The plant communities of a foredune in southeastern Brazil

1998 ◽  
Vol 76 (8) ◽  
pp. 1323-1330 ◽  
Author(s):  
Raimundo Paulo Barros Henriques ◽  
John DuVall Hay
Keyword(s):  
Species Composition ◽  
Correspondence Analysis ◽  
Stress Gradient ◽  
High Stress ◽  
Detrended Correspondence Analysis ◽  
Southeastern Brazil ◽  
Important Species ◽  
Middle Range ◽  
Dca Ordination ◽  
Using Data

Species composition, biomass and environmental characteristics of a coastal plant community of southeastern Brazil, was studied using data from 110 quadrats collected on the foredune of Barra de Maricá, Rio de Janeiro, Brazil. Indirect and direct gradient analyses were used to describe the foredune community. Ordination by detrended correspondence analysis (DCA) indicated the existence of three vegetation groups: pioneer, embryo dunes and a zone of fixed dunes with blow out areas. The gaps observed between groups were attributed to discontinuities in environmental factors. Most of the variation in species composition was expressed by the second axis of the DCA ordination, which was correlated with the distance from the beach bank. The second axis is interpreted as a stress gradient, with high stress in the pioneer zone decreasing to fixed dunes. The coenocline analyzed by direct gradient ordination, was divided into three segments equivalent to Groups detected by DCA ordination. The important species were: Althernanthera maritima St. Hil. in the pioneer zone, and Sporobolus virginicus (L.) Kunth, Mariscus pedunculatus (R. Brown) T. Koyama, and Mitracarpus frigidum K. Sch. in the embryo dunes. The grassPanicum racemosum (Spreng) was associated with areas of fixed dune. that were also characterized by Mollugo verciticillata L. Both biomass and species richness were lower at the high stress disturbance ends of the gradient, with their maximum value in different portions of the middle range of the gradient.Key words: detrended correspondence analysis, direct gradient analysis, foredune communities, vegetation zonation.

Ordination by detrended correspondence analysis (DCA) of the vegetation of Swartboschkloof, Jonkershoek, Cape Province

Bothalia ◽  
1987 ◽  
Vol 17 (1) ◽  
pp. 121-129 ◽  
Author(s):  
D. J. Mcdonald
Keyword(s):  
Soil Moisture ◽  
Plant Communities ◽  
Correspondence Analysis ◽  
Detrended Correspondence Analysis ◽  
Vegetation Classification ◽  
Environmental Data ◽  
Strongly Correlated ◽  
Intensive Study ◽  
Dca Ordination ◽  
Soil Moisture Status

The data of a Braun-Blanquet vegetation classification was ordinated using detrended correspondence analysis (DCA). This was done at the Fynbos Biome intensive study site, Swartboschkloof, Jonkershoek, to investigate the factors determining the distribution of the plant communities. Superimposition of environmental data on the DCA ordination confirmed the indications of the Braun-Blanquet classification that the distribution of plant communities is most strongly correlated with soil geology and, to a lesser extent, with soil moisture status. The ordination also proved useful for examining the relationships between the transitional communites and the distinct communities of Swartboschkloof.

scholarly journals How do plant communities and flower visitors relate? A case study of semi-natural xerothermic grasslands

2013 ◽  
Vol 82 (2) ◽  
pp. 99-105 ◽  
Author(s):  
Damian Chmura ◽  
Paweł Adamski ◽  
Zygmunt Denisiuk
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Plant Communities ◽  
Correspondence Analysis ◽  
Positive Relationship ◽  
Detrended Correspondence Analysis ◽  
Permanent Plots ◽  
Moisture Index ◽  
Rarefaction Analysis ◽  
Flower Visitors

<p>The paper examines the relationships between the species composition of flower visitors and plants in the semi-natural xerothermic grasslands in southern and central Poland. Thirty 10 × 10 m permanent plots were laid out in total, mainly in nature reserves. The vegetation units studied were classified according to the Braun-Blanquet system; these were phytocoenoses of the <em>Festuco-Brometea</em> classes <em>Inuletum ensifoliae</em>, <em>Adonido-Brachypodietum pinnati</em> and the transitional plant community. Entomological research was performed using the Pollard method within the same plots. A particular site was visited only once and different sites were studied between April and August 2008. We applied, among others, co-correspondence-analysis Co-CA, detrended correspondence analysis (DCA) and redundancy analysis (RDA) to investigate the co-occurrence patterns of plants and flower visitors and their biotopic requirements. We found that the species composition of flower visitors cannot be predicted by floristic composition when the duration of the study is restricted to one day (but under similar weather conditions); however, there is a positive relationship between the species richness of insects and plants and a positive relationship between the number of plant species and the abundance of flower visitors. The Ellenberg moisture index and the cover of meadow species significantly explained the species composition of insects. The three various vegetation units and five dominant xerothermic species, i.e. <em>Adonis vernalis</em>, <em>Anemone sylvestris</em>, <em>Inula ensifolia</em>, <em>Linum hirsutum</em> and <em>Carlina onopordifolia</em> that were studied across time differed in the species richness of insects. Our results demonstrate that possible patterns in the species composition and the assembly rules of flower visitors are not apparent when the Pollard method is applied. Based on the data obtained using this method, the flower visiting assemblages seem not to be driven by competition and they primarily show a tendency to co-occur which can be an artifact. A plant-focused method that included a rarefaction analysis yielded more insightful results and shed more light on the differences between the dominant plants that shape the physiognomy of plant communities in a possible pollination specialization.</p>

