Anthropogenic load on phytocenoses in agroecosystems of the suburban area Natalya Vladimirovna Polyakova. The significance of the impact of animals on plants for the organization of phytocenoses Human influence on phytocenoses

Course work is devoted to the topic of human influence on phytocenoses. The work consists of 32 pages, the list of sources used includes 17 titles. The course project covers the following issues in detail:
1. Geobotany as a science
2. The concept of phytocenosis
3. Formation of phytocenosis
4. Composition and structure of phytocenoses
5. Classification of phytocenoses
6. Dynamics of phytocenoses
7. The influence of anthropogenic factors on phytocenoses

Earth is a green planet. Plants can be found everywhere: in the forest, in the field, at the bottom of the ocean, in a drop of water and on the top of a mountain. They are found in the form of trees, shrubs, subshrubs and herbs. All green plants have a special property - using the energy of the sun to create organic substances from carbon dioxide and water. They are natural laboratories in which the process of photosynthesis occurs. Thanks to this process, our planet receives a huge amount organic matter. Plants are also of great importance as a source of oxygen, without which life on Earth is impossible. Only green plants are capable of absorbing carbon dioxide from the atmosphere on a large scale. Of great importance in human life are cultivated plants grown to produce fruits, fruits and vegetables. vegetables, grains, etc. and eat them and store them for the winter. And for farm animals, grain crops and silage are collected, which are also necessary for the life of animals because they contain nutrients. Without the participation of plants, one of the most important processes on Earth - the process of soil formation - is impossible. Vegetation cover prevents river banks and mountain slopes from collapsing and counteracts soil deflation. In general, vegetation is a powerful natural factor, the importance of which is difficult to overestimate.
With the development of mankind, phytocenoses have undergone modification in the course of evolution. As civilization developed, especially after the Industrial Revolution of the late Middle Ages, humanity became increasingly capable of capturing and using vast masses of vegetation to satisfy its growing needs. The intensity of human consumption of energy, material resources and food is growing in proportion to the population and even outpacing its growth. V.I. Vernadsky wrote: “Man becomes a geological force capable of changing the face of the Earth.” This warning was prophetically justified. The consequences of anthropogenic activity are manifested in depletion natural resources, destruction of natural ecosystems, changes in the structure of the Earth's surface. Anthropogenic impacts lead to disruptions in almost all natural biogeochemical cycles, in particular in phytocenoses.
The topic of this work is very relevant today, because today the anthropogenic impact on phytocenoses has acquired its maximum significance since the advent of mankind.
The purpose of this work is to study the human influence on phytocenoses.
Objectives: research scientific literature on the topic under consideration; - study the concept of phytocenosis; - determine the impact of anthropogenic actions on phytocenoses

Introduction………………………………………………………………………………………...4
1. SCIENCE OF GEOBOTANY……………………………………………………………......6
2. PHYTOCOENOSIS AS A BIOLOGICAL SYSTEM……………………….8
2.1. The concept of phytocenoses…………………………………………….8
2.2. Formation of phytocenoses………………………………………….8
2.3. Composition of phytocenoses……………………………………………10
2.4. Structure of phytocenoses……………………………………………...17
2.5. Classification of phytocenoses……………………………………..19
2.6. Dynamics of phytocenoses……………………………………………22
3. HUMAN INFLUENCE ON PHYTOCOENOSES……………………………24
CONCLUSION…………………………………………………………….31
REFERENCES………………………………………………………32

1. Bykov, B.A. Geobotany/ B.A. Bykov. - 3rd ed., revised. - Alma-Ata, 1978. - 288 p.
2. Theoretical foundations of modern phytocenology / B.M. Mirkin, rep. ed. G.S. Rosenberg. - Moscow: Science, 1985. - 136 p.
3. Sukachev, V.N. Dendrology with the basics of forest geobotany / V.N. Sukachev. - L.: Goslestekhizdat, 1938. - 120 p.
4. Shennikov, A.P. Introduction to geobotany / A.P. Shennikov. - L.: Leningrad State University Publishing House, 1964. - 158 p.
5. Clements, F.E. Ecology of the world / F.E. Clements., revised. - L.: Goslekhtekhizdat, 1997.- 215 p.
6. Prokopyev, E.P. Introduction to geobotany / E.P. Prokopyev. - Tomsk: TSU Publishing House, 1997. - 284 p.
7. Phytocenology: principles and methods / B.M. Mirkin, G.S. Rosenberg. - Moscow: Science, 1978. - 212 p.
8. Biology with basic ecology: textbook for students institutions of higher professional education / F.S. Lukatkin [etc.] - 2nd ed., - Moscow: Publishing Center "Academy", 2011. - 242 p.
9. Blumenthal, I.H. Essays on the taxonomy of phytocenoses / I.Kh. Blumenthal; edited by Yu.N. Neshataeva. - St. Petersburg: Leningrad State University, 1990. - 224s.
10. Zakhvatkin, Yu.A. Fundamentals of general and agricultural ecology / Yu.A. Zakhvatkin, - St. Petersburg: Mir, 2003. - 360 p.
11. Botolov, N.A. Forest in our life / N.A. Bolotov. - Moscow: Timber Industry, 1976. - 88 p.
12. Bochkareva, T.V. Ecological “genie” of urbanization / T.V. Bochkareva. - Moscow: Mysl, 1988. - 268s.
13. Ilkun, G.M. Atmospheric pollutants and plants / G.M. Ilkun. - Kyiv: Naukova Dumka, 1978. - 246s.
14. Kuznetsov, E.I. Irrigated agriculture: textbook / E.I. Kuznetsov, E.N. Zabakunina, Yu.F. Snipich. - Moscow: Federal State Budgetary Educational Institution of Higher Professional Education RGAZU, 2012. - 117 p.
15. Golovanov, A.I. Reclamation agriculture / A.I. Golovanov [et al.] - Moscow: Agroproimizdat, 1986. - 328 p.
16. Kurdyukov V.V. Consequences of pesticides on plant and animal organisms / V.V. Kurdyukov. - Moscow: Kolos, 1982.-128 p.
17. Student works. General requirements and design rules. STO-020690024.101-2014; input 2014.29.12. - Orenburg

Final qualifying (diploma) work

Anthropogenic impact on phytocenoses in the vicinity of the Takhtamukai village of the Republic of Adygea

Introduction

vegetation biogeocenosis phytocetonic anthropogenic

IN last years ecological problems became not only problems of biological conservation of nature, but also problems of a socio-political nature. In modern conditions, the health of the population largely depends on ecological state quality environment. However, the action of certain environmental factors poses a threat not only to plants and animals, but also to human health. Due to the intensification of anthropogenic impact on the natural environment, negative consequences arise that directly or indirectly affect all living organisms [Abregov, Kozmenko, Pashkov, 2002].

Harmful substances entering the natural environment with wastewater, emissions into the air or accumulating as industrial and household waste, as well as radio active substances and other factors affecting the ecosystem do not disappear without a trace. Even their low concentrations, acting for a long time, can negatively affect both animals and plants, and human health [Abregov, Kozmenko, Pashkov, 2002].

The Republic of Adygea has traditionally been and is considered one of the environmentally friendly subjects Russian Federation However, there are a number of problems here too:

environmental pollution during transportation, storage and use of chemical plant protection products;

emergency releases and leaks from gas and oil pipelines;

emissions of toxic substances into the atmosphere from mobile sources;

solid landfills household waste;

burning crop residues in fields;

pollution with toxic natural waste.

The most dangerous from a medical and environmental point of view are storage areas for deteriorated pesticides, as well as solid household and industrial waste[Abregov, Kozmenko, Pashkov, 2002].

The species composition, physiognomic appearance, structure, vital state of plants and productivity of plant communities reflect all the features of living conditions, including the degree of anthropogenic pollution. Biomonitoring at the population or phytocenosis level allows one to obtain data on the general state of the natural environment [Egorova, 2000].

In this regard, this work is relevant.

The purpose of the work is to study the anthropogenic impact on phytocenoses in the vicinity of the village of Takhtamukai in the Republic of Adygea.

To achieve this goal, the following tasks were identified:

To establish the species composition of the vegetation cover in the vicinity of the village of Takhtamukai;

2. Conduct taxonomic and biomorphological analyses;

Conduct an environmental analysis;

.Conduct phytocenotic analysis;

5.Conduct a chemical analysis of the soil;

6. Identify changes in phytocenoses in the vicinity of the village of Takhtamukai as a result of anthropogenic impact.

1. Analytical review

Any land area occupied by plants does not represent a random combination of any number of species and biotypes living independently of each other. Each plant community arises and develops under certain conditions external environment, as a result of complex interaction between the plants of the community and other components of their habitat [Pachossky, 1927]. The branch of botany that studies the patterns of formation of plant communities and their interaction with the environment is called phytocenology.

At the end of the 19th century, in a number of countries, as a result of the study of their vegetation cover, the idea of ​​regular combinations of plants growing together - plant communities, emerged, the need for their study as a special object was substantiated, and the tasks of the scientific discipline studying plant communities were formulated [Alekhin, Syreyshikov, 1926; Pachossky, 1927].

The name phytocenology became widespread in the USSR and some European countries; in other countries the terms phytosociology and plant ecology are used [Alyohin, 1938].

The tasks of phytocenology include the study of the floristic, ecobiomorphic and cenopopulation composition of phytocenoses, relationships between plants, structure, ecology, dynamics, distribution, classification and history of the emergence of phytocenoses [Pachossky, 1927].

As a result of these studies, the species composition of phytocenoses is revealed (including vascular plants, mosses, lichens, algae, fungi, bacteria and actinomycetes), the composition of coenopopulations, structure, dynamics, including changes caused by human activity, the conditions that ensure maximum production of phytocenoses are clarified, including the creation of artificial highly productive phytocenoses [Alekhin, Syreyshikov, 1926].

The foundations of this science in our country were laid by Academician V.N. Sukachev. Soviet botanists made a great contribution to the development of phytocenology. They studied the vegetation of one sixth of the Earth’s territory, developed theoretical problems and methods for studying phytocenoses: V.V. Alekhin, E.M. Lavrenko, A.P. Shennikov, L.G. Ramensky, V.B. Sochava et al.

Currently, phytocenology is theoretical basis protection, proper use and increasing the productivity of natural and man-made phytocenoses. The results of phytocenological studies are used for planning and rational use of forest, forage and other lands, in geological and hydrogeological studies, etc. [Voronov, 1973].

The main object of study of phytocenology is phytocenosis - a specific plant community in a certain territory, characterized by its composition, structure and interaction between plants, as well as between them and the environment [Pachossky, 1927]. These interactions are manifested in various directions.

First of all, in a phytocenosis there is competition between different species and individuals within a species for light, water, minerals, and space. This competition leads to the death of a huge number of individuals during the formation of the community, to the suppression of a significant number of species and has a formative effect on the plants of the phytocenosis [Ramensky, 1971].

Since plants of different species and life forms with different ecological characteristics take part in the formation of a phytocenosis, the community acquires a special structure in the form of tiers. Tiering is inherent in any phytocenosis, but it is especially pronounced in the forest. The tallest trees here make up the first tier, less tall ones - the second, undergrowth shrubs - the third, shrubs, grasses, mosses and lichens - the fourth and fifth. Temporarily, plants may be in a layer unusual for them, for example, tree seedlings are in the fifth, young growth is in the canopy of the fourth or third layer [Ramensky, 1971; Voronov, 1973].

The main taxonomic unit in geobotany is the plant association. An association is the smallest, most easily visible physiognomic unit of vegetation cover, a collection of vegetation areas that have the same physiognomic appearance, structure, species composition and are located in similar habitat conditions.” Thus, an association is similar communities of plants. Associations of phytocenoses differ in a number of characteristics - species and floristic composition, tiers, abundance of species, projective cover, quantitative ratio of species. Associations are combined into groups of associations, groups of associations into formations, formations into classes of formations and types of vegetation [Alekhin, Syreishikov, 1926; Voronov, 1973].

