Fine-scale patterns of vegetation and environmental factors on an ombrotrophic mire expanse: a numerical approach

The vegetation within an ombrotrophic mire expanse in SE Norway is studied in detail. Percentage cover of 45 species in 436 sample plots (16 ×16 cm), dispersed on 26 transects, are recorded. In addition, species abundance in 6976 subplots (4×4 cm) are recorded. 14 variables are recorded for each of the sample plots, while only distance to the water-table is estimated for the subplots. Spatial co-ordinates are supplied for all sample- and subplots. DCA ordination of a data-set consisting of 412 sample plots reveals two ecologically interpretable vegetational gradients: the hummock-hollow gradient (DCA 1), and a gradient associated with the peat-production of the bottom layer (DCA 2). Passive DCA of subplots is used to get an impression of within sample plot heterogeneity, and shows that the fine-scale compositional turnover may be considerable. Partitioning of the variation in species abundance data is done by use of (partial) CCA. The fraction of unexplained variation is rather large for all the tested data-sets, but within the total variation explained, both distance to the water-table and spatial structure explain large parts.     

Geographical and ecological differentiation in Greek Fagus forest vegetation

Question: Which are the gradients of floristic differentiation in Greek beech (Fagus sylvatica) forests? Which is the role of geographical and ecological factors in this differentiation? Location: Beech forests of the plant geographical regions Northeast, North Central and East Central Greece. Methods: A total of 1404 published and unpublished phytoso‐ciological relevés were used in the analyses. TWINSPAN and DCA were applied to classify and ordinate the relevés. Altitude, Indicator Values of relevés and their X and Y coordinates were used in a posteriori interpretation of the ordination axes. Kendall's correlation coefficients were calculated between DCA relevé scores and explanatory variables. Multiple linear regression was used to partition the variation explained by the first two DCA axes, between the geographical and the ecological variables. Results: Classification resulted in 14 vegetation units defined by species composition. Two types of gradients, ecological and geographical, were revealed by the DCA of all releves. The partition of the variation accounted for by the first and second DCA axis was attributed mainly to ecological and geographical variables, respectively. Conclusions: Beech forests of northeast and Central Greece show phytogeographical differences, while ecologically similar vegetation units occur in both regions. A west‐east gradient is revealed in Greek beech forest vegetation. The extent of the study area, its position along regional gradients and the comprehensiveness of the data set that is analysed determine the types of the gradients which can be revealed in a vegetation study.     

Relationships between the vegetation and soil conditions in beech and beech-oak forests of northern Germany

In this study we examine the relationships between the vegetation of beech and beech-oak forest communities (Hordelymo-Fagetum, Galio-Fagetum, Deschampsio-Fagetum, Betulo-Quercetum) and their soil conditions in the lowlands of northern Germany, based on 84 sample plots. In all plots the vegetation was recorded and soil parameters were analysed (thickness of the O- and the A-horizons, pH, S-value, base saturation, C/N, mean Ellenberg moisture indicator value). The vegetation classification according to the traditional Braun-Blanquet approach was compared with the result of a multivariate cluster analysis. Vegetation-site relationships were analysed by means of an indirect gradient analysis (DCA).Both traditional classification methods and the cluster analysis have produced comparable classification results. So far as the species composition is concerned, a similar grouping of sample plots was found in both approaches. Multivariate cluster analysis thus supports the classification found by the Braun-Blanquet method. The result of the DCA shows that the four forest communities mentioned above represent clearly definable ecological units. The main site factor influencing changes in the species composition is a base gradient, which is best expressed by the S-value. In addition, within the series Hordelymo-Fagetum - Galio-Fagetum - Deschampsio-Fagetum the C/N-ratios and the thickness of the organic layers (O-horizon) increase continuously. By contrast, the floristic differences between oligotrophic forest communities (i.e., Deschampsio-Fagetum and Betulo-Quercetum) cannot be explained by a base gradient and increasing C/N-ratios. It is suggested that a different forest management history in some cases (e.g., promotion of Quercus robur by silvicultural treatments) is responsible for differences in the species composition, but on the other hand the result of the DCA indicates that Fagus sylvatica is replaced by Quercus robur with increasing soil moisture (i.e., with the increasing influence of a high groundwater table). Summarizing these results, it can be concluded that the ecological importance of single site factors affecting the species composition changes within the entire site spectrum covered by the beech and beech-oak forests of northern Germany.     

