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When working with rare plant species, applying morphometric techniques is one of the main ways to obtain a representative data set on plant individuals and the state of particular populations growing in different ecological conditions and experiencing different degrees of anthropogenic load. Zygophyllum pinnatum, an understudied species growing on the territory of the Republic of Bashkortostan, the Orenburg region, and the Republic of Kazakhstan, is referred as a rare species. The purpose of the work is to study morphometric parameters and reveal the vitality structure of the Z. pinnatum coenopopulations in two regions of the Russian Federation (the Republic of Bashkortostan and Orenburg region) and in the north-west of the Republic of Kazakhstan (the Aktobe Region). Applying standard morphometric techniques, we analyzed the state of 16 coenopopulations of the species. Judging by most morphometric parameters, the leadership belongs to the individuals from the "Troitsk Cretaceous Mountains" coenopopulation located in the Sol-Iletsky District of Orenburg oblast, where, apparently, the most optimal plant conditions are formed (the absence of human impact and low projective cover of the grass stand to have a favorable effect). The minimum values for most parameters are recorded in the coenopopulations located on the territory of the Republic of Kazakhstan, resulting from arid growing conditions. The variability of most characters is within the normal range of the species response (Cv--5.0-44.6%). The discriminant function analysis revealed the morphostructural similarity of individuals from most coenopopulations. Regarding vitality, eight coenopopulations are prosperous, and another eight are depressed. The condition of the species coenopopulations is stable; however, the species is not provided with proper protection measures. Therefore, further monitoring of its habitats and improvement of environmental measures are necessary. [ABSTRACT FROM AUTHOR]

The results of a study of the biological and ecological features of the invasive species Elaeagnus angustifolia L. in the territory of Southern Ural are provided. This species is actively naturalized mainly in river floodplains and around other reservoirs. It is included in the Black Book of Flora of Central Russia and Siberia, and black lists of the Middle Volga region and Voronezh, Orenburg, and other oblasts. The total number in the investigated coenopulations was estimated as 18 000–20 000 specimens. It is naturalized in various types of phytocoenoses, from steppe meadows to halophytic communities. Most of the investigated coenopulations are located in an arid climate with little precipitation. The northernmost coenopopulations are in more favorable natural and climatic conditions. DCA ordination of communities reveal the leading environmental factors: continental climate, moisture, soil acidity, rich soils with nitrogen, and moisture variability. E. angustifolia specimens vary in height from 2 to 8 m. Tall plants are noted mainly on unsalted habitats with sufficient moisture. Lower plants are found in saline or dry habitats. A study of reproductive biology revealed that the highest indicators of fruit parameters are observed in Aslykul, Izobilnoye, and Sol-Iletsk coenopulations, and the minimum indicators of fruit parameters are noted in the Tatarskaya Kargala coenopulation. Regression analysis of the dependence of the nucleus fraction on the fruit weight showed that, with an increase in fruit weight, a decrease in the nucleus fraction is observed. The naturalization of E. angustifolia in river floodplains negatively affect the growth, development, and resumption of native forest-forming species, which leads to irreversible consequences of the degeneration of floodplain forests. [ABSTRACT FROM AUTHOR]

The results of our study of the invasive species Hordeum jubatum L. in various ecological–geographical conditions of the Southern Urals are presented. The 32 coenopopulations (CPs) of the species in the Bashkir Cis-Ural and Trans-Ural regions in Orenburg and Chelyabinsk oblasts were investigated. The populations studied were revealed to belong to several types of vegetation communities, namely, the Polygono avicularis–Hordeetum jubati association (Abramova and Golovanov, 2016), the derivate community Hordeum jubatum [Scorzonero–Juncetea gerardii], the derivate community Hordeum jubatum [Cynosurion], and the derivate community Hordeum jubatum [Artemisietea vulgaris/Stellarietea mediae]. Our study of key morphometric parameters has shown that the undisturbed CP Zamorskoye-1 (Orenburg oblast) was in the lead, where the growth conditions were favorable for the species. The most variable morphometric parameters among the populations are as follows: the number of generative shoots, the leaf length, and the quantity of seeds. In the 17 prospering CPs, the prevalence of individuals of the highest class was noted; they were located in the undisturbed or weakly disturbed habitats. One CP was attributed to equilibrium ones, and the others were depressive. By the results of our cluster analysis, three CPs located in different geographic zones and having the maximum or minimum values in the majority of their morphometric parameters are most different from the total data set. Further monitoring of the centers of invasion and distribution of Hordeum jubatum species across the territory of the Southern Urals is necessary. [ABSTRACT FROM AUTHOR]

Southern Ural is a unique region in Eurasia with a high variety of flora and vegetation. Mountain relief predominates in the steppe and forest-steppe landscapes. Stony habitats and petrophytic vegetation are widespread here. It is characterized by a high diversity of flora and numerous endemic, rare, and endangered plants. The dataset of 3614 relevés of forb and shrub communities from the territory of Southern Ural and adjacent regions is analyzed. Formalized methods of cluster analysis, an assessment of moistening using the ecological indices of plants, and the definition of indicator species are used. Patterns of changes in the species composition of petrophytic communities along the moistening gradient are determined. It is found that, with an increase in moisture, the number and cover of petrophytic species in communities on rocky habitats decreases. On the contrary, the role of indifferent species is growing. Five groups of species indicating different gradient segments are determined. Based on the results of cluster analysis, four large units of petrophytic vegetation are identified. Desert-steppe communities have the greatest floristic originality among vegetation on rocky habitats. Obligate petrophytes predominate in their diagnostic combination, many of which grow on limestone outcrops. These communities are found in the south of Orenburg oblast, mainly in the dry steppe landscapes of Southern Ural. Dwarf subshrub–bunchgrass steppes are widespread within the steppe landscapes and are common in the forest steppe of Ural. Forb–bunchgrass petrophytic steppes are widely represented in the northern part of the steppe zone and in the southern forest-steppe regions, as well as in the forest-steppe landscapes of Middle Ural. Meadow petrophytic steppes are found in forest-steppe and forest landscapes. [ABSTRACT FROM AUTHOR]