With a more detailed study of the structure of forest phytocenoses, parcels are identified - territorially isolated plant microgroups.

When establishing a plant association, the main indicator is the species composition of vegetation layers. But among the species included in the association, it is very important to identify those that determine the structure of the community and determine the creation of a special environment inherent in this community. Such plant species are called edificators of associations [Alekhin, Syreishikov, 1926].

Thus, a plant association can be defined as a set of phytocenoses that are homogeneous in the relationships between plant species in accordance with environmental conditions, homogeneous in structure, species composition of tiers and occupying growing conditions with a homogeneous complex of environmental factors. A plant association is the basic systematic unit of vegetation.

Like species in plant taxonomy, each plant association is also given a specific name, usually double. The first word of the name is generic, corresponds to the name of the association edifier; the second (species) is most often given by the name of a characteristic plant of another tier, grass or moss cover, or by the names of indicator plants [Voronov, 1973].

In accordance with this, the plant association is characterized by a mainly homogeneous species composition, a homogeneous sinusial structure, reflecting the corresponding composition ecological types plants, and a certain composition of environmental factors influencing the phytocenotic process. To determine a plant association, the names of plant species are usually used, but in some cases - those playing a leading role in the community (edificators and dominants), and in others - species that have diagnostic significance (the so-called characteristic, differentiating, and constant); The ways of constructing names are also different. Plant associations are combined into groups; they can also be subdivided into smaller taxa - subassociations. Plant associations with similar lower layers, but differing in the composition of the dominant layer, are called replacement (vicarious). If plant communities united into one plant association do not have a homogeneous composition, but are a mosaic of fragments of different communities, then such a plant association is called mosaic. The naturally repeating alternation of communities of several plant associations, represented by relatively small areas, is defined as a complex of associations [Voronov, 1973].

2. Physiographic characteristics of the study area

.1 Boundaries of the study area

Administratively, the study area is located on the territory of the Takhtamukaisky district of the Republic of Adygea (3 km from the city of Krasnodar) [Takhtamukaisky district..., 1999].

The Republic of Adygea is one of the picturesque corners of the Russian Federation, located in the central part of the North-West Caucasus, in the basins of the Kuban, Laba and Belaya rivers [Kanonnikov, 1984].

The republic includes 7 administrative districts, including the Takhtamukay district (Figure 1).

Takhtamukai district is located in the north-west of the republic. It borders in the east with the Teuchezhsky district of Adygea, in the north - with the Dinsky district, the city of Krasnodar, in the west - with Seversky, in the south - with the city of Goryachiy Klyuch and the Belorechensky district of the Krasnodar Territory [Buzarov, Spesivtsev, 2000].

The total area of ​​the district is 466.5 km 2. The Takhtamukaysky district includes the following rural districts: Afipsipsky, Starobzhegokaysky, Yablonovsky, Enemsky, Takhtamukaysky, Kozetsky and Shendzhiysky. There are a total of 28 settlements in the region, the largest of which are Yablonovsky and Enem. The administrative center of the district is the village of Takhtamukai [Takhtamukaisky district..., 1999].

Figure 1 - Location of Takhtamukay district

2.2 Features of the geological structure and relief

The history of the geological structure of the territory of Adygea is complex. Since the Proterozoic era, there has been a geosynclinal region where thick sedimentary strata accumulated, and then mountain folds were formed more than once, which were destroyed and submerged again. Modern Caucasus Mountains formed in the Mesozoic and Cenozoic as a result of Alpine mountain building [Buzarov, Spesivtsev, 2000].

The plain and foothill parts are represented by the young Epihercynian Scythian plate. Within the Scythian plate on the territory of the republic, the Kuban trough is distinguished, separated from other troughs by swell-like

uplifts passing into the Adygei ledge. The Kuban trough is composed of Neogene deposits and covered with alluvial and fluvioglacial pebbles and loams. The modern relief of Adygea was formed over a long geological time. It is changing even now under the influence of external and internal forces of the Earth. The northern part of the Trans-Kuban Plain is elevated above sea level by 20 - 40 m, and the southern part - 200 - 500 m [Varshanina, Melnikova, Khachegogu, 2001].

In the Takhtamukai region, the surface of the plain is slightly undulating. A significant part of the region is located in the valley of the Kuban River and is a plain with a pronounced microrelief. In rice systems, the microrelief is smoothed out as a result of microplaning. The surface of the watershed plains has gentle and very gentle slopes [Takhtamukaisky district..., 1999].

2.3 Climate

According to the agroclimatic zoning adopted in the “Agroclimatic Directory for the Krasnodar Territory”, the Takhtamukaisky district is included in the 2nd agroclimatic region.

The climate in the vicinity of the village of Takhtamukai is determined by the main climate-forming factors: solar radiation, the atmospheric circulation system, the nature of the underlying surface and anthropogenic activity [Varshanina, 1995].

The position of the village in the south of Russia determines the high altitudes of the sun above the horizon. At noon on June 22, the sun's height above the horizon is 68.5°, and on December 22 - 22°. The amount of heat reaching the earth's surface depends on the height of the sun. On average, lowland areas receive 117 - 120 kcal/cm3 of total radiation per year. The duration of sunshine is 2200-2400 hours per year, which is 800-900 hours more than in Moscow [Buzarov, Spesintsev, 2000].

Predominant air masses: moderate and moderate continental. Also, continental tropical air comes from Central Asia, and sea tropical air comes from the Mediterranean Sea. In winter, this air causes thaws (February windows), in summer - heat, in spring and autumn - warm weather, sometimes rains [Krasnopolsky, 2001].

The underlying surface leads to the distribution of heat and moisture. In winter, the Black Sea has a warming effect; in summer, winds from the sea bring coolness and moisture.

The climate is also influenced by the activities of people who change the nature of the underlying surface. Construction of large reservoirs, destruction of forests, plowing large territories change the moisture content in the soil and air, temperature conditions. In the atmosphere, the amount of gases of anthropogenic origin increases every year: oxides of carbon, nitrogen, sulfur, organic compounds, which also affects the distribution of heat at the earth’s surface [Krasnopolsky, 2001].

Average temperatures in the village of Takhtamukai, throughout the year, differ slightly from average temperatures in the Krasnodar Territory. The coldest month is January. Average January temperatures are minus 2°C. Average in July monthly temperature air is 25.27°C. Annual quantity precipitation increases from north to south. It is 550 - 700 mm [Buzarov, Spesintsev, 2000].

The depth of the snow cover fluctuates due to frequent thaws. In the village of Takhtamukai it averages 5 - 10 cm [Buzarov, Spesintsev, 2000].

Air humidity is an important climate characteristic for humans and animals. Its value is judged by the magnitude of absolute and relative air humidity, which primarily depend on air temperature. Maximum value absolute humidity air is observed in the warm season, and minimal in the cold season. Relative humidity. On the contrary, it is greatest in the cold season and least large in the warm season. In the village of Takhtamukai, the minimum value of relative humidity is 63% (in some years 30 - 35%). In December - January, relative humidity has a maximum value of 85% [Varshanina, Melnikova, Khachegu, 2001].

The republic has a high frequency of strong winds, with a speed of more than 15 m/sec. The average number of days with strong wind ranges from 13 to 20 days, and the maximum number in some years reaches 36 - 57 [Buzarov, Spesintsev, 2000].

The greatest frequency of winds is observed in early spring - in February and March. Strong winds cause significant damage agriculture. They cause lodging of crops, shedding of fruits, and breakage of trees [Krasnopolsky, 2001].

In temperate latitudes, air transport prevails from west to east - “western transport”. But in the North Caucasus, this general transport is disrupted under the influence of the underlying surface. The system of the Greater Caucasus prevents free circulation - “local winds”; the proximity of the Black and Azov seas. In the northern lowland part of the republic as a whole, winds of the eastern, northeastern, western and southwestern directions predominate throughout the year. In January, the frequency of winds from the eastern and northeastern directions is greatest. This is due to the transfer of air from the east, from areas under the influence of the Asian maximum atmospheric pressure, towards the area formed over the Black Sea low pressure. In July, winds from the western and southwestern directions prevail on the plains due to the fact that in the summer a region is formed over the Black Sea high pressure[Korovin, 1979].

2.4 Hydrology

In Adygea, 5 reservoirs have been created, 3 of which: Shapsugskoye, Takhtamukayskoye and Shendzhiyskoye, are located on the territory of the Takhtamukaysky district [Varshanina, Melnikova, Khachegu, 2001].

Reservoirs are artificial reservoirs designed to retain, accumulate, store and redistribute water over time.

In the vicinity of the village of Takhtamukai (9 km south of Krasnodar) in the floodplain of the Sups River there is the Takhtamukai Reservoir. Built in 1964 for the purpose of irrigating agricultural land. The area of ​​its mirror is 9.4 km, length 4 km, width 3 km, average depth 2.5 m, volume 15 million m 3. The water surface in many places is covered with vegetation [Kabayan, 2001].

Groundwater, like surface water, is an important type of natural resources of the republic. The role of groundwater is difficult to assess because groundwater is the most precious mineral resource. The groundwater of Adygea is part of the Azov-Kuban artesian basin [Kabayan, 2001].

According to the conditions of occurrence and distribution, they are divided into three main types [Kabayan, 2001]:

water in bedrock Paleozoic rocks;

waters in Mesozoic and Tertiary sediments;

and groundwater of Quaternary formations.

Groundwater in the lowland areas of the republic is suitable for water supply and irrigation. Their mineralization does not exceed 0.5 g/l. In terms of their chemical composition, they are often hydrocarbonate-calcium [Kabayan, 2001].

Takhtamukai district is located near the river. Kuban on the flat part. The Afips, Uneubat and Sups rivers flow on its territory, and there are also two ponds [Takhtamukaisky district..., 1999].

Superficial water bodies are subject to contamination by wastewater and collector-drainage waters (Table 1).

Table 1 - Discharge of wastewater and collector-drainage waters into surface water bodies in the Takhtamukay district in 2009, million m 3 [Spesivtsev, 2002]

Total Polluted Clean, without cleaning Regulatory cleaned 213.763.3150.10.2 2.5 Soil cover

Soil is the upper layer of the earth's crust, covered with vegetation and possessing fertility. This is a complex natural historical formation that arose as a result of the interaction of many factors: soil, climate, plant and animal organisms, terrain, soil and groundwater, economic activity man and time [Varshanina, Melnikova, Khachegu, 2001].

According to the diversity of soil and climatic conditions, the territory of the Krasnodar Territory and the Republic of Adygea is divided into 5 zones: Northern, Central, Western, South Foothill and Black Sea. The territory of the village of Takhtamukai, like the city of Krasnodar, belongs to the Central zone. The soil and climatic conditions of this zone for most cultivated crops are the best in the region. In the autumn-winter period, the soil is well moistened [Ashinov, Zubkova, Karpachevsky, 2008].

In the Takhtamukai region, as in the Republic of Adygea as a whole, there are the most fertile lands in our country. The soil cover is represented by leached compacted chernozems, as well as meadow (floodplain) soils with a heavy mechanical composition and unfavorable water-physical properties (Figure 2).

The appearance and structure of leached chernozems are characterized by:

) greater thickness of humus horizons;

) strong leaching of humus horizons (easily soluble carbonate salts are removed from them); effervescence from the action of 10% hydrochloric acid (HCl) is detected in the C horizon below 140 cm;

) darker color compared to typical chernozems;

) the structure of the upper horizon is granular-lumpy, turning into a lumpy-nutty structure in the second half of the soil profile [Pecherin, 1989].

These morphological features are due to the meadow-steppe vegetation that previously grew here. The humus content in the soil is about 4 - 5% of the soil weight and in a two-meter thickness it is equal to 650 - 740 tons [Pecherin, 1989].

