Differentiation of forest vegetation across bioclimatic sector border (western part of the West Sayan Ridge)

A detailed description of the forests of the northern and southern macroslopes of western part of the West Sayan Ridge has been performed and differences in their forest vegetation have been analyzed. Along the West Sayan Ridge watershed, the important botanical and geographical boundary of the Altai-Sayan Mountains occurs. Its northern macroslope belongs to the humid bioclimatic sector; bioclimatic conditions throughout the southern macroslope vary in its different parts: the central and eastern parts are resided in the semihumid sector, while the western one is settled in the «rain shadow», where vegetation is similar to the semiarid sector one. The West Sayan background vegetation type is forest. The work is based on 120 complete geobotanical relevés made by the authors in 2019 using standard methods on test plots of 20 × 20 m. These plots had been uniformly distributed on a 300-kilometer transect crossing the northern and southern macroslopes of West Sayan’s western part. After all, 9 basic units of forest communities have been revealed, 6 of them are found to be altitudinal zone forests. These plant community positions in ecological-phytocenotic and floristic classification hierarchy have been ascertained. The altitudinal allocation and areas of altitudinal zone forests have been characterized and analyzed; the scheme of altitudinal zonation has been specified; the pictures in the text illustrate those results. In West Sayan’s western part, the northern and southern macroslopes are shown to have different altitudinal zone boundary marks and a different set of forest communities: six types of forests follow each other from north to south throughout 300 km. The significant hierarchical level of syntaxonomic differences of altitudinal zone forests on northern and southern macroslopes supports the presence of a bioclimatic barrier. In ecological-phytocenotic classification hierarchy these differences are reflected by the rank of classes of formations (deciduous, dark coniferous, and light coniferous forests substitute each other); in floristic classification hierarchy – the rank of classes (the forests of Brachypodio–Betuletea, Asaro–Abitetea, Vaccinio–Piceetea, and Rhytidio–Laricetea substitute each other from north to south).

Typological diversity and ecological-geographical characteristics of the forest cover of southern part of the Evenki region

The article presents the results of preliminary comprehensive ecological and geographical studies of the forest cover of the middle taiga subzone of Central Siberia. The higher syntaxa of forests were identified using the ecological-floristic classification of vegetation (Braun-Blanquet approach). All forest communities in the region are classified as Vaccinio – Piceetea Br.-Bl. in Br.-Bl. et al. 1939 and are represented by the following orders: Ledo palustris – Laricetalia gmelinii Ermakov in Ermakov et Alsynbayev 2004 – coniferous (mainly larch) forests of Northern Eurasia on permafrost soils characterized by stagnant moisture and low heat supply; Piceo obovatae – Pinetalia sibiricae Ermakov 2013 – typical Siberian dark coniferous forests; Lathyro humilis – Laricetalia gmelinii Ermakov et al. 2002 – boreal forests with the participation of xeromesophilic moderately thermophilic species, widespread in the ultracontinental climate of East, South Siberia and Mongolia. The features of their ecology and geographic regularities and the participation of order communities in the formation of forest cover in different parts of the studied region were considered.

Typification and correction of the meadow vegetation syntaxa of the class Molinio–Arrhenatheretea Tx. 1937 in the Southern Nechernozemye of Russia

The article presents the typification and correction of the syntaxa of grass vegetation, established at different times for the Southern Nechernozemye of Russia. 3 associations and 5 subassociations are validated according to the requirements of the International Code of Phytosociological Nomenclature (Theurillat et al., 2021). The description of syntaxa is given according to the plan: name, synonyms, nomenclature type (holotype or lectotype), diagnostic species (their single blocks were used without dividing into characteristic, differential and constant), definition (verbal diagnosis). The belonging of associations and subassociations to the highest classification units is indicated in accordance with the modern hierarchical system of floristic classification of vegetation in Europe (Mucina et al., 2016). All of these units belong to the group of Intrazonal boreo-temperate grasslands and heath.

