Phytocenosis- any specific grouping of plants, throughout the space it occupies, is relatively homogeneous in appearance, floristic composition, structure, and conditions of existence and is characterized by a relatively identical system of relationships between plants and habitat.

The main signs of phytocenoses:

1. Species composition of phytocenosis is determined by climate, edaphic (soil) conditions, dissected relief, the impact of biogenic and anthropogenic factors, and the biological characteristics of species. The totality of individuals of a species within a plant community forms a coenotic population, or cenopopulation. Cenopopulations include plants of different ages, as well as dormant stages, for example, seeds or modified underground shoots of flowering plants.

2. Quantitative ratios of species in the community determine its appearance and reflect the coenotic processes in it. The quantitative relationship between plants in a phytocenosis is expressed by such an indicator as the abundance of a species. It is expressed as the number of individuals per unit area. On the basis of quantity, they distinguish dominants species that dominate the community. Dominance is determined by the projective cover of the species, the number of individuals, their weight or volume. Dominants are the most productive types of phytocenosis. In the event that two or more species simultaneously prevail in the phytocenosis, they are called codominants. anthropophytes– species are random in the phytocenosis, their stay in this community can be short-term. The ratios between the species of phytocenosis are determined by the adaptability of these species to living together and environmental conditions.

Quality Role different populations within the community is also not the same. edificators are the creator species, the builders of the plant community, which determine the main features of its phytogenic environment. Edificators have a maximum environmental role, they affect the water, temperature regime of the environment, the course of the soil-forming process. In this regard, edificators largely determine the species composition and structure of the phytocenosis. Assectaroths- species that have little effect on the creation of a phytogenic environment, these are secondary species that are part of different tiers. satellites- species that are always found only singly.

3. The next sign of phytocenosis is layering – placement of plant organs of various species at different heights above the soil surface and at different depths in the soil. Each tier has its own microenvironment and is, to some extent, an independent formation. At the same time, the tier is part of a single whole - phytocenosis. The number of community tiers is determined by many factors, including climate, soil conditions, and biological and ecological features of the species. Layering ensures the existence of a large number of individuals in a limited area and a more complete use of environmental factors (illumination, water, mineral resources) by plants. The greatest number of tiers is observed in favorable conditions. The tiered arrangement of plants reduces competition and ensures the stability of communities.

4. Mosaic - horizontal dismemberment within the phytocenosis. Mosaic patches are called microgroupings. Usually microgroups are small (up to several meters in diameter). The presence of mosaicity is a consequence of the heterogeneity of microconditions in the phytocenosis: microrelief, differences in the mechanical and chemical composition of soils, and litter thickness. At the same time, the formation of mosaicity is associated with the mutual influence of plants on each other (the creation of shading, the specifics of the litter that affects the soil-forming process,

5. The next feature is synusiality . Synusia- structural parts of a phytocenosis, characterized by a certain species composition, a certain ecological character of the species and spatial isolation. Synusia can be both a tier (if the species that make it up belong to the same life form), and a microgroup (in homogeneous phytocenoses).

Along with spatial synusia, seasonal synusia are also distinguished, represented by species of the same seasonal development. They are characterized by ecological isolation and a certain phytocenotic role in the community.

6. Physiognomy - the appearance of the phytocenosis, which is determined by the life forms that make up the phytocenosis.

7. Periodicity Phytocenoses are characterized by seasonal changes in all vital processes of plants.

8. Nature of the habitat - a set of ecological features of a given area, which determine the possibility of the existence of a biocenosis. A habitat is understood not only as a place where a phytocenosis grows, but also as a qualitative characteristic of a given area. The quality of a habitat is determined primarily by climate, altitude, surface shape, rocks and their influence on soil-forming processes, physicochemical and biological characteristics of soils, groundwater regime, and the possibility of flooding the area.

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1. Characteristics of phytocenoses

1.1 Forest phytocenosis

1.2 Meadow phytocenosis

1.3 Ruderal phytocenosis

1.4 Coastal-aquatic phytocenosis

2. Geobotanical description of phytocenosis

1. Characteristics of phytocenoses

1.1 Forest phytocenosis

Forest phytocenosis - a forest community, a community of woody and non-woody vegetation, united by the history of formation, common development conditions and growing area, the unity of the circulation of substances. The forest community reaches its maximum degree of homogeneity within the geographic facies, where various plant species are in complex relationships with each other and with the ecotope. Depending on the ecotope, composition, ecology of tree species, stage of development, simple (single-tier) and complex (multi-tier) forest communities are distinguished.

The forest is a complex complex. Parts of this complex are in continuous interactions between themselves and the environment. In the forest there are a variety of tree and shrub species, their combinations, a variety of tree ages, their growth rate, ground cover, etc.

Thus, the main component of the forest as a whole - woody vegetation, in addition to a separate forest cenosis, receives a more definite shape. A relatively homogeneous set of trees within these boundaries is called a forest stand. Young woody plants included in the forest phytocenosis, depending on their age and development, are usually called self-seeding or undergrowth in a natural forest. The youngest generation - seedlings.

In a forest plantation, along with woody vegetation, there may also be shrubs. Forest phytocenosis is also characterized by ground cover. Therefore, the Plantation is a forest area that is homogeneous in terms of tree, shrub vegetation and living ground cover.

1.2 Meadow phytocenosis

Meadow - in a broad sense - a type of zonal and intrazonal vegetation, characterized by the dominance of perennial herbaceous plants, mainly grasses and sedges, under conditions of sufficient or excessive moisture. A property common to all meadows is the presence of herbage and sod, due to which the upper layer of the meadow soil is densely penetrated by the roots and rhizomes of herbaceous vegetation.

