UAV survey of sand knolls in the Tsasucheysky Bor Nature Reserve

The paper examines development of sand knolls under the influence of climatic and anthropogenic factors in Southern Zabaykalye within the territory of Tsasucheysky Bor nature reserve. The sand knolls were studied on-site with instruments and aerial surveying. Grain size distribution of the soil cover was studied. The floristic composition of the sand knolls represented by motley grass-grasses and herbs-grasses steppe communities with varying degrees of projective cover was investigated. The analysis of the field survey data from an unmanned aerial vehicle (UAV) made it possible to obtain the main morphometric parameters of the sand knolls, and overlaying aerial photographs on historic satellite images allowed to trace how they changed in time. The studies showed that the movement of the studied sand knolls with time as Aeolian formations under the influence of wind erosion is unlikely, as the sand knolls are currently mostly covered by steppe vegetation, and only about 20% of the areas are bare. The analysis of satellite images and aerial photographs showed that over the last twenty years the sand knolls had not moved or changed their size.

Vegetation of the natural monument “Urochishche Kuzilinka” and its surroundings (Orel region)

The article describes the calciphytic steppe communities located in the territory of the natural monument “Urochische Kuzilinka” and its surroundings (Orel region). The communities were assigned to the association Onosmato simplicissimae–Salvietum nutantis Averinova ass. nov. That unit was included in the sub-union Bupleuro falcati–Gypsophilenion altissimae Averinova 2005 (union Festucion valesiacae Klika 1931, order Festucetalia valesiacae Soó 1947, class Festuco–Brometea Br.-Bl. et Tx. ex Soó 1947) on the basis of a diagnostic species analysis. The new association was characterized. Results of the ordination analysis of leading environmental factors for the described communities are provided.

Comparative analysis of phytolith spectra of steppe and forest phytocoenoses

The primary research goal is to identify differences and diagnostic features of the phytolith spectra of the steppe and forest phytocoenoses. The paper presents the research results of recent soils from various communities. The authors employ the phytolith analysis method. The isolation of phytoliths from recent soils has been carried out with the help of the maceration method and from plants – the dry ashing method. The authors counted the phytoliths using the Olympus BX-51 light microscope. Additionally, the authors have compiled the spectra using the 2C software. The paper compares the phytolith spectra of plain and mountain steppe phytocoenoses. The comparison reveals that the considered plain communities are more similar in phytolith composition than the mountain ones. The following morphotypes are common for all spectra: low conical rondel particles and psilate ribbed particles. These are the forms that characterize steppe communities. Analysis of phytolith spectra of the mountain forest communities demonstrates that the presence of ribbed particles of psilate is common for all spectra. The common feature of all forest spectra is the presence of psilate symmetrical particles, polylobate trapeziforms, lanceolates (trichomes) with a massive base, and trapeziform bilobate (“Stipa-type”) particles. In the spectra of all pine forests, there is a low content or complete absence of needle phytoliths. Diagnostic features of individual phytocoenoses have not been found. The most significant is the ratio of individual phytolith forms in the phytolith spectrum. The comparative analysis of phytolith spectra of the phytocoenoses in the south of western Siberia is carried out for the first time.

Status and life strategy of Orchis punctulata Steven ex Lindl. (Orchidaceae) in the South-Eastern Crimea

This article presents the results of the population studies of rare protected species Orchis punctulata (Orchidaceae). Based on analysis of local floras in eastern and southeastern Crimea and personal observations, we identified the three most numerous populations of O. punctulata: two in the steppe (on the Tepe-Oba mountain ridge) and one in forest communities (on the Kiziltash mountain ridge). The ontogenetic, demographic, and vitality structures of the populations were studied. We also assessed the life strategies of the species in different habitats. The populations in steppe communities were characterized by high number and density parameters. O. punctulate often formed large clusters and was dominated here. A small number and low density characterized the population in the forest community; the distribution of individuals within the population was scattered. The age spectra were also different. The populations in steppe communities had a left-sided spectrum with a maximum in immature individuals, while in forest communities, it had a bimodal spectrum with maximums in generative (with a predominance of mature and old generative) and immature individuals. Specimens from forest communities were more extensive than those of steppe communities, they had longer leaves and inflorescences, and their inflorescences had a more significant number of flowers. As a result, the population in the forest community had a higher vitality index. It included individuals of the highest and middle class of vitality. The populations in the steppe community consisted of all classes of vitality or only of middle and lower classes. Thus, optimal environmental conditions for the growth of species are in forests. At the same time, a low level of regeneration and competition from other plants hinder its wide distribution. As a result, the species exserts as a phytocenotic patient (S-strategy). In steppe communities, the species is characterized by a mixed patient-explerant-violant strategy (SRC strategy).

