Monitoring of vegetation in the coastal zone of Lake Vshivoe

. The article presents the results of the current state of flora of the coastal zone of Vshivoe Lake. This is a natural drainless water body at the watershed of the Grachevka and Egorlyk rivers. The composition and structure of plant biodiversity were identified and GPS coordinates for rare and endangered plant species were established. In the course of expeditionary studies of the coastal zone 30 m wide, we observed the disappearance of the water mirror and the increase of steppe vegetation species, the appearance of trees, shrubs. Throughout the entire coastline in the association Phragmites australis + Typha latifolia with a dense projective coverage of 81 to 98% grows 125 species of higher vascular plants belonging to 37 families and 95 genera. The species composition of coastal-water vegetation in 2022, compared to 2014, has decreased by one species, the species composition has changed in favour of weeds, there is afforestation of the territory at the expense of shrubs, they become more to 3-5 pcs per 100 m². Anthropogenic and climatic factors led to an increase in the number of steppe species from 24 to 32 and ruderal species from 17 to 32 species in 2022 compared to 2014. Four species of sedges, Carex riparia , C. melanostachya, C. hordeistichos, C. vulpina, were found and determined from 8 previously discovered rare species of the Red Books of the Russian Federation and Stavropol Krai, were found and determined: Tulipa biebershteiniana, Bellevalia sarmatica, Iris halophila, Iris taurica, Paeonia tenuifolia, Adonis vernalis, Dactylorhiza incarnata, Anemone sylvestris, which is 6.78 % of the floristic composition of the area. It was established that the majority of rare and endangered species populations in natural habitats are growing with a predominance of vegetative and juvenile individuals.


Introduction
Conservation of biodiversity of fauna and flora is a prerequisite for sustainable development of the biosphere.At the present stage of society development, the everincreasing anthropogenic pressure on the Earth's natural envelope leads to intensive processes of vegetation cover transformation, simplification of plant communities structure and disappearance of rare phytocenoses.In this regard, it is especially important to study flora and vegetation cover in detail at the regional level.The main form of flora conservation is the protection of plant communities.A special role in this belongs to SPNR, the main task of which is to conserve natural objects -individual species, populations, communities or the whole biocenosis [1].
To assess biodiversity conservation, it is necessary to monitor the most vulnerable plant species listed in the Red Data Books of the state and regional levels, as well as rare and unique phytocenoses.Their disappearance is the first sign of unfavourable conditions in a biocenosis.Therefore, identification and assessment of the current state of populations of rare and protected plant species and rare plant communities in specially protected natural areas is one of the key points in the creation and then the effectiveness of conservation activities.
Lake Vshivoye is a natural drainless water body at the watershed of the Grachevka and Egorlyk rivers, included in the state nature reserve "Vshivoye Lake" by the resolution of the Government of Stavropol Krai in 2012, the boundary of which runs along the shoreline.The area -259.5 ha, is located 3 km south-east of the village of Demino (N -44°58'9"; E -42°4'25"; h -550 m).The Rremuchy and Kholodny creeks flow into the lake on the southern shore.It appeared about 1 million years ago in the bottom of an ancient dead valley between the Stavropolskaya and Kholodnaya mountains and represents a remnant of a palaeodolin that existed at the end of the Neogene.The lake basin is composed of Miocene sediments [2].Observations of the lake have been conducted for the last 300 years.The lake is ancient and is in a dystrophic stage of development, gradually turning into a swamp, because of which its flora and fauna are literally changing before our eyes.The water level is directly related to the amount of precipitation and spring floods.As practice has shown, in order to preserve any natural objects, it is necessary, first of all, to preserve the habitat.Despite geographical accessibility, the study of vegetation biodiversity in the vicinity of the Vshivoe Lake remains scattered and insufficient.
Currently, there is an initial stage of pasture degradation of riparian vegetation and an associated increase in the role of poisonous, thorny and weedy vegetation.The most reliable and effective method of conservation of floristic resources is the protection of plant species in nature and natural habitats, in which the optimal development and renewal of plants is ensured, and the most accessible method of control over biological diversity and its conservation is monitoring, the purpose of which is to record and analyse its results.The work was carried out in accordance with the state assignment and the theme of the research work: "Search, mobilisation and conservation of genetic resources of cultivated plants and their wild relatives for the study, conservation and use of biodiversity of cultivated plant forms" in 2014 and 2022.
Over the last 10 years, the hydrological regime of Lake Vshivoe has changed, the area of the coastal zone has increased, and the plant community around it has changed.The aim of the research is to determine the current state of the vegetation of the changed shoreline.The tasks were set -to identify the composition and structure of plant biodiversity of the coastal zone of the Lake Vshivoe.To establish GPS-coordinates for rare and endangered plant species.

