塔里木河中下游湿地及周边植物群落与环境因子的关系初探

选取塔里木河中下游湿地及周边16个典型植物群落样地调查和环境因子数据,采用主分量分析(PCA)排序技术和回归分析,定量分析湿地及周边植物群落在空间上的分布格局,以及群落结构特征和环境梯度之间的关系.结果表明,影响塔里木河中下游湿地及周边植物群落分布的第1主分量中,土壤水分和盐分影响最大,贡献率为35.70％;在第2主分量中,土壤养分的影响最大,贡献率为25.97％.植物群落分布的生境可分为沼生轻盐中营养生境、湿生中盐中营养生境、中生中盐低营养生境和中旱生重盐低营养生境4种类型.沿不同生境依次分布着沼泽植被、草甸植被、河岸疏林和盐生荒漠 盐化灌丛植被.塔里木河中下游湿地及周边植物群落的生态优势度与土壤水分和盐分复合梯度呈显著的一元线性相关.二元回归分析结果显示,塔里木河中下游湿地及周边土壤水分和盐分复合梯度与多样性指数和生态优势度二元指标呈极显著相关.     

江西省水生维管束植物群落与环境因子关系的初步研究

植物群落与环境因子关系的研究是植物生态学的一个中心议题[1],主要通过直接梯度分析和间接梯度分析的方法进行定量描述和解释。排序是梯度分析的一个主要技术[2 ],如极点排序 (ＰＯ)、相互平均法 (ＲＡ)、主分量分析 (ＰＣＡ)、典范分析 (ＣＣＡ)等排序技术已被广泛应用于植被的梯度分析中[1,3]。对于水生维管束植物的研究已有不少报道 ,其中有许多研究者注意到了水环境 (如水深、底质、水化学性质、流速等 )对水生维管束植物生态分布的影响[4,5],但缺乏对水生维管束植物与水环境关系的数量分析研究。据此 ,作者通过对水生维管束植物群落及…     

林区火灾后植物群落与冻土环境的多元分析

本文运用国际较为先进的双向指示种分析(TWINSPAN)多元等级分划分类方法和无趋势对应分析(DCA)排序方法对大兴安岭阿木尔林区1987年特大森林火灾后的植物群落进行了研究。通过排序结果和冻土环境的多元分析,得出：DCA排序轴1代表了土壤岩性与地形的梯度而决定植物群落的分布;DCA排序轴2则反映了森林火烧的程度梯度,并通过冻土融化深度和浅层地温值的变化而影响植物群落的分布,运用相关回归分析方法,定量地找出了它们之间相互关系的回归方程。 据此,进而探讨了该地区森林火灾后冻土环境的变化对植物次生演替方向和进程的影响。     

Effects of environmental factors on the distribution of plant communities in a semi-arid region of the Qinghai-Tibet Plateau

Against the background of global climate warming, the relationship between plant communities in high-cold ecosystems and environmental gradients has attracted much attention. We investigated the relationship between the distribution of plant communities and environmental factors in a semi-arid region of the Qinghai-Tibet Plateau. We analyzed the effects of environmental factors on the distribution of plant communities using two-way indicator species analysis and canonical correspondence analysis. The most important factor explaining the distribution of plant communities was the depth of the active layer of permafrost (denoted as PF), followed by soil water content at 40-cm soil depth. There was a strong correlation between these two factors. With changes in the PF, the dominant species in plant communities showed an obvious transition. The indices of species richness and species diversity decreased markedly with increasing PF, whereas biomass and vegetation coverage showed weaker responses to changes in the PF. The distribution structure for plant communities in this area mainly results from changes in the PF. Furthermore, the PF has remarkable and important effects on the characteristics of the plant community.     

拉萨河流域亏组山植物物种丰富度和群落特征研究

为研究草地植物群落、物种丰富度及其分布格局与影响因子之间的关系,该文以拉萨河流域林周县卡孜乡亏组山为研究地点,对山体垂直样带(3900～5100 m)植物群落特征、植物物种丰富度与各影响因子之间的关系进行了研究.研究区域共设置了13个样带(每隔100 m设一个样带),每样带设置0.5 m×0.5 m的5个样方进行植被调...     