Herb-rich spruce forests in W Nordland, N Norway: an ecological and methodological study

The vegetation of herb-rich spruce forests in three localities in Brønnøy municipality, W Nordland, N Norway, has been analysed using 120 sample plots, each 25 m², distributed by a restricted random method. In connection with every sample plot a set of ecological variables have been measured. The most important gradients for the differentiation of the vegetation were identified by DCA ordination and statistical analysis of the vegetational and the ecological data sets. The gradients were: (1) the nutrient gradient, (2) the soil moisture gradient and (3) the microclimate gradient. The importance of choice of ordination technique (DCA or LNMDS) relative to the importance of the choice of some parameters in DCA and LNMDS has been evaluated. Indicating from this evaluation were (1) the choice of weighting function prior to DCA ordination can be as important as the choice of ordination technique when the data set is small; (2) choice of dimensionality in LNMDS is normally not as decisive for the ordination result as the choice of ordination technique and (3) when the data set is larger, the choice of scale range is less decisive for the ordination result than the choice of dimensionality in LNMDS.     

On the relationship between sample plot size and beta diversity in boreal coniferous forests

Nested sample plots of three sizes (16, 1, and 1/16 sq. m) from three different studies of Norwegian coniferous forests have been subjected to DCA ordination using the same choice of options. At each sample plot size, species quantities are recorded as frequency in 16 subplots. Beta diversity, measured as length of the first DCA axis, invariably increased upon lowering of sample plot size. The same applied to the eigenvalues of the axes. This is explained as a consequence of the weakening of structure in the data matrices when the fine-grained patterns of the vegetation are emphasized.     

Gradient analysis of dry grassland vegetation in Denmark

Abstract. We present a gradient analysis of 620 vegetation samples covering most of the floristic and environmental variation in semi‐natural grassland vegetation on well‐drained soils in Denmark. Vegetation was sampled using frequency in subplots. Explanatory variables were surface inclination, aspect, pH, geographical co‐ordinates together with indications of soil type. Detrended Correspondence Analysis revealed four floristic gradients that could be interpreted in ecological terms by measured variables supplemented with site calibrations based on weighted averaging of Ellenberg's indicator values. All four axes were interpreted using rank correlation statistics, and linear and non‐linear multiple regression of sample scores on explanatory variables. The first gradient was from dry calcareous to humid acidic grasslands; the second reflected an underlying gradient in fertility; the third reflected regional differentiation and the fourth was associated with variation in intensity of competition as indicated by association with calibrated Grime‐CSR values for the plots. We applied subset ordination to the data as a supplement to traditional permutation and correlation statistics to assess the consistency of ordination results. DCA axes 1 and 2 were consistent in space and time. This gradient analysis is discussed in a context of plant strategy theory and species diversity models. Ecocline patterns lend support to the view that grazing not only favours the ruderal strategy but also the stress‐tolerant strategy. The low rank of competition as an explanatory variable for the floristical gradients supports the notion that competitive effects play a subordinate role for species composition compared to microclimate and soil conditions in infertile semi‐natural grasslands.     

Quantitative classification and ordination of forest communities in Pangquangou National Nature Reserve

Quantitative analysis of ecological relationships between vegetation and the environment has become an essential means in the field of research of modern vegetation ecology. In this article, based on data from 84 quadrates, forest communities in this reserve were investigated using TWINSPAN, DCA and DCCA. The results will be helpful in the construction and development of Pangquangou National Nature Reserve. Using TWINSPAN, the forest communities were classified into seven types. The distribution pattern of vegetation reflects the comprehensive influence of environments. The results of DCA and DCCA clearly reflect the relationship between the pattern of forest communities and environmental gradients. The ordination result of DCCA indicates that altitude is more important than other environmental factors because the change of altitude gradient will lead to changes in the temperature and humidity gradients. The first of the DCA ordination axes indicates the humidity gradient, and the second indicates the temperature gradient. All these results show that the main factors restricting the distribution of communities in this reserve are temperature and humidity. The ecological meaning of the ordination axis in DCCA is much clearer than that in DCA, and the species-environment correlation of DCCA is more obvious than DCA. The first DCCA axis indicates the altitude gradient among the communities, while the second is the gradient in aspect and slope among the communities. DCCA ordination can simultaneously express similarities of species and environment. Therefore, the quadrat location in the DCCA ordination figure is much closer than in the DCA.     

