Analysis of Planktonic Rotifer Assemblages from Sudbury, Ontario, Area Lakes of Varying Chemical Composition

1987 ◽  
Vol 44 (10) ◽  
pp. 1692-1701 ◽  
Author(s):  
Hugh J. MacIsaac ◽  
Thomas C. Hutchinson ◽  
W. Keller
Keyword(s):  
Chemical Composition ◽  
Species Composition ◽  
Correspondence Analysis ◽  
Detrended Correspondence Analysis ◽  
Species Distributions ◽  
Acid Lakes ◽  
Acid Ph ◽  
Rotifer Community ◽  
Planktonic Crustaceans ◽  
Rotifer Communities

Planktonic rotifer samples were collected from 47 Sudbury, Ontario, area lakes to determine factors influential to species distributions. The lakes ranged from highly acidic and metal contaminated to circumneutral with low metal concentrations. Median rotifer abundance was substantially higher in non-acid (pH > 5.2) than in acid (pH < 5.2) lakes, although differences in species distributions were evident. Application of detrended correspondence analysis to rotifer species densities revealed broad separation of communities from acid and non-acid lakes. Assemblages from acid lakes were highly similar in species composition and dominance, while those from non-acid lakes were generally much more heterogeneous. It was hypothesized that planktonic rotifer communities converged in species composition as a consequence of the stress of lake acidification, in a pattern similar to that previously described for planktonic crustaceans. Among the best predictors of rotifer community composition were lake pH and the concentrations of manganese and aluminum.

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.

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.

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.

scholarly journals Psocid taxocenoses structure and diversity (Insecta: Psocoptera) in the forest ecosystems of the Piceeti–fageta s. lat. zone in the Western Carpathian Mts.

2011 ◽  
Vol 59 (5) ◽  
pp. 95-104 ◽  
Author(s):  
Otakar Holuša
Keyword(s):  
Cluster Analysis ◽  
Species Composition ◽  
Correspondence Analysis ◽  
Dominant Species ◽  
Forest Ecosystems ◽  
Forest Type ◽  
Detrended Correspondence Analysis ◽  
Vegetation Zones ◽  
Characteristic Species

Psocid taxocenoses (Psocoptera) were studied in forest ecosystems of the Western Carpathian Mts. during 1997–2001. As a study frame, vegetation tiers (= altitudinal vegetation zones) were used. Lower units of forest typological system (forest type complexes) were used for a classification of ecological conditions as well. Only a part of material, i.e. individuals that was found in the forest ecosystems of Piceeti-fageta s. lat. communities (= the 6th spruce-beech vegetation tier) was evaluated for purpose of this work. This vegetation tier is widespread in higher parts of mountains (the Moravskoslezské Beskydy Mts. and partly in the Oravské Beskydy Mts.). 554 adults comprising 17 species were found in total in the 6th vegetation tier. As eudominant species, the following ones were found: Caecilius despaxi, Caecilius burmeisteri, Mesopsocus unipunctatus, and Stenopsocus lachlani; as dominant species, the following ones were found: Caecilius flavidus and Reuterella helvimacula. In natural geobiocenoses with the level of naturalness of 1 or 2, the following species were found: as eudominant species: Mesopsocus unipunctatus, Stenopsocus lachlani, Caecilius despaxi, Amphigerontia bifasciata and Reuterella helvimacula. Dominant species was Caecilius burmeisteri and Caecilius flavidus. 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 6th vegetation tier was as follows – Cecilius despaxi – Stenopsocus lachlani – Mesopsocus unipunctatus – Reuterella helvimacula.

scholarly journals Detecting the driving forces underlying the divergence of spruce forests in China: evidence from phytocoenology, morphology and phylogenetics

2019 ◽  
Vol 13 (1) ◽  
pp. 59-69 ◽  
Author(s):  
Guo-Hong Wang ◽  
Hai-Wei Zhao ◽  
Meng An ◽  
He Li ◽  
Wei-Kang Zhang
Keyword(s):  
Species Composition ◽  
Correspondence Analysis ◽  
Driving Forces ◽  
Geographical Location ◽  
Detrended Correspondence Analysis ◽  
Mean Annual Precipitation ◽  
Spruce Forests ◽  
Species Analysis ◽  
Moisture Conditions ◽  
Phylogenetic Divergence

Abstract Aims We aimed to elucidate the driving forces underlying the geographical distribution of spruce forests, as well as the morphological and phylogenetic divergence among spruce species in China. Methods One hundred and seventy two sites across the entire range of spruce forests in China (23°–53° N, 75°–134° E, 250–4300 m a.s.l.) were sampled for species composition, geographical coordinates, and topographic and climatic variables. Sixteen spruce taxa, which are naturally distributed in China, were respectively grouped into morphologically defined sections and phylogenetically distinct clades. Multivariate approaches, including two-way indicator species analysis, principal components analysis, detrended correspondence analysis, canonical correspondence analysis (CCA), and partial CCA, were used for data analysis. Important Findings The 172 samples grouped into 13 spruce forests, the geographical distributions of which were closely related to climate and geographical location. The variation in species composition explained by the geographical coordinates (32.01%) was significantly higher than that explained by the climatic (27.76%) and topographic variables (23.32%). Of the three morphologically defined sections, sect. Omorica occurred mainly in wetter habitats with a mean annual precipitation of ca. 229 mm and 426 mm higher than the habitats of sect. Casicta and sect. Picea (P &lt; 0.01), respectively. Of the two phylogenetically distinct clades, Clade-II (an older clade) occurred in habitats with warm winters and cool summers whose mean temperature in the coldest month was ca. 8–10°C higher, yet accumulated temperature during the growing season (≥ 5°C) was ca. 297–438°C lower, than the habitats of Clade-III (a younger clade) (P &lt; 0.01). Our data support the hypothesis that geographical location may be a greater determinant of variation in species composition. In addition, moisture conditions tend to be the key determinants that account for the divergence among the morphologically defined sections, while the phylogenetic divergence among spruce species is mainly affected by temperature conditions. While the clades or sections of the spruce species in question carry strong climatic signals, their divergences are subject to different selective pressures.

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