Figure 2 - Soils of the North-West Caucasus according to G.M. Solyanika

Meadow floodplain soils of forest-steppe and steppe zones They are distinguished by a thick humus layer with intensive staining with humus and less ferruginization in the lower part of the profile. In these soils, carbonate, solonetzic, and solonchakous content are already observed [Khachegu, 2001].

The humus horizon A1 is dark gray or brownish-gray with a heavy loamy granulometric composition with a significant amount of “residual” humus introduced with alluvium, with a thickness of 30 to 50 cm. In the upper part of the horizon, dense (3 - 6 cm) turf is isolated. It has a granular structure with rusty-brown spots and veins. B1 is a transitional horizon with spots of gleyization and ferrugination associated with hydrogenogenic processes. Bg is a gley horizon of bluish-gray tones, the degree of gleying varies greatly, and often has a layered structure. СDg - layered alluvium, usually heavily gleyed, with layers of buried peat. They are formed in the central floodplain during inundation by calm flood waters and the deposition of a relatively small amount of loamy and clayey alluvium. After the flood subsides, the upper boundary of the capillary fringe is constantly or periodically located within the soil profile. It develops under wet forb-grass meadows in the steppe and stucco zones [Khachegu, 2001; Solyanik, 2004].

As a result of rice cultivation, so-called rice soils were formed in the area. They were formed in the process of using meadow and meadow-chernozem soils for rice paddies. These soils have now acquired meadow-bog properties and will be difficult to restore in the near future [Khachegu, 2001].

2.6 Vegetation cover

The flora of the Republic of Adygea is extremely diverse and unique. This is due to the heterogeneity of the relief, climate, soils on the territory of the republic, as well as the history of its formation. Before the cold snap, at the end of the Tertiary - at the beginning of the Quaternary periods, the vegetation on its territory resembled tropical. The cooling of these periods led to the formation and spread of plant communities characteristic of the modern Caucasus. In the last millennium, changes in vegetation cover occur under the influence of human activity [Nagalevsky, Chistyakov, 2003].

The vegetation cover in the vicinity of the village of Takhtamukai contains many plants useful to humans: ornamental, melliferous, technical, food, and medicinal. There are many valuable forage plants, especially legumes and cereals. Forests abound in fruit and berry plants [Litvinskaya, 1993].

In the past, the Kuban-Azov Plain was occupied by forb-turf-grass steppes [Litvinskaya, Tilba, Filimonova, 1983]. Now they are almost all plowed. These are grain-growing areas, with the presence of oilseeds, sugar beets, horticulture, meat and dairy farming, and poultry farming [Litvinskaya, 1984]. The plowed area of ​​the steppes of the territory is 77%. Up to 10 - 12% of the area is occupied by residential areas and roads. In this regard, the vegetation cover of landscapes is mostly represented by the synanthropic variant [Pechorin, 1989].

3. Material and research methods

.1 Object of study

The object of our research is the natural phytocenoses of the surroundings of the village of Takhtamukay in the Republic of Adygea, which are subject to anthropogenic influence. The following anthropogenic sources of pollution were selected: the LLC New Technologies enterprise (Figure A.1) and the highway (Figure A.2).

The materials for writing the work were: herbarium of vegetation of the study areas, field notes, diaries and photographs.

The species affiliation of herbarium specimens was established using the following keys: “Flora of the North-West Caucasus” by A.S. Zernova “Identifier of higher plants of the North-Western Caucasus and Ciscaucasia” [Kosenko, 1970], “Identifier of plants of the Caucasus” [Grossheim, 1949].

3.2 Geobotanical research methods

Geobotanical platforms measuring 1 m 2were laid out by the random method [Voronov, 1973], as well as by the transect method [Alyohin, 1938], combining random and systematic selection.

An association was adopted as the main taxonomic unit, which was distinguished by the common composition of dominant and co-dominant species, by the floristic core of associated species and is considered as a unit of the lowest rank. The association unites areas of vegetation cover with the same species of the dominant layer, a common set of characteristic species and the same successional tendency [Alekhin, Syreyshikov, 1926].

To assess the numerical abundance of individuals of individual species, there are a number of scales, of which the Drude eye scale was used in our work [Dospehov, 1965]. This method usually takes into account not only the abundance of the species, but also the degree to which it covers the surface. The Drude assessment is carried out separately for each group of plant species that are similar in size. In this scale, the degree of abundance of a particular species is indicated by points (words or numbers). The Drude scale is presented in Table 2.

Table 2 - Species abundance assessment scale according to Drude

According to Drude According to the six-point digital verbal system Socialis (soc) 6 Plants are abundant, form a background, close Copiosus (cop 3)5There are a lot of plants Copiosus (cop 2)4There are many plants, scattered Copiosus (cop 1)3OccasionallySparsae (sp)2Plants in small quantities, inclusionsSolitariae (sol)1Plants are singleUnicum (un)+Single specimens occur

3.3 Ecological research methods

For ecological analysis of flora, the classification of ecomorphs (hydromoph and heliomorph) is usually used. The classification is based on the types of plant relationships to the water regime of soils for hydromorphs and the types of plant relationships to sunlight - heliomorphs. When identifying the life forms of plants, the most famous biomorphological classifications of H. Raunkier and I.G. were used. Serebryakova.

3.4 Chemical methods

To conduct a chemical analysis for the content of pollutants, soil samples were taken at different distances (5, 10, 25 m) from sources of anthropogenic impact - the highway and the New Technologies LLC enterprise (Appendix A).

Soil sampling, storage, transportation and preparation for analysis were carried out in accordance with GOST 17.4.4.02-84 “Nature conservation. Soils. Methods for collecting and preparing soil samples for chemical, bacteriological and helminthological analysis".

The measurements were carried out on an iCAP 6500 inductively coupled plasma atomic emission spectrometer (Thermo Scientific, USA) for heavy metals and on a UV-2401 PC spectrophotometer for phenols.

The pH of soil samples was determined using an Expert-001 pH meter.

4. Anthropogenic impact on phytocenoses in the vicinity of the village of Takhtamukai, Republic of Adygea

.1 Taxonomic analysis

As a result of the research, it was found that the flora of vegetation in the vicinity of the Takhtamukai village includes 61 plant species belonging to 57 genera and 25 families (Table 3).

Table 3 - Species composition of vegetation in the vicinity of the village of Takhtamukai of the Republic of Adygea

Family Willow species (Salicaceae)1. Brittle willow - Salix fragylis L.2. White willow - Salix alba L.3. White poplar - Populus alba L.Nuts (Juglandaceae)4. Walnut - Juglans regia L.Beech (Fagaceae)5. English oak - Quercus robur L.Mulberry (Moraceae)6. Black mulberry - Morus nigra L.Hemp (Cannabaceae)7. Common hop - Humulus lupulus L.Nettles (Urticaceae) 8. Stinging nettle - Urtica urens L.Buttercups (Ranunculaceae)9. Clematis wholeleaf - Clematis integrifolia L.10. Small mousetail - Myosurus minimus L.11. Field buttercup - Ranunculus arvensis L.Poppy (Papaveraceae)12. Great celandine - Chelidonium majus L.13. Hybrid poppy - Papaver hybridum L.Brassicas (Brassicaceae)14. Austrian tortoiseshell - Rorippa austriaca (Grantz.) Bess.Brassicas (Brassicaceae)15. Field yarutka - Thlaspi arvense L.16. Common shepherd's purse - Capsella bursa-pastoris (L.) Medik.17. Common nocturnal - Hesperis matronalis L.Mock orange (Philadelphaceae)18. Caucasian mock orange - Philadelphus caucasicus Koehne.Pink (Rosaceae)19. Small-leaved hawthorn - Crataegus microphila C. Koch20. Caucasian pear - Pyrus caucasica Fed.21. Oriental apple tree - Malus orientalis Uglitzk.22. Creeping cinquefoil - Potentilla reptans L.23. Spread plum - Prunus divaricata Lebed.24. Gray blackberry, ogina - Rubus caesius L.Legumes (Fabaceae)25. Meadow chin - Lathyrus pratensis L.26. Creeping clover - Tripholium repens L.27. Small alfalfa - Medicago minima (L.) Bartalini28. Vetch mouse pot - Vicia cracca L.Maple (Aceraceae)29. Ash-leaved maple - Acer negundo L.St. John's worts (Hypericaceae)30. St. John's wort - Hypericum perforatum L.Umbelliferae (Umbelliferae)31. Field eryngium - Eryngium campestre L.32. Common borer - Aegopodium podagraria L.33. Rough hogweed - Heracleum scabrum AlbovPrimroses (Primulaceae)34. Common primrose - Primula vulgaris Huds.Borage (Boraginaceae)35. Oriental crooked flower - Lycopsis orientalis L.Lamiaceae / Lamiaceae36. Geneva's tenacious - Ajuga genevinsis L.37. Moldavian snakehead - Dracocephalum moldavica L.38. White yasnotka - Lamium album L.39. Field mint - Mentha arvensis L.Plantains (Plantagynaceae)40. Large plantain - Plantago major L.Buckwheat (Polygonaceae)41. Horse sorrel - Rumex confertus L.Poaaceae42. Mice green - Setaria viridis (L.) Beauv.43. Bonfireless brome - Bromus inermis L.44. Field fire - Bromus arvensis L.45. Timothy grass - Phleum pretense L.46. ​​Timothy grass nodosum - Phleum nodosum L.47. Hedgehog team - Dactylis glomerata L.48. Poa angustifolia - Poa angustifolia L.49. Creeping wheatgrass - Elytrigia repens (L.) Nevski.50. Thin-legged thin - Koeleria cristata (L.) Pers.51. Meadow fescue - Festuca pratensis Huds.52. Southern reed - Phragmites australis (Cav.) Trin. ex Steud.Olive (Oleaceae)53. Tall ash - Fraxinus excelsior L.Asteraceae54. Californian cocklebur - Xanthium californicum Greene.55. Dandelion officinalis - Taraxacum officinale Wigg.56. Field thistle - Cirsium arvense (L.) Scop.57. Common yarrow - Achillea millefolium L.Asteraceae58. Ambrosia wormwood - Ambrosia artemisiifolia L.59. Wormwood paniculata - Artemisia scoparia Waldst. et Kit.Amaranthaceae (Amaranthaceae)60. White shchiritsa - Amaranthus albus L.Dogwoods (Cornaceae)61. Svidina southern - Svida austrialis (C.A. Mey) Pojark. Ex Grossh.

As can be seen from Table 3, in the vegetation cover of the surroundings of the village of Takhtamukai, the families Poaceae, Asteraceae and Rosaceae are most fully represented in terms of species.

Taxonomic analysis showed that monotypic families predominate and their share is 60% (Figure 3). These include 15 families: Aceraceae, Moraceae, Polygonaceae, Amaranthaceae, etc. 7 families are oligotypic: Brassicaceae, Ranunculaceae, Salicaceae, Apiaceae, Papaveraceae, Lamiaceae and Fabaceae. The fewest are polytypic; these include 3 families: Rosaceae, Asteraceae and Poaceae.

Figure 3 - Taxonomic analysis of the flora in the vicinity of the village of Takhtamukai

4.2Biomorphological analysis

The flora of the study area is dominated by perennials - 30 species. Rare biomorphs for the study area are biennials and shrubs.

When studying life forms according to Raunkier in the biomorphological spectrum (Figure 4) of the flora of the study area, it was found that hemicryptophytes predominate (21 species or 34% of the total number of species). The second place is occupied by therophytes (26%), followed by phanerophytes - 20%. Cryptophytes are represented by 11 species (18%). The smallest number of chamephytes is 1 species, which is 2%.

Figure 4 - Biomorphological spectrum of the flora in the vicinity of the village of Takhtamukai

4.3 Environmental analysis

When conducting an ecological analysis of the flora, we were based on the relationship of plants to moisture and light.

As a result of the study, the following ecomorphs of plants in relation to moisture were identified (Figure 5):

hygrophytes (22 species or 36%);

mesophytes (39 species or 64%).

