Vegetation Analysis and Environmental Relationships of Riverain Plants in the Aswan Reservoir, Egypt

The present study analyses plant diversity and evaluates the relationship between edaphic variables and the distribution and grouping of plant species in the Aswan Reservoir area, South Egypt. The dominant families were Fabaceae, Poaceae, and Asteraceae, forming 38.82% of the total flora recorded. The main bulk of the flora recorded (50.59%) belonged to the cosmopolitan, neotropical, pantropical, and palaeotropical chorotypes. A TWINSPAN analysis produced 10 vegetation clusters. Inundation levels showed a high correlation with species richness. The seasonally inundated area in Bute El-Hasaya and Maezana Belal (cluster V) had the highest species richness (36.50), while the lowest species richness (4.50) was in the shoreline of Philae, Awad, and Heisa islands (cluster IX). The DCA ordination depicted the environmental gradient expressed by the cluster analysis, and the resulting vegetation groups represented a distinct microhabitat. The CCA ordination indicates that the separation of vegetation group (A) along the axis was affected by the concentration of K, Mg, and CO3, and the vegetation group (B) was significantly associated with the total dissolved salts and the concentration of Cl. Moreover, the vegetation group (C) correlated significantly with pH, electrical conductivity, organic matter content, and SO3, HCO3, PO4, Na, and Ca concentrations.

Syntaxonomy of steppe depression vegetation of Ukraine

Aims: To revise the syntaxonomy of the vegetation of steppe depressions (pody), in particular (1) to identify the associations and to reveal their environmental, structural and compositional peculiarities; (2) to assign the associations to higher syntaxa; and (3) to correct nomenclatural aspects according to the ICPN. Study area: Steppe zone of Ukraine, Left-Bank of the Lower Dnieper basin. Methods: 641 relevés were included in the final analysis in the PCOrd program integrated into Juice software. Two expert systems (EVC and EUNIS-ESy) were used to assign relevés to vegetation classes and to EUNIS units. Results: The analysis resulted in nine clusters, which were interpreted as Festuco-Brometea (two units), Molinio-Arrhenatheretea (three units), Isoёto-Nanojuncetea (three units) and one derivate community of the Festuco-Puccinellietea. Detailed characteristics of the species composition, structure, distribution, and environmental conditions are provided for each unit. According to the DCA ordination, the leading factors of the syntaxa differentiation are soil moisture and fluctuating water level. Conclusions: We could clarify the placement of steppe depression vegetation in the system of syntaxonomic units of Europe. The previously described syntaxa of the rank of alliance (Myosuro-Beckmannion eruciformis), suballiance (Galio ruthenici-Caricenion praecocis), and six associations are validated. Two associations and two subassociations are described as a new to science. Taxonomic references: Euro+Med PlantBase (https://www.emplantbase.org), except Mosyakin and Fedoronchuk (1999) for Phlomis scythica Klokov & Des.-Shost. and Tulipa scythica Klokov & Zoz. Syntaxonomic references: Mucina et al. (2016) for syntaxa from alliance to class level; Dubyna et al. (2019) for associations. Abbreviations: DCA = Detrended Correspondence Analysis; DES = Didukh Ecological Scales; EUNIS = European Nature Information System; EVC = EuroVegChecklist; GIVD = Global Index of Vegetation-Plot Databases; ICPN = International Code of Phytosociological Nomenclature.

On the ecology of lawn communities in the cities of the Republic of Bashkortostan, Russia

