Towards objectivity in vegetation classification: the example of the Austrian forests

We present a numerical classification of 2145 objectively sampled relevés from the entire forest area of Austria (Central Europe). The sample sites were selected by a combined method involving a systematic matrix and stratified random sampling. A TWINSPAN classification led to 32 clusters which are described in detail. Three main groups can be distinguished: (1) Alpine-dinaric coniferous forests on carbonate soils, (2) Coniferous forests on acid soils and (3) Deciduous forests. These groups correspond with accuracy to the classes Erico-Pinetea, Vaccinio-Piceetea and Querco-Fagetea in the traditional Braun-Blanquet system. Thus, the value of the Braun-Blanquet approach is supported by more or less objective sampling and numerical classification methods. The assumption of the objective existence of ecological species groups is strongly supported, too. Moreover, our results may help to solve some controverse points discussed in the European forest classification regarding the delimination between the three mentioned classes. This revised version was published online in August 2006 with corrections to the Cover Date.     

云南大山包黑颈鹤自然保护区草甸植被的数量分类和排序

在法瑞学派样地调查法的基础上,采用双向指示种分析（TWINSPAN）和趋势对应分析（DCA）对大山包黑颈鹤自然保护区草甸植被进行数量分类和排序研究。调查样地包含114个物种,分属31科72属,其中禾本科（14种）、菊科（13种）、蓼科（8种）、石竹科（6种）、玄参科（6种）等科所含物种较多。经TWINSPAN分类,106个样地分为20个聚组,根据其指示种确定为20个群丛。样地DCA和物种DCA排序结果反映了植物群丛与指示种之间的一致关系,排序轴的生态学意义说明水分和海拔两个环境因子同时影响该区草甸植被的分布。     

Composition and ecology of the Quercus coccifera L. communities along the eastern Adriatic coast (NE Mediterranean)

The aim of this study is to classify and describe all plant communities with Quercus coccifera covering the entire eastern Adriatic coast and islands from north Croatia to south Albania, and to relate their species composition, chorotypes and life forms to environmental factors using Pignatti ecological indicator values. From total 70 phytosociological relevés, we identified and described four floristically and ecologically distinctive vegetation communities (two new proposed subassociations, one association and stand each) using TWINSPAN and the Braun-Blanquet classification scheme. In Croatia and Montenegro, Q. coccifera is forming macchia within the Fraxino orni–Quercetum cocciferae pistacietosum lentisci. Quercus coccifera occurs only sparsely in south Croatia as a shrubland within Fraxino orni–Quercetum cocciferae nerietosum oleandri subassociation or macchia within the Erico arboreae–Arbutetum unedonis association. Despite the difference in biogeographic position and bioclimates, low shrubby Albanian Q. coccifera stands are more closely related to the Q. coccifera communities from the western Mediterranean. Eastern Adriatic communities appear exclusively within the Querceta ilicis vegetation zone and spread within the meso-Mediterranean belt. They nevertheless are an important part of the region's natural heritage and management plans must ensure that all forms of land are used in a sustainable way.     

山西北部地区沙棘群落的数量分类和排序研究

采用双向指示种分析法对山西北部地区沙棘群落进行分类和排序研究,结果将山西北部地区沙棘群落划分为14个群系,并论述了各群系的特征。DCA排序进一步说明了群系的分布格局与水分和土壤的密切关系,结果表明组成沙棘灌丛的种群对群落生境具有指示作用,能客观反映群落的生境特征．     

Urban plant ecology patterns and processes: a case study of the flora of the City of Plymouth, Devon, U. K.