An external manifestation of the structure of meadow phytocenoses is the features of vertical and horizontal placement in space and time of aboveground and underground plant organs. In the existing phytocenoses, the structure took shape as a result of a long-term selection of plants that have adapted to growing together in these conditions. It depends on the composition and quantitative ratio of the phytocenosis components, the conditions of their growth, the form and intensity of human impact.

Each stage of phytocenosis development corresponds to a special type of their structure, which is associated with the most important property of phytocenoses - their productivity. Separate types of phytocenoses differ greatly from each other in terms of the volume of the aboveground environment used by their components. The height of low-grass stands is not more than 10-15 cm, tall-grass - 150-200 cm. Low-grass stands are typical mainly for pastures. The vertical profile of the herbage varies seasonally from spring to summer and autumn.

Different types of meadows are characterized by a different distribution of phytomass within the volume of the medium used. The most obvious manifestation of the vertical structure is the distribution of mass in layers (along the horizons) from 0 and further along the height.

Usually the first tier is made up of cereals and the tallest species of herbs, the second tier is dominated by low species of legumes and herbs, the third tier is represented by a group of small herb and rosette species. Low-lying (waterlogged) and floodplain meadows often have a layer of ground mosses and lichens.

In anthropogenically disturbed grass stands, the typically formed layered structure is also disturbed.

In meadow communities, especially multispecies and polydominant ones, there is always a more or less pronounced horizontal heterogeneity of the herbage (spots of clover, strawberry, golden cinquefoil, etc.). In geobotany, this phenomenon is called mosaic or microgrouping.

Mosaic in meadow phytocenoses arises as a result of an uneven distribution of individuals of individual species. And each species, even its age groups, is specific in the vertical and horizontal placement of its aboveground and underground organs. The uneven distribution of species within the phytocenosis is also due to the randomness in the dispersal of seeds (bulbs, rhizomes), the survival of seedlings, the heterogeneity of the ecotope, the influence of plants on each other, the peculiarities of vegetative propagation, the impact of animals and humans.

The boundaries between individual types of mosaicity cannot always be clearly drawn. Often, the horizontal division of phytocenoses is determined not by one, but by several reasons. Episodic mosaicity, along with phytogenic, is the most common. It is especially pronounced in the distribution of some species (angelica, cow parsnip) in places of their mass seeding (under shocks, near generative individuals), spots appear with a predominance of these species. Their power and participation in the creation of phytomass initially increases, and then decreases due to the mass extinction of individuals as a result of the completion of the life cycle.

In the meadows (unlike forests), small-contour mosaics are common. Meadows are also characterized by the movement of microgroups in space: disappearance in some places and appearance in others. Mosaic is widespread, represented by various stages of vegetation restoration after disturbances caused by deviations from average weather conditions, animals, human activities, etc.

1.3 Ruderal phytocenosis

Ruderal plants are plants that grow near buildings, in wastelands, landfills, in forest belts, along communication lines, and in other secondary habitats. As a rule, ruderal plants are nitrophils (plants that grow abundantly and well only on soils sufficiently rich in assimilable nitrogen compounds). Often they have various devices that protect them from destruction by animals and humans (thorns, burning hairs, poisonous substances, etc.). Among the ruderal plants there are many valuable medicinal plants (dandelion officinalis, common tansy, motherwort, large plantain, horse sorrel, etc.), melliferous (medicinal and white melilot, narrow-leaved Ivan tea, etc.) and fodder (awnless bonfire, creeping clover, wheatgrass creeping, etc.) plants. Communities (ruderal vegetation) formed by ruderal plant species, often developing in places completely devoid of ground cover, give rise to restorative successions.

1.4 Coastal-aquatic phytocenosis

forest ruderal phytocenosis vegetation

The floristic composition of coastal aquatic vegetation depends on various environmental conditions of water bodies: the chemical composition of water, the characteristics of the soil that makes up the bottom and banks, the presence and speed of the current, pollution of water bodies with organic and toxic substances.

The origin of the reservoir is of great importance, which determines the composition of phytocenoses. Thus, lake-type floodplain water bodies, located in similar natural conditions and characterized by similar hydrological characteristics, have macrophyte flora similar in composition.

The species composition of plants inhabiting the coastal zone of reservoirs and the aquatic environment is quite diverse. In connection with the aquatic environment and lifestyle, three groups of plants are distinguished: real aquatic plants, or hydrophytes (floating and submerged); air-water plants (helophytes); coastal aquatic plants (hygrophytes).

2. Geobotanical description of phytocenosis

Playground№ 1

5 * 5 meters.

June 11, 2013

Habitat:

Ufa, park of foresters of Bashkiria

Phytocenosis type: Forest

The projective soil cover is 60%.

Crown density 95%.

Layered:

1 tier Linden heart-shaped lat. Tnlia cordbta family Tiliaceae;

2 tier Norway maple Acer platanoides Sapindáceae ;

3 tier Rough elm êlmus glbbra Ulmaceae;

Mountain ash Surbus aucupbria Rosaceae;

4 tier Euonymus warty Euonymus verrucosa Celasfraceae;

Norway maple Acer platanoides Sapindáceae.

Grass layer.

Chin forest Lathyrus sylvestris Fabacea;

Dandelion officinalis Tarbxacum officinble.

Playground№ 2

Plot 5 * 5 meters.

June 11, 2013

Habitat:

Phytocenosis type: Forest.

The projective soil cover is 80%.

Crown density 60%.

Layered:

1 tier Rough elm êlmus glbbra Ulmaceae;

2 tier Norway maple Acer platanoides Sapindáceae;

3 tier Rowan ordinary Surbus aucupbria Rosaceae;

Pedunculate oak Quürcus rubur Fagaceae.

Grass layer.