This article provides information on the ecology of lawn communities in the cities of the Urals of the Republic of Bashkortostan (Ufa, Sterlitamak, Salavat, Ishimbay, Meleuz, Birsk, Neftekamsk, Yanaul). On the basis of 195 relevés, the ecological regimes of lawn communities and their species were determined using the ecological scales of Landolt. DCA ordination of the relevés confirmed their floristic differentiation into 4 associations, 2 subassociations, and 5 facies assigned to the alliance Cynosurion cristati of the class Molinio–Arrhenatheretea. The main contribution to the differentiation of communities is made by the thermoclimatic factor, soil moisture and nutrient regimes. The ranges of values of environmental factors of the lawn communities are determined. When conditions deteriorate, there is a succession of lawn communities from subass. typicum of the ass. Leontodono–Poetum pratensis via the subass. cichorietosum intybi of the same association to the ass. Poo pratensis– Plantaginetum majoris. At the same time, species diversity first increases due to the invassion of synanthropic species, and then decreases. Lawns considered to belong to synanthropized vegetation when the number of synanthropic species reaches 56–63 %. Along with traditional herbal mixtures with Poa pratensis, herbal mixtures with Festuca rubra and Lolium perenne are recommended, the combination of which better corresponds to a fairly wide range of environmental conditions of the Urals. Regular maintenance, watering and mowing are also necessary, which extend the life of the lawns.

The Subnival Vegetation of Moquegua, South Peru: Chasmophytes, Grasslands and Cushion Communities

The present work is a phytosociological synthesis and syntaxonomic overview of the vegetation of the highest subnival parts (superpuna) of the open alpine vegetation of the high plateaus (puna) of the Andes of Moquegua, South West Peru, as related to the main environmental gradients. Using TWINSPAN and DCA ordination analysis, 153 phytosociological relevés were analyzed. For each association, subassociation and community, the syntaxonomy, floristic diversity and relation with environmental variables are described. The syntaxonomy and synecology of superpuna vegetation was studied in 19 localities at an altitude of 4450–4800 m. The study area has a pluviseasonal climate with yearly rainfall (December-April). Four main highland vegetation types were distinguished: 1. slope and scree chasmophyte vegetation composed of shrubs, cushions, ground rosettes and grasses, 2. grasslands (grazed and ungrazed) characterized by great species richness in shrubs, cushions, ground rosettes, grasses and herbs, 3. vegetation of plateaus with cushions, shrubs, ground rosettes, herbs and grasses and 4. nitrophilous vegetation with high cover and low species richness. Within the vegetation of the orotropical and cryorotropical bioclimatic belts three phytosociological classes can be distinguished: Argyrochosmetea niveae (chasmophytic vegetation), Calamagrostietea vicunarum (grasslands with cushions), Anthochloo lepidulae-Dielsiochloetea floribundae (highland slopes and plateaus) and a nitrophylous community. One new association from rock and scree slopes was described within the Saxifragion magellanicae (Argyrochosmetea niveae). Within the Calamagrostion minimae, which comprises grasslands with cushions and mat-forming plants, one new association with two subassociations could be distinguished. Within the grassland and cushion associations of the Azorello-Festucion (Calamagrostietea vicunarum), three new associations were described, comprising nine subassociations. In the Anthochloo-Dielsiochloetalia one new and one previously described association and one community are distinguished. In addition, the nitrophilous community of Tarasa nototrichoides and Urtica flabellata has been described. In total the vegetation comprised 172 vascular species belonging to 32 families. Our study provides the first syntaxonomic revision of chasmophytes, cushion associations and high-altitude grasslands in the Andes of North Moquegua. The proposed syntaxonomic scheme contains the associations distributed under similar habitat conditions throughout the Southern Andes of Peru, but also the associations reflecting the local floristic and environmental patterns. The subnival vegetation of Moquegua hosts some rare endangered and/or protected plant species.

Seedling dynamics and community forecast for disturbed forests of the Western Himalayas: a multivariate analysis