广佛地区典型湿地类型植物多样性与土壤因子的关系

为了解土壤影响湿地植物多样性的主要因子,在广佛地区9大湿地类型选取18个样地作为研究对象,通过样方调查以及内业试验获得湿地群落物种组成分布、植物多样性、土壤状况等数据,运用方差分析、典范冗余分析(RDA)、典范对应分析(CCA)对群落分布、植物多样性与土壤因子之间的相关性进行分析。经实地调查,统计出湿地植物312种,隶属90科198属,以禾本科(Gramineae)、莎草科(Cyperaceae)、菊科(Compositae)等为优势科。草本植物占绝对优势,占79.17%。主成分评价结果表明, 近海及海岸湿地土壤养分水平较高。RDA排序分析结果表明土壤因子对植物多样性影响较大的指标是土壤有机质、全氮、全磷、全钾、碱解氮;CCA排序结果表明土壤环境因子对湿地草本植物群落分布主要影响因子为pH、速效钾、有效磷。各研究结果表明,湿地生态系统比陆地生态系统更为复杂和脆弱,植物群落与土壤环境因子之间的关系也更为复杂,湿地植被的分布格局、群落多样性、群落结构和土壤条件及其相互关系受到人为干扰的类型和强度影响更加明显。     

祁连山北坡灌木群落数量分类与排序

植物群落的空间分布格局是异质生境条件下物种种间相互作用的结果,其分异规律及其与环境因子的关系研究有助于认识植物的生态适应性。本文基于祁连山北坡28个样地的调查数据,采用双向指示种分析法(TWINSPAN)和典范对应分析(CCA)法探讨了灌木群落的空间分布与环境因子间相互关系。结果表明:(1)TWINSPAN分类将祁连山北坡灌木植被划分为盐爪爪+珍珠猪毛菜(Ass.Kalidium foliatum+Lyonia ovalifolia)、灌木亚菊+合头草(Ass.Ajania fruticulosa+Sympegma regelii)、合头草+茵陈蒿(Ass.Sympegma regelii+Artemisia capillaries)、珍珠猪毛菜+多根葱(Ass.Lyonia ovalifolia+Allium polyrhizum)、甘蒙锦鸡儿+针茅(Ass.Caragana opulens+Stipa capillata)、鬼箭锦鸡儿+高山柳(Ass.Caragana jubata+Salix cupularis)和金露梅+珠芽蓼(Ass.Dosiphora fruticosa+Polygonum viviparum)等7个群丛类型;(2)CCA排序结果表明,海拔和土壤全盐量是影响祁连山北坡灌木群落分布的主要环境因子,有机质、土壤含水量、土壤容重和p H值是次要因子,速效磷和速效钾对植物群落的影响较弱。     

历山自然保护区森林群落的典范主分量分析

典范主分量分析是结合环境因子数据的排序方法,能够有效地研究植物群落与环境间的关系．本文应用其对山西历山自然保护区森林群落与环境的关系进行了研究,结果表明它的双序排序图较好地描述了群落与环境的生态关系．海拔高度等地形因子是影响历山森林植被分布的主要因素,土壤有机质、N、P、Cu、Mn、Zn等对植被也有明显影响。     

松嫩草原区农牧林复合系统中小型土壤动物群落生态研究

通过野外选择样地,设置样方,调查了温带地区松嫩草原区农牧林复合系统中小型土壤动物群落的生态特征．结果表明,中小型土壤动物的优势类群是球角跳虫科(Hypogastruridae)、辐螨(Actinedida)、革螨(Gamasida)和甲螨(Oribatida),常见类群是节跳虫科(Isotomidae)和叶蝉科(Jassidae),从玉米田、草地和杨树林3个子系统的对比分析看,草地物种最丰富,多样性最高,生境条件最优越,中小型土壤动物的个体数和类群数随土层深度的增加而递减,表聚性明显;但3个子系统的垂直分布特征不完全相同,运用主成分分析方法,分析了主要土壤环境要素和气侯要素与中小型土壤节肢动物群落的相关关系,发现土壤环境要素是影响中小型土壤动物群落的主导因子。     