Comparative analysis of two approaches to large-scale mapping of forest vegetation in the Southern Nechernozemye of Russia

The results of the comparative analysis of traditional forest typology data and the data of floristic classification by the J. Braun-Blanquet approach for large-scale mapping of forest vegetation from the Southern Nechernozemye of Russia are presented. 3 model forest areas located in the forestries in borders of different botanic-geographical districts with specific climatic and edaphic conditions have been chosen to make the comparative analysis of cartographic materials (Bryansk and Smolensk Regions). A comparison of existing afforestation plans and created geobotanical maps demonstrates the difference in the number of recognized typological units. In all cases, a smaller number of units are noted for the geobotanical maps with a scale 1 : 25 000. A decrease in the number of typological units can be explain by the lack of information on the age of tree stands. Another reason is, probably, the assignment of some forest stands with the predominance of different indigenous species to a single association. However, the same typological units, distinguished by the predominance of tree species, may correspond to different units of floristic classification, which may increase the number of typological units on the geobotanical map. Some features of the Braun-Blanquet approach such as the allocation of units, primarily based on a comparison of the floristic composition of plant communities, allows attributing both natural stands and forest cultures to a single syntaxon. This also reduces the number of typological units on the geobotanical map. The plans of afforestation show the present-day species composition and the age of the studied stands, but the dynamic interrelations of forest communities are not reflected there. Therefore, it is more effective to reflect the dynamics of vegetation of forest communities in accordance with the methodology adopted when creating geobotanical maps. In this case, the succession state of communities and their links to classification units of higher ranks has been taken into account by the allocation of temporary facies with the predominance of small-leaved species at the site of indigenous broad-leaved or coniferous forests. The deductive approach with the identification of non-rank «communities» also makes it possible to separate into separate syntaxa and time-unstable, unformed or poorly floristic communities. Typically, such forests are formed by coniferous cultures in the zone of deciduous forests. The unformed «semi-forest» communities in the lowland swamps are also placed into the same category. They are often formed after felling, initiating or intensifying bogging under conditions of fluctuating moisture. The use of a single colorimetric scheme for forest stands in different climatic and edaphic conditions, reflected in the TLU (forest conditions) system, can be considered not quite correct. Stands with the predominance of the same species can correspond to different zonal-conditioned TLUs. At the same time, communities of some syntaxomomical taxa of floristic classification can be formed in different TLUs and their diversity corresponds to the width of the ecological amplitude of the types of plant communities. The more stenotopic communities, the smaller number of TLUs corresponding to their habitats. The afforestation plans and geobotanical maps can be used by different ways in forestry. The traditional afforestation plans are widely used in forestry planning. However, the geobotanical map supplemented with information on the dynamic relationships of stands allows making more efficient prediction of scenarios of forest stand development under known forest conditions. In addition, cartographic materials on the proposed geobotanical basis reflect the general botanical and geographical trends of vegetation, and the syntaxa of the floristic classification always have a certain chorological content, thus, they can be used as zonal-climatic indicators. This feature is reflected in their compliance with TLU, which are specifically distinguished for different natural zones.

Syntaxonomic scheme of grassy vegetation of the upper Prut and Siret river basins

This is the first time that ecological-floristic classification scheme of grassy vegetation of the upper Prut and Siret basins within Ukraine was set up based on the analysis of field research and literature resources. The foundations for syntaxonomic scheme of vegetation was database of geobotanical descriptions «Vegetation of Bukovina», which was created on the Department of botany, forestry, garden and park management in the shell of TURBOVEG. This database contains more than 5000 geobotanical descriptions made in accordance with standardized approach. There was used cluster analysis based on modified TWINSPAN algorithm in JUICE shell for allocation of vegetation units. Syntaxonomic scheme of grassy vegetation of the researched area includes 9 classes, 21 orders, 33 alliances.

Ecological and biomorphological features of the steppe communities of the central part of the Piedmont Crimea

The article analyzes the syntaxonomic structure of the steppe communities of the central foothill part of the Crimea. They belong to the class Festuco-Brometea Br.-BI. et R.Tx., two orders, two unions and two sub-unions, five associations. For coenoflora at the level of associations of ecological-floristic classification, a detailed systematic, arealogical, ecological-biomorphological analysis was carried out for the first time. The most significant differences in the structure of the communities of steppe vegetation described on the basis of ecological-floristic classification are revealed. Significant participation in the formation of communities of species of Mediterranean origin and shrubs has been established. Moreover, unlike the rest of the communities, the associations of Asphodelinetum tauricae Didukh 1983 association are characterized by the dominance of these floral elements in their structure. The steppe communities of the studied region are characterized by significant xerophytization of the vegetation cover.