Quantitative classification and ordination of forest communities in Pangquangou National Nature Reserve

Quantitative analysis of ecological relationships between vegetation and the environment has become an essential means in the field of research of modern vegetation ecology. In this article, based on data from 84 quadrates, forest communities in this reserve were investigated using TWINSPAN, DCA and DCCA. The results will be helpful in the construction and development of Pangquangou National Nature Reserve. Using TWINSPAN, the forest communities were classified into seven types. The distribution pattern of vegetation reflects the comprehensive influence of environments. The results of DCA and DCCA clearly reflect the relationship between the pattern of forest communities and environmental gradients. The ordination result of DCCA indicates that altitude is more important than other environmental factors because the change of altitude gradient will lead to changes in the temperature and humidity gradients. The first of the DCA ordination axes indicates the humidity gradient, and the second indicates the temperature gradient. All these results show that the main factors restricting the distribution of communities in this reserve are temperature and humidity. The ecological meaning of the ordination axis in DCCA is much clearer than that in DCA, and the species-environment correlation of DCCA is more obvious than DCA. The first DCCA axis indicates the altitude gradient among the communities, while the second is the gradient in aspect and slope among the communities. DCCA ordination can simultaneously express similarities of species and environment. Therefore, the quadrat location in the DCCA ordination figure is much closer than in the DCA.     

川西北甘南云冷杉林的DCA排序、环境解释和地理分布模型的研究

 本文应用DCA排序的方法进行了四川西北部和甘肃南部云冷杉林的梯度分析,建立了植物群落梯度环境解释的数学模型和植物群落地理分布的数学模型。研究结果表明：影响川西北甘南云冷杉林植物群落地理分布的生态梯度中最显著并起主导作用的是温度梯度和水分梯度。在水分梯度上,大致有这样的植被序列,由较湿的藓类和杜鹃冷杉及云杉林,中生性的箭竹冷杉林和云杉林,偏旱的高山栎冷杉林和云杉林;处于恢复中期的桦木林的生境也偏旱,但一般不如高山栎林。冷杉林比云杉林更趋于阴湿的生境。 在温度梯度上,呈现出灌木云杉林—桦木林—落阔冷杉林—高山栎云杉林—箭竹云杉林—箭竹红桦林—高山栎冷杉林—藓类红桦林—藓类云杉林—箭竹冷杉林—藓类云冷杉林—藓类冷杉林—小叶章云杉林—杜鹃冷杉林的排序。基本特征是：川西北和甘南的云杉林的温度需求高于冷杉林。川西北云冷杉林与甘南云冷杉林在DCA排序轴上没有明显的区别。虽然川西北地区云冷杉林的海拔分布高于甘南地区,但是其纬度也低于甘南,故在温度条件上基本一致。在水分梯度上,川西北云冷杉林的湿度要稍大于甘南云冷杉林。利用植物地理分布的数学模型和有关的图、表,详细地分析了植物群落的空间分布,进行了环境解释,并找出了主导的环境因子。     

Relating variation in the understorey of beech forests to ecological factors

A data set of beech (Fagus sylvatica) forests in the Basque Country (Northern Spain), including biotic (floristic relevés) and environmental data (pH, organic matter, slope, altitude, rock cover), is analyzed in order to describe the relationships between understorey composition and environmental parameters. An ordination technique (DCA) is used to display the floristic gradients, and the interpretation of the floristic space in environmental terms is carried out by a spatial analysis technique (kriging). The composition of the beech forest understorey responds to a complex environmental gradient in the study area. Forests growing on acid substrata differ markedly from those growing on soils with higher pH, as the sharp transition between the pH 5 and 6 isolines reflects. When pH values exceed 6, organic matter content becomes the most important factor explaining the vegetation pattern and the rate of change is greater as organic matter content tends to change at a smaller scale than sample size and, as a consequence many transitional forms are found.     

Succession of terrestrial macrofungi along a deglaciation gradient at Glacier Blåisen, South Norway