Thistle is common Cirsium vulgare Asteraceae;

Primulceae

Stinging nettle Urtnca diuica Urticaceae;

Chin forest Lathyrus sylvestris Fabacea;

Fragrant bedstraw Galium odoratum rubiaceae;

sedge Carex vesicaria Cyperaceae;

City gravel Gthum urbbnum Rosaceae;

Dandelion officinalis Tarbxacum officinble Asteraceae;

Site number 3.

Plot 2 * 2 meters.

June 11, 2013

Habitat:

Ufa, park of foresters of Bashkiria.

Phytocenosis type: meadow

grass tier:

Mouse peas Vncia crbcca LegumesFabaceae;

Cumin ordinary Cbrum cbrvi Apiaceae;

· Buttercup caustic Ranculus bcris Ranunculaceae;

· Veronica oak Veronica chamaedrys Plantaginaceae;

Starworm hard-leaved Stellaria holostea L. Caryophyllbceae;

· Regular cuff Alchemilla vulgaris Rosaceae;

· meadow bluegrass Poa pratthnsis Poaceae;

Bonfire awnless Bromus inermis Pobceae;

· Meadow foxtail Alopecurus pratensis Poaceae;

Red clover Trifolium pratthnse Fabaceae;

creeping clover Trifolium repensMoth;

Green strawberries Fragbria virndis Pink.

Site №4

Plot 2 * 2 meters.

Habitat:

Ufa, park of foresters of Bashkiria.

Phytocenosis type: spruce forest

The projective soil cover is 2%.

Layered:

1 tier Norway spruce Pnceabbies Pinaceae;

2 tier Norway maple Acer platanoides L Sapindáceae;

3 tier Norway maple Acer platanoides L Sapindáceae.

Grass layer.

Geranibceae;

Dandelion officinalis Tarbxacum officinble Asteraceae.

Site №5

Plot 2 * 2 meters.

Habitat:

The projective soil cover is 100%.

White resin Silthne latifatlia Caryophyllbceae;

meadow timothy grass Phleum pratense Pobceae;

· Umbrella hawk Hieracium umbellatum L Asteraceae;

Wormwood high Artemisia vulgaris L. Asteraceae;

Common leucanthemum Leucanthemum vulgare Asteraceae;

wild lettuce Lactura scariolaAsteraceae;

Bedstraw soft Galium mollugo Rubiaceae;

· Upright cinquefoil Potentílla erécta Rosaceae;

field bindweed Convolvulus arvensis L. Convolvulaceae;

odorless chamomile Tripleurospermum inodorum Asterbceae;

· Yarutka field Thlbspi arvinse Brassicaceae;

Violet tricolor Vnola trncolor Violbcea;

Common bruise Ichium vulgbre Boraginaceae;

common flaxseed Linaria vulgaris Crophulariaceae;

hiccup grey-green Bertéroa incána Brassicaceae;

Plantain lanceolate Plantbgo lanceolbta Plantaginaceae;

Velcro splayed Lappula squarrosa, Boraginaceae;

Wormwood common Artemnsia vulgbris Asteraceae;

varicose-leaved Cirsium heterophyllum Asteraceae.

Site №6

Plot 2 * 2 meters.

Habitat:

Ufa, Kirovsky district, slope base, monument to Salavat Yulaev.

Phytocenosis type: ruderal community

The projective soil cover is 100%.

Timothy meadow Phleum pratense Pobceae;

· Artemisia vulgaris L. Asteraceae;

wild lettuce Lactura scariola Asteraceae;

· Bedstraw soft Galium mollugo Rubiaceae;

Potentilla erecta Potentílla erécta Rosaceae;

· Meadow goat grass Tragopogon pratensis Asteraceae;

· Brim multi-colored Coronilla varia Fabaceae;

meadowsweet Filipíndula ulmbria Rosaceae;

· Burnet officinalis Sanguisurba officinblis Rosaceae;

Common bruise Ychium vulgbre Boraginaceae;

· Gray-green hiccup Bertéroa incbna Brassicaceae;

Wormwood Artemnsia vulgbris Asteraceae;

· Cirsium heterophyllum Asteraceae.

Summary table of species and families

families
Linden heart-shaped lat. Tnlia cordbta
Norway maple Acer platanoides
Rough elm Ulmus glbbra
Burnet officinalis Sanguisurba officinblis
meadowsweet Filipíndula ulmbria
Cinquefoil erect Potentnlla erйcta
Sorbus aucupbria
Common cuff Alchemilla vulgaris
Strawberry green Fragbria virнdis
City gravel Güum urbánum
Euonymus verrucosa
Cirsium heterophyllum Cirsium heterophyllum
Wormwood Artemnsia vulgbris
Chamomile odorless Tripleurospermum inodorum
Meadow goat grass Tragopogon pratensis
Lettuce wild Lactura scariola
Dandelion officinalis Tarbxacum officinble
Leucanthemum vulgare
Wormwood Artemisia vulgaris
Umbrella hawk Hieracium umbellatum
Cirsium vulgare Cirsium vulgare
Stinging nettle Urtnca diuica
Brim multi-colored Coronilla varia
Mouse peas Vncia crbcca
Red clover Trifolium pratynse
Mouse peas. Vncia crbcca
Creeping Clover Trifolium repens
Forest chin Lathyrus sylvestris
Bedstraw soft Galium mollugo
Fragrant bedstraw Galium odoratum
Bubble sedge Carex vesicaria
Cumin ordinary Cbrum cbrvi
Ranunculus ranunculus bcris
Plantain lanceolate Plantbgo lanceolbta
Veronica oak Veronica chamaedrys
Caryophyllbceae
Smolyovka white Silеne latifуlia
Chickweed Stellaria holostea
Bluegrass meadow Poa pratйnsis
Timothy grass Phleum pratense
Bonfire Bromus inermis
Meadow foxtail Alopecurus pratensis
Norway spruce Pнcea bbies
Common stork Erudium cicutbrium
Monetary loosestrife Lysimachia nummularia
Field Bindweed Convolvulus arvensis
Hiccup gray-green Bertéroa incbna
Yarutka field Thlбspi arvйnse
Violet tricolor Vnola trncolor
Common bruise Ychium vulgbre
Velcro splayed Lappula squarrosa
Common flax Linaria vulgaris
Pedunculate oak Quürcus rubur

findings

We have discovered and analyzed 52 species from 24 families. The average number of species in families is 3. Thus, the following families are distinguished as leading ones:

Asteraceae

Bodjak variegated Cirsium heterophyllum, wormwood Artemnsia vulgbris, odorless chamomile Tripleurospermum inodorum, meadow goat's beard Tragopogon pratensis, wild lettuce Lactura scariola, dandelion officinalis Tarbxacum officinble, common daisy Leucanthemum vulgare, sagebrush high Artemisia vulgaris, hawkweed Hieracium umbellatum, common waterpipe Cirsium vulgare.

Rosaceae

Burnet officinalis Sanguisurba officinblis, meadowsweet Filipíndula ulmbria, erect cinquefoil Potentílla erécta, mountain ash Surbus aucupbria, ordinary cuff Alchemilla vulgaris, green strawberry Fragbria virndis, urban gravel Güum urbánum.

Fabacea

Vyazel multi-colored Coronilla varia, red clover Trifolium pratynse, mouse peas Vncia crbcca, creeping clover Trifolium repens, forest rank Lathyrus sylvestris.

Poaceae

Bluegrass meadow Poa pratynsis, meadow timothy Phleum pratense, awnless fire Bromus inermis, meadow foxtail Alopecurus pratensis.

Conclusions on phytocenoses.

In the forest phytocenosis No. 1, the dominant species were the heart-shaped linden lat. Tnlia cordbta and Norway maple Acer platanoides.

In the forest phytocenosis No. 2 rough elm êlmus glbbra and Norway maple Acer platanoides.

In the meadow phytocenosis, the dominant species were caraway Cbrum cbrvi, meadow bluegrass Poa pratynsis, awnless fire Bromus inermis, ranunculus caustic Ranculus bcris.

In the spruce forest, the dominant species was the species Norway spruce Pricea bbies. Grass cover was sparse, with less than 5% soil coverage.

General conclusion.

In forest communities, the vegetation was represented more by woody forms, such as the heart-shaped linden. Tnlia cordbta, Norway maple Acer platanoides, rough elm Ъlmus glbbra, mountain ash Sуrbus aucupbria, English oak Quйrcus rubur. The variety of herbaceous vegetation was not as great as that of the meadows.

In meadow communities, the dominant families were Poaceae and Fabacea.

In ruderal communities, the dominant family was Asteraceae, represented by species: varicose-leaved Cirsium heterophyllum, wormwood Artemnsia vulgbris, odorless chamomile Tripleurospermum inodorum, meadow goat's beard Tragopogon pratensis, wild lettuce Lactura scariola, medicinal dandelion Tarbxacum officinble, common daisy Leucanthemum vulgare, sagebrush high Artemisia vulgaris, hawkweed Hieracium umbellatum.

Thus, it can be concluded that certain families are characteristic of each phytocenosis. There are also species whose presence is characteristic of all studied phytocenoses, for example, the species Dandelion officinalis Tarbxacum officinble.

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Phytocenosis is characterized by:

1. certain species composition;
2. structure, or otherwise, the features of the placement of components in space and time;
3. conditions of existence.

Species composition of phytocenosis. The existing phytocenosis has its own physiognomy and certain signs. The most important sign phytocenosis is floristic composition- a set of plant species included in the phytocenosis. The number of species that make up the phytocenosis may be different. Phytocenoses consisting of a single plant species are very rare in nature. Single-species phytocenoses formed by lower plants are usually denoted by the word "colony". In the case when one type of higher plant, “thicket”, takes part in the formation of a phytocenosis, the name of the higher plant that is part of the phytocenosis (nettle thickets, raspberry thickets, etc.) is placed next to the word “thicket”.

In nature, there are predominantly complex phytocenoses, which include not only higher plants, but also lower plants. The total number of species found in the composition of the phytocenosis throughout the area occupied by it depends on the conditions of existence (habitat conditions) of the phytocenosis and the history of its development. At the same time, the size of the area occupied by the phytocenosis is also of considerable importance. The number of species registered on the accounting site, established within the described phytocenosis, gives an idea of ​​its species richness and species diversity.

Phytocenosis (from the Greek φυτóν - “plant” and κοινός - “general”) is a plant community that exists within the same biotope. It is characterized by the relative homogeneity of the species composition, a certain structure and system of relationships between plants with each other and with the external environment. Phytocenoses are the object of study of the science of phytocenology (geobotany).

Phytocenosis is a part of 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 circulation of matter and energy. Soil properties, microclimate, composition of the animal world, such characteristics of biogeocenosis as biomass, bioproductivity, etc., depend on vegetation. In turn, the elements of phytocenosis are plant cenopopulations - aggregates of individuals of the same species within the boundaries of phytocenoses.

The layering was first described by the Austrian scientist L. Kerner in 1863. In the spruce forest, he distinguished: tree layer, fern layer and moss layer. Then the Swedish scientist Gult identified 7 tiers in the forests of northern Finland:

1. upper woody,
2. lower arboreal,
3. undergrowth,
4. top herbal,
5. medium herbal,
6. lower herbal,
7. ground.

Vertical structure has two polar variants connected by smooth transitions: tiered and vertical continuum. Thus, layering is not an obligatory characteristic, but uneven height of plants is a widespread phenomenon.

Layering allows coexistence in the community of species of different quality in terms of their ecology, makes the habitat ecologically more capacious, creates a large number of ecological niches, especially in relation to the light regime.