Meadows diversity in the Valdaisky National Park

The results of a geobotanical survey of meadow vegetation in the Valdaiskiy National Park (Novgorod region) are presented. In accordance with the floristic classification it has been established that the meadows of the region belong to the class of European mesophilic meadows Molinio-Arrhenatheretea . Two associations were revealed. In the floodplains of rivers and streams, communities of wet meadows of the association Lysimachio vulgaris-Filipenduletum ulmariae are common. It belongs to the alliance Filipendulion ulmariae of the order Filipendulo ulmariae-Loletalia uliginosi . On river terraces and watersheds, communities of the association Anthoxantho odorati-Agrostietum tenuis , belonging to the alliance Cynosirion cristati of the order Arrhenatheretalia , are developed. The significant importance of the meadows for the conservation of natural biodiversity and cultural heritage of the Novgorod region is noted.

New association of weed vegetation in the Southern Ural

A geobotanic survey was carried out and the diversity of weed communities of the steppe zone of the Orenburg and Ilek administrative Districts of the Orenburg Region was revealed. As a result of the synthaxonomic analysis, the studied communities are assigned to the new association Amarantho blitoidis-Lactucetum tataricae ass. nov. hoc loco in the system of units of ecological-floristic classification of Eurasia vegetation. The association united weed communities of spring wheat, sunflower, less often - rye, barley, corn and sorghum, emerging mainly on well-drained swollen soils in the flood of the Ural River. The cenophlora is characterized by the presence of bondate and optional psammophytes - Chondrilla brevirostris , Helichrysum arenarium , Ceratocarpus arenarius , etc. The communities of the association occupy an extreme position on gradients of aridity and moisturization factors among other weed vegetation communities of the Southern Ural. The North American alien species Euphorbia glyptosperma Engelm has been discovered for the first time in the Orenburg Region (subgenus Chamaesyce Raf., section Anisophyllum Roep.). Currently this species is expanding its range from the south of the Russian Federation. Other alien plants have been noted as part of the communities: Amaranthus blitoides S. Wats., A. retroflexus L., Conyza canadensis (L.) Cronq., Xanthium album (Widder) Scholz et Sucopp.

Geomorphology and Altitude Effects on the Diversity and Structure of the Vanishing Montane Forest of Southern Ecuador

(1) Background: Neotropical montane forests represent one of the most diverse world ecosystems; however, they are also among the most threatened ones mostly due to deforestation. Our main goal is to classify and clarify the forest types based on the changes in basal area (BA), tree density, and species composition of montane forests in Southern Ecuador, and to determine the influence of critical environmental and geomorphological factors. (2) Methods: One hundred thirty-two temporary plots of 400 m2 were installed in homogeneous and well-conserved forest stands. We identified and measured all trees >10 cm diameter breast height (DBH). We modeled species diversity (Fisher’s alpha) change in relation to climatic, altitudinal, and geomorphological gradients using GLM and Kruskall-Wallis analyses. The change in composition was determined using cluster analyses (BIOENV analysis followed by a LINKTREE procedure). Non-metric multidimensional scaling (NMDS) was used to analyze changes across climatic and geomorphological gradients. Finally, we used a SIMPER analysis to identify the species that contributed most to the floristic dissimilarity among the identified altitudinal forests types. (3) Results: The floristic groups were determined by altitude, temperature, and isothermality, but also some geomorphological variables and lithology were used. Plots located in low hills have higher alpha diversity compared to the high hills and dissected mountains. (4) Conclusions: Altitude is the most important factor responsible for the division of structural and floristic groups. In addition, those plots located on the whitish tuff have higher alpha value diversity compared with plots in andesitic tuffs. Precipitation on the wettest quarter (>839 mm) and isothermality (>90.5) are the most relevant climatic factors driving the floristic classification.