A survey of terrestrial macrofungi along a deglaciation gradient from the glacier forefront to the established vegetation has been performed. The study was accomplished along a transect from Lake Finsevann to Glacier Blåisen, South Norway. Fortysix 6 m × 6 m plots divided into 9 subplots were positioned along this transect. The frequency of fruit bodies of each species in each plot was given on a 0–9 scale reflecting their occurrence in the subplots. Biotic and abiotic environmental variables for the plots were also recorded. The numerical methods used include principal component analysis (PCA), detrended correspondence analysis (DCA), and canonical correspondence analysis (CCA). Totally 99 species of macrofungi were recorded; 80.8 % of the species belonged to the Basidiomycota and 19.2 % to the Ascomycota. About one third of the species was only found once. In general, the species richness was highest on the glacier forefront, lowest in the most established vegetation. The proportion of species of Ascomycota was highest close to the glacier front. The main gradient in the data set was shown related to the primary ecological succession following the retreat of glaciers. The second gradient was possibly related to fine scale variation due to local moisture, microtopography, and secondary distribution. Of the variation in composition of species, 3 % can be ascribed to abiotic variance, 10 % to vascular plant variance, and 16 % to the combination of the abiotic and vascular plant component of variation. The results are discussed in the light of the time since deglaciation and the influence of certain biotic and abiotic environmental factors.     

Simulation of multidimensional community patterns: towards a comprehensive model

Ecological gradients in the field layer of southern boreal forests in South Finland were studied in relation to the dominant tree species and the age of forest stands. The data are from a systematic sample of 529 plots from an area of 150 × 200 km, collected in the Third National Forest Inventory in 1951–53. Detrended correspondence analysis (DCA) was applied to log-transformed species cover values. It revealed three main gradients: fertility, moisture, and the effect of cattle grazing in forests (still extensive in the early 1950's). The fertility gradient dominated the first axis and the two latter sources of variation confounded with it in a complex manner in the first two axes of DCA. The second DCA axis was associated with canopy effects on understory pattern, with Pinus and Picea having opposite and Betula intermediate effects. These results were compared with an ordination model of Cajander's forest site types, based on DCA of independent, ideal data of 107 indicator species. The fertility gradient recovered by the model was almost identical to that obtained from the field data. The gradient was also stable from intermediate-age (40–69 yrold) to older forests. The forest site types showed rather large overlaps with main neighbouring types in composition of ground vegetation or nutrient status of the humus. Competitively efficient feather-mosses, which are dependent on nutrients released from the tree crowns, are considered important regulators of the understory vegetation. Accordingly, alternative approaches to the forest site type classification to be used in boreal forests treated by modern intensive forestry should give more weight to the effect of the canopy trees.     

Reseating of ecological gradients. III. The effect of scale and niche breath measurements

Abundances of eleven Sphagnum species in 800 sample plots are used to investigate the effect of DCA rescaling on Levins' measure of niche breadth relative to three partitions of the water-table gradient in a boreal Norwegian mire: (1) sample plots classified into 15 categories, each spanning an interval of 2 cm vertical extent, (2) as (1), but sequence of categories rescaled by DCA and sample plots reorganized into 15 categories with uniform beta diversity, and (3), sample plots ordinated by DCA and classified into 15 categories with uniform beta diversity by subdivision of an ordination axis highly correlated with median water-table. Habitat niche breadth is shown to be dependent on four issues (in order of supposedly decreasing importance): (1) scale, (2) noise level of data, (3) homogeneity of individual samples, and (4), weighting function. Six problems relevant to interpretation of measurements of niche breadth are discussed: (1) range of measures, (2) spacing of categories, (3) scale, (4) choice of gradients, (5) number of samples, and (6), comparability of studies. For measures of habitat niche breadth to be biologically meaningful, four conditions have to be satisfied: (1) the gradients studied have important impact on the studied species, (2) sampling is adequate, (3) scaling of gradients is in compositional turnover, and (4), comparability is demonstrated prior to comparison with other studies. Revisions of current methods are proposed. The role of DCA in niche studies is particularly emphasized.     

神农架川金丝猴栖息地森林群落的数量分类与排序

在神农架川金丝猴生境典型地段设立样方58块,根据样方资料对神农架川金丝猴栖息地的森林群落用组平均法分类和DCA排序.用组平均法将58块样地分为9个群系,依据《中国植被》的分类原则和系统将研究区植物群落划归为7个植被型.样地的DCA排序较好地揭示了该区森林群落的分布格局与环境梯度的关系;DCA第二轴明显地反映出森林群落的海拔梯度变化,沿DCA第二轴从右到左,海拔逐渐升高;第一轴表现了各植物群落或植物种所在环境的坡度、坡向,即水分和光照因素,沿第一轴从下到上,坡度渐缓、坡向渐向阳.其中海拔梯度是环境因子中对森林群落起决定性作用的因子.研究表明,巴山冷杉+糙皮桦-大齿槭+尾萼蔷薇-高原露珠草+星果草群系发育较好,高大树木占有较大的比例,是神农架川金丝猴最适宜栖息地.7个植被型物种丰富度指数在群落梯度上呈规律性波动.其中针叶林和针叶-阔叶混交林中,物种丰富度指数在群落梯度上的总体趋势表现为灌木层＞草木层＞乔木层;在常绿阔叶林和常绿-落叶阔叶混交林中,该趋势为灌木层＞乔木层＞草本层;在落叶阔叶林中,其丰富度指数的趋势为灌木层＞草本层和乔木层.不同植被类型川金丝猴食源植物种类在群落梯度上的变化趋势与物种丰富度指数相同,但地衣类植物作为川金丝猴冬季的重要食物只在针叶林和针叶-阔叶混交林中生长.本研究为制定栖息地保护计划,更好地保护神农架川金丝猴提供了科学理论依据.     