The present study focuses on the forest structure of highly disturbed sites in Western Himalayan regions in Pakistan. In this study, the regeneration potential of conifer species is a key point for the assessment of future conifer status in disturbed environment by employing multivariate techniques. The forests are composed of four conifer species Pinus wallichiana A. B. Jacks, Pinus roxburghii Sarg., Cedrus deodara (Roxb.) G. Don, and Abies pindrow (Royle ex D. Don) Royle., associated with broadleaved species Quercus baloot Griffith, Quercus dilatata Raf., and Aesculus indica (Wall. ex Cambess.) Hook. Cluster analysis shows five groups when Pinus wallichiana (PW) forms the largest group, incorporates with other conifers and broadleaved species and in some cases it overlaps with its subgroups forming a pure larger group. Similarly in DCA (ordination) overlapping exists in all the axes while elevation is the only variable that shows a highly significant (P < 0.001) correlation with conifers. Cedrus deodara (CD) with Quercus baloot (QB) and Aesculus indica (AI) shares a significant (P < 0.05) correlation in the same habitat while there is no correlation between the remaining conifers. It is anticipated that overlapping in cluster analysis and ordination and non-significant correlations in cluster analysis and ordination are due to the highly disturbed nature of the sites. It is also suggested that seedling recruitment and development are highly affected due to the anthropogenic disturbance. Therefore, proper maintenance of the forest, proper management and conservational practice should be imposed.

Syntaxonomy and ecological differentiation of the pioneer vegetation of Ukraine. 2. Helichryso-Crucianelletea maritimae, Festucetea vaginatae, Koelerio-Corynephoretea canescentis classes

Pioneer psammophytic vegetation is usually developed on wind-drift sandy substrates such as arenas, spits, beaches, river terraces, and this vegetation occupies significant areas in all three natural zones of Ukraine. The Koelerio-Corynephoretea canescentis class was represented by 13 associations, 3 alliances and 1 order; Festucetea vaginatae class by 22 associations, 2 alliances and 1 order; Helichryso-Crucianelletea maritimae by 10 associations, 4 alliances and 1 order. The results of cluster analysis and synoptic tables of the classes are presented. 9 alliances are briefly described. Leading factors of territorial and ecological differentiation are identified. It was found that the territorial distribution of plant communities is influenced by the character of ecotope mesorelief, soil composition and humus horizon thickness, as well as the degree of eolian processes development. The main factors of their ecological differentiation are soil acidity, salt regime and ombroregime. Based on the results of DCA-ordination of syntaxa within certain vegetation classes, it was found that their distribution is influenced by factors that correlate with the environment-specific conditions. It has emerged that an ecological differentiation of syntaxa within Festucetea vaginatae is determined by the integrated effect of gradients, and soil salinity is leading among them. Temperature regime and climate continentality are leading factors in the distribution of syntaxa within the Koelerio-Corynephoretea canescentis class. The gradients of ombroregime and soil humidity have a significant impact. The distribution of communities of the Helichryso-Crucianelletea maritimae class in the ecological space is determined mainly by factors of variability of damping, ombroregime and climate continentality. The author’s syntaxonomic concept assumes the independence of the studied classes: Koelerio-Corynephoretea canescentis, Helichryso-Crucianelletea maritimae and Festucetea vaginatae, conside­ring that the leading factors of community differentiation of the Festucetea vaginatae and Koelerio-Corynephoretea canescentis classes are the origin (genesis) of sandy substrates, as well as soil acidity. Phytosociological analysis of a large number of relevés of coastal littoral vegetation also provides support for independence of the Helichryso-Crucianelletea maritimae and Ammophiletea classes diffe­rent floristically and ecologically. A review of the psammophytic vegetation of Ukraine will determine the place of the selected syntaxonomic units in the pan-European system.

Floristic areas of the Middle Volga region: materials to the analysis

The publication presents some quantitative characteristics of the 17 pre-selected floristic areas of the Middle Volga region (the total number of species, number of indigenous taxa and the number of differentiating species). Based on the available data, a linear regression is constructed, illustrating the relative dominance of allochthonous or autochthonous trends in the development of flora in the selected areas. The cluster analysis of the species lists of the floristic areas was completed, and then DCA-ordination of the selected areas was implemented. It is revealed that the forest-steppe areas of the Cis-Volga and Trans-Volga regions are situated by the level of species richness, and the number of species in the selected floristic areas is increasing from West and East towards the Volga.

