylogenetic and trait properties were compared with two different sets of null assemblages, one maintaining species frequency distributions (constrained) and one not (unconstrained). Results Applying different null models resulted in varying degrees of overdispersion and clustering, but overall patterns of deviation from random expectations remained the same. Contrary to theoretical predictions, phylogenetic and trait diversity were relatively independent from one another. Phylogenetic diversity showed no patterns along the elevational gradient, whereas trait diversity showed significant trends for epiphytes. Main conclusions Under stressful environmental conditions (drought at low elevations and frost at high elevations), epiphytic fern assemblages tended to be clustered with respect to trait characteristics, which suggests environmental filtering. Conversely, under less extreme environmental conditions (middle of the transect), the sorting was biased towards high differentiation (overdispersion), presumably because of interspecific competition and trait shifts among closely related species (character displacement). 相似文献
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山西岚县皇姑梁小流域人工植物群落生态 总被引：7，自引：0，他引：7
应用双向指示种分析法（TWINSPAN）和除趋势对应分析（DCA）等数量分析方法,对山西岚县皇姑梁小流域人工植物群落生态关系进行研究,将该人工植被划分为12个群丛,分别位于不同的海拔高度和坡向。分类结果很好地反映了人工植物群落类型及优势种的分布与环境因子的关系,并在DCA二维排序图上得到了较好的验证。DCA排序轴反映了群落土壤含水量、坡向、海拔高度、人工植被恢复时间和物种多样性的梯度变化,表明土壤含水量、坡向、海拔高度、物种类型及其配置模式是影响人工植物群落分布和变化的主要环境因子,不同物种配置模式对群落演替和物种多样性变化有重要影响,油松＋华北落叶松．沙棘、小叶杨＋油松、油松-沙棘、油松-柠条锦鸡儿等组成的乔灌混交林的物种多样性高于柠条锦鸡儿灌木纯林,并且油松＋华北落叶松-沙棘混交林的物种多样性高于小叶杨＋油松混交林,混交林的生态恢复效果优于纯林,并且对该小流域的生态恢复作用明显。华北落叶松适合在该小流域海拔较高的梁坡顶、半阳坡、半阴坡和阴坡生长,小叶杨适合在其海拔较低的沟底、半阳坡和半阴坡生长,而油松、沙棘、柠条锦鸡儿的生态适应性强,可在其不同海拔和坡向生长。人工植物群落的演替进程,遵循地带性植物群落演替规律。随着群落演替,野生植物不断侵入,油松、华北落叶松、小叶杨等人工林郁闭度增加,沙棘、柠条锦鸡儿等逐渐退化,油松、华北落叶松、小叶杨等出现枯枝、死株现象,这是自然稀疏的结果,亟待加强管理。 相似文献
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Jorge García-Girón Jani Heino Francisco García-Criado Camino Fernández-Aláez Janne Alahuhta 《Ecography》2020,43(8):1180-1190
Biotic interactions are fundamental drivers governing biodiversity locally, yet their effects on geographical variation in community composition (i.e. incidence-based) and community structure (i.e. abundance-based) at regional scales remain controversial. Ecologists have only recently started to integrate different types of biotic interactions into community assembly in a spatial context, a theme that merits further empirical quantification. Here, we applied partial correlation networks to infer the strength of spatial dependencies between pairs of organismal groups and mapped the imprints of biotic interactions on the assembly of pond metacommunities. To do this, we used a comprehensive empirical dataset from Mediterranean landscapes and adopted the perspective that community assembly is best represented as a network of interacting organismal groups. Our results revealed that the co-variation among the beta diversities of multiple organismal groups is primarily driven by biotic interactions and, to a lesser extent, by the abiotic environment. These results suggest that ignoring biotic interactions may undermine our