Diversity partitioning and community structure of epiphytic bryophytes along an elevational gradient in the north-eastern Madagascar

2020 ◽  
Vol 42 (1) ◽  
pp. 32-48
Author(s):  
LOVANOMENJANAHARY MARLINE ◽  
TERRY A. J. HEDDERSON ◽  
CLAUDINE AH-PENG
Keyword(s):  
Species Composition ◽  
Beta Diversity ◽  
Elevational Gradient ◽  
The North ◽  
Β Diversity ◽  
Spatial Turnover ◽  
North Eastern ◽  
Interesting Approach ◽  
Sampling Scale ◽  
Total Diversity

Understanding spatial variation in species composition of different communities is key to understanding the processes that generate and maintain biodiversity. The partitioning of diversity into hierarchical scale-related components is an interesting approach to quantitatively defining the overall net biodiversity from hierarchically scaled studies and is a useful method in studies of conservation biology and restoration. This paper deals with the additive partitioning of the overall diversity and the partitioning of beta-diversity of epiphytic bryophytes along an elevational gradient in Madagascar. The aim is to describe the variation in species composition between sites and to elucidate why different species occur in different communities in the Marojejy National Park (250–2050 m). We looked at the contribution of α and β diversity to total diversity were calculated from four hierarchical scales: microhabitat (50 cm2), quadrat (4 m2), plot (100 m2) and elevation (every 200 m). Furthermore, we documented how the two components of beta-diversity (turnover and nestedness) are influenced by variation in elevation. Our result suggests that more variation in species richness was found within the elevational scales, than within microplot scales, confirming that beta diversity at the largest sampling scale is the largest contributor to the total diversity. It indicates that bryophyte species among sample within each level are a subsample of the same species pool. This study shows evidence that the beta-diversity of epiphytic bryophyte assemblages is dominated by high spatial turnover due to recruitment of new species along the Marojejy transect, a clear pattern for mountains.

scholarly journals Evaluation of Developmental Structures and Cenopulation State Cerastium davuricum Fisch. ex Spreng. in the Highlands of the Lesser Caucasus

2021 ◽  
Vol 7 (6) ◽  
Author(s):  
R. Guliyeva
Keyword(s):  
Species Composition ◽  
Biological Characteristics ◽  
Age Composition ◽  
The North ◽  
First Case ◽  
North Eastern ◽  
Lesser Caucasus ◽  
Favorable Conditions ◽  
Economic Use ◽  
North Eastern Part

On the highlands of the north – eastern part of the Lesser Caucasus were investigated ontogenetic characteristics Cerastium davuricum in different type of plants. There are found that cenopopulation spices goes through a 4- and 10-year periods. Age composition cenopopulations species is very variable and is associated with the biological characteristics of species composition of the sward, the economic use of pastures. In research found the following types of cenopopulation: normal, invasive, regressive. Meanwhile, the predominance of vegetative individuals in the population in the first case indicates the weakness of cenopopulation, and in the second case, the high number of generative individuals indicates the sustainability of cenopopulation. This arrangement of population under less favorable conditions compared with another one.

scholarly journals Beta Diversity of Demersal Fish Assemblages in the North-Eastern Pacific: Interactions of Latitude and Depth

PLoS ONE ◽  
2013 ◽  
Vol 8 (3) ◽  
pp. e57918 ◽  
Author(s):  
Marti J. Anderson ◽  
Nick Tolimieri ◽  
Russell B. Millar
Keyword(s):  
Beta Diversity ◽  
Fish Assemblages ◽  
Demersal Fish ◽  
Eastern Pacific ◽  
The North ◽  
North Eastern

scholarly journals Diversity Patterns of Different Life Forms of Plants along an Elevational Gradient in Crete, Greece

Diversity ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 200 ◽  
Author(s):  
Maria Lazarina ◽  
Athanasios Charalampopoulos ◽  
Maria Psaralexi ◽  
Nikos Krigas ◽  
Danai-Eleni Michailidou ◽  
...  
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Large Scale ◽  
Regional Scale ◽  
Elevational Gradient ◽  
Life Forms ◽  
Species Pool ◽  
Diversity Patterns ◽  
Β Diversity ◽  
Α Diversity

Elevational gradients provide a unique opportunity to explore species responses to changing environmental conditions. Here, we focus on an elevational gradient in Crete, a climate-vulnerable Mediterranean plant biodiversity hotspot and explore the diversity patterns and underlying mechanisms of different plant life forms. We found that the significant differences in life forms’ elevational and environmental ranges are reflected in α- diversity (species richness at local scale), γ-diversity (species richness at regional scale) and β-diversity (variation in species composition). The α- and γ-diversity decreased with elevation, while β-diversity followed a hump-shaped relationship, with the peak varying between life forms. However, β-deviation (deviation from null expectations) varied significantly with elevation but was life formindependent. This suggests that species composition is shaped by the size of the available species pool which depends on life form, but also by other deterministic or stochastic processes that act in a similar way for different life forms. The strength of these processes varies with elevation, with hotter–drier conditions and increased human activities filtering species composition at lowlands and large-scale processes determining the species pool size overriding local ecological processes at higher elevations.