In the series single-tier - two-small-tier - multi-tier - imperfectly tier (vertical-continuous) communities, an increase in floristic richness is observed.

Consistent use of the concept of tiering has a number of theoretical difficulties associated with the fact that:

1. not all communities are vertically discrete;
2. it is not clear if the tiers are layers or elements "inserted" into each other;
3. it is not clear where to attribute lianas, epiphytes, undergrowth.

To overcome these difficulties, Yu. P. Byallovich formulated the concept of a biogeocenotic horizon - a vertically isolated and vertically further inseparable structural part of a biogeocenosis. From top to bottom, it is homogeneous in the composition of biogeocenotic components, in their interconnection, the transformations of matter and energy occurring in it, and in the same respects it differs from neighboring, above and below, biogeocenotic horizons.

The vertical parts of plant communities, respectively, form phytocoenotic horizons. Each of them is characterized not only by the composition of autotrophic plant species, but also by a certain composition of the organs of these plants. With this approach to the analysis of the vertical structure, there are no controversial issues, including where to attribute lianas, epiphytes, or undergrowth.

horizontal structure

Most plant communities are characterized by heterogeneity of horizontal composition. This phenomenon is called the mosaic of phytocenoses. Mosaic elements are most often called microgroups, although a number of researchers have proposed their own terms - microphytocenoses, cenoquants, cenocells. The notion of a parcel stands apart. - element of horizontal heterogeneity of biogeocenosis.

The uneven distribution of species is due to a number of reasons. There are types of mosaic according to their origin:

1. Phytogenic mosaicity due to competition, changes in the phytoenvironment or the specifics of plant life forms (the ability to vegetatively reproduce and form clones).
2. Edaphotopic mosaicity associated with the heterogeneity of the edaphotope (roughness of the microrelief, different drainage, heterogeneity of soils and litter, their thickness, humus content, granulometric composition, etc.).
3. Zoogenic mosaicity caused by the influence of animals, both direct and indirect (indirect) - eating, trampling, deposition of excrement, the activity of digging animals.
4. Anthropogenic mosaicism is associated with human activities - trampling due to recreational stress, grazing of farm animals, mowing grass and cutting down forest plant communities, resource harvesting, etc.
5. Exogenous mosaicity due to external abiotic environmental factors - the influence of wind, water, etc.

Mosaic- a special case of horizontal heterogeneity of vegetation cover. Studying the horizontal heterogeneity of the vegetation of any region, researchers distinguish between two concepts, two circles of phenomena - mosaic and complexity.

In contrast to mosaic characterizing the intracenotic horizontal heterogeneity, complexity is the horizontal heterogeneity of the vegetation cover at the supraphytocenotic level. It manifests itself in the regular alternation of individual phytocenoses or their fragments within the same landscape.

The complexity of the vegetation cover is determined by the micro- or mesorelief, which serves as a kind of redistributor of the load of the main environmental factors and thus differentiates the landscape into habitats with different ecological regimes.

There are complexes and combinations of communities. Complexes are communities that are genetically related to each other, i.e. which are consecutive stages of one successional process.

Sometimes they talk about the synusial structure of plant communities, thus highlighting the special structural elements of the phytocenosis - sinusia.

Synusia- these are structural parts of the plant community, limited in space or time (i.e., occupying a certain ecological niche) and differing from one another in morphological, floristic, ecological and phytocenotic respect.

Well distinguished in broad-leaved forests is the synusia of spring forest ephemeroids, the "pseudo-meadow" synusia in deserts, or the synusia of annuals in some types of vegetation.

Phytocenosis (or plant community) is any set of plants that live on a given homogeneous area of ​​the earth's surface, only with their inherent relationships both between themselves and habitat conditions and therefore creating their own special environment, phytoenvironment (Sukachev, 1954).

Phytocenosis is any specific grouping of plants throughout the space it occupies, relatively homogeneous in appearance, floristic composition, structure, conditions of existence and characterized by a relatively similar system of relationships between plants and with the environment (Shennikov, 1964).

Phytocenosis - a set of co-growing plants - is a part of a biocenosis - a set of co-living organisms. The science of biocenoses is called biocenology (from the Greek bios - life). Thus, phytocenology is a part of biocenology (Voronov, 1963).

V. N. Sukachev proposed to call biogeocenosis (1940) a plant community, together with its animal population and the corresponding part of the earth's surface, characterized by certain properties of the microclimate, geological structure, soil and water regime.

The first definition of a plant community was given by G. F. Morozov (1904) for a forest, and then (1908) extended by V. N. Sukachev to all plant communities. The term "phytocenosis" was used by I.K. Pachosky for "pure thickets" (formed by one plant species) in 1915 and for all communities - by Sukachev in 1917 and Hams in 1918.

Phytocenosis, or plant community, is a set of plants growing together in a homogeneous area, characterized by a certain composition, structure, composition and relationships of plants both with each other and with environmental conditions. The nature of these relationships is determined, on the one hand, by the vital, otherwise, ecological properties of plants, on the other hand, by the properties of the habitat, i.e. the nature of the climate.

Between plants in a phytocenosis there are relations of two genera. Firstly, growing side by side, plants of the same species or plants of several species (plants of different species often grow side by side in a phytocenosis) compete with each other for the means of life; between them there is a struggle for existence (in the broad metaphorical sense, as Charles Darwin understood it). This competition, on the one hand, weakens plants, but on the other hand, it forms the basis of natural selection, the most important factor in speciation and, consequently, in the process of evolution. Secondly, plants in a phytocenosis have a beneficial effect on each other: shade-loving herbs live under the canopy of trees, which cannot grow or grow poorly in open places; plants with weak climbing or climbing stems - lianas - rise on tree trunks and branches of shrubs; epiphytes not associated with the soil settle on them (Sukachev, 1956).