陕西子午岭生态因素对植物群落的影响

为探讨生境对植被格局分布的影响,对黄土高原马栏林区60块样地进行植被学调查的基础上,采用17个环境指标刻画植物群落的空间位置、地形和土壤特征;利用双向指示种分析(TWINSPAN)划分了该区不同演替阶段的植物群落类型;利用前向选择法(forward selection)及Monte Carlo检验对不同演替阶段植物群落物种组成影响显著(p＜0.05)的环境因子进行筛选;利用去势典范对应分析(DCCA)排序方法分析不同演替阶段植物群落分布格局与环境的关系;利用偏典范对应分析(partial CCA)定量分离环境、空间及其交互作用对植被格局总体变异的影响.结果表明:(1)马栏林区的植物群落可划分为13个类型,分别属于4个不同的演替阶段;(2)对演替初期阶段群落影响显著的环境因子是土壤含盐量和碱解氮,对演替过渡阶段群落影响显著的环境因子是海拔和腐殖质厚度,对演替亚顶级阶段群落影响显著的因子是海拔、坡向、枯落物厚度、腐殖质厚度和pH值,而对演替顶级阶段群落分异影响显著的因子是海拔、坡向、pH值和速效磷;(3)不同演替阶段群落的生态学特性和分布规律与环境空间的生态梯度格局吻合较好;(4)随着演替的进行,环境因子单独对植物群落的影响越来越大,而样地位置单独作用和样地位置与环境因子的交互作用之和越来越小.     

桂林岩溶石山青冈群落数量分类与排序

植物群落的数量分类和排序可以客观地揭示植物群落与环境之间的关系,从而能为植被恢复与重建、森林经营与管理和生物多样性保护等提供理论依据。基于群落学调查和环境因子测定数据,采用Ward聚类、双向指示种分析(TWINSPAN)和多元回归树(MRT)对桂林岩溶石山青冈群落进行数量分类,选用冗余分析(RDA)进行排序,分析其与环境因子之间的关系。结果表明:(1)3种分类方法所得结果基本一致,可将桂林岩溶石山青冈群落划分为3个群丛类型,分别为青冈-粗糠柴+龙须藤+红背山麻杆-三穗薹草群丛(Ass.Cyclobalanopsis glauca-Mallotus philippensis+Bauhinia championi+Alchornea trewioides-Carex tristachya)、青冈-龙须藤+红背山麻杆+干花豆-宽叶沿阶草+三穗薹草群丛(Ass.Cyclobalanopsis glauca-Bauhinia championi+Alchornea trewioides+Fordia cauliflora-Ophiopogon platyphyllus+Carex tristachya)、青冈-粗糠柴+干花豆-三穗薹草群丛(Ass.Cyclobalanopsis glauca-Mallotus philippensis+Fordia cauliflora-Carex tristachya);(2)冗余分析结果较好地反映出各群丛类型的分布格局及其与环境梯度的相互关系,在10个环境因子中,岩石裸露率、土壤含水量、pH值、全氮、全磷、全钾、速效钾这7个环境因子对群落的分布影响显著。土壤含水量和全钾含量可能是影响该植物群落物种组成与分布的重要生态因子。     

Vegetation-environment relationships on a species-rich coastal mountain range in the fynbos biome (South Africa)