Aim Using a large database that has been created over the past 5 years with the RECORDER package, presence/absence data for 829 species of vascular plants in the 103 1-km² squares that cover the city of Plymouth (pop. 243,373) have been analysed by two-way indicator species analysis (TWINSPAN ) and canonical correspondence analysis (CCA) to establish the major species assemblages and to examine their spatial distribution across the city in relation to variation in land use. Location The City of Plymouth. Methods Nine groupings of squares emerged and their distribution was mapped across the city. Interpretation of those groups and their variation in relation to the land use ordination axes showed that TWINSPAN groups lying along the first axis of variation correlated floristic variation with the process of urban development and the historical evolution of urban structure. The second axis appeared to be related to particular remnant semi-natural habitats within the city that could be regarded as ‘hot-spots’ for survival of many plant species. Species were categorized into four types on the basis of their recency and mode of arrival in the city and by using the historical flora of Plymouth produced by T. R. Archer-Briggs in 1880. Variations in the sources of species in relation to the TWINSPAN classification groups were then examined. A second ordination was also computed; this time with geological, altitudinal and distance variables. TWINSPAN groups were then superimposed on the ordinations using polygons to assist with biogeographical interpretation. Results and conclusions The results of both the multivariate analyses and distribution of species by source are then discussed in the context of previous research into urban plant ecology, particularly in Central Europe. The problems of inferring process from pattern in this meso-scale study are reviewed and suggestions are made for further research into urban ecology and biogeography in the city.     

High altitude montane wetland vegetation classification of the Eastern Free State,South Africa

Wetlands occur where biotic and abiotic conditions combine to create unique habitats and plant assemblages. These systems have anaerobic or hydric soil resulting from waterlogging and are found across all nine biomes in South Africa. Wetlands can thus be regarded as hosting azonal vegetation. On Platberg, the freshwater wetlands are embedded within the Grassland Biome forming distinct units. Platberg wetlands were surveyed and described to explain and document vegetation of this inselberg. Additional aims were to elucidate Afro-montane floristic links with the Drakensberg Alpine Centre, and provide data for conservation management. The study site is located in the Eastern Free State, South Africa, on edge of the Great Escarpment. It is one of an archipelago of more than 20 inselbergs stretching north from the Drakensberg. A total of 51 sample plots (30 m²) were located in a randomly stratified manner within the wetland units to include all variations in the vegetation. The data was analysed using the TWINSPAN classification algorithm, refined by Braun-Blanquet procedures. The analysis showed the wetlands divided into five communities, six sub-communities and six variants. The wetland communities had an average of 13.56 species per relevé, ranging from 7 to 29 species per sample plot. Numerous floristic links with the Drakensberg Alpine Centre, the Cape Floristic Region and the Grassland biome were found. Platberg shows vegetation and hydrogeological affinity with low altitude freshwater and the high altitude Lesotho Mires of the Drakensberg Alpine Centre. A list of high altitude wetland species was compiled.     

JUICE,software for vegetation classification

Abstract. The program JUICE was designed as a Microsoft® WINDOWS® application for editing, classification and analysis of large phytosociological tables and databases. This software, with a current maximum capacity of 30 000 relevés in one table, includes many functions for easy manipulation of table and header data. Various options include classification using COCKTAIL and TWINSPAN methods, calculation of interspecific associations, fidelity measures, average Ellenberg indicator values, preparation of synoptic tables, automatic sorting of relevé tables, and export of table data into other applications (word processors, spreadsheet programs or mapping packages). JUICE is optimized for use in association with TURBOVEG which is the most widespread database program for storing phytosociological data in Europe.     

Die Biozönosen der PHLEGERschen Benthos-Faunen vom Mississippi-Sund und -Delta

A table demonstrates the distribution of benthonic Foraminifers in litoral areas of the Mississippi mouth. 40 species, taken from 274 stations, allow the following associations to be recognized: Ammoastutetum ineptae, Ammobaculitetum exigui, Cibicidinetum strattoni, and Elphidietum gunteri. Each association is limited to a distinct region which has its suitable hydrographical conditions. Each can be divided into 2-5 sub-associations. All biocoenoses are characterised by their own species. The 4 associations corresponding to the terminology of Braun-Blanquet belong to 2 alliances, Ammoscalarion fluvialis and Beccarion, which come under the order Ammobaculetalia salsi.     