Species composition and distribution of commercial penaeid prawn catches in the Gulf of Carpentaria, Australia, in relation to depth and sediment type

1994 ◽  
Vol 45 (3) ◽  
pp. 317 ◽  
Author(s):  
IF Somers
Keyword(s):  
Species Composition ◽  
Species Group ◽  
Individual Species ◽  
Sediment Type ◽  
Muddy Sand ◽  
The North ◽  
North Eastern ◽  
Black Tiger Prawn ◽  
Tiger Prawn ◽  
Catch Statistics

To describe the distribution of the commercial penaeid species caught in the Gulf of Carpentaria, species composition data were drawn from studies conducted in the gulf between 1977 and 1992, supplemented with data from commercial catches monitored by fishers trained in species identification. The catch is made up of eight species in four commercial species groups. Three species account for most of the catch: the banana prawn Penaeus merguiensis (about 41%) and the tiger prawns P. esculentus (24%) and P. semisulcatus (23%). Three others, the endeavour prawns Metapenaeus endeavouri (8%) and M. ensis (3%) and the king prawn P. latisulcatus (1%), are found in commercial quantities but usually as incidental components of catches. Two species, the black tiger prawn, P. monodon, and the red-spot king prawn, P. longistylus, are caught only occasionally. At a fine spatial scale (six-nautical-mile grids), each species group was found to consist largely of just one species, and the ratio of one species to another within a species group were relatively stable over time. By using these ratios in combination with fishers' logbook data, it was possible to refine annual catch statistics for the gulf to the level of species rather than, as in the past, just to species group. The spatial distributions of individual species were found to be related to depth and/or sediment type. Catches of P. merguiensis were mainly from the eastern and southern gulf, and in waters shallower than 20 m, but were not associated with any particular sediment type. The brown tiger prawn, P. esculentus, was most abundant in the southern gulf and shallower parts of the western gulf (< 35 m deep). The sediments in these areas were sand or muddy sand. In contrast, the grooved tiger prawn, P. semisulcatus, was most abundant in the north-eastern gulf and the deeper parts of the western gulf (>35 m deep) where sediments were mud or sandy mud. The blue-tailed endeavour prawn, M. endeavouri, was the most widespread of the species in the gulf, but, like P. esculentus, it was most abundant in the south-eastern gulf and shallower parts of the western gulf, where sediments were either sand or muddy sand. The red endeavour prawn, M. ensis, was more limited in its distribution, with highest abundance in the north-eastern gulf and in the deeper parts of the western gulf (35-45 m). Here, the sediments were more than 60% mud.

scholarly journals Beta diversity patterns of Bromeliaceae growing on rocky cliffs within the Atlantic Forest in southern Brazil

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Edilaine Andrade Melo ◽  
Jorge Luiz Waechter
Keyword(s):  
Environmental Factors ◽  
Species Composition ◽  
Atlantic Forest ◽  
Beta Diversity ◽  
Variation Partitioning ◽  
Floristic Composition ◽  
Spatial Effects ◽  
Environmental Predictors ◽  
Diversity Patterns ◽  
Β Diversity

Abstract: In recent years there has been increasing attention in patterns of β-diversity and mechanisms related to variations in species composition. In this study, we evaluated beta diversity patterns of bromeliads growing on cliffs immersed in Atlantic Forest. We hypothesized that the species composition varies according to the spatial scale, inferring that there is a replacement of species influenced mainly by environmental factors. The study was carried out on sandstone cliffs included in contiguous but distinct vegetation formations: Evergreen and Seasonal forests. Twenty-four vertical rocky outcrops were sampled. The spatial variation in species composition was evaluated by two β-diversity components, turnover and nestedness. Multivariate analysis and variation partitioning were performed to distinguish niche and stochastic processes. We recorded 26 bromeliad species and a significantly higher contribution of turnover explaining beta diversity. Environmental factors affect β-diversity patterns of Bromeliaceae. However, individually, the environmental predictors do not explain the data variation. Environmental variations spatially structured, and spatial variables determinate the dissimilarity in the composition of bromeliads on cliffs. Thus, our results revealed that both environmental and spatial effects can act together to define the floristic composition of rock-dwelling bromeliad communities.