Classification and diversity of perennial sand-dune vegetation in Serbia

Sand dunes are one of the critically endangered habitats in Europe. This vegetation type is under a strong anthropogenic influence. Its natural value is very high since many plant species with a narrow distribution are found there. The classification of Serbian sand-dune vegetation and the status of the described associations has not been validated by numerical analyses. This research presents an evaluation of sand-dune vegetation in Serbia on the basis of literature data, as well as new releves. Psammophytic vegetation in Serbia was classified into two alliances, annual and ruderal Bassio laniflorae-Bromion tectori and perennial Festucion vaginate. The aim of this research was the classification of the alliance Festucion vaginatae, perennial, drought-tolerant, tussock-forming vegetation on sand. As proposed by OptimClass, Jaccard distance and flexible beta data (?=-0.25) were used for the classification. Classification results were confirmed by detrended correspondence analysis (DCA) ordination. The result of the classification established that only two associations, Alysso gmelini-Festucetum vaginatae and Festucetum vaginatae, are present in Serbia. These associations are divided into groups that mostly correspond to traditional subassociations.

Vegetation composition and ecological gradients of subtropical-moist temperate Ecotonal forests of Nandiar Khuwar Catchment, Pakistan

Present study was conducted in the mixed Pinus roxburghii Surgent and Pinus wallichiana A.B. Jackson forests of Nandiar Khuwar catchment Battagram District of Pakistan. The aim of this study was to examine the spatial pattern of vegetation composition and its relationship to microclimatic and edaphic factors. Vegetation sampling was carried out using 12 stands between elevations of 1250 - 2050 m in the study area. Four plant communities were recognized through TWINSPAN classification. Life form was dominated by nanophanerophytes and leaf size spectra were dominated by microphyll. The maximum similarity index value (32.9) was recorded between P. roxburghii, P. wallichiana, Q. incana community and Q. incana, P. roxburghii, P. wallichiana community. In Bray-Curtis ordination, maximum ordination score (0.746) was recorded for axis 1. In DCA ordination, maximum gradient length (2.43) was recorded for axis 1 with eigenvalue 0.35. In CCA ordination, maximum eigenvalue was recorded for axis 1 (0.35). The total variance (inertia) in the species data was 2.15, explanatory variables account for 100%. On axis 1 the maximum correlation (−0.749) and maximum tau value (−0.565) was recorded for wet bulb. On axis 2 the maximum negative correlation value was recorded for temperature (−0.553) and maximum tau value was recorded for slope aspect (−0.480).

Abundance and diversity of black flies (Diptera: Simuliidae) in rivers of the Andean Eastern Hills of Bogotá (Colombia),

Black flies are abundant benthic organisms in well-oxygenated running water and are considered effective bioindicators of water quality. Information on the ecology of these organisms at the species level is important, since up to now information has mainly been available on a family level. The aim of this study was to evaluate the composition of black flies and their relationships to a group of physical and chemical factors in four small rivers of the Eastern Hills around Bogotá, Colombia. These headwaters are protected by the Empresa de Acueducto y Alcantarillado de Bogotá. Black fly larvae and pupae were collected during four sampling periods during the dry season to the early rainy season of 2012. Multivariate methods were used to determine the presence of each species in relation to dissolved oxygen, nitrates, pH, temperature, and water velocity. PCA ordination revealed a physicochemical environment with a tendency towards a certain homogeneity in the fourrivers studied. The DCA ordination confirmed that in La Vieja River the G. ortizi complex dominated while S. muiscorum was dominant in the other three rivers. Similarly, according to the NMDS, the composition of black flies in Arzobispo and Chorro de Padilla rivers was similar, while that of El Delirio and La Vieja rivers were different, especially in this last river. The rivers hadlow species richness (four species and one species complex). Simulium muiscorum was negatively correlated with dissolved oxygen, temperature and current velocity while S. ignescens was associated with slightly more oxygenated waters and S. furcilatum with fastercurrents.The low species diversity and richness for the four rivers is consistent with previous report sof low Neotropical diversity of black flies. Results showed that simuliid species could possibly be good indicators of the environmental conditions of Eastern Hills rivers around Bogotá.