长江故道湿地植被的数量分类与排序

采用双向指示种分析法（TWINSPAN）和除趋势对应分析法（DCA）对长江故道湿地植被做分类和排序研究。TWINSPAN分类将湿地植被234个样方分为28个群丛,论述了各群丛的群落学特征。DCA排序结果反映了植物群落类型与环境梯度之间的关系,表明影响群丛分布格局的主导生态因子为生境的水分条件。TWINSPAN数量分类在DCA排序图中有较为明确的分布范围和界限,两者的结合使用,能很好地反映群落与环境因子间的生态关系。     

锦屏水电站植被数量分类与排序

以锦屏梯级水电站大河湾段植被为研究对象,以河流流向为基础布置样方,将50个样方物种重要值及其环境因子进行TWINSPAN数量分类和DCA排序,结果显示:(1)由TWINSPAN数量分类将植被划分为7种类型,雅致雾水葛(Pouzolzia elegans)灌草群落为该区域的主要群落.(2)以TWINSPAN数量分类为基础的DCA二维排序图将样方分为6个生态类型,DCA 二维排序图横轴从左至右海拔高度逐渐降低;排序纵轴由下至上坡度逐渐升高.(3)以TWINSPAN数量分类在DCA排序图中有明确的分布范围和界限,DCA排序与TWINSPAN数量分类结合使用,能很好反映群落与环境因子间的生态关系.     

桂林岩溶石山青冈栎群落的数量分析

应用双向指示种分析(TWINSPAN)和除趋势对应分析(DCA)方法对桂林岩溶石山青冈栎群落进行数量分类与排序。通过TWINSPAN分类,将青冈栎群落60个样方划分为8个群丛类型,探讨了各群丛类型的基本特征。结果表明:DCA排序与TWINSPAN分类结果较一致,DCA排序较好地体现了各群丛类型与环境因子的相互关系,DCA第一排序轴主要反映了坡度的变化梯度;DCA排序图的对角线基本体现了坡向的变化梯度。坡度的变化是影响岩溶石山青冈栎群落物种组成与分布的重要生态因子。     

Alnus glutinosa – dominated wetland forests of the Baltic Region: community structure,syntaxonomy and conservation

Community structure, syntaxonomy and conservation aspects of Alnus glutinosa-dominated forests in the Baltic States, Central Europe, southern Fennoscandinavia and north-western part of the Commonwealth of Independent States are surveyed. Communities of the black alder wetlands, subjected to cluster analysis (TWINSPAN, GROUPAGE) and correspondence analysis (CANOCO) and synsystematically treated following the Braun-Blanquet approach, belong to Alnion (Carici elongatae-Alnetum Schwick. 33 with two subassociations, Sphagno squarrosi-Alnetum Sol.-Gorn. ex Pried. 96) and Alno-Ulmion (mainly Circaeo-Alnetum Oberd. 53) forests in the Baltic Region. The indicator values sensu Ellenberg, site ecology, floristic assemblages and the phytogeographical features point at a high affinity of these forests in a wide geographical area. Eleven syntaxonomical approaches by classifying central and north-eastern European alderwoods have been analysed. These differ in Alnion classification and distinguish from 2 to more than 10 syntaxa at the level of association. The actual distribution of less disturbed black alder wetlands and areas under these forests in Europe suggests that the SE part of the Baltic Region could be the key area for Alnus glutinosa-dominated wetlands. Thus, it deserves an establishment of an international network of standard protected areas so as to maintain the diverse community samples and elaborate the principles of sustainable management. Abbreviations: In figures CLT PALU means Caltha palustris, CAL PALU – Calla palustris. Abbreviations of all other species follow first 3 and 4 letters of the genus and species name, respectively. Nomenclature: Tabaka et al. (1988) for vascular plants, Abolina et al. (1984) for mosses.     