A phytocenosis is characterized by a certain set of plants that form it (species composition), a certain structure, and confinement to a certain habitat. Due to the change in the environment by plants, the phytocenosis creates its own environment - the phytoenvironment.

Phytoenvironment is the environment of plant communities (Dudka, 1984).

The term phytocenosis (plant community) can be applied both to specific areas of vegetation cover and to designate taxonomic units of various ranks: for an association, for a formation, for a type of vegetation, etc.

Four types of phytocenosis boundaries can be distinguished: sharp, mosaic, bordered, diffuse. Sharp boundaries of phytocenoses can be observed both with a sharp change in environmental conditions and with a gradual one. Even with very sharp boundaries, the introduction of the edificator of one community to the outskirts of another community is usually observed. Mosaic boundaries are characterized by the fact that in the contact zone of two phytocenoses, small areas of one cenosis are included in the array of another, i.e., complexes formed by both bordering phytocenoses develop, as it were. Border boundaries differ from other boundaries in that a narrow border of a community is observed in the contact zone, which differs from both bordering communities. Diffuse boundaries are characterized by a gradual change in space of one phytocenosis by another.

Phytocenosis with its animal population is a biocenosis. Biocenosis - a set of plants and animals inhabiting a habitat area with more or less homogeneous conditions of existence (biotope), formed naturally or under the influence of human activity, continuously developing and characterized by certain relationships between members of the biocenosis and between the biocenosis and the habitat (Pavlovsky, Novikov, 1950).

A population is a group of individuals of a species that is geographically or ecologically isolated from other groups of individuals of the same species. A group of individuals of a species in a phytocenosis is a population of this species.

Different individuals of the same species in the phytocenosis are present in a different state, in other words, the population of each species is heterogeneous in composition. Its individuals may differ from each other, for example, by age phases. The following main periods of plant life are distinguished: latent period (period of primary dormancy); the virgin (virgin) period, in itself three states of plants: shoot, juvenile (youthful) and premature (adult virgin); generative period; senile (senile) period (Rabotnov, 1945, 1950).

There are many definitions of life forms. IG Serebryakov (1962) points out that the doctrine of life forms has now acquired at least two aspects - ecological-morphological and ecological-cenotic, closely related to each other.

From an ecological and morphological point of view, a life form, according to I. G. Serebryakov, is “a peculiar general appearance (habitus) of a certain group of plants (including their aboveground and underground organs - underground shoots and root systems), arising in their ontogenesis as a result of growth and development in certain environmental conditions. This habitus historically arises in given soil and climatic conditions as an expression of the adaptability of plants to these conditions.

From an ecological-coenotic point of view, a life form is “an expression of the ability of certain groups of plants for spatial settlement and fixation in the territory, for their participation in the formation of vegetation cover.”

Raunkier in 1905-1913 built a system of life forms based on the position of the buds of plant renewal when the plant endures an unfavorable period caused by a decrease in temperature or a lack of moisture. This system was subsequently modified and supplemented by I.K. Pachosky (1916), who proposed to base it on the amount of losses incurred by a plant when its organs die off during an unfavorable season (Voronov, 1963).

The main characteristics of a phytocenosis include the species and age composition of the plants that form it, as well as its spatial structure.

Species composition of phytocenoses. Each phytocenosis is characterized by a special species composition peculiar to it. Its complexity or simplicity is determined by the indicator of species (floristic) saturation, which is understood as the number of species per unit area of ​​a phytocenosis.

According to the value of the species saturation indicator, phytocenoses can be divided into three groups: a) floristically simple, consisting of a small number of species (up to one to two dozen), b) floristically complex, including many dozens of species, c) phytocenoses, occupying an intermediate position in terms of species saturation .

The species diversity of phytocenoses is influenced by a number of factors. A certain role in this regard is played by the general physiographic and historical conditions, on which the species richness of the flora of each particular region depends. And the richer the flora of the area, the more there will be candidate species that can settle in each specific phytocenosis.

The floristic diversity of phytocenoses also depends on the habitat conditions: the more favorable they are, the more complex the species composition, and, conversely, floristically simple phytocenoses are formed in unfavorable habitats.

Animals and humans can also influence the species diversity of phytocenoses (Prokopyev, 1997).

The age composition of populations is the distribution of individuals of the coenotic population by age and development phases. The age of plants is the lifespan of a whole plant or its separate part, from its inception to the moment under study. Age is measured in units of time (calendar age) or in the number of leaves or plastochrones laid down (physiological age) (Dudka, 1984).

Depending on the ratio of age groups, T. A. Rabotnov (1995) distinguishes three types of cenopopulations: invasive, normal, and regressive.

Analysis of the age composition of cenopopulations is important in the study of phytocenoses. It allows you to find out the current state of individual cenopopulations and phytocenosis as a whole, predict the direction of their further development, helps develop a regime for the rational use of phytocenoses, and solve problems of their optimization and protection (Yaroshenko, 1969).

The vertical structure of phytocenoses is due to the fact that the plants growing in it have an unequal height, and their root systems penetrate the soil to different depths. As a result, the phytocenosis is divided in the vertical direction (in its aboveground and underground spheres) into separate more or less separated layers, which leads to a more complete use of habitat resources by plants.

There are three main elements of the vertical structure: layer, canopy and phytocenotic horizon.

In herbaceous plants, layering is expressed in points.

1 point Tall plants (stems of cereals and tall forbs).

2 points. Plants of the second largest size (stalks of lower cereals, forbs and other plants).

3 points. Low growing plants.

4 points. Mosses, lichens and very low herbaceous plants 1-5 cm tall (Zorkina, 2003).