The species-rich fynbos of the southern Langeberg Mountains, South Africa was studied along three transects (a) to evaluate the compatibility of a floristic classification of the southern Langeberg vegetation with a fynbos biome-wide structural classification of mountain vegetation, (b) to describe the environmental gradients to which the vegetation responds and (c) to investigate the relationship between the vegetation and the abiotic environmental variables which determine the pattern of distribution of the fynbos communities on the southern Langeberg.Principal Components Analysis (PCA) was used to determine correlations between environmental variables independent of vegetation data. Similarities between the 46 communities (determined by floristics) from the three transects were determined using cluster analysis and grouped into 14 higher-level units. Detrended Correspondence Analysis (DCA) was then used for indirect gradient analysis after which Canonical Correspondence Analysis (CCA) was used in a direct gradient analysis of the vegetation with the environmental variables.Compatibility between the floristic and structural classification of the vegetation was analysed. The PCA principal gradient was defined as one from sites with high rock cover, shallow soils and north aspects to those with low rock cover, deeper soils and south aspects. The second gradient is most strongly positively correlated with percentage organic carbon and most strongly negatively correlated with soil clay content. In contrast to the PCA, the DCA showed that the principal gradient is a precipitation gradient, with the response of the vegetation dominated by the change from wet to dry conditions and from low to high winter incoming radiation. The CCA showed that the variation in the mountain habitats to which the vegetation responds can be predicted from a combination of a few environmental variables. The principal gradient was one of change from high to low mean annual precipitation with an opposite change in winter incoming radiation. The second gradient was described by percentage surface rock cover and soil clay content. A simple model using the environmental factors selected in the CCA was proposed for predicting the distribution of floristically determined community groups in the fynbos vegetation of the Langeberg and the southern Cape coastal mountains in general.     

Effects of ecological factors on plant communities of Ziwuling Mountain, Shaanxi Province, China

This paper explores the relationships between environmental factors and community patterns. In 60 plots in the Malan Forest Region of the Loess Plateau, 17 variables were used as indicators of spatial position, soil and topography characteristics. Plant community types were analyzed by TWINSPAN (Two-way Indicator Species Analysis). Significant environmental factors were selected by forward selection and Monte Carlo tests. The relationship between communities and environmental factors was identified by DCCA (Detrended Canonical Correspondence Analysis). Partial CCA (Canonical Correspondence Analysis) partitioned observed compositional variation into components explained by environment, locality and covariation between them. The results showed that: (1) the plant communities can be divided into 13 types including 4 different successional stages. (2) Salt and alkali-hydrolyzable nitrogen are the significant factors related to plant community distribution at early stage. Elevation and humus thickness are the significant factors in the transitional stage. Elevation, slope, aspect, thickness of forest floor, humus thickness and pH are the significant factors for the sub-climax stage. Elevation, slope, aspect, pH and available phosphorus are the significant factors for the climax stage. (3) The ecological characters and the distribution patterns of plant communities in different successional stages are consistent with environmental gradients. (4) As succession proceeds, the impact of environmental conditions on plant communities increases, while the total influence of spatial location, and the interaction between the spatial location and environmental factors decrease.     

Effects of ecological factors on plant communities of Ziwuling Mountain, Shaanxi Province, China

This paper explores the relationships between environmental factors and community patterns. In 60 plots in the Malan Forest Region of the Loess Plateau, 17 variables were used as indicators of spatial position, soil and topography characteristics. Plant community types were analyzed by TWINSPAN (Two-way Indicator Species Analysis). Significant environmental factors were selected by forward selection and Monte Carlo tests. The relationship between communities and environmental factors was identified by DCCA (Detrended Canonical Correspondence Analysis). Partial CCA (Canonical Correspondence Analysis) partitioned observed compositional variation into components explained by environment, locality and covariation between them. The results showed that: (1) the plant communities can be divided into 13 types including 4 different successional stages. (2) Salt and alkali-hydrolyzable nitrogen are the significant factors related to plant community distribution at early stage. Elevation and humus thickness are the significant factors in the transitional stage. Elevation, slope, aspect, thickness of forest floor, humus thickness and pH are the significant factors for the sub-climax stage. Elevation, slope, aspect, pH and available phosphorus are the significant factors for the climax stage. (3) The ecological characters and the distribution patterns of plant communities in different successional stages are consistent with environmental gradients. (4) As succession proceeds, the impact of environmental conditions on plant communities increases, while the total influence of spatial location, and the interaction between the spatial location and environmental factors decrease.     