Caucalido platycarpi-Vicietum michauxii — a new weed association from crop fields of Kyrgyzstan (Middle Asia)

The study presents the results of geobotanical investigations conducted in crop fields in the western Tian Shan Mts in Kyrgyzstan (Middle Asia). The main research focused on classification of weed communities developing within this poorly investigated area, were conducted in the vicinity of Bishkek and Kara-Balta in 2010. Altogether, 299 phytosociological relevés were sampled using the Braun-Blanquet method. Based on all segetal vegetation patches, the analyses distinguished a new association: Caucalido platycarpi-Vicietum michauxii. The results of these phytosociological studies fill a gap in the knowledge about the syntaxonomical diversity of the Middle Asia region, which is one of the most crucial for segetal weed species. The study shows that anthropogenic agrocoenoses could harbour relatively rich flora. Extensively cultivated fields could especially serve as a suitable habitat for many xerothermophilous and heliophilous plants. More than 75 species in vegetation plots, mainly permament weeds, have been found. There is also a considerable share of species coming over from swards, screes and meadows.     

Phytosociology of Juniperus excelsa M.Bieb. forests in Alborz mountain range in the north of Iran

Juniperus excelsa is one of the specific tree species in the mountainous areas of Iran. It forms the mountainous forests of Irano-Turanian vegetation region. Despite the considerable spread of J. excelsa in Iran, there is no detailed and valid published study on the phytosociology of Iranian juniper stands. The aim of this research is to identify these associations and their characteristics in Alborz mountains in the north of Iran. To this goal, a set of data including floristic data according to Braun-Blanquet method, and important environmental characteristics, were collected. To classify the vegetation, TWINSPAN was used and phytosociology tables were analysed with JUICE software. Diagnostic species were determined by measuring the degree of fidelity and using statistically meaningful measurements. According to the results, the vegetation was classified into six associations and five subassociations. Among them are Cotoneastro nummulariis-Juniperetum excelsae ass. nov., Lonicero ibericae-Juniperetum excelsae ass. nov., Rhamno pallasii-Juniperetum excelsae ass. nov., Rhamno p.-Juniperetum e. ajugetosum chamaecisti subass. nov., Rhamno p.-Juniperetum excelsae gypsophiletosum aretioidis subass. nov., Amygdalo lycioidis-Pistacietum atlanticae hymenocratretosum bituminosoris Kashipazha et al. 2007, Feruletum ovinae ass. nov., Artemisio aucheri-Astragaletum veri Asri 2004, and Artemisio aucheri-Onobrychidetum cornutae ass. nov. The introduced juniper associations were placed in class Junipero-Pistacietea Zohary 1973 and order Juniperetalia excelsae nov.     

内蒙古锡林郭勒草原大针茅-克氏针茅群落的种间关联特征分析

内蒙古锡林郭勒草原处于我国典型草原分布区, 但部分地区有戈壁针茅(Stipa gobica)等荒漠成分侵入, 并与大针茅(S. grandis)和克氏针茅(S. krylovii)共同形成斑块状格局分布, 目前尚不清楚群落中优势种之间的相互作用关系。采用2 × 2列联表, 通过方差分析、Pearson相关分析和Spearman秩相关分析等研究方法, 对大针茅+克氏针茅群落的大针茅斑块、克氏针茅斑块和戈壁针茅斑块中的24种主要植物的种间联结动态进行了定量分析。结果表明: 1)群落主要成分总体上种间联结呈无关联, 种间关联松散; 2) 3种针茅斑块的种间关联分析, 验证了由于干扰、竞争、土壤环境与植物相互作用形成的斑块分布格局, 此结果为种对正、负关联理论提供了有力证据; 3) 同一种对的联结性质(正关联或负关联)或关联程度因斑块不同而发生改变, 根据24个优势种群对环境的适应方式和主导生态因素, 可将它们划分为3大生态种组。     