The horizontal structure of phytocenoses is determined primarily by the nature of the distribution of plants over their area. Currently, it is customary to distinguish three main types of distribution of cenopopulations - regular, random and contagious.

The uneven distribution of plants in phytocenoses depends on several reasons and, first of all, on the characteristics of their reproduction and growth form. In this regard, V.N. Sukachev (1961) proposed to distinguish between two types of plant growth: 1) solitary growth, in which individuals of the cenopopulation grow apart from each other, developing one, sometimes two or three shoots from the root and multiply exclusively by generative means; 2) group growth is characterized by the fact that individual individuals or their shoots grow crowded, in groups.

The following main forms of group growth are distinguished: a) a bunch (or a bush); b) turf (or pillow); c) patch; d) curtain; d) spot.

Depending on the type of distribution of dominant coenopopulations, two types of horizontal structure arise - diffuse and mosaic. The diffuse structure is characterized by a more or less uniform (homogeneous) horizontal structure. It arises in those cases when the dominant cenopopulations are distributed evenly - according to regular or random types. True, practice shows that there are practically no completely homogeneous natural phytocenoses, since in nature there are no and cannot be cases of an absolutely uniform distribution of all phytocenosis cenopopulations. Therefore, we can only talk about a relatively diffuse composition of phytocenoses.

The mosaic structure is characterized by a clearly heterogeneous (spotted) distribution of dominant cenopopulations, as a result of which small areas are distinguished in the phytocenosis, differing from each other in composition and structure. There are three main categories of elements of the mosaic structure: a) elements of a larger volume that stand out within the entire above-ground part of the phytocenosis; b) elements of the smallest volume that stand out within one subordinate tier; c) elements of an intermediate volume that stand out within several subordinate tiers. In the naming of these structural parts of the phytocenosis, there is a great discrepancy. Following A. A. Korchagin (1976), they are respectively designated as: a) microcenosis, b) microgrouping, c) congregation.

In accordance with the above factors of uneven distribution of cenopopulations, L. G. Ramensky (1938) and T. A. Rabotnov (1974) distinguish the following types of mosaic: 1) episodic; 2) ecotopic; 3) phytogenic; 4) clonal; 5) zoogenic; 6) anthropogenic.

Later, T. A. Rabotnov (1995) added several more types of mosaic: a) age mosaic, associated with a change in the impact of plants on the environment with increasing age; b) demutational mosaicism associated with the restoration of vegetation in disturbed areas of the community; c) mosaic, due to the formation of nanorelief by plants - tussocks, pillows, etc.; d) mosaicity arising under the influence of two factors, for example, eolian-phytogenic mosaicity, common in arid areas and due to the accumulation of fine earth carried by the wind in shrub clumps.

In the Anglo-American geobotanical literature, patterns or spots are considered as structural parts of the horizontal heterogeneity of the vegetation cover (Korchagin, 1976), which, in the understanding of most authors, do not have definite boundaries and regular repetition. In connection with the continuous change in the area of ​​the phytocenosis of environmental conditions, the patterns form a motley carpet of continuously changing unstable combinations of various species. Thus, the patterns differ from the microcenoses, congregations, and microgroups that are more or less stable in time and are apparently characteristic of some herbaceous phytocenoses with a highly variable structure.

The productivity of a plant is the amount of organic mass (biomass) produced by one plant per year, and the seed productivity is the number of seeds produced by one copy of the plant per year. In the same sense as productivity, the terms productivity of phytocenosis, annual growth of plant mass, and productivity are used (Voronov, 1963).

Community products - organic substances produced by biocenosis, or phytocenosis. They differ: total primary production - the amount of organic matter introduced into the cenosis system by producers through photosynthesis and chemosynthesis; net primary production - the same, but minus the substances spent on respiration and consumed by heterotrophic organisms; total secondary production - the amount of organic matter created by heterotrophic organisms - consumers; net secondary production - the same, but minus the substances spent on respiration and consumed by other heterotrophs; stock of products (Bykov, 1973).

Productivity - the amount of useful products obtained from a certain area of ​​a phytocenosis or agrocenosis (Dudka, 1984).

Phytomass (from Greek phyton - plant and mass) - expressed in units of mass, the amount (wet, dry or deashed) of plant matter (populations, phytocenoses, etc.) per unit area or volume. In different phytocenoses, the phytomass has different stratigraphy and different fractional composition (Bykov, 1973).

Phytocenosis is characterized by species composition, quantitative and qualitative relationships between plants, layering, mosaic, physiognomy, periodicity, synusiality, and the nature of the habitat.

species composition. The composition of phytocenosis includes higher plants, bacteria, algae, accinomycetes, fungi and lichens. They grow on the soil, in the soil, and some are epiphytic plants. The totality of individuals of a species within a plant community forms a coenotic population, or cenopopulation. The species composition of a community is a set of cenopopulations. A species is a system of populations. A population is a group of individuals that is an elementary subdivision of a species, its elementary evolutionary structure.

Cenopopulations of individual species in the same plant community can differ greatly from each other both in the number of individuals per unit area and in the ratio of individuals of different age groups (age spectrum).

The main age periods of plant life are latent, virgil, generative, senile. The presence in the population of a plant species in different age phases ensures the stable position of the species in the community and is an indicator of its normal viability. There are populations of invasive, normal and regressive types.

Populations of an invasive, i.e., invading, type only take root in a phytocenosis and can exist in the form of seedlings, juvenile or immature individuals. Seeds of such species are introduced from outside and eventually occupy an important position in the phytocenosis or do not take root in it at all. Populations of the regressive type have lost the ability for generative renewal. They do not bloom, and if they bloom and bear fruit, then their seeds do not germinate or the seedlings are not viable. The noted signs characterize a population that is dying out, i.e., leaving a given phytocenosis. Plants of populations of the normal type pass through the entire development cycle in the phytocenosis. They are represented by individuals of different periods of life from spores and seeds to adults. In terms of cenosis, these are the main populations of phytocenosis.