Figure 5 - Ecomorphs in relation to moisture

In relation to light (Figure 6), we identified ecomorphs:

heliophytes (40 species or 66%);

sciophytes (16 species or 26%);

heliosciophytes (5 species or 8%).

Figure 6 - Ecomorphs in relation to light

4.4 Phytocenotic analysis

When conducting geobotanical research, we established 6 test sites at different distances from sources of anthropogenic impact (5, 10 and 25 m). As a result, 6 main associations, their dominants, codominants, assectators, as well as the layering and abundance of plants were identified.

Wheat grass-forb association(Figure B.1) is located at a distance of 5 m from the highway in the vicinity of the village of Takhtamukai. The dominant herb is purple damselfish. The codominant is creeping wheatgrass, the assectator is dandelion. The structure of the association is presented in Table 4.

Table 4 - Structure of the wheatgrass-forb association

Name of plants Tier Plant height, cm Abundance according to Drude Creeping wheatgrass 3100 - 90cop 3Purple lily230 - 25cop 2Dandelion officinalis225 - 23cop2

The grass stand is presented in two tiers. The height of the first tier is 100-90 cm: creeping wheatgrass. The height of the second tier is 30 - 25 cm: purple damask, dandelion. Total projective coverage 60%. The share of creeping wheatgrass accounts for 30%, purple grass - 20%, and dandelion - 10%.

Reed-forb association(Figure B.2) is located 10 m from the highway in the vicinity of the village of Takhtamukai. The relief is calm, slope 1 - 2°. The dominant species are forbs - angustifolia bluegrass and slender-legged bluegrass. The codominant species is southern reed. The assectator is buttercup. The grass stand is presented in three tiers. The height of the first tier is 110 - 100 cm: southern reed. The height of the second tier is 35 - 30 cm: thin-legged and thin. The height of the third tier is 30 - 25 cm: angustifolia bluegrass, field buttercup. Total projective coverage - 70%. The share of southern reed accounts for 30%, slender grass - 25%, field buttercup - 10%, and angustifolia bluegrass - 5%. The structure of the association is presented in Table 5.

Table 5 - Structure of the reed-forb association

Plant name Tier Plant height, cm Abundance according to Drude Southern reed 1110 - 100 sor 3Thin-legged thin 235 - 30 sor 2Poa angustifolia 330 - 25 sor 2Buttercup 32 - 20sol Brome-forb association(Figure B.3) is located 25 m from the highway in the vicinity of the village of Takhtamukai. The relief is calm, the slope is 4 - 5°. The soils are chernozem. The dominant species is the field brome. Assectators are creeping wheatgrass, paniculata wormwood, and hooked thistle. The grass stand is presented in two tiers. The height of the first tier is 80 - 70 cm: field brome, creeping wheatgrass. The height of the second tier is 40 - 35 cm: paniculata wormwood, hooked thistle. The total projective coverage is 50%. The share of field brome is 25%; paniculata wormwood - 15%; creeping wheatgrass - 5%; hooked thistle - 5%. The structure of the brome-forb association is presented in Table 6.

Table 6 - Structure of the brome-forb association

Plant name Tier Plant height, cm Abundance according to Drude Field brome 280 - 70 rubbish 3Wormwood paniculata340 - 35cop 1Creeping wheatgrass370 - 60cop 1Hooked thistle135 - 30sp

Forb-vetch association(Figure B.4) is located 5 m from the enterprise “New Technologies LLC”, located in the vicinity of a. Takhtamukay. The terrain is calm, slope 2 - 3°. The soils are clayey. The dominant species is mouse pea vetch, the codominant is shepherd's purse. The assectator is the common cress. The grass stand is presented in two tiers. The height of the first tier is 70 - 60 cm: mouse vetch, codominant - shepherd's purse, the height of the second tier is 30 - 25 cm: common cress. Total projective coverage 60%. The share of mouse vetch is 30%, the share of shepherd's purse is 25%, and the share of colza is 5%. The structure of the association is presented in Table 7.

Table 7 - Structure of the forb-vetch association

Plant name Tier Plant height, cm Abundance according to DrudeVicka mouse peas 170 - 75 litter 3Common shepherd's purse 155 - 60 litter 2Common cress 225 - 30sol

Sorrel-forb association(Figure B.5) is located 10 m from the LLC New Technologies enterprise. The terrain is calm, slope 3°. The soils are carbonate, low-humus, thick, clayey soils. The dominant species is horse sorrel, the codominant is creeping wheatgrass, and the assectator is green mouse grass. The grass stand is presented in two tiers. The height of the first tier is 60 - 50 cm: horse sorrel, creeping wheatgrass, the height of the second tier is 40 - 30 cm: green mice. Total projective coverage 70%. The share of horse sorrel accounts for 35%, the share of creeping wheatgrass accounts for 25%, and the share of green mice accounts for 10%. The structure of the association is presented in Table 8.

Table 8 - Structure of the sorrel-forb association

Plant name Tier Plant height, cm Abundance according to Drude Horse sorrel 160 - 50 rubbish 3Creeping wheatgrass 170 - 60 rubbish 2Mice green240 - 30sol

Fescue-forb association(Figure B.6) is located 25 m from the LLC New Technologies enterprise. The relief is calm, slope 3 - 5°. The soils are carbonate, low-humus, thick, clayey soils. The dominant is meadow fescue, the co-dominant is field brome, and the assectifier is mouse vetch. The grass stand is presented in two tiers. The height of the first tier is 100 cm: meadow fescue, the height of the second tier is 70 cm: field brome, vetch, mouse peas. Total projective coverage 40%. The share of meadow fescue is 25%, the share of field brome is 10%, and the share of vetch mouse pea is 5%. The structure of the association is presented in Table 9.

Table 9 - Structure of the fescue-forb association

Plant name Tier Plant height, cm Abundance according to Drude Meadow fescue 1110 - 100 litter 3Field fire280 - 70 rubbish 2Vetch mouse peas275 - 70sol

4.5 Soil chemical analysis

Chemical analysis was carried out in 2013 from soil samples taken in the vicinity of the village of Takhtamukai near the highway and the New Technologies LLC enterprise.

Near each of these pollutants, 3 plots were laid at different distances from the object (5, 10 and 25 m).

Soils sampled near the highway were tested for heavy metals: lead, zinc, cadmium, arsenic, nickel, copper (Table D.1).

Analysis data for the content of heavy metals showed an increase in their concentration near the highway (Figure 7).

Figure 7 - Content of some heavy metals along the highway

In relation to another anthropogenic source of pollution (the LLC New Technologies enterprise), experimental plots were also laid out at a distance of 5, 10 and 25 m, where soil samples were taken for analysis for phenols (Table D.2).

The research results showed that the content of phenols in the immediate vicinity (5 m) of this object is characterized by a fairly high content (Figure 8).

Figure 8 - Content of phenols in the soil near the enterprise "New Technologies LLC"

Also, all points from two objects were examined for soil acidity. The research results indicate alkalization of the soil in close proximity to objects of anthropogenic pollution.

4.6 Analysis of anthropogenic impact on phytocenoses in the vicinity of the village of Takhtamukai

The species composition, physiognomic appearance, structure, vital state of plants and productivity of plant communities reflect all the features of living conditions (climate, soil, position in the relief), the history of development and connections between elements of the community, both in space and time [Egorova, 2000 ].

Phytocenotic signs of bioindication include features of the structure of the vegetation cover: abundance and dispersion of plant species, layering, mosaic, degree of closeness [Biological control..., 2007].

To study the anthropogenic impact on phytocenoses in the vicinity of the village of Takhtamukai, we established 3 test sites at different distances (5, 10 and 25 m) from 2 sources of anthropogenic impact: the LLC New Technologies enterprise and the highway.

As a result of the research, the main changes in associations in phytocenoses were identified. When moving away from the linear source of pollution (the highway), there was an increase in the height of the grass stand and the total projective cover from 60% at a distance of 5 m to 70% at a distance of 10 m. With further distance from the highway, these indicators fell, which is associated with the predominance of turf grasses. The most resistant to anthropogenic impact in this area is creeping wheatgrass, which forms a wheatgrass-forb association in the immediate vicinity of the highway. At a distance of 10 m, three tiers were observed in the structure of the reed-forb association. At a distance of 25 m from the highway, a brome-forb association was discovered, which included a fairly large number of assectators.

When moving away from another source of anthropogenic impact (enterprise), there was also an increase in the height of the tiers by an average of 10 cm and the total projective cover up to 70% at a distance of 10 m. The following sequence of association changes was discovered: forb-vetch - sorrel-forb - fescue-forb .

Thus, with distance from sources of anthropogenic impact, the following changes occurred: the abundance of species, their projective cover, in the structure of the association - dominants, codominants, assectators, as well as the layering and height of the grass stand.

Conclusion

Based on the results of the work, the following conclusions were made:

.The flora of vegetation in the vicinity of the village of Takhtamukai includes 61 plant species belonging to 57 genera and 25 families.

.Taxonomic analysis showed that monotypic families dominate (15): Aceraceae, Moraceae, Polygonaceae, Amaranthaceae, etc.; there are 7 oligotypic families: Brassicaceae, Ranunculaceae, Salicaceae, Apiaceae, Papaveraceae, Lamiaceae and Fabaceae; polytypic - 3: Rosaceae, Asteraceae and Poaceae.

.Analysis of life forms according to H. Raunkier made it possible to identify the predominant life form among the plants in the vicinity of the village of Takhtamukai - hemicryptophytes (34%). The second place is occupied by therophytes (26%), followed by phanerophytes - 20%. Cryptophytes make up 18%, the least number of chamephytes - 2%.

.Ecological analysis showed that mesophytes (39 species) predominate among hydromorphs, and heliophytes (40 species) predominate among heliomorphs.

.On the territory of the study area, 6 main associations were identified: wheatgrass-forbs, brome-forbs, reed-forbs, sorrel-forbs, fescue-forbs, forbs-forbs. Their structure, composition and abundance of species have been studied, and dominants, codominants and assectators have been identified.

.When conducting a chemical analysis of the soil, results were obtained indicating an increase in the content of heavy metals near the highway by 1.2 - 1.7 times and the content of phenols near the enterprise by 1.5 times. Soil analysis for acidity showed a shift in pH to the alkaline side both near the highway (from 6.88 to 7.21) and in the immediate vicinity of the New Technologies LLC enterprise (from 6.8 to 7.6).

.When moving away from sources of anthropogenic impact, an increase in the height of the grass stand by 10 cm and the total projective cover from 60% (at a distance of 5 m) to 70% (at a distance of 10 m) is observed.

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Phytocenosis(from the Greek φυτóν - “plant” and κοινός - “common”) - a plant community that exists within one biotope. It is characterized by relative homogeneity of species composition, a certain structure and system of relationships of plants with each other and with the external environment. According to N. Barkman, phytocenosis is the essence of a specific segment of vegetation in which internal floristic differences are less than differences with the surrounding vegetation. Phytocenoses are the object of study of the science of phytocenology (geobotany).

Phytocenosis is part of the biocenosis along with zoocenosis and microbiocenosis. The biocenosis, in turn, in combination with the conditions of the abiotic environment (ecotope) forms a biogeocenosis. Phytocenosis is the central, leading element of biogeocenosis, as it transforms the primary ecotope into a biotope, creating a habitat for other organisms, and is also the first link in the cycle of substances and energy. The properties of soils, microclimate, the composition of the animal world, such characteristics of biogeocenosis as biomass, bioproductivity, etc., depend on vegetation. In turn, the elements of phytocenosis are cenopopulations of plants - collections of individuals of the same species within the boundaries of phytocenoses.

Formation of phytocenosis

The formation of phytocenoses can be considered as dynamic aspect(change of communities), and in terms of their formation on free areas of the earth's surface.