Classification of meadow vegetation in the USSR

The scientific classification of meadow vegetation (mesophilous grasslands) was already available in the 1930's due to A. P. Shennikov who suggested to apply new classification principles, on the basis of species dominance. This classification became subjected to criticism, as the criteria proposed did not correspond to the nature of the classification object and as meadow community dominants were instable. In 1971 the Soviet phytocenology was influenced by the ideas of the Braun-Blanquet classification, but before completely adopting it, the Soviet geobotanists employed the so-called dominant-determinant principles of classification, when differential species and dominants were simultaneously used for association determination. In the seventies phytocenoses on the floristic basis, were used though their syntaxonomic analysis was not performed. In 1981, the All-Union conference on vegetation classification was held in Ufa. This conference gave careful consideration to the problem of the floristic classification in the USSR, stated that impressive progress had been achieved in meadow classification on the floristic basis and recommended to use more strict principles for phytocenosis determination alongside with syntaxonomic analysis and subordination of the existing higher syntaxons of the Braun-Blanquet system. The perspectives for implementation of the Braun-Blanquet principles in the USSR are elucidated and a tentative question is raised on the necessity to develop some new classes in order to reflect the specific character of the meadows in the USSR.     

浙江省红楠生境地群落数量分类和环境解析

为探讨群落结构与环境因子对红楠Machilus thunbergii在浙江省分布及发展的影响,采用双向指示种分类(TWINSPAN)、典范对应分析(CCA)并结合种间联结分析,对浙江省172个红楠生境地群落进行数量分类排序与环境解析。结果表明:(1)TWINSPAN将172个样地群落分成8个群落类型,红楠在群落中为优势种或主要伴生种。群落类型的不同是影响红楠生长及更新的重要原因。(2)海拔高度及坡度是决定红楠分布及发展的主导环境因子。红楠作为优势种的生境地主要特征为海拔900m以下、坡度35°以下。(3)甜槠(Castanopsis eyrei)、青冈(Cyclobalanopsis glauca)、木荷(Schima superba)为群落中的稳定优势种,种间联结结果显示与红楠均为显著正关联。     

Multiple species effects and spatial autocorrelation in detecting species associations

Abstract. The traditional approach to the analysis of species association within a community, based upon co-occurrence in sampling units such as quadrats, has been to test all pairs of species, using a 2 × 2 contingency table for each pair. It has long been recognised that all these tests are not independent of each other, but there is an additional problem in that the association between any particular pair may depend on the combination of the other species that are present or on the environmental factors that determine that combination. We use a 2^k contingency table to examine this problem and find that pairwise associations are not independent of the other species. The second problem that we consider is the effect of spatial autocorrelation in the data which makes the statistical tests too liberal. In the absence of a derived solution for a deflation factor to correct the test statistic calculated from a 2^k table, we describe a Monte Carlo approach that provides an approximate solution to this problem. In our data the amount of deflation that is necessary for a 2^k table is small compared to the amount required for the 2 × 2 tables used to test pairwise association.     

Continuum or zonation? Altitudinal gradients in the forest vegetation of Mt. Kilimanjaro

Based on the analysis of 600 vegetation plots using the method of Braun-Blanquet (1964) the composition of the whole vascular forest plant flora with about 1220 species was studied in the forests of Mt. Kilimanjaro. The altitudinal distribution of all strata (trees, shrubs, epiphytes, lianas and herbs) along a transect of 2400 m is discussed with respect to altitudinal zonation and ecological factors. With uni-dimensionally constraint clustering significant discontinuities were revealed that occurred simultaneously in the different strata. Thus even in structurally highly complex, multilayered tropical montane forests distinct community units exist that can be surveyed and classified by the Braun-Blanquet approach. This observed zonation was significantly correlated with altitude, temperature and soil acidity (pH); rainfall was of importance in particular for the zonation of epiphytes. Other key factors were humidity (influenced by stable cloud condensation belts) and minimum temperature (in particular the occurrence of frost at 2700 m altitude upslope). The contrary results of other transect studies in East Africa in respect to continuity of change in floristic composition appear to be caused by different sampling methods and intensities or mixing of data from areas with different climate conditions, whereas species richness did not influence the clarity of floristic discontinuities on Kilimanjaro and other parts of East Africa.