The TRM Model of Potential Natural Vegetation in Mountain Forests

Due to advances in spatial modeling and improved availability of digital geodata, traditional mapping of potential natural vegetation (PNV) can be replaced by ecological modeling approaches. We developed a new model to map forest types representing the potential natural forest vegetation in the Bavarian Alps. The TRM model is founded on a three-dimensional system of the ecological gradients temperature (T), soil reaction (R), and soil moisture (M). Within such a “site cube” forest types are defined as homogenous site units that give rise to forest communities with comparable species composition, structure, production and protective functions. The three gradients were modeled using regression algorithms with area-wide, high resolution geodata on climate, relief and soil as predictors and average Ellenberg indicator values for temperature, acidity and moisture of vegetation plots as dependent variables summarizing plant responses to ecological gradients. The resulting predictor-response relationships allowed us to predict gradient positions of each raster cell in the region from geodata layers. The three-dimensional system of gradients was partitioned into 26 forest types, which can be mapped for the whole region. TRM-based units are supplemented by 22 forest types of special sites defined by other ecological factors such as geomorphology, for which individual GIS rules were developed. The application of our model results in an intermediate-scale map of potential natural forest vegetation, which is based on an explicit function of temperature, reaction and moisture and is therefore consistent and repeatable in contrast to traditional PNV maps.     

Fine‐scale five‐year vegetation change in boreal bog vegetation

Abstract. Within an ombrogenous part of N. Kisselbergmosen, Rødenes, SE Norway, fine‐scale changes in species abundance, successional trends relative to the main gradients (as represented by DCA axes), and co‐ordinated change within pairs of the bottom layer species are studied. Data sets were sampled twice with a five‐year interval, and included species abundance and cover of mud bottom, naked peat and litter in 436 sample plots (16 cm× 16 cm), and species abundance in 6976 subplots (4 cm× 4 cm). Depth from the surface of subplots to the water table was estimated in 1991. Most summers and growing seasons were somewhat drier than normal in the 5‐yr period. The area covered by mud‐bottom, naked peat and litter increased significantly, as did the frequencies of the dwarf shrubs Calluna vulgaris and Andromeda polifolia in hummocks and upper lawn. Sample plots were significantly displaced downward the peat productivity gradient (DCA 2), reflecting the reduced cover of many bottom layer species, including all Sphagnum spp. Significant coordinated changes in cover of bottom layer species are described. The changes observed in hummocks support the existence of a local regeneration cycle, as suggested by other researchers. Some of the vegetation changes seem parallel to those reported from areas with a higher nitrogen deposition, but it is not likely that nitrogen deposition alone is the major cause of the observed changes. Between‐year variation in population size and climatic fluctuations may as well explain the observed changes.     

Dynamics of understory vegetation in an old-growth boreal coniferous forest, 1988–1993

Abstract. Understorey vegetation changes in a South Norwegian old-growth coniferous forest were studied between 1988 and 1993 in 200 1-m² vegetation plots. Our aims were to quantify the amount of between-year compositional change, and to elaborate the environmental basis for long-term vegetation change, including the previously identified gradient structure with a major gradient related to topography (and soil nutrient status and soil depth) and a minor gradient reflecting paludification and canopy coverage. Species richness (yearly mean and cumulative species number) and change in species richness differed between vascular plants and cryptogams, and between forest types. The number of vascular plant species decreased in pine forest in dry years; bryophyte species number increased in spruce forest. Statistically significant vegetation change, as tested by constrained ordination (CCA) with time as the constraining variable, is demonstrated for most one-year periods and for the five-year period in most forest types. Vegetation change along identified gradients, measured as plot displacement along DCA ordination axes, also occurred. The magnitude of year-to-year vegetation change was related neither to forest type nor to one-year period; different responses to climatic and environmental change were observed in each forest type. The largest average displacement observed, from medium-rich spruce forest towards poor spruce forest, was interpreted as a long-term trend. Humus-layer pH decreased by ca. 0.25 units from 1988 to 1993, most strongly in medium-rich spruce forest where exchangeable Ca decreased and Al and Mn increased strongly. Our study supports the hypothesis that vascular plants show a long-term and broad-scale response to soil acidification. Change in bryophyte composition is linked to some very long growing-seasons. Detailed analysis of short-term vegetation dynamics enhances the interpretation of long-term changes and stresses the complementarity of univariate and multivariate methods in the analysis of vegetation change.     