北方典型沼泽湿地高低土壤水分下植物群落特征

北方沼泽湿地在水源供给、缓解水土流失、遏制草地沙化等方面具有重要作用,明确其植物群落物种组成和多样性特征对提升其生态系统服务功能具有重要意义。目前,在北方地区开展大尺度湿地植被调查的研究仍相对较少。土壤水分是驱动植物群落发展的主导环境因素之一,为了解高低土壤水分背景下湿地植物群落特征差异及关键驱动要素,对我国7个北方典型沼泽湿地的植物群落物种组成及多样性特征进行了调查,分析了植物群落物种组成及多样性特征与环境因子的关系,以及沼泽湿地植物群落内克隆植物的分布特征。研究结果发现不同沼泽湿地的植物群落物种组成和多样性差异显著,但无明显的地带性分布规律,物种分布呈现区域性。群落物种多样性受降水、温度、土壤养分等多种环境因素的共同影响。沼泽湿地高低土壤水分背景下植物群落的物种组成和多样性差异显著,低土壤水分下植物群落物种多样性指数显著高于高土壤水分下植物群落。低土壤水分下物种多样性主要受降水和总氮影响,而高土壤水分下物种多样性主要受温度和总磷的影响。高土壤水分下克隆植物物种数和盖度在沼泽湿地植物中占有较高的比例,表明克隆植物比非克隆植物更适应高土壤水分环境。研究结果表明了7个沼泽湿地植被的区域性...     

Study on Life-Form Spectrum of Plant Community in Dongling Mountain

According to the classification system of life-form provided by Raunkiaer, Danmark ecologist, the life-form of plant communities in Dongling Mountain was analysed, and the life-form spectrum was organized. Ordination and classification of the life-form of plant community were done by principle component analysis (PCA) and systemic cluster analysis. The relationship between environmental factors (climate and soil) and plant life-form gradient was analysed by double sieving progressive regression method, and mathematical models were set up. The results showed that the characters of life-form of plant community were conformed to the general regular pattern of warm temperate plant life-form of the world, i. e the hemicryptophyte occupies highest percentage in the community. The result of ordination and classification of life-form of plant community is similar to the result of those of plant species of the community. The reaction to temperature gradient is most sensitive in geophyte and mid-phaenerophyte, less in little-phaenerophyte. The reaction to moisture gradientis most sensitive in chamaephyte and short-phaenerophyte. The percenage of hemicryptophyte is relatively stable in this area, indicating a strong binding force of the zones. The statistical models of elevant and life-form spectrum of plant community are better correlated with the mid-phaenerophyte, short-phaenerophyte and geophyte.     

蒋家沟流域不同海拔灌草层群落特征与土壤关系的研究

为了解干热河谷区不同海拔梯度植物群落灌草层物种多样性与土壤养分、水分之间的关系,该文选择干热河谷典型流域——蒋家沟流域作为研究区域,在流域内海拔1 400～3 000 m范围设置样带,对样带内8个海拔梯度的植物群落进行样方调查,统计不同海拔梯度灌草层的物种组成,测定土壤养分、土壤含水量和持水量,并将土壤指标与植被多样性指数进行主成分分析和皮尔逊相关性分析。结果表明:流域内样地共发现灌草层植物32科77属80种,且灌草层植物群落组成、土壤有机碳(SOC)含量、全磷(TP)含量、土壤含水量和持水量均受海拔梯度的影响显著(P<0.05)。其中,土壤含水量、持水量、植物群落的丰富度指数和多样性指数均随着海拔升高不断增加,且高海拔区域SOC含量显著高于中低海拔区域(P<0.05)。土壤TP含量与Pielou指数、土壤含水量与Margalef指数、Shannon-Wiener指数和物种数均呈显著正相关(P<0.05),说明除海拔梯度外,土壤养分、水分含量是影响植物群落灌草层组成和多样性的关键因子。     