Methods and materials
Observations on the state of biocenosis were conducted from 2014 to 2022 in the Shpakovsky district of Stavropol Krai -the coastal zone of Lake Vshivoe.The study area is located within the V moderately humid region in terms of moisture availability, and insufficiently hot subarea with SCC 1.1-1.3 in terms of heat availability.Climatic conditions in this area are favourable in terms of moisture supply.There are 500 to 700 mm of precipitation per year, the sum of effective temperatures during the vegetation period is 2800-3200 ºC.The terrain is rugged.The frost-free period lasts 180-190 days, the snow cover is 10-12 cm high, in some years it may be 70-80 cm, but it is unstable.Eastern winds prevail in winter.Precipitation in summer is heavy.The number of days with dry weather is from 50 to 60 [3,4].
During the expedition and field research we applied the method of route survey, which allows to cover different elements of relief with the specificity of plant communities' characteristic for them as much as possible.10 x 10 m sample plots were laid, through the whole territory of the detected population by the transect method or, in some cases, indiscriminately covering the most characteristic plant communities.Travelling was carried out at different times of the year, which allowed to observe the studied objects in different phases of development.Locations of species populations were established by point mapping.The study of species composition of phytocenosis was carried out by the standard method of geobotanical site description [5,6].The list of plant species growing in phytocenoses is the most important characteristic of the systematic composition of plant communities.The quantitative composition of plant species serves as an essential feature of any phytocenosis.It is necessary to take into account all plant species growing in the study area.Systematic composition involves analysing the distribution of species by families allows us to judge about soil and climatic factors, the current state of the flora, as well as the degree of human influence on the territory and its components [7].Systematic descriptions and new combinations were given in accordance with the International Code of Botanical Nomenclature [8,9,10].Monitoring of rare species in culture and in nature was carried out according to the "Programme and Methods of Observations of Cenopopulations of Plant Species of the Red Book of the USSR" [11].
Sozological studies of rare species were carried out by analysing the categories of protection and status of the species.Population viability was determined on a 5-point scale.The abundance of species was determined according to Drude: Cop³ -very abundantly, Cop² -abundantly, Cop¹ -quite abundantly, Sp 3 -abundantly scattered, Sp 2 -scattered, Sp 1sparsely, Sol -sporadically (insignificantly), Un -on the site in a single sample [12].The category of protection means the degree of importance of preserving the gene pool of a given species and is divided into five categories: regional endemics, subendemics, relict species with point habitats in the region and rare outside the region: glacial and xerothermic relicts, species not belonging to the first four categories -rare due to natural causes [13,14].
Increasing anthropogenic impact on the environment leads to changes in natural phytocenoses, a decrease in the number of species of the indigenous component of the flora and an increase in the number of synanthropic species.The assessment of anthropogenic impact on phytocenosis was determined by analysing geobotanical descriptions and determining the phytocenotic spectrum.After that, the degree of synanthropisation of communities was calculated using the method of R. I. Burda [15,16].Assessment of the degree of synanthropisation using a five-point system is as follows: 1 point -the content of synanthropic species at this site is not more than 1%, i.e., they are sporadically embedded in the general background of vegetation; 2 points -the content of synanthropic species on the site does not exceed 10%.They occur among several plants forming a mass admixture to the background ones; 3 points -the content of synanthropes on the site does not exceed 30%.Here they occur among many species, forming a significant part of the total background; 4 points -the content of synanthropes on the site does not exceed 50%, i.e., their dominance is obvious.Synanthropes constitute the main mass of the vegetation cover; 5 points -synanthropes content on the site is more than 50%.Synanthropic species occupy most of the site, i.e., they dominate, forming a general background in which all other types of vegetation are embedded In turn, the synanthropised vegetation can be divided into three groups according to the level of synanthropisation: 1. Communities of high level of synanthropisation -the share of synanthropic species from 51 % to 80 %.
2. Communities of medium level of synanthropisation -the share of synanthropic species from 31% to 50%.
3. Communities of low level of synanthropisation -the share of synanthropic species from 11% to 30%.
In case of synanthropisation, there is an increase in floristic richness at the initial stages of anthropogenic impact.Subsequently, there is a noticeable decrease in the number of both native and introduced species.As a result of synanthropisation, rare plant species, as well as species growing at the border or outside their range, disappear first of all.The reduction in their number is associated with the destruction of their habitats.