There are primarily free areas that were not populated by plants in the past and do not contain their rudiments. Phytocenoses can form on them only when diaspores are introduced from the outside. Such areas include rocky outcrops, fresh river and sea sediments, the exposed bottom of reservoirs, areas freed from glaciers, lava fields, etc. In general, they occupy insignificant areas on Earth.

Secondary vacant areas are formed in places where vegetation previously existed, but was destroyed due to the influence of some unfavorable factor. Examples include burnt areas, scree, unseeded arable land, areas of phytocenoses eaten away by pests or livestock. In most cases, soil and diasporas are preserved on them, and the formation of phytocenoses occurs much faster than in initially free areas. The formation of a phytocenosis is a continuous process, but can be conditionally divided into stages:

• according to V.N. Sukachev:

1. Lack of phytocenosis- random composition of species; lack of interaction between plants; very weak impact on the environment; lack of expression of structure.
2. Open phytocenosis- unstable composition, mainly from annuals; structure with separate coenopopulations that do not interact with each other.
3. Closed undeveloped phytocenosis- loss of a significant part of the pioneer species; patchy structure with the penetration of individual plants into clusters of other species; tiering is planned.
4. Closed developed phytocenosis- relatively constant species composition; difficulty in introducing new species; interaction of all coenopopulations; pronounced tiering.

• according to A.P. Shennikov:

1. Pioneer group- coenopopulations are small in number, there are no relationships between them
2. Group-thicket community- coenopopulations are distributed in clumps in which interaction between plants occurs
3. Diffuse community- coenopopulations mix, a system of interspecific interactions is developed

• according to F. Clements:

1. Migration- introduction of diasporas
2. Ecesis- consolidation of the first settlers
3. Aggregation- formation of groups of offspring around mother plants
4. Invasion- mixing of coenopopulations
5. Competition- development of competitive relations due to a sharp increase in crowd density
6. Stabilization- formation of a sustainable closed community

E. P. Prokopyev, summing up the various division schemes of the process of formation of a phytocenosis, proposes to distinguish three stages in it:

1. Receipt of primordia into a free area. The species composition of the emerging phytocenosis will depend on the species composition of plants in the surrounding area and the nature of the distribution of their diaspores, and the main role will be played by the rudiments of allochoric species, mainly anemochores.
2. Ecotopic (abiotic) selection. Not all diasporas that land on a free plot will take root on it: some will not germinate, and some of those that have sprouted will die in their young state due to an unfavorable combination of abiotic factors. Established plants will be pioneers for this territory.
3. Phytocenotic selection. Due to the reproduction and settlement of pioneer species throughout the site, they will begin to influence each other and change the ecotope, forming a biotope (habitat). The primary abiotic environment of the ecotope turns into a secondary biotic - phytoenvironment. Under the influence of the phytoenvironment and the mutual influence of plants, some pioneer species that are not adapted to it fall out. This may occur, for example, due to shading or allelopathy. At the same time, new species, already adapted to the given phytoenvironment, are established on the site.

Factors of phytocenosis organization

Factors in the organization of a plant community can be divided into four groups: characteristics of the environment (ecotope), the relationship between plants, the influence of heterotrophic components (animals, fungi, bacteria) on vegetation and disturbances. These groups of factors determine the combination and characteristics of cenopopulations of species in a phytocenosis.

Ecotop is the main factor in the organization of phytocenosis, although it can be significantly transformed by the biotic influences of plants or disturbances. Abiotic factors influencing community organization include:

• climatic (light, heat, water regimes, etc.)
• edaphic (granulometric and chemical composition, humidity, porosity, water regime and other properties of soils and soils)
• topographic (relief characteristics)

Plant relationships are divided into contact And mediated : transabiotic- through abiotic environmental factors and transbiotic- through third organisms.

Influence on the organization of phytocenoses heterotrophic components biogeocenoses are extremely diverse. The influence of animals is manifested in pollination, eating, spreading seeds, changing the trunks and crowns of trees and associated characteristics, loosening the soil, trampling, etc. Mycorrhizal fungi improve the supply of plants with mineral nutrients and water, and increase resistance to pathogens. Nitrogen-fixing bacteria increase the supply of nitrogen to plants. Other fungi and bacteria, as well as viruses, can be pathogens.

Violations, both anthropogenic and natural origin can completely transform the phytocenosis. This occurs during fires, felling, livestock grazing, recreational load, etc. In these cases, derivative phytocenoses are formed, which gradually change towards the restoration of the original one if the impact of the disturbing agent has ceased. If the impact is long-term (for example, during recreation), communities are formed that are adapted to existence at a given level of stress. Human activity has led to the formation of phytocenoses that did not previously exist in nature (for example, communities on toxic industrial waste dumps).

Interactions of organisms in phytocenoses

The presence of a system of relationships between plants is one of the main signs of the existing phytocenosis. Studying them, due to the large overlap and strong influence of abiotic factors, is a difficult task and can be implemented either in the form of an experiment in which the relationships of two specific species are studied, or by isolating such relationships from a complex of others using methods of mathematical analysis.

Direct (contact) mutual influences

Symbiotic relationship manifest themselves in the coexistence of plants with fungi and bacteria (including cyanobacteria). Accordingly, they distinguish mycosymbiotrophy And bacteriosymbiotrophy.

Plants that form mycorrhiza can be divided into two groups according to their requirements for the presence of mycosymbiont:

• obligate mycosymbiotrophs - incapable of development without a mycosybiont (family Orchidaceae)
• facultative mycosymbiotrophs - capable of existing without a mycosymbiont, but developing better in its presence

Bacteriosymbiotrophy - symbiosis of plants with nodule bacteria ( Rhizobium sp.). It is not as widespread as mycosymbiotrophy - about 3% of the plants of the world flora enter into symbiosis with bacteria (mainly the legume family (about 86% of family species), as well as some species of the Poaceae, Birch, Sucker, and Buckthorn families). Nodule bacteria play the role of nitrogen fixers, converting atmospheric nitrogen into forms accessible to plants. There are root and leaf forms of interaction. In the root form, the bacteria infect the roots of the plant, causing intense local cell division and the formation of nodules. Leaf bacteriosymbiotrophy occurs in some tropical plants and is still poorly studied.

One of the methods of three-field culture is based on the ability of plants of the legume family to enter into symbiosis with nodule bacteria.

Epiphytes, settling on plants - phorophytes they use the latter only as a substrate, without entering into physiological interactions with them. Epiphytic forms are found in groups of angiosperms, ferns, mosses, algae and lichens. Epiphytes reach their greatest diversity in tropical rainforests.

In ecological terms, the relationship between epiphytes and phorophytes is usually represented by commensalism, but elements of competition may also appear:

• epiphytes partially intercept light and moisture from phorophytes
• by retaining moisture, they contribute to the decay of the phorophyte
• By shading the phorophyte, epiphytes reduce its effective photosynthetic surface
• growing profusely, can cause deformation or breakage of phorophytes

Lianas, bringing their leaves closer to the light during growth, receive benefits from cohabitation with the supporting plant, while the latter is mainly harmful, both direct - due to the mechanical impact of the liana and the breaking / death of the supporting plant, and indirect - due to the interception of light by the liana, moisture and nutrients.

Lianas also reach their greatest diversity in tropical rainforests.

Transabiotic interactions

The influence of plants on each other, mediated by abiotic environmental factors. They arise due to the overlap of phytogenic fields of neighboring plants. Divided into competition And allelopathy.

Competition develops either due to the initial limitation of habitat resources, or as a result of a decrease in their share per plant due to overpopulation. Competition leads to a decrease in resource consumption by the plant and, as a consequence, a decrease in the rate of growth and storage of substances, and this, in turn, leads to a decrease in the quantity and quality of diaspores. Distinguish inside- And interspecific competition.

Intraspecific competition affects the fertility and mortality rates in a coenopopulation, determining the tendency to maintain its numbers at a certain level, when both values ​​balance each other. This number is called maximum density and depends on the amount of habitat resources. Intraspecific competition is asymmetrical - it affects different individuals differently. The total phytomass of the cenopopulation remains constant in a fairly large range of density values, while the average mass of one plant begins to steadily decrease when thickened - law of constant harvest(C=dw, where C is the yield, d is the coenopopulation density and w is the average weight of one plant).

Interspecific competition is also widespread in nature, since the vast majority of phytocenoses (except for some agrocenoses) are multispecies. The multispecies composition is ensured by the fact that each species has an ecological niche characteristic only of it, which it occupies in the community. Moreover, the niche that a species could occupy in the absence of interspecific competition is fundamental, tapers to size implemented. In a phytocenosis, differentiation of ecological niches occurs due to:

• different plant heights
• different depths of penetration of the root system
• contagious distribution of individuals in the population (in separate groups/spots)
• different periods of growing season, flowering and fruiting
• unequal efficiency of plants' use of habitat resources

When the overlap of ecological niches is weak, coexistence of two cenopopulations can be observed; when there is a strong overlap, the more competitive species displaces the less competitive one from the habitat. The coexistence of two highly competitive species is also possible due to the dynamism of the environment, when one species or another gains a temporary advantage.

Allelopathy- the influence of plants on each other and on other organisms through the release of active metabolites into the environment both during the life of the plant and during the decomposition of its remains. Allelopathic activity of one type or another is determined by a certain set of chemical substances of different nature, qualitative and quantitative composition which significantly depends on external conditions. Allelopathically active substances are released both aboveground organs (mainly leaves) and underground, mainly in three ways:

• active secretion through glands or hydathodes
• washout by precipitation
• excretion through decomposition of litter by microorganisms

The sum of secretions of various plants in a phytocenosis is its biochemical environment. Since the composition of secretions is not constant, we can talk about the existence of an allelopathic regime of phytocenosis, along with water, air, etc.

Transbiotic interactions

Indirect influences of some plants on others through third organisms (other plants, animals or fungi). The impact can manifest itself both at the level of an individual organism and at the level of an entire coenopopulation. Transbiotic interactions can be:

When a phytocenosis is formed, the primary abiotic environment of the ecotope turns into a phytoenvironment, and the ecotope itself turns into a biotope. In this case, the phytocenosis influences almost all abiotic factors, changing them in one direction or another.

Light regime of phytocenosis

Inside any phytocenosis, the light regime will differ from the light regime of an open area not occupied by vegetation. Such differences arise due to the fact that light in the phytocenosis is redistributed in a certain way and the following processes occur:

• reflection of part of the world outside the phytocenosis
• absorption of part of the light by plants (including during photosynthesis)
• penetration of light into the phytocenosis

Due to the reflection and absorption of light by plants, only a small part of it reaches the soil level, which is especially clearly visible in multi-tiered forest phytocenoses: under the canopy of a pine forest, the illumination is, on average, 25-30%, of an oak forest - about 3%, and of a tropical rainforest. - about 0.2% of full illumination (on an open surface in the same geographical conditions).

Illumination in the phytocenosis is heterogeneous: it changes both in the vertical and horizontal directions. When moving from the upper boundary of the phytocenosis to the soil level, the illumination drops abruptly, primarily due to the characteristics of foliage (the density and arrangement of leaves in space) on each tier.

In herbaceous phytocenoses, two types of illumination are distinguished: cereal And dicotyledonous. The cereal type is typical for communities with a predominance of plants with vertically oriented leaves (cereals, sedges) and is characterized by a gradual decrease in illumination from top to bottom. Dicotyledonous type - for communities with horizontally oriented leaves; characterized sharp jumps illumination and is similar in this regard to changes in illumination in forest communities.

In aquatic ecosystems, in addition to plants, water and particles suspended in it also participate in the absorption and reflection of light, as a result of which the existence of plants at great depths becomes impossible. In transparent fresh water bodies, illumination becomes less than 1% at depths of more than 5-10 meters, as a result of which higher plants in such conditions are found at depths of no more than 5, and algae - no more than 20 meters, but in clear waters seas and oceans individual species red algae penetrate to a depth of several hundred meters.