understanding of assembly mechanisms in spatially extensive areas and decrease the accuracy and performance of predictive models. We further found strong spatial dependencies in our analyses which can be interpreted as functional relationships among several pairs of organismal groups (e.g. macrophytes–macroinvertebrates, fish–zooplankton). Perhaps more importantly, our results support the notion that biotic interactions make crucial contributions to the species sorting paradigm of metacommunity theory and raise the question of whether these biologically-driven signals have been equally underappreciated in other aquatic and terrestrial ecosystems. Although more research is still required to empirically capture the importance of biotic interactions across ecosystems and at different spatial resolutions and extents, our findings may allow decision makers to better foresee the main consequences of human-driven impacts on inland waters, particularly those associated with the addition or removal of key species. 相似文献
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生境过滤和扩散限制是影响森林群落间物种组成差异(β多样性)的主要生态过程。为了探究生境过滤和扩散限制对亚热带马尾松(Pinus massoniana)群落物种和谱系β多样性的相对贡献,该文以浙江省遂昌县37个马尾松林样地为研究对象,结合物种和谱系β多样性分析,探讨了影响群落间物种组成差异主要生态机制; 通过计算群落内物种β多样性指数(Bray-Curtis指数)和谱系β多样性指数(Dnn指数和Dpw指数),分析土壤、地形等生境因子和地理距离与物种和谱系β多样性之间的相关性,并通过方差分解分析生境因子和地理距离对物种和谱系β多样性的相对作用大小; 此外,还进行了不同径级和生长型的上述相关性分析和方差分解。结果表明:(1)Bray-Curtis指数与土壤、地形因子和地理距离均显著正相关,Dnn指数仅与地理距离显著正相关,Dpw指数与土壤因子和地理距离均显著正相关。(2)环境因子对Bray-Curtis指数和Dpw指数的解释度均高于地理距离的解释度。(3)从物种多样性角度来说,生境因子对不同生长阶段Bray-Curtis指数的解释度均高于地理距离的解释度; 从谱系多样性角度来说,地理距离对幼树阶段的Dnn指数和Dpw指数的解释度更高,生境因子则对成树阶段的Dpw指数的解释度更高。由此可以推论,生境过滤是驱动该地区马尾松林物种和谱系β多样性的主要生态机制,扩散限制仅在幼树阶段对马尾松林谱系β多样性起主导作用。 相似文献
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自然保护区如何设置才能够最大程度保护生物多样性, 是保护生物学的研究热点; 阐明beta多样性特征、组分格局及其影响因素是保护生物学的重要基础。本研究选取小兴安岭凉水国家级自然保护区不同功能区(核心区、缓冲区、实验区)及毗邻地区(保护区外)共80块样方作为研究对象, 调查每块样方的保护位置(经纬度、海拔、坡位、坡度、坡向)和群落结构(郁闭度、林龄、乔木树高、胸径、灌木树高、地径), 并采集0-20 cm土壤样品, 测定土壤理化性质(有机碳、全氮、pH值、电导率、含水量、容重)。将样方间的beta多样性分解为物种周转和物种多度差异两种组分, 通过Mantel分析、冗余分析和方差分解分析解析非生物因子(地理地形、保护强度、土壤因子)和生物因子(群落结构)对beta多样性及其组分的影响。结果表明: (1)乔、灌、草3层中, 物种周转组分对于beta多样性的贡献均占主导地位(65%-73%), 物种多度差异贡献较小。(2) Mantel检验结果表明, 乔、灌、草3层beta多样性及其组分与地理地形指标显著相关的因子最多; 土壤因子只对乔木层和灌木层beta多样性及组分有影响, 对草本层影响不大。其中坡位、坡度、乔木树高和保护强度均与保护区乔、灌、草3层beta多样性显著正相关(P < 0.05)。(3)植物整体beta多样性受地理地形影响最大, 但存在乔、灌、草差异。乔木层beta多样性受生物因子影响最大; 灌木层的土壤因子解释力分别为地理地形和生物因子的2倍; 而草本层主要受地理地形的影响, 其解释力分别是土壤和生物因子的26倍和3倍。乔木胸径对植物beta多样性差异具有最大的解释作用。本研究结果表明, 未来保护区设置需要根据保护植物的类型, 选择适当的林分结构、土壤和地理地形等, 以增强保护区植物多样性保护的效果。 相似文献
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The ratio of species extinctions to introductions has been comparable for many insular assemblages, suggesting that introductions could have ‘compensated’ for extinctions. However, the capacity for introduced species to replace ecological roles and evolutionary history lost following extinction is unclear. We investigated changes in bird functional and phylogenetic diversity in the wake of extinctions and introductions across a sample of 32 islands worldwide. We found that extinct and introduced species have comparable functional and phylogenetic alpha diversity. However, this