Plant composition in the Maya Biosphere Reserve: natural and anthropogenic influences

We studied the floristic composition and stand structure of lowland forests of the Maya Biosphere Reserve (MBR) of El Petén, Guatemala. Sampling was performed over a gradient of human influence, including a newly established returnee community (migrant), the cooperative Unión Maya Itzá, as well as an adjacent protected area within the core area of the MBR. Five 1-ha plots, each divided into 100 contiguous 10 × 10 m² subplots, were used to record presence of all tree and vine species. The study area is a low-diversity rainforest with a canopy layer dominated by species of Fabaceae, a shrub layer dominated by Rubiaceae, and vines dominated by Bignoniaceae. Vines were conspicuous both in number and in diversity. Variation in both tree life-form composition and canopy abundance pattern apparently reflect variation in intensity of forestry among the plots. The similarities between the plots in the cooperative (a logging plot and a settlement plot) with regard to species area curves, and mean number of tree and understory species per subplot, may indicate effects of disturbance (in general) on vegetation structure. Detrended correspondence analysis (DCA) was used to investigate gradients in species composition among the five plots (125 subplots) and to generate hypotheses about vegetation–environment relationships. The study area appears as a mosaic of site-specific forest types or associations determined by a particular species or groups of co-dominant species. The main environmental characteristics of the area determining species composition and structure are related to the drainage of soils and human disturbance.     

Vegetation - environment relationships of old hay meadows at Sverveli, Telemark, S Norway

The vegetation of traditionally managed species-rich hay meadows at Sverveli, Telemark, S Norway was studied applying an indirect gradient approach. The vegetation in 93 randomly placed sample plots was analysed in order to detect the main vegetational gradients. Ecological measurements were recorded from each plot. The relationships between vegetation and environment were studied by DCA and LNMDS ordinations and non-parametric correlation analysis. Both ordinations revealed the same two ecologically interpretable vegetation gradients. Soil moisture was identified as the most important environmental factor in determining the species composition, followed by soil nutrient content. The contents of P, K. and Mg in the soil were more strongly correlated with the main vegetational gradients than was soil N. Differences in management history may explain some of the observed variation in species composition that was not accounted for by the recorded environmental variables.     

Can tissue element concentration patterns at the individual species level indicate the factors underlying vegetation gradients in wetlands?

Question: Do tissue element concentrations at the individual species level vary along major vegetation gradients in wetlands, and can they indicate environmental conditions? Location: West Carpathians. Methods: Total plant species composition was recorded in plots distributed along a poor to rich gradient within spring fens and along the gradient from fens to wet meadows. Eriophorum angustifolium (Cyperaceae) and three broadleaf dicotyledonous herb species were collected from the vegetation plots. Tissue N, P, K, Ca and Fe concentrations, N:P and N:K ratios of the species were determined. Each variable was correlated with the sample scores along the first two axes of the DCA ordination, which represented the two main vegetation gradients. Results: K and Ca concentrations in a particular species correlated well with the vegetation gradients, thus indicating changes in the element availability to the species. The trends were sometimes contradictory to known patterns at the community level, but the differences could be ecologically interpreted. Contrary to Ca and K, patterns in N, P and Fe concentration appeared to be more species‐specific. E. angustifolium had a lower K and Ca concentration than the broadleaf herbs. Conclusions: Compared to community‐level measurements, element concentrations in individual species correlated less with observed vegetation gradients. Trends found at the species level may indicate changes in ecological conditions affecting the species, although they need not correspond with trends found at the community level. We conclude that the species‐level approach cannot substitute, but can advance, the community‐level approach in searching for mechanisms underlying vegetation gradients within wetlands.