Plants in phytocenoses also change the qualitative composition of the spectrum, selectively absorbing and reflecting light with a certain wavelength. Hard UV radiation (λ< 280 нм), вредное для живых структур plant cell, almost completely (up to 95-98%) is absorbed by the epidermis of leaves and other integumentary tissues. The visible part of the solar spectrum (physiologically active radiation) is absorbed up to 70% by photosynthetic pigments, while the blue-violet and red parts of the spectrum are more intensely absorbed, and the green part is much weaker. IR radiation with λ > 7000 nm is absorbed up to 97%, and with λ< 2000 нм - очень слабо.

The permeability of leaves to light also varies and depends, first of all, on the thickness and structure of the leaf, as well as the light wavelength. Thus, leaves of medium thickness transmit up to 10-20% of light, very thin leaves - up to 40%, and thick, hard leaves covered with a waxy coating or pubescence may not transmit light at all. IR and green light have the greatest penetrating ability; other parts of the spectrum penetrate the leaves much less.

The light regime also changes during the day, throughout the year and depending on the age composition of plants in the phytocenosis.

Thus, phytocenoses change the lighting conditions of the ecotope, forming a special, spatially heterogeneous light regime. The specificity of this regime in each specific phytocenosis determines the set of species, their distribution and the structure of the phytocenosis as a whole.

Thermal regime of phytocenosis

An area of ​​the Earth's surface devoid of vegetation receives heat both directly from the Sun and indirectly through scattered light from the sky and back radiation from the heated atmosphere. The incoming heat is partially reflected back into the atmosphere, partially absorbed and removed into the deeper layers of the Earth, and partially radiated back into the atmosphere by the heated soil. All processes of heat intake and removal form a heat balance.

The heat balance changes throughout the day: during the day, during the insolation phase, it turns out to be positive, at night - negative. The heat balance is also affected by weather conditions, terrain, time of year and geographical position ecotope.

Phytocenoses significantly change the thermal regime of the ecotope, since plants:

• reflect part of the sunlight back into the atmosphere, reducing the flow of heat into the phytocenosis
• absorb sunlight and spend it later on physiological processes
• release some heat during breathing
• carry out transpiration and guttation
• absorb part of the heat emitted by the soil
• reduce evaporation from the soil surface
• slow down the movement of air masses

Also change thermal regime ecotope occurs due to condensation and physical evaporation of moisture from the surface of plants.

The main energy exchange in a phytocenosis occurs not at the soil surface, as in an area devoid of vegetation, but in the upper closed phytocenosehorizon, which heats up the most during the day and cools the most at night.

In general, the thermal regime of the phytocenosis has the following features compared to that of an area devoid of vegetation:

• maximum temperatures decrease and minimum temperatures increase
• daily and seasonal temperature amplitudes are smoother
• average annual temperature is lower

Air regime of phytocenosis

The influence of phytocenosis on the air regime is manifested in changes in the speed of movement and air composition. Wind speed in phytocenoses decreases from top to bottom and from a more open area to a less open one. The dynamics of air composition are determined mainly by changes in the concentrations of oxygen and carbon dioxide during photosynthesis and respiration. The CO 2 content is subject to more significant fluctuations: in the first half of the day it decreases, which is associated with the intensification of photosynthesis, in the second half of the day it increases and reaches a maximum at night. The change in oxygen content in the air occurs synchronously, but in the opposite direction. There is a certain variability in the content of CO 2 and O 2 by season: for example, in temperate forests, the lowest concentration of CO 2 is observed in the spring, when the leaves bloom and the vital processes of plants intensify.

Humidity regime of phytocenosis

Structure of phytocenosis

Depending on the specifics of the research in the concept of “biocenosis structure”, V.V. Masing identifies three directions that he developed for phytocenoses.

1. Structure, as a synonym for composition (specific, constitutional). In this sense, they talk about species, population, biomorphological (composition of life forms) and other structures of the cenosis, meaning only one side of the cenosis - the composition in in a broad sense. In each case, a qualitative and quantitative analysis of the composition is carried out.

2. Structure, as a synonym for structure (spatial, or morphostructure). In any phytocenosis, plants are characterized by a certain affinity to ecological niches and occupy a certain space. This also applies to other components of the biogeocenosis. Between the parts of the spatial division (tiers, sinusia, microgroups, etc.) you can quite easily and accurately draw boundaries; you can plot them on a plan, calculate the area, and then, for example, calculate the resources of useful plants or food resources of animals. Only on the basis of data on the morphostructure can one objectively determine the points at which certain experiments were performed. When describing and diagnosing communities, the spatial heterogeneity of cenoses is always studied.

3. Structure, as a synonym for sets of connections between elements (functional). The basis for understanding structure in this sense is the study of relationships between species, primarily the study of direct connections - the biotic connex. This is the study of chains and nutrition cycles that ensure the circulation of substances and reveal the mechanism of trophic (between animals and plants) or topical (between plants - competition for nutrients in the soil, for light in the above-ground sphere, mutual assistance).

All three aspects of the structure of biological systems are closely interrelated at the cenotic level: the species composition, configuration and placement of structural elements in space are a condition for their functioning, that is, life activity and production of plant mass, and the latter, in turn, largely determines the morphology of cenoses. And all of these aspects reflect the environmental conditions in which the biogeocenosis is formed.

The phytocenosis consists of a number of structural elements. There are horizontal and vertical structure of phytocenosis. The vertical structure is represented by tiers, distinguished by visually determined horizons of phytomass concentration. The tiers consist of plants of “different heights”. Examples of layers are 1st tree layer, 2nd tree layer, ground cover, moss-lichen layer, understory layer, etc. The number of layers may vary. The evolution of phytocenoses is moving in the direction of increasing the number of tiers, as this leads to a weakening of competition between species. Therefore, in older temperate forests North America the number of layers (8-12) is greater than in similar younger forests of Eurasia (4-8).

The horizontal structure of the phytocenosis is formed due to the presence of tree canopies (under which an environment is formed, somewhat different from the environment in the inter-canopy space), terrain heterogeneities (which cause changes in groundwater levels, different exposures), and the species characteristics of some plants (reproducing vegetatively and forming monospecies “spots” , changes in the environment of one species and the response of other species to this, allelopathic effects on surrounding plants), animal activities (for example, the formation of patches of ruderal vegetation on rodents).

Naturally repeating spots (mosaics) in a phytocenosis, differing in the composition of species or their quantitative ratio, are called microgroups, and such a phytocenosis is mosaic.

Heterogeneity may also be random. In this case it is called variegation.

Dynamics of phytocenoses

Phytocenoses are characterized by a constant species composition and living conditions, but continuous changes still occur there. The property will change is called dynamism.

Dynamic processes can be reversible and irreversible.

Reversible

1. Daily allowances – are associated with the daily rhythm of life of the plants forming the phytocenosis; are expressed in changes in the activity of transpiration, respiration, photosynthesis, in the daily movements of flowers and leaves, in the rhythm of opening and closing flowers. They are determined by the characteristics of the phytoclimate created by the plant community.

2. Seasonal - determined by the peculiarities of the rhythm of development of the species forming the phytocenosis. These changes allow more plant species to exist together than if they had evolved simultaneously. For example, in spring - early ephemeroids, in summer - late summer grasses, shrubs, trees.

3. Fluctuations are year-to-year changes associated with unequal conditions for the existence of plants in different years. The composition does not change; the size and age composition of the population may change.

Irreversible

(succession, evolution of communities, disturbances of communities).

Succession is a gradual change in phytocenoses, irreversible and directional, caused by internal or external reasons in relation to phytocenoses. Primary and secondary successions are distinguished. Primary successions begin on lifeless substrates (rocks, cliffs, river sediments, shifting sands), while secondary successions begin on substrates on which vegetation was present but disturbed (recovery after a forest fire).

Classification of phytocenoses

When classifying phytocenoses, similar communities are combined into groups - classification units.

The lowest classification unit is association(a set of homogeneous phytocenoses that have more or less the same appearance, similar floristic composition and the same dominant species in the tiers). The names of the associations are given by listing the Russian names of the dominant plants of each tier of the phytocenosis, starting from the uppermost tier (Scots pine + Norway spruce - lingonberry + blueberry - moss pleurocium) or the Latin generic and species names of the dominants (Pinus sylvestris + Picea abies - Vaccinium vitis-idaea + Vaccinium myrtillus - Pleurozium schreberi) with the addition of lat suffixes to the base. -etum, -osum, -estosum: Piceetum oxalidosum (from Picea and Oxalis) - oxalis spruce forest.

A formation is a set of associations in which the same plant species dominates in the upper tier (for example, pine forests, oak forests, etc.)

Ordination is the construction of a series of phytocenoses based on a gradual change in any environmental factor in a certain direction. Thus, it is possible to carry out ordination based on the soil moisture factor. In this case, a number of communities will result, where each will take its appropriate place depending on the moisture conditions in which it develops, and the outermost of them will correspond to the most humid soils, and the opposite - to the driest.

ARID ECOSYSTEMS, 2015, volume 21, no. 1 (62), p. 53-59 =--- INDUSTRY PROBLEMS OF ARYLAND DEVELOPMENT

UDC 6332.03:581524(47067)

ON THE TRANSFORMATION OF MEADOW PHYTOCOENOSES UNDER THE INFLUENCE OF ANTHROPOGENIC AND NATURAL FACTORS

© 2015 P.M-S. Muratchaeva, R.M. Zagidova, P.A. Batyrmurzaeva

Caspian Institute of Biological Resources of the Dagestan Scientific Center of the Russian Academy of Sciences Russia, 367000 Makhachkala, Gadzhieva St., 45 Email: [email protected]

Received 05/16/2014.

Based on the analysis of phytocenotic indicators, the results of studying the state of meadow communities in the Prisulak Lowland are presented.

Key words: structure of phytocenosis, floristic composition, species diversity, abundance of species, above-ground phytomass.

The general trend in the dynamics of meadow vegetation in lowland Dagestan has been associated in recent years with the processes of steppification, and in many cases, salinization and desertification. Coastal and deltaic phytocenoses of the young plain are formed under the influence of zonal and local conditions

The changing level regime of the Caspian Sea, groundwater, high summer temperatures and strong anthropogenic pressure (unregulated grazing, wind erosion, secondary salinization). A variety of factors determines the diversity of lithological, soil and plant cover. Changes of different levels from meadow and meadow-swamp to steppe and semi-desert vegetation were first noted by E.V. Schiffers (1953).

The purpose of the study is to study the state of meadow communities by assessing phytocenotic indicators: the structure of vegetation cover, projective cover, species diversity, abundance of species and the amount of above-ground production, identifying patterns emerging in species and floristic composition.

Material and methods

The research was carried out at two key sites located in the Prisulak lowland in the Babayurt administrative region. Botanical descriptions were accompanied by descriptions of soil sections and soil formation conditions.

Key area No. 1. Geographic coordinates of the site: 43022"77.4"N, 47010"14.4"E. Meadow solonchak, medium loamy soil on ancient alluvial loamy deposits. The land is a pasture. Groundwater with mineralization 15.9 g/l. opened in spring at a depth of 126 cm, in autumn at a depth of 175 cm. The humidity of genetic horizons is relatively high - in spring 16.4 -20.4%, indicators that are subject to radical changes in individual seasons.

Key site No. 2 is located 10 km south of the first site. Meadow solonchak, medium loamy soil on alluvial loamy deposits. The relief is a plain with microdepressions. The land is a fallow land, an old arable grassed meadow, an abandoned area. Groundwater has not been tapped. The humidity of genetic horizons in the spring is 10.6-16.6%.

In spring and autumn, with the laying of geobotanical plots of 10x10 m and taking mowed samples (0.25 m2) in eight repetitions. At each site, the total projective cover of the soil with vegetation was taken into account, the growing season phases, the height of plants and their abundance on the Drude scale, the vital state of species and species diversity were determined. The cut phytomass was sorted into agrobotanical groups: cereals, legumes, forbs, dried to an air-dry state, and the structure and size of the above-ground phytomass was determined.