Steppe communities within the coast of the Taman Peninsula

The article presents the results of field research in 2019–2020 of plant communities of the abrasive coast of the Taman Peninsula. The biomorphological structure of populations is dominated by annual species, which indicates a high dynamism associated with exogenous processes. Ecologically, the dominant species are xerophytes and xeromesophytes, as well as species with a wide eco-amplitude. The process of unification of the studied flora is low and amounted to 17 %. The generalized floristic list includes 231 plant species from 48 families. In the study area, 7 species of Red Book plants were found, of which 2 species were included in the Red Book of the Russian Federation.

About some discussion issues on steppe typology and florocenotypes related to them in vegetation of South Siberia

The phytogeographic ecotonicity of Southern Siberia (SS) is reflected in the features of its flora and vegetation, in particular the steppes. The recognition of only a floristic criterion in the typology of vegetation impoverishestheir real cenotic diversity. It is necessary to accept the florocenogenetic concept with fractional landscape-biomorphological types – florocoenotypes in the spirit of P. N. Ovchinnikov. By the genesis, the most ancient are the zonal sod grass(feather grass) steppes. However, the initial should be considered the Achnatherums and, in general, the communities ofshort-awned great-feather grass (Tsvelev, 1977), which formed steppe groups in the Tertiary savannoid complexes. Theformation of mountain cereal steppes – with fescue, oat, bluegrass, etc. took place synchronously with cryoxerophytization, starting from the Oligocene. The originality of the SS steppes is given by some rare steppe communities, which arecoenogenetically close to the tragacanth, friganoid, shiblyak and ephemeral steppes of mountainous Central Asia. Theseare distinctive relict steppes in the belt of the Altai, Sayan and Transbaikal mountains, which include communities of viviparous grassland steppes in the foothills of Western Altai, tragacanth-oxytropis steppes of southeastern Altai, and communities of the Tuvan and Daurian shiblyak, as well as groups of Altai friganoids with Ziziphora clinopodioides, Thymusaltaicus and Allium pallasii.

Features of the flora and vegetation of the Pyatigorye’s upland steppes (ecoregion of the Caucasian Mineral Waters)

The article deals with the issues of localization and landscape preference of Pyatigorye’s phytocenoses ofthe upland steppes. The syntaxonomic composition of the steppe communities on the studied territory, as well as the typesof the floristic core, are indicated. It consists of graminoids, mesothermal perennials of long vegetation, caudex herbs ofan ephemeroid type of development, and bulbous geophytes. The features of communities, the reasons for their spatialdifferentiation are revealed. The distribution of species by relief elements and communities was determined expertlyon the basis of field studies (2018–2021). It was concluded that the main factors determining the diversity of uplandsteppe vegetation in the studied region are the nature of the destruction of the parent rock and soil development, the levelof insolation and ecotope moisture. The steppe communities of Pyatigorye on carbonate underdeveloped thin skeletalchernozems are distinguished by their species richness. In most of them, Stipa pulcherrima plays a high phytocenotic role,as well as other sod and dense bush grasses. Species of the “southern” steppe and Caucasian forbs, incl. petrophytes playsignificant role. The communities include rare species in the region: Astragalus brachycarpus, Dictamnus gymnostylis,Leopoldia tenuiflora, Paeonia tenuifolia, Iris pumila, I. aphylla, Orchis tridentata, Asphodeline taurica, Lamyra echinocephala,Linum tauricum, Onosma caucasica, Cerasus incana, Cephalaria coriacea. The studied representative communities areimportant for the conservation of the biological diversity of the region. Habitats of rare species are of scientific importanceand are of nature conservation interest.

Vegetation of the Dniester Canyon and assessment of its adaptive potential

Syntaxonomy of the natural vegetation of the Dniester Canyon, including 20 classes, 30 orders, 44 alliances, and 71 associations, is presented. The natural vegetation of the canyon is formed by communities of the classes Carpino-Fagetea sylvaticae, Quercetea pubescentis, Quercetea robori-petraeae, Alno glutinosae-Populetea albae, Crataego-Prunetea, Festuco-Brometea, Trifolio-Geranietea sanguine, Molinio-Arrhenatheretea, Sedo-Scleranthetea, Phragmito-Magnocaricetea, Bolboschoenetea maritimi, and Isoëto-Nanojuncetea. Grassland vegetation is characterized by the highest syntaxonomic diversity. Quantitative assessment of syntaxonomic diversity in the three-dimensional system of ecological strategies of species according to Ramensky-Grime (CRS) was carried out. Adaptive capabilities, i.e. the potential for possible further development of forest, shrub and grassland habitats, have been assessed. It has been found that the dynamics of forest shrub, grass meadow and steppe communities is determined by successive endoecogenetic processes. In petrophytic communities, fluctuation changes are not manifested and successional changes are rather limited. Significant fluctuations are inherent in floodplain grasslands that depend on the sharp variability of moisture during the growing season. At the same time, it is emphasized that actual realization of these processes depends on influences of external drivers that can be considered as regulatory factors in possible development of syntaxa.