Discussion on “The grinding wheel and production” at the North-Eastern Section of the Institution

1942 ◽  
Vol 21 (8) ◽  
pp. 315
Author(s):  
Bowen ◽  
Vickery ◽  
Buchanan ◽  
Swallow ◽  
Perks ◽  
...  
Keyword(s):  
Grinding Wheel ◽  
The North ◽  
North Eastern

The influence of submesoscale eddies on hydrochemical parameters and structural and functional characteristics of phytoplankton in the north-eastern part of the Black Sea

2019 ◽  
pp. 24-40
Author(s):  
Sergey B. Kuklev ◽  
Vladimir A. Silkin ◽  
Valeriy K. Chasovnikov ◽  
Andrey G. Zatsepin ◽  
Larisa A. Pautova ◽  
...  
Keyword(s):  
Anticyclonic Eddy ◽  
The Black Sea ◽  
Hydrochemical Parameters ◽  
North East ◽  
The North ◽  
Seasonal Thermocline ◽  
North Eastern ◽  
Quantitative Indicators ◽  
The City ◽  
North Eastern Part

On June 7, 2018, a sub-mesoscale anticyclonic eddy induced by the wind (north-east) was registered on the shelf in the area of the city of Gelendzhik. With the help of field multidisciplinary expedition ship surveys, it was shown that this eddy exists in the layer above the seasonal thermocline. At the periphery of the eddy weak variability of hydrochemical parameters and quantitative indicators of phytoplankton were recorded. The result of the formation of such eddy structure was a shift in the structure of phytoplankton – the annual observed coccolithophores bloom was not registered.

Kyiv park "Nivki" and "Teremki" forests and ecological analysis of their habitats

2014 ◽  
Vol 25 (3-4) ◽  
pp. 53-68
Author(s):  
I. V. Goncharenko ◽  
H. M. Holyk
Keyword(s):  
Standard Deviation ◽  
Species Composition ◽  
Human Impact ◽  
Soil Nitrogen ◽  
Beta Diversity ◽  
Plant Cover ◽  
Alpha Diversity ◽  
Light Regime ◽  
Individual Species ◽  
Anthropogenic Pressure

Cenotic diversity and leading ecological factors of its floristic differentiation were studied on an example of two areas – Kyiv parks "Nivki" and "Teremki". It is shown that in megalopolis the Galeobdoloni-Carpinetum impatientosum parviflorae subassociation is formed under anthropogenic pressure on the typical ecotope of near-Dnieper hornbeam oak forests on fresh gray-forest soils. The degree of anthropogenic transformation of cenofloras can be estimated by the number of species of Robinietea and Galio-Urticetea classes, as well as neophytes and cultivars. Phytoindication for hemeroby index may be also used in calculation. We propose the modified index of biotic dispersion (normalized by alpha-diversity) for the estimation of ecophytocenotic range (beta-diversity) of releves series. We found that alpha-diversity initially increases (due to the invasion of antropophytes) at low level of antropogenic pressure, then it decreases (due to the loss of aboriginal species) secondarily with increasing of human impact. Also we found that beta-diversity (differential diversity) decreases, increasing homogeneity of plant cover, under the influence of anthropogenic factor. Vegetation classification was completed by a new original method of cluster analysis, designated as DRSA («distance-ranked sorting assembling»). The classification quality is suggested to be validated on the "seriation" diagram, which is а distance matrix between objects with gradient filling. Dark diagonal blocks confirm clusters’ density (intracluster compactness), uncolored off-diagonal blocks are evidence in favor of clusters’ isolation (intercluster distinctness). In addition, distinction of clusters (syntaxa) in ordination area suggests their independence. For phytoindication we propose to include only species with more than 10% constancy. Furthermore, for the description of syntaxonomic amplitude we suggest to use 25%-75% interquartile scope instead of mean and standard deviation. It is shown that comparative analysis of syntaxa for each ecofactor is convenient to carry out by using violin (bulb) plots. A new approach to the phytoindication of syntaxa, designated as R-phytoindication, was proposed for our study. In this case, the ecofactor values, calculated for individual releves, are not taken into account, however, the composition of cenoflora with species constancies is used that helps us to minimize for phytoindication the influence of non-typical species. We suggested a syntaxon’s amplitude to be described by more robust statistics: for the optimum of amplitude (central tendency) – by a median (instead of arithmetic mean), and for the range of tolerance – by an interquartile scope (instead of standard deviation). We assesses amplitudes of syntaxa by phytoindication method for moisture (Hd), acidity (Rc), soil nitrogen content (Nt), wetting variability (vHd), light regime (Lc), salt regime (Sl). We revealed no significant differences on these ecofactors among ecotopes of our syntaxa, that proved the variant syntaxonomic rank for all syntaxa. We found that the core of species composition of our phytocenoses consists of plants with moderate requirements for moisture, soil nitrogen, light and salt regime. We prove that the leading factor of syntaxonomic differentiation is hidden anthropogenic, which is not subject to direct measurement. But we detect that hidden factor of "human pressure" was correlated with phytoindication parameters (variables) that can be measured "directly" by species composition of plant communities. The most correlated factors were ecofactors of soil nitrogen, wetting variability, light regime and hemeroby. The last one is the most indicative empirically for the assessment of "human impact". We establish that there is a concept of «hemeroby of phytocenosis» (tolerance to human impact), which can be calculated approximately as the mean or the median of hemeroby scores of individual species which are present in it.

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