Results and discussion

The studies were carried out during the growing season in the central part of the Prisulak lowland. The territory is represented by a slightly undulating microrelief with tubercular-recessed microrelief. Association of cereals, solyanka, and wormwood. The hillocks are occupied by bushes of salt marsh wormwood (Artemisia monogyna), and the depressions are occupied by petrosimonia oppositifolia. Wormwood and petrosimonia are the main habitat-forming species. Grasses and ephemerals are interspersed in the herbage of wormwood and petrosimonia, ephemerals and ephemeroids are characterized by good condition, their root system is located in the slightly saline upper soil horizons. The root system of cereals (Puccinellia gigantea, Elytrigia repens) penetrates deeper into the soil.

The floristic composition in the spring is represented by 15 plant species belonging to 9 families, which indicates poor species richness (Table 1).

The largest number is found in Roaceae - 6 species, followed by Limoniaceae in second place - 2 species. Seven families have one representative each: Asteraceae, Chenopodiaceae, Brassicaceae, Caryophyllaceae, Scrophylariaceae, Elaeagnaceae, Tamaricaceae. The representation of life forms is approximately the same: annuals - 7 species, perennials - 8 species, of which perennial herbaceous - 5, tree - 1, shrub - 1, subshrub - 1 (Table 1).

The projective cover varied over a wide range and amounted to 40-80% in the spring. The dominant grass stands, wormwood and petrosimonia, were in the growing season. The average height of wormwood in the spring was 10.6 cm, petrosimonia - 4.7 cm, cereals and ephemerals were in the early heading, heading and fruiting phase and had an average height, depending on the species, from 9 to 23 cm.

According to the degree of abundance, the plant species of spring synusia can be arranged in a row: saline wormwood > Petrosimonia antifolia > gigantic anemone > Meyer's grasshopper > creeping wheatgrass > Japanese brome > bulbous bluegrass > wheatgrass > other species (Table 1).

In the hot summer months, ephemerals and ephemeroids burn out, along with this, the growth of wormwood and other plants that are in a state of summer dormancy at this time also stops.

Change spring period autumn was accompanied by changes in the structure and species composition of plants. The autumn migration of salts leads to a quantitative decrease in the species composition.

The floristic composition in the autumn period is represented by only seven plant species, which is 46.7% in relation to the spring synusia (Table 1). Solonchak wormwood and petrosimonia contrafolia, as in spring, are the dominant herbaceous plants.

The projective cover of soil with vegetation in autumn was 70-90%, its increase was due to the strong growth of wormwood and petrosimonia in the autumn after rains. The average height of wormwood plants was 32.6 cm, petrosimonia and kermek Meyer were 11.3 and 10.3 cm, respectively.

According to the degree of abundance, the species of autumnal synusia can be arranged in a row: saline wormwood > Petrosimonia antifolia > Meyer's kermek > other species.

Table 1. The species composition of plant Poaceae-salsola-aster aceaeassociations.

form* of vegetation** vegetation* *

Elf Caspian Sucker

Shrubs:

Subshrubs:

ON THE TRANSFORMATION OF MEADOW PHYTOCOENOSES UNDER THE INFLUENCE OF ANTHROPOGENIC AND 55

NATURAL FACTORS

Artemisia monogyna Asteraceae pl. soc. veg. soc. dry, veg.,

Solonchak wormwood Compositae sor.3, sor.2 bottles, col.

beginning pl. pl.

Limonium Meyeri Limoniaceae pl. sor.1, rose sor.1, sp.3 color, beginning

Kermek Meyer Kermek sp3. pl., pl.

Puccinellia gigantea Poaceae pl. sor.1 beginning count, - -

Beskilnitsa gigantica Cereal stakes.

Elytrigia repens Wheatgrass Poaceae Cereals pl. sor.1 sp.2 beginning count, count - -

Phleum phleoides Timothy grass Roaceae Cereals many. sp.1 count sol. count

Forbs:

Petrosimonia oppositifolia Petrosimonia Chenopodiaceae Chenopodiaceae. sor.2 veg. cop.3 pl.

antifolia

Psylliostachys spicata Psylliostachys spicata Limoniaceae Kermekovye islands. sp.1 color sol. pl.

Ephemera, ephemeroids:

Bromus japonicus Poaceae o. sp.3 count - -

Japanese brome Cereals

Eremopyrum triticeum Poaceae o. sp.2 count - -

Wheat mortuk Cereal sp.1

Poa bulbosa Poaceae pl. sp.2 count - -

Bluegrass bulbous Cereals

Veronica polita Scrophylariaceae o. sol. pl. - -

Veronica dvoyachata

Erophila verna Brassicaceae o. sol. pl. - -

Spring stonefly Cruciferous

Cerastium glutinosum Caryophyllaceae o. sol. pl. - -

Carnation sticky

Note: In tables 1 and 3. *Life form: plural. - perennials; O. - annuals. **Plant phenophases: beginning. veg. - beginning of the growing season; veg. - vegetation; bottle - budding; color - flowering; count - heading; pl. - fruiting; roses - sockets; milestone - shoots. Note: in tables 1 and 3 life form: mn.-perennial plant; o.- annuals. phenophaseplants: nach.veg.-the beginning of the growing season; eg.-vegetation; but.- budding; col.-flowering; nr.-earing; pl.-fruiting; roses.-outlet; all.-the shoots.

The total above-ground phytomass in the spring was 16.85 c/ha. In the autumn season, a significant increase (1.4 times) was noted in the total above-ground phytomass, consisting of representatives of the solyanka-wormwood synusia (Table 2). In the total above-ground phytomass of the spring period, the share of forbs is almost 2 times higher than the share of grasses; in the autumn, the above-ground phytomass is represented almost entirely by forbs, the presence of grasses is insignificant - this is autumn undergrowth in the form of seedlings or in the regrowth phase (the beginning of the secondary vegetation of ephemerals and ephemeroids).

According to the scale of pasture digression (Tsatsenkin et al., 1978), as well as based on the analysis of the obtained phytocenotic indicators - structure, species diversity, projective cover, height, vital state of species, as well as the amount of above-ground phytomass, it can be noted that the studied cereal-salt grass -the wormwood community of the Prisulak lowland is at the stage of moderate degradation, as evidenced by a decrease in participation in the herbage

cereals, an increase in the number of forbs (wormwood and solyanka).

Table 2. Aboveground phytomass reserves (air-dry weight) on meadow saline soil (2013). Table 2. Stocks of above-ground phytomass (air-dry weight) in saline meadow soil (2013).

Season of Sinusia Aboveground phytomass, c/ha

grasses forbs common

Spring Grass-solyanka-wormwood 5.92 10.93 16.85

Autumn Solyankovo-wormwood 0.10 23.70 23.80

The plant community of site No. 2 is forb-grass, where the dominant grass stand is the perennial rhizome grass Cynodon dactylon with long creeping, easily rooted shoots, a good turf-former, a pasture forage plant, readily eaten by all types of animals.

The site is subject to strong anthropogenic influence (grazing). The grass stand was grazed to such an extent that it was not possible to take cuttings, but despite this, the projective cover of the soil with vegetation in both seasons is very high - 90-100%, due to the fact that the pigweed covers the soil with a thick carpet (shoot height 2-4 cm).

The floristic composition in spring is represented by 29 plant species belonging to 15 families, which indicates poor species richness (Table 3). The largest number is in Poaceae - 9 species, Asteraceae is in second place - 4 species, Fabaceae is in third - 3 species, in the families Apiaceae and Brassicaceae there are 2 species each. 10 families each have one representative: Plantaginaceae, Scrophulariaceae, Rubiaceae, Liliaceae, Rosaceae, Caryophyllaceae, Geraniaceae, Elaeagnaceae, Tamaricaceae, Amaranthaceae. In terms of life forms, perennials prevail - 17 species, of which perennial herbaceous - 14, trees, shrubs and subshrubs, one species each, annuals account for 12 species. In the autumn, the floristic composition decreased by more than 2 times (13 species in total). Ephemerals, ephemeroids and some cereals fell out of the grass stand (Table 3).

Table 3. Species composition of plants of the forb-grass association (2013). Table 3. The species composition of plants forb-grass association.

Group of species, species Family Life - Spring Autumn

nenny abundance phase abundance phase ve

form* of vegetation** vegetation**

Elaeagnus caspica Elaeacnaceae pl. sol. color sol. color, square

Elf Caspian Sucker

Shrubs:

Tamarix ramosissima Tamaricaceae pl. sol. color sol. color, square

Tamariskaceae

Subshrubs:

Artemisia taurica Asteraceae pl. sol. veg. sol. veg.

Artemisia tauride Asteraceae

Cynodon dactylon Poaceae pl. soc. veg. soc. veg., count.

Pork palmate Cereals

Puccinellia gigantea Poaceae pl. sol. count - -

Bestilnitsa giant Cereals

Elytrigia repens Poaceae pl. sol. count - -

Wheatgrass Cereals

G TRANSFORMATION OF THE BEST PHYTOCEIOUS UNDER THE INFLUENCE OF LHTROPOGEYS AND 57

OTOTO,^« FACTOROB

Lolium rigidum Rigid chaff Roaceae Cereals o. sol. count - -

Hordeum leporinum Rabbit barley Roaceae Cereals o. sol. count - -

Trifolium repens Creeping clover Fabaceae Legumes pl. cop.3 veg., color. cop.3 cop.2 veg.

Trifolium campestre Field clover Fabaceae Legumes o. sol. veg., color - -

Lotus corniculatus Fabaceae Legumes pl. sp.1 veg., fl. sp.1 veg.

Forbs:

Plantago lanceolata Plantaginaceae Plantain pl. cop.2 roses cop.2 roses

Taraxacum officinale Dandelion Asteraceae Compositae pl. cop.1 rose cop.1 rose

Sonchus arvensis Field sow thistle Asteraceae Compositae pl. sol. roses sol. pink, color

Sonchus palustris Sow thistle Asteraceae Compositae pl. sp.2 rose sp.3 pink, color

Potentilla reptans Cinquefoil Rosaceae Rosaceae pl. sp.1 veg. sp.2 veg.

Galium verum Spring bedstraw Rubiaceae Rubiaceae pl. sol. veg. sol. veg.

Ornithogalum arcuatum Ornithogalum arcuatum Liliaceae Liliaceae pl. sol. veg. - -

Daucus carota Wild carrot Apiaceae Umbrella o.d. sol. veg. sol. veg., color, pl.

Caucalis lappula Velcro trailer Apiaceae Umbrella o. sol. color, square - -

Amaranthus retroflexus Amaranthaceae Amaranthaceae. sol. veg., bottle. - -

Rapistrum rugosum Wrinkled turnip Brassicaceae Cruciferous o. sol. fetus. - -

Ephemera, ephemeroids:

Roa bulbosa Poa bulbosa Roaceae Cereals pl. sol. count - -

Eragrostis collina Hill bent Roaseae Cereals pl. sol. count - -

Bromus japonicus Japanese brome Roaseae Cereals o. sol. count - -

Veronica polita Veronica double Scrophulariaceae sol. color, square - -

Erodium ciconium Stork cranebird Geraniaceae Geraniaceae o. sol. pl. - -

Cerastium glutinosum Caryophyllaceae Caryophyllaceae sol. pl. - -

Thlaspi arvense Brassicaceae Brassicaceae sol. pl. - -

The dominant species of the grass stand, as well as other species, were mainly in the growing season in both seasons; in the autumn, a small number of Cynodon dactylon individuals were in

In the heading phase, legumes (Trifolium repens) grew in groups in the depressions, small forbs (Taraxacum, Plantago, Sornhus) in the form of rosettes were diffusely interspersed in the grass stand. Individual plants in places inaccessible to animals (among the bushes of tamarisk and oleaster were in the heading, flowering and fruiting phase). In general, the grass stand was low-growing; young and juvenile plants predominated. The ecological spectrum of species is represented by mesophytes, xeromesaphytes, and mesoxerophytes.