基于系统发育及功能性状的不同坡向荒漠植物群落构建研究——以博湖县沙化封禁保护区为例

荒漠植物群落构建机制的研究有助于荒漠生态系统植物资源的保护及系统平衡稳定的维持。基于系统发育与功能性状相结合的方法,以博湖县沙化封禁保护区植物群落为研究对象,在研究区内纵向沙垄的不同坡向上(丘间、阴坡、阳坡)设置样方,进行植物群落物种功能性状和土壤因子的调查与测定,通过检验植物群落物种功能性状的系统发育信号,分析不同坡向植物群落物种系统发育结构和功能结构的表现模式,利用主成分分析(PCA)和线性回归模型(Linear regression model)筛选出影响物种共存的环境因子,进而揭示研究区干旱荒漠生态系统植物群落物种共存的驱动因素。结果表明：(1)研究区植被主要以耐旱的灌木和藜科草本植物为优势种;不同坡向土壤因子具有异质性,丘间、阴坡土壤养分、水分更为丰富。(2)研究区样地植物群落物种10个功能性状指标的系统发育信号K值均小于1,说明物种功能性状受系统进化影响较小,物种功能性状未表现出系统发育保守性。(3)不同坡向系统发育结构均趋于发散,限制相似性在植物分布中占主导作用;丘间和阴坡上较丰富的土壤肥力是物种功能结构发散的主要原因,阳坡物种功能结构表现为聚集效应,生境过滤为其驱动因素...     

Environmental Factors Influencing Coastal Vegetation Pattern: New Insights from the Mediterranean Basin

Coastal dune ecosystems show strongly dynamic interactions between abiotic and biotic factors. The relationship between plant communities and environmental factors has been previously studied in oceanic dune systems, but few studies have been conducted along Mediterranean coasts. In this study we analyze the relative contribution of environmental factors associated with two of the main drivers of vegetation zonation: soil and wind. We chose two representative coastal dune systems in the western Mediterranean Basin subject to low levels of human disturbance. Within 54 plots we recorded floristic and environmental data. Vegetation zonation and relationships with environmental variables were investigated through unconstrained and constrained ordinations, correlation, and variance partitioning. Environmental factors shift along the gradient from coastal to inland dunes, concomitantly with the pattern of community types from annual beach communities to shrub-covered fixed dunes. This general gradient is similar both in the Mediterranean and in the oceanic coastal ecosystems, with the same factors that show similar trends along the dune profile. However, our results highlight some peculiarities of the Mediterranean dune systems in relation to the amount of variation explained by environmental factors. While most studies conducted in oceanic ecosystems find that wind-related parameters may control the vegetation zonation, in our study areas we observed a minor importance of the wind-related variables when compared to soil properties. In particular, organic matter and grain-size variability were found to be closely correlated with the distribution of plant communities along the gradient.     

甘肃祁连山国家自然保护区植物群落分布格局及其与环境因子的关系

植物群落分布格局是环境因子和人类活动共同作用的结果,尤其是海拔梯度被认为是植物群落分布格局的决定性因子,为探求甘肃祁连山国家自然保护区植物群落分布格局与环境因子的关系及其驱动机制,该文在野外调查的基础上,运用数量分类和除趋势典范对应分析(DCCA)排序等方法,探讨了研究区内植物群落特征及其与环境因子的关系。结果表明：(1)88个样方共记录物种85种,隶属30科56属,利用双向指示种分析法(TWINSPAN)将其分为9个植物群落。(2)9个植物群落在DCCA排序图上聚集分布,呈现出较好的环境梯度,其中海拔对植物群落分布格局影响最大,其次为降水、温度、坡度、坡向和土壤腐殖质。(3)影响植物群落空间分布格局的变量中,环境因子占25.24%,空间因子占13.21%,空间因子和环境因子交叉作用占9.03%,群落分布格局未被空间因子和环境因子解释部分占52.52%,这部分主要反映了人类活动对研究区植物群落分布格局的影响。该研究成果对区域内植被的生态恢复和生物多样性的稳定维持具有重要意义。