was distributed at different positions in functional space and in the phylogeny, indicating a ‘false compensation’. Introduced and extinct species did not have equivalent functional roles nor belong to similar lineages. This makes it unlikely that novel island biotas composed of introduced taxa will be able to maintain ecological roles and represent the evolutionary histories of pre‐disturbance assemblages and highlights the importance of evaluating changes in alpha and beta diversity concurrently. 相似文献
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季节变化是鸟类群落的重要特征之一,其引起的环境变化决定着鸟类群落构建过程中不同驱动因子的作用力。因此,了解鸟类群落结构的季节变化,对于全面认识生物群落结构具有重要意义,尤其利用谱系多样性来探讨鸟类的季节性变化和推断群落聚集规律越来越受到关注。2018年1—12月,采用样线法对澳门生态一区和二区2块湿地进行逐月调查,记录水鸟的物种丰富度和多度,并分析水鸟谱系多样性的季节动态。结果显示,1)共记录水鸟37种,隶属于6目9科,目、科、种中数量最多的依次为:鸻形目Charadriiformes物种数为15种,鹭科Ardeidae物种数为11种,白鹭Egretta garzetta多度为540只。2)生态一区和二区水鸟的物种丰富度在冬季最高,其次为秋季;生态一区和二区的物种多度分别在秋季和冬季最高;谱系多样性和平均成对谱系距离的季节变化规律与物种丰富度的相似。3)生态一区和二区的鸟类群落分别在春、秋、冬季和秋季趋向于谱系发散,而在其他时间大多呈现出谱系聚集。谱系发散可能表明了种间竞争在群落构建中作用更大,而谱系聚集则表明了环境过滤对繁殖季水鸟群落构建具有重要作用。结果表明,湿地水鸟群落的驱动因子... 相似文献
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《Insect Conservation and Diversity》2018,11(2):174-184
- Our objectives were to assess how turnover and nestedness contribute to beta‐diversity patterns of the Zygoptera in Amazonian streams, and to relate these components of beta diversity to environmental, spatial and biogeographic predictors. Our first hypothesis is that the turnover is the most important component of beta‐diversity patterns due to the historical isolation of all or part of the areas located in the interfluves of the major Amazonian rivers. Our second hypothesis is that the interaction between environmental conditions and the area of endemism (biogeography) would be the most important predictor of beta‐diversity patterns.
- To test these hypotheses, we compiled data on the Zygoptera communities from 172 Amazonian streams. We used three sets of predictor variables: (i) environmental variables, (ii) area of endemism (biogeographic) and (iii) spatial filters.
- The turnover explained 99.36% of the beta diversity, corroborating our first hypothesis. Together, environmental and biogeographic variables were the best predictors of beta‐diversity patterns. For turnover, however, the biogeographic variables were the best predictors, contrary to our second hypothesis.
- We found high gamma diversity, but low alpha diversity in the Zygoptera communities. This paradox is explained by the high turnover among sites within the study landscape. This pattern of diversity is related to both historical biogeographic factors and the spatial structuring of environmental conditions in the Amazon region. In the light of our results (high turnover and beta diversity), and their correspondence with areas of endemism, adequate conservation of Amazonian Zygoptera diversity will depend on the establishment of so‐called mega‐reserves throughout the major Amazonian interfluves and, whenever possible, in the areas with adequate environmental conditions for the greatest possible number of species, otherwise, most species may be at a constant risk of extinction.