Phytosociology and gradient analysis of a subalpine treed fen in Rocky Mountain National Park, Colorado

1996 ◽  
Vol 74 (8) ◽  
pp. 1203-1213 ◽  
Author(s):  
J. Bradley Johnson
Keyword(s):  
Species Composition ◽  
Correspondence Analysis ◽  
Species Distribution ◽  
Gradient Analysis ◽  
Vegetation Type ◽  
Detrended Correspondence Analysis ◽  
Tree Density ◽  
Small Scale ◽  
Groundwater Temperature ◽  
Strong Control

The vegetation of a subalpine fen in Colorado was studied. Insight was sought into the community structure and factors influencing species distribution of a vegetation type heretofore undescribed in the southern Rocky Mountains. A vegetational gradient was evaluated using detrended correspondence analysis (DCA). Four types of vegetation were subjectively defined; these same types were distinguished by the DCA. DCA further revealed marked differences in the vegetation occurring on peat hummocks versus in hollows. Species composition was related to environment using canonical correspondence analysis (CCA). Water-table depth, hummock height, shading, groundwater temperature, and conductivity were significantly correlated with species distribution, accounting for 51% of the total species variance. Univariate regression was used to examine how tree density varied with environment. The above factors, except for shading and conductivity, were also significantly correlated with tree density. It is suggested that the peat hummocks that form on this moderate fen provide an environment similar to that of an ombrotrophic bog and that these "miniature bogs" form in areas unable to support expansive bogs. Further, these hummocks provide small-scale environmental heterogeneity that exerts a strong control over species composition that would not be evident in studies based on samples of a large areal extent. Keywords: Colorado, gradient analysis, ordination, heterogeneity, peatlands, phytosociology.

scholarly journals Psocid taxocenoses (Insecta: Psocoptera) in the forest ecosystems of the Querci-fageta s. lat. zone in the Western Carpathian Mts. and Polonic subprovincy

2013 ◽  
Vol 61 (3) ◽  
pp. 637-646
Author(s):  
Otakar Holuša
Keyword(s):  
Cluster Analysis ◽  
Czech Republic ◽  
Species Composition ◽  
Correspondence Analysis ◽  
Dominant Species ◽  
Forest Ecosystems ◽  
Detrended Correspondence Analysis ◽  
The Czech Republic ◽  
Vegetation Zones ◽  
Characteristic Species

Structure of psocid taxocenoses (Psocoptera) were intensively studied in forest ecosystems of the Western Carpathian Mts. and Polonic biogeographical subprovincy during 1997–2001 in the Czech Republic. Vegetation tiers (= altitudinal vegetation zones) were used as a study frame. Only a part of material, i.e. individuals that was found in the forest ecosystems of Querci-fageta s. lat. communities (= the 3rd oak-beech vegetation tier) was evaluated for purpose of this work. This vegetation tier is widespread in large part of the Opavská pahorkatina hills, in large parts of Podbeskydská pahorktina hills, in the Bílé Karpaty hills and in the foothills of the Vsetínské vrchy hills. 1201 adults comprising 29 species were found in total in the 3rd vegetation tier. As eudominant species, the following ones were found: Peripsocus subfasciatus, Caecilius flavius and Stenopsocus lachlani, as dominant species, the following ones were found: Philotarsus parviceps and Caecilius piceus. In natural geobiocenoses with the level of naturalness of 1 or 2, the following species were found: as eudominant species: Caecilius flavidus, Peripsocus phaeopterus, as dominant species, the following ones were found: Caecilius piceus, Peripsocus subfasciatus, Philotarsus parviceps and Elipsocus moebiusi. Taxocenoses of psocids were evaluated by Detrended Correspondence Analysis (DCA) and Divisive Cluster Analysis (DvClA). This material was compared to another material gained from various vegetation tiers in the Western Carpathians Mts. The characteristic species composition of psocids in the 3rd vegetation tier was as follows – Elipsocus moebiusi – E. hyalinus – Philotarsus parviceps – Ectopsocus meridionalis – Caecilius flavidus.

scholarly journals Composition and diversity of psocid (Insecta: Psocoptera) taxocoenoses in forest ecosystems of the Abieti-fageta s. lat. zone in the Western Carpathian Mts.