The species composition of the phytocenosis is determined by the climate, edaphic conditions, the dissected relief, the impact of biogenic and anthropogenic factors, the biological characteristics of the species, and other reasons.

The number of species growing per unit area is the species (floristic) saturation of the community, which indicates the completeness of the use of the environment within the phytocenosis.

Quantitative and qualitative relationships between plants. A quantitative indicator of the importance of a species in the life of a phytocenosis is its abundance. It is expressed in weight categories, points, the number of individuals per unit area. The ratios between individuals of a phytocenosis are a consequence of the adaptation of species to living together and are determined by environmental conditions. They are not stable. Changes are primarily a reaction to the natural course of meteorological conditions during the season of the year, for many years, or are caused by the peculiarities of the relationship between plants, biogenic and anthropogenic factors.

The qualitative role of different populations in the composition of communities is not the same. In phytocenosis, it is customary to distinguish between dominants (condominants), subdominants, assectators, anthropophytes.

Dominants - species that prevail in the community. By the predominance of a species is meant its greater role in comparison with other species. The predominance is determined by the projective cover of the species, the number of individuals, their weight or volume. This is the most productive population of phytocenosis.

If the phytocenosis is simultaneously dominated by two or more species belonging to the same ecobiomorph, they are called condominants.

Species that mainly determine the specific environment of the community, i.e., have the maximum environmental role, are called edificators. They largely determine its species composition and structure, since they affect the water, temperature regime of the environment and acidity, and at the same time the nature and course of soil-forming processes.

Subdominants - species that prevail in the subordinate layers of the phytocenosis constantly or in certain seasons.

Assectators are secondary species, included in the composition of various tiers.

Anthropophytes are random species in the phytocenosis. Their stay can be completely anthropogenic.

Dominants, subdominants, assectators and arthropophytes are called phytocoenotypes.

Layered. In the process of formation of phytocenosis, plants develop various ecological niches in space. Layering refers to the arrangement of plant organs of various species at different heights above the soil surface and at different depths in the soil. The main structural part of the phytocenosis is the layer. A layer is a part of the population of a phytocenosis, ecologically and phytocenotically isolated in space, and sometimes in time.

Each tier has its own microenvironment (lighting, temperature, humidity, air composition and movement) and is, to some extent, an independent formation. At the same time, the tier is part of a single whole - phytocenosis. In forests, 3-5 tiers are usually distinguished: I (A) - trees of the first size, II (A') - trees of the second and third sizes, III (B) - shrubs (undergrowth), IV (C) - grasses and shrubs, V (D) - mosses and lichens.

Mosaic - horizontal dismemberment within a phytocenosis. Mosaic spots are called microphytocenosis, microassociation, microgrouping.

A microgroup is the smallest element of the horizontal division of a plant community, covering all its tiers and therefore having a certain integrity, which does not exclude a constant relationship with other microgroups both in space and in time.

The presence of microcenoses is primarily a consequence of the heterogeneity of conditions in a phytocenosis, namely, microconditions of a very different order, mutual influences, features of vegetative and mixed reproduction of individual plants. Of paramount importance are the mutual influence and conditions of the ecotope: nanorelief, differences in the mechanical and chemical composition of soils, moisture, shading, litter thickness, and litter features.

Synusality

Synusia are structural parts of phytocenoses, characterized by a certain species composition, a certain ecological character of the species that make them up, and spatial (or temporal) isolation, and, consequently, a special phytocenotic environment (microenvironment) created by the plants of this synusia.

Synusia is not any structural part of a phytocenosis, but formed by a group of plants with a homogeneous or similar ecology. A tier can also be a synusia, if the species that make it up belong to the same life form, and a microgroup (in homogeneous phytocenoses).

Phytocenosis is a complex complex of synusia. The study of individual synusia allows us to more fully understand the species composition, structure and dynamics of phytocenosis.

Physiognomy. The appearance of the phytocenosis, i.e. its physiognomy is determined by the life forms that make up the phytocenosis. The appearance of a phytocenosis, determined by the phases of seasonal development, is called an aspect.

The combination of plants with different rhythms of seasonal development makes it possible for a large number of species to co-exist in communities and make fuller use of the environment by plants.

Periodicity. The seasonal change of aspects is associated with seasonal changes in the life of the community. The frequency of phytocenosis is characterized by seasonal changes in all life processes of plants (transpiration, respiration, photosynthesis and the release and consumption of various substances from the environment, reproduction, etc.), which are determined by the seasonal course of meteorological conditions and physicochemical processes occurring in the soil.

the nature of the habitat is a set of ecological features of a given area, which determine the possibility of the existence of biocenoses. A habitat is understood not only as a place where a phytocenosis grows, but also as a qualitative characteristic of a given area. The quality of the habitat is determined by many factors, the most important of which are the climate of the area, the height above sea level, the shape of the surface (exposure, the angle of inclination of the slopes), rocks and their influence on the soil-forming process, the groundwater regime, the possibility of flooding the area, the origin, type, age of the soil and its physical, chemical and biological features. In the habitat of a phytocenosis, the influences of all components are closely intertwined.

The essential features of phytocenosis are phytocenotic relationships between plants and differences in the phytoenvironment. If mutual influences between plants are not expressed, it means that there is simply a grouping, or aggregation, of plants, but there is no phytocenosis.

Phytocenosis classification units

The classification unit of phytocenoses is an ascending series: an association, a group of associations, a formation, a group of formations, a class of formations, and a type of vegetation.

A plant association (type of phytocenosis) combines phytocenoses with a simultaneous species composition, a homogeneous synusial structure that reflects the composition of ecological plant types, and homogeneous