Results and discussion
The results of population-species and ecosystem studies carried out in the coastal zone of Lake Vshivoe allowed us to lay the foundation for monitoring the status of rare and endangered plant species.When studying the species diversity of flora of the investigated area of the coastal zone 30 metres wide, we noted the disappearance of the water mirror, at the same time there is an increase in the area of steppe vegetation, the appearance of trees (Malus orientalis Uglitzk., Prunus stepposa Kotov., P. cerasifera Ehrh.) and shrubs (Tamarix ramosissima Ledeb., Rosa canina L., Crataegus sp.) (Table 1).Throughout the entire coastline in the association Phragmites australis + Typha latifolia with a dense projective coverage from 81 to 98%, the species composition includes more than 125 higher vascular plants from 37 families and 95 genera.
Despite the high degree of similarity, the species composition of coastal aquatic vegetation in 2022, compared to 2014, decreased by one species, changed in favour of weedy plants, there is afforestation of the territory at the expense of shrubs, they become more (afforestation of the territory by increasing the number of shrubs up to 3-5 pcs.per 100 m²).Designations: Rb -ruderal, Ra -segetal; S -forest, Pa -plain, St -steppe; Abhydrophilic, Aa -hygrophilic, Db -psammophilic, Da -calcetrophilic, Dc -halophilic; []location.
Crimean (Iris taurica), narrow-leaved peony (Paeonia tenuifolia), spring mountain flower (Adonis vernalis), blood-red palchatokorenny (Dactylorhiza incarnata).forest windflower (Anemone sylvestris), which is 6.78 % of the floristic composition of the area [17,18].It was found that most of the populations of rare and endangered species in natural habitats are growing (with a predominance of vegetative and juvenile individuals), their vitality on a five-point scale is estimated at 4-5 points.A complete ontogenetic spectrum without the presence of blue individuals was observed.
Anthropogenic (intensive ploughing of the eastern coastal zone, while on the western and southern sides regular haying and uncontrolled grazing is carried out) and climatic (decrease in the amount of precipitation in the summer period from 2014 to 2022) factors led in 2022 to an increase in the number of steppe species from 24 to 32 and ruderal -from 17 to 32 species (Fig. 1), compared to 2014.In this community synanthropic species make up 27 %, which gives us the opportunity to attribute it to a low level of synanthropisation.

Conclusions
1. On the basis of research in the cenosis of the coastal zone of Lake Vshivoe, 125 species of higher vascular plants belonging to 95 genera and 37 families have been identified.2. Anthropogenic and climatic factors led to the reduction of one species in 2022 compared to 2014 and to the change of species composition in favour of weed plants from 17 to 32, the afforestation of the territory is observed due to the increase in the number of shrubs up to 3-5 pcs.per 100 m².The level of synanthropic species is 27 %.3. Rare and endangered species were found, accounting for 6.78 % of the species diversity of the zone: Tulipa biebershteiniana, Bellevalia sarmatica, Iris halophila, Iris taurica, Paeonia tenuifolia, Adonis vernalis, Dactylorhiza incarnata, Anemone sylvestris, 4 species of sedges Carex riparia, C. melanostachya, C. melanostachya, C. hordeistichos, C. vulpina out of 8 species found earlier.

Table 2 .
Changes in the systematic composition of the cenosis of the coastal zone of the Vshivoe