According to the abundance, the species of spring synusia can be arranged in a row: pigweed palmate > creeping clover > lanceolate plantain > dandelion officinalis > swamp sow thistle > horned sweet potato = creeping cinquefoil > other species. The abundance of species in autumn synusia differs little from that in spring (Table 3).

Meadow vegetation is subject to intensive grazing, which is illustrated by the dominance of grass grass (Cynodon dactylon), the presence of low-growing legumes (Trifolium repens), and low-growing perennial forbs (Potentilla reptans). Perennial forbs are mainly represented by rosette species (Plantago lanceolata, Taraxacum officinale). The dominant position is occupied by species with creeping, rooting above-ground shoots (Cynodon dactylon, Trifolium repens, Potentilla reptans). The herbage is dominated by species in which most of the phytomass is located in the surface horizon, which is an adaptive ecological trait that helps to better tolerate trampling by livestock and persist with low and frequent grazing. All these species quickly grow back after being grazed, and some of them are vegetatively mobile (Trifolium repens), represented by ecotypes that reproduce both by seeds and vegetatively (Andreev, 1981). Adaptive traits should also include the high seed productivity of plants that are resistant to grazing, which determines their ability to quickly colonize cleared-out areas in pastures and maintain their position there. The seed productivity of dandelion is 12.2 thousand seeds per plant (Fisyunov, 1984). The seeds do not have a dormant period and can germinate immediately after falling, providing the possibility of repopulating knocked out places throughout the entire growing season. Seed germination in the soil lasts 2-3 years or more (Larin, 1956). Many species resistant to grazing (Poa bulbosa, Trifolium repens) are very flexible and have a wide ecological amplitude. Poa bulbosa has 2 ecotypes: mesophytic and xerophytic. With abundant moisture in fertile clay soil, viviparous forms of Poa bulbosa are formed. The bulbs remain viable for 8-12 years; when there is a lack of moisture and on sandy poor soils, seed-producing plants develop (Andreev, 1981).

Conclusion

The dynamics of long-term impact on pasture ecosystems of natural and anthropogenic factors (frequently recurring droughts, wind erosion, overgrazing, plowing, irrigation, tillage) caused significant changes in indigenous meadow and meadow-steppe communities, which affected the structure of the vegetation cover: turf grass fell out of the grass stand grasses (feather grass), furrowed fescue (fescue) and steppe species of forbs, which were replaced by dry-steppe and semi-desert haloxerophytic species that tolerate grazing well (species of Artemisia, Poa bulbosa, Bromus japonicus and others). For this reason, meadow and meadow-steppe communities over time transformed into cereal-saltwort-wormwood, ephemeral-wormwood and wormwood communities (Yarullina, 1983; Muratchaeva, Khabibov, 2004).

Based on the analysis of phytocenotic indicators: structure, species diversity, projective cover, height, vital state of species, as well as the amount of above-ground production, it can be concluded that the studied cereal-saltwort-wormwood community of the Prisulak lowland is at the stage of moderate degradation, as evidenced by a decrease in the share of in the structure of the cenosis of cereals (Poaceae) and an increase in the number of forbs: wormwood (Artemisia monogyna) and saltwort (Petrosimonia oppositifolia).

The forb-grass community on the meadow saline medium-loamy soil is under the influence of high pasture load, which caused a transformation of the cenosis: grasslands (Cynodon dactylon) dominate on the site, and low-growing legumes (Trifolium repens, Lotus corniculatus) with creeping, rooting above-ground shoots are present. Perennial forbs are also low-growing and are represented mainly by rosette ruderal

ON THE TRANSFORMATION OF MEADOW PHYTOCOENOSES UNDER THE INFLUENCE OF ANTHROPOGENIC AND 59

NATURAL FACTORS

species (Plantago lanceolata, Tasaxacum officinade, Sonchus palutris), i.e. dominated by species in which most of the phytomass is located in the surface horizon, which is an adaptive property of meadow plants that ensures their pasture tolerance. In the herbage of the forb-grass community there are a lot of weed species that have no nutritional value, with the inclusion in some cases of harmful ones (Rapistrum rugosum, Caucalis lappula, Thlaspi arvense, etc.) (Ibragimov, 1965; 1990).

The patterns of degradation of meadow phytocenoses, as well as other plant communities under the influence of anthropogenic and natural factors, are (Vinogradov, 1996; Murachaeva et al., 2013) depletion of floristic composition, simplification of structure, decrease in species diversity, disappearance and replacement of valuable species with high nutritional value by poorly eaten ruderal and weed species. The negative consequences of anthropogenic impacts lead to a decrease in productivity, sustainability, and loss of genetic resources of meadow flora.

REFERENCES Andreev N.G. 1981. Grassland farming. M.: Kolos. 383s.

Vinogradov B.V. 1996. Study of indicators when monitoring desertification in the south of Russia //

Arid ecosystems. T.2. No. 4. P.38-54. Ibragimov K.G. 1965. Weeds and field plants of the Terek-Sulak interfluve of the DASSR // Botany, plant physiology and plant growing. Makhachkala. Dagestan book publishing house. P.3-14.

Ibragimov K.G. 1990. Weeds of the Dagestan Autonomous Soviet Socialist Republic // Productivity and flora of legumes and

cereal plants in Dagestan. Makhachkala. Publishing house Dagestan branch of the ANSSSR. P.12-21. Larin I.V. 1956. Forage plants of hayfields and pastures of the USSR. M.: Selkhozizdat. T.3. 859s. Muratchaeva P.M-S., Khabibov A.D. 2004. Forage resources of winter pastures in Dagestan and trends in their development in modern conditions // Soil and biological resources of the southern regions of Russia. Makhachkala. Publishing house DnC RAS. P.26-30. Muratchaeva P.M.S., Khabibov A.D., Shakhnazarova A.B., Suleymanova R.M. 2013. On the patterns of stages of manifestation of digressions in ephemeral-wormwood communities of the Terek-Kuma Lowland // Arid ecosystems. T.19. No. 1 (54). P.67-77. Ramensky L.G. 1971. Selected works. Problems and methods of studying vegetation cover. L.: Science. 336s.

Rodin L.E., Remezov N.P., Bazilevich N.I. 1968. Guidelines for the study of dynamics

biological circulation in phytocenoses. L.: Science. 143p. Fisyunov A.V. 1984. Weeds. M.: Kolos. 32s.

Tsatsenkin I.A., Savchenko I.V., Dmitrieva S.I. 1978. Guidelines for the ecological assessment of forage lands in the tundra and forest zones of Siberia and the Far East by vegetation cover. M.: Publishing house. All-Russian Research Institute of Feeds. 301s. Shiffers E.V. 1953. Vegetation of the North Caucasus and its natural feeding grounds. M.L.: BIN ANSSSR.

Yarullina N.A. 1983. Primary biological productivity of soils in the Terek delta. M.: Science. 88s.

THE TRANSFORMATION OF THE MEADOW PHYTOCOENOSES UNDER THE INFLUENCE OF ANTHROPOGENIC AND NATURAL FACTORS

© 2015. P.M.S. Muratchaeva, R.M. Zagidova, P.A. Batyrmurzaeva

Precaspian Institute of Biological Resources of Dagestan scientific center of RAS Russia, 367000, Makhachkala, Gadjieva str., 45, E-mail: pibrdncran@mail

Based on the analysis of phytocoenotic indicators presented the results of the study of grassland communities Prisulakskoy lowlands.

Keywords: structure phytocenosis, floristic composition, species diversity, species abundance, above-ground phytomass.

On modern stage anthropogenic impact on the Earth's vegetation can be reduced to three main forms:

1. complete destruction of vegetation cover;

2. creation of cultural phytocenoses in place of natural vegetation;

3. synanthropization of vegetation cover.

Around the globe, 20 hectares of forests are cut down in one minute. The creation of cultural phytocenoses in place of natural vegetation is the creation of crops, gardens, soil and protective plantings. Synanthropization of vegetation cover is a gradual change in the composition and structure of vegetation cover under the influence of anthropogenic factors. Synanthropization is manifested in the following: the replacement of indigenous phytocenoses with derivatives, the replacement of endemic plants by cosmopolitans. All this leads to impoverishment and monotony flora. The depletion of flora has two aspects: a decrease in species diversity; reduction in genetic diversity. The first is caused by the extinction of species. In this case, endemic species usually disappear faster. The second is due to the disappearance of the species' location. The more diverse the habitat conditions of a species, the richer the gene pool. Now there is a significant decrease in the species richness of various phytocenoses. For example, in the Netherlands, on an area of ​​20 km2, on average, the number of species decreased from 250 to 180; hayfields, pastures, etc. were especially affected (losing up to 60-70% of species richness).

If before the appearance of humans it is believed that one species disappeared on average every thousand years, then from 1850 to 1950. this interval was 10 years, after 1950 - one year. It is now believed that one species disappears in one day. The flora of the islands, often represented by endemic species, is rapidly disappearing. For example, of the 1,500 endemic species of the Hawaiian Islands, 500 species are considered rare and endangered. Small populations of species located outside the main range or on its border are quickly dying out. In densely populated, industrialized areas (especially near large cities), the disappearance of plant species occurs more intensely than in agricultural areas.

Anthropogenic impact on the evolutionary process is manifested in at least four directions:

1. reduction of genetic heterogeneity of species;

2. fragmentation of plant populations and their increasing isolation;

3. hybridization between previously separated taxa;

4. the appearance of endemics of technogenic substrates and contaminated places.

Reducing genetic heterogeneity of individual species. Humans are reducing the number and size of populations, which leads to a decrease in the genetic diversity of species. The replacement of natural forest ecosystems with forest crops has led in some areas to a reduction in the genetic diversity of woody plants by more than a hundred times.

Fragmentation of plant populations and their increasing isolation. Previously widespread plant communities are reduced in size and dismembered into a number of isolated fragments. In accordance with this, plant populations are reduced and dismembered. Geographical or environmental barriers that arise between them create an environment for small populations that is close to that of island populations. The existence of plant species in the form of small populations creates the preconditions for the emergence of a series of taxa of intraspecific and even species rank.

Hybridization between previously separated taxa. Under the influence of anthropogenic factors, geographical and environmental barriers between related but previously isolated groups are often eliminated. This occurs as a result of habitat transformation, disruption of the structure of plant communities, mass introduction of introduced species, etc. For example, in England, two species of hawthorn - smooth and single-pistillate - were initially ecologically separated. Smooth hawthorn grew in forests, single-pistillate hawthorn grew in open areas. Logging led to thinning of forests, as a result, two species of hawthorn appeared in one area, and hybrids between species appeared. Hybrids between Polish and European larch appeared in Poland.

The appearance of endemics of technogenic substrates and contaminated places. In the process of activity, man creates new substrates that are populated by plants. In the vicinity of Lake Medvezhye in Canada, with close occurrence of uranium ores, a large number of mutants of fireweed and blueberry were noted.

Currently, Europe's forests are dying rapidly. One of the reasons for the death is air pollution. The impact of air pollution is to weaken the vital activity of foliage and needles, tree trunks and roots.

Studies conducted in Germany have identified four main types of pollution impacts: 1 the direct effect of gases on vegetation; 2 precipitation of heavy metals and their accumulation in soil; 3 acidic effect on plants and soil; 4 effect of nitrogen saturation.

Three classes of interactions between atmospheric pollutants and forest ecosystems have been identified. When the content of pollutants is low (first-class interaction), the vegetation and soils of forest ecosystems function as their absorbers. Depending on the nature of the pollutants, their effect can be unnoticeable or stimulating (like fertilizers).

At average pollutant levels (second class interactions), some tree species are negatively affected. This influence is expressed in an imbalance and metabolism of nutrients, decreased immunity to pests and diseases, and increased morbidity. The biomass and productivity of plants decreases, the species composition and structure of communities changes.