2009 ◽  
Vol 55 (No. 4) ◽  
pp. 184-192 ◽  
Author(s):  
O. Holuša
Keyword(s):  
Cluster Analysis ◽  
Species Composition ◽  
Correspondence Analysis ◽  
Dominant Species ◽  
Forest Ecosystems ◽  
Forest Type ◽  
Detrended Correspondence Analysis ◽  
Vegetation Zones ◽  
Characteristic Species

Psocid (Psocoptera) taxocoenoses were studied in forest ecosystems of the Western Carpathian Mts. in 1997–2001. As a study frame, vegetation tiers (VT = altitudinal vegetation zones) of geobiocoenological or forest-typological system were used. Lower units of forest typological system (forest type complexes) were used for the classification of ecological conditions and the material found in forest ecosystems of <I>Abieti-fageta</I> s. lat. communities (5<sup>th</sup> fir-beech VT) was evaluated in detail. This VT is the most widespread in the regions under study (the Moravskoslezské Beskydy Mts., the Vsetínské vrchy Hills and Javorníky). 2,023 adults comprising 28 species were found in the 5<sup>th</sup> VT. <I>Caecilius burmeisteri</I> was found as eudominant species; <I>Philotarsus picicornis, Caecilius flavidus</I> and <I>Peripsocus subfasciatus</I> were found as dominant species. In natural geobiocoenoses with the level of naturalness 1 or 2, the following species were found: <I>Mesopsocus unipunctatus, Caecilius flavidus</I>, and <I>Caecilius burmeisteri</I> as eudominant and <I>Caecilius despaxi</I> as dominant. Taxocoenoses of psocids were evaluated by Detrended Correspondence Analysis (DCA) and Divisive Cluster Analysis (DvClA). The axes were interpreted in DCA-analysis as follows: the <I>x</I>-axis denotes the influence of VTs and the <I>q</I>-axis refers to the influence of hydricity. This material was compared with other material obtained from various vegetation tiers in the Western Carpathians Mts. The characteristic species composition of psocids in the 5<sup>th</sup> VT was as follows: <I>Caecilius flavidus – C. burmeisteri – C. despaxi – Metylophorus nebulosus – Philotarsus picicornis</I>.

Significance of current velocity gradients for distribution patterns of charophytes versus mosses and vascular plant communities in a lowland stream

2015 ◽  
Vol 44 (2) ◽  
Author(s):  
Emilia Jakubas ◽  
Maciej Gąbka
Keyword(s):  
Species Composition ◽  
Correspondence Analysis ◽  
Current Velocity ◽  
Vascular Plants ◽  
Vascular Plant ◽  
Detrended Correspondence Analysis ◽  
Water Current ◽  
Chara Vulgaris ◽  
Lowland Stream ◽  
Chara Globularis

AbstractThe study focused on the relationships between charophytes and the surrounding species composition and environmental factors in a lowland stream (Flinta stream, Western Poland). A total of 32 vegetation plots (4 m × 4 m) and 13 environmental variables were tested. Detrended correspondence analysis (DCA) and canonical correspondence analysis (CCA) were used to describe the relationships between the species composition and the selected variables. Dominance curves of aquatic plants, response curves (GAMs model) of charophytes and other macrophytes to the velocity gradient (the most important environmental factor, the Monte Carlo test) were prepared. In this study, 2 species of charophytes were recorded: Chara vulgaris and Chara globularis and 5 other co-occurring macroscopic algae, 2 mosses and 10 vascular plants. In the studied stream, charophytes occupied the separate niche. Chara vulgaris stands with moss vegetation were found in stream sections with the highest velocity of the water current (0.29 m s-1 mean), and the Chara globularis (with dominant Potamogeton species), preferred sections with the smallest water current velocity (0.19 m s-1 mean).Charophytes seem to respond to ecological gradients differently from mosses and vascular plants. These differences are related to current velocity, pH, conductivity and organic matter in bottom sediments, and to the niche differentiation associated with them.

scholarly journals Compositional change in fish assemblages along the Andean piedmont - Llanos floodplain gradient of the río Portuguesa, Venezuela

2004 ◽  
Vol 2 (2) ◽  
pp. 85-92 ◽  
Author(s):  
David J. Hoeinghaus ◽  
Kirk O. Winemiller ◽  
Donald C. Taphorn
Keyword(s):  
Species Composition ◽  
Fish Assemblages ◽  
Anthropogenic Impacts ◽  
Species Turnover ◽  
Elevation Gradient ◽  
Detrended Correspondence Analysis ◽  
Fish Ecology ◽  
Compositional Change ◽  
Dca Ordination ◽  
Fish Species Composition

The Llanos is an extensive area of savannas and floodplains in central and western Venezuela that encompasses a gradual elevation gradient from the río Orinoco to the foothills of the Andean piedmont. The río Portuguesa is one of the major rivers in this region that until recently had escaped major anthropogenic impacts and still maintains substantial seasonal fish migrations. However, little work has been conducted on fish ecology in this river. The present study analyzes museum collections sampled at 28 locations along the longitudinal gradient of the río Portuguesa to assess similarity of species composition from the foothills of the Andean piedmont to the lowland llanos floodplain. The standardized samples used in this analysis contained greater than 133 species representing 6 orders and 27 families, dominated by characiforms (61 species) and siluriforms (52 species). Detrended correspondence analysis (DCA) ordination of samples revealed a continual pattern of compositional change, and species are added at a faster rate than they are lost as one moves from the foothills of the piedmont to the low llanos. Based on DCA, samples from three elevational segments were found to significantly differ in fish species composition. Assemblages in the upper reaches contained unique species of loricariid catfishes, small pimelodid and trichomycterid catfishes, and small characiforms not observed at lower elevations. The lowland reach contained species of cichlids, large catfishes and characids not collected from the other two regions. Samples from the middle region revealed transitional species composition. Longitudinal species turnover probably reflects differences in environmental characteristics such as a water velocity, substrate composition and disturbance regime. Findings from this broad-scale analysis contribute to a baseline for future studies of fish ecology in this region.

Species composition of demersal fish in the Rockall Trough, north-eastern Atlantic, as determined by different trawls

1992 ◽  
Vol 72 (1) ◽  
pp. 213-230 ◽  
Author(s):  
J. D. M. Gordon ◽  
O. A. Bergstad
Keyword(s):  
Species Composition ◽  
Continental Slope ◽  
Correspondence Analysis ◽  
Detrended Correspondence Analysis ◽  
Demersal Fish ◽  
Depth Zone ◽  
North Eastern ◽  
Rockall Trough

The variation in species composition of continental slope fishes as determined by the catches of different trawls towed either on single or paired warps was analysed by Detrended Correspondence Analysis (DCA). The catches of two trawls, a semi-balloon trawl (OTSB) and a Granton trawl (GT) were very similar when towed on paired warps. Significant differences were found between the catches of the OTSB trawl towed on single and paired warps. The DCA effectively provided information on the important gradients, e.g. depth, trawl type, and indicated which species were most abundant in the different depth zones and trawl types. Detailed accounts of the abundance and biomass of different species by trawl type and depth zone are given and the observed pattern of distribution discussed.

Longitudinal structure of fish assemblages in a minimally disrupted stream

Biologia ◽  
2011 ◽  
Vol 66 (5) ◽  
Author(s):  
Ladislav Pekárik ◽  
Miroslav Švátora ◽  
Jaroslav Černý ◽  
Ján Koščo
Keyword(s):  
Correspondence Analysis ◽  
Fish Species ◽  
Western Europe ◽  
Fish Assemblages ◽  
Detrended Correspondence Analysis ◽  
Environmental Parameters ◽  
Distribution Patterns ◽  
Longitudinal Distribution ◽  
Important Species ◽  
Ordination Method

AbstractThe longitudinal distribution patterns of fish species are affected by both natural and anthropogenic variables. The role of these factors on the formation of species assemblages is well documented in North America and Western Europe, but detailed information is lacking from Central and Eastern Europe, and the Carpathian region especially. Therefore, we examined the structure of fish assemblages in response to six key environmental parameters in a natural stream system (Udava stream basin, Slovakia). We used the indirect ordination method of gradient analysis (Detrended Correspondence Analysis, DCA) to analyse the species groups and their connections to the sampled sites and to recognize the strongest gradient of assemblage composition. Subsequently, we used the direct ordination method (Canonical Correspondence Analysis, CCA) to identify the strongest gradients in relation to selected variables. Two major gradients were identified that follow the upstream-downstream pattern of fish communities and three variables (distance from source, depth and site slope) are correlated with the first CCA axis (P < 0.05) and two variables (depth and vegetation cover) are correlated with the second CCA axis (P < 0.05). We assume that these factors influence the temperature and the amount of dissolved oxygen that can cause oxygen and temperature stress to intolerant species (e.g., salmonids). Based on these results, we assume that the economically important species, brown trout and grayling, are not native to the stream basin and this status is only the consequence of natural factors. Furthermore, the results suggest that the Udava stream offers favourable conditions for fish species distribution — a view supported by the high variability of particular variables within the proposed model.

Sign in / Sign up

Export Citation Format

Share Document