Development of the "black list" of the flora for the Chelyabinsk region of Russia

. The results of the study of alien species of the Chelyabinsk region, which form invasions in different ecological and geographical conditions of the region, are presented. A preliminary "black list" of the flora of the region has been compiled, including 64 species of invasive alien plants. Using the recommendations for compiling regional "Black Books" or "Black List", the species included in the specified list are ranked by us into four categories according to their invasive status. Information is based on indications of reliably known places of introduction and growth of alien species, sources and time of introduction, degree of naturalization and communities with their participation. The presented materials reflect the state of invasive processes in the region and can be used to prepare the "Black Book of the Southern Urals".


Introduction
In the Chelyabinsk region, as in many other territories of the Russian Federation, there is a change in the composition of the flora due to the introduction of alien species into its composition from other physical and geographical zones and territories [1,2]. In some areas of the region, the number of invasive plants becomes threatening for natural phytocenoses. For example, such a situation develops in the Chelyabinsk and Kashtak forests, where invasive species play a clearly destructive role, and there is a visual deformation of plant communities. The same picture is emerging in certain territories of the municipalities of the region. Many real reasons contribute to the penetration of invasive species into degraded phytocenoses in the territories of settlements and around them. Invasive processes intensified in the early 2000s, when, due to the crisis of the late 1990s, large areas of abandoned agricultural land appeared, which became optimal sites for invasions [3].
Invasions of alien organisms today are the main factor in the anthropogenic transformation of natural ecosystems. The most aggressive alien species, leading to a reduction in floristic diversity and the displacement of native species, are recognized as the main threat to natural biodiversity [4][5][6].
In Russia, the inventory of alien species is largely completed. Reviews were compiled for different regions of Russia, covering more than 80% of the territory of our country [7,8]. A preliminary list of invasive plants in Russia has been published, including 730 species [9]. A database of alien species of animals and plants in Russia has been created and patented, which is available on the Internet [10].
Separate information on the distribution of invasive species in the Chelyabinsk region has been published since the early 2000s [11]. In addition, the problem of the study of adventitious alien plants in the Botanical Garden of the Chelyabinsk State University is constantly being solved.
The creation of "Black Books" and "black lists" is the result of an inventory of the invasive fraction of the regional flora. Drawing up "black lists" according to a single methodology contributes to a comparative analysis of invasive floras and the behavior of individual aggressor species in various regions of the Russian Federation. Being a kind of database, "black lists" serve as a source of information about the distribution, distribution and composition of the most aggressive and active species of the adventive flora fraction. The accumulated and published information makes it possible not only to highlight the problem of phytoinvasions, but also to determine a strategy for their regulation in order to preserve natural biological diversity, and to direct efforts to limit the spread of aggressive alien species.
The purpose of our study is to compile a preliminary "black list" of the flora of the Chelyabinsk region based on the data of many years of field floristic surveys and analysis of published sources.

Materials and methods
The Chelyabinsk region is located in the northern part of the ridge belt of the Southern Urals and its foothills with adjacent parts of the high foothill plains, as well as relatively small areas of the West Siberian Lowland and the East European Plain. The territory of the region is 87.9 thousand km 2 .
The Chelyabinsk region is located in two parts of the world -Europe and Asia, the border between which runs along the main watershed of the Urals (between the Volga and Ob basins).
The territory of the region is distinguished by a significant variety of natural conditions, which determine the heterogeneity and mosaic nature of the vegetation cover and the richness of the flora.
The climate of the Chelyabinsk region is temperate continental with long cold winters, short warm summers and short springs and autumns. The most significant influence on the climate of the region is exerted by air masses formed over the Asian continent and moistened Atlantic air masses. The mountains of the Southern Urals are also an important climatic frontier, separating climatic regions of varying degrees of continentality. Another important climatic boundary passes in the flat trans-Ural part of the region in the latitudinal direction and serves as the boundary between the West Siberian forest and steppe climatic regions.
The average annual air temperature varies from +0.1º C in the north of the region to +1.9º C in the southeast. The duration of the growing season with an average daily temperature above 5ºC averages 154-161 days in the forest zone of the region and 162-168 days in the forest-steppe and steppe zones.
In the mountainous forest part of the region, the annual amount of precipitation is 500-800 mm, in the forest-steppe and steppe zones it is 270-400 mm.
The territory of the Chelyabinsk region is located within three natural zones -forest, forest-steppe and steppe. The boundaries between the zones are, at the same time, the most important floristic boundaries in a given territory. Accordingly, vegetation of three natural zones is represented on the territory of the regionforest, forest-steppe and steppe.
In this work, one of the modern approaches to assessing the invasive status of alien species is used [1]. This approach defines the main criteria that allow specific alien species to be assigned to one of four categories of invasive status. The invasive status is assessed depending on the activity of an alien species in the region, the degree of its naturalization and the type of habitats being developed.

Results
Currently, according to our data, at least 300 adventitious species are found in local plant communities. Of this number, approximately 1/5 of the species are the most active and show signs of invasiveness in different ecological and geographical conditions of the region [3,13]. We have included information on 64 species of invasive plants in the preliminary "black list": Status 1alien species that actively invade natural and semi-natural biocenoses, disrupting succession relationships, changing the composition and structure of communities. Acting as dominants, they often form single-species thickets that displace or prevent the resumption of species of the natural system. On the territory of the Chelyabinsk region, this group includes 10 species: Acer negundo L., Elaeagnus angustifolia L.,  In total, 64 species from 29 families and 53 genera are currently included in the "black list". Almost a quarter of their composition are representatives of the family Asteraceae (14 species; 22%). The number of invasive neophytes of the Chelyabinsk region includes 16 tree species (5 trees, 11 shrubs), 1 semishrub, 24 annuals, 3 biennials, 1 aquatic perennial and 19 perennial terrestrial herbaceous species. Perennials, for the most part, have a high ability for vegetative reproduction.
The authors of this work adhere to the terminology of adventitious species by Yu.K. Vinogradova and co-authors [1]. To compile the "black list", we used the following classification: colonophytealien species resumes, but its distribution is limited mainly to places of drift; epecophytealien species that has spread over one or more anthropogenic habitats; agriophytealien species that has penetrated into natural cenoses.

Conclusion
As a result of the work on the inventory of the invasive fraction of the regional flora, we have identified 64 of the most invasive species that represent a real and potential danger to natural ecosystems. The listed species have spread quite widely or have begun active dispersal in natural, semi-natural and anthropogenic habitats of the Chelyabinsk region. Invasive processes in the Chelyabinsk region are growing, every year new adventitious species appear, some of which can harm agriculture and forestry, urban landscaping. It will decrease life quality for the peoples, making migration from the region more intensive [12]. All invasive and potentially invasive alien species should be subject to constant monitoring, since they are considered one of the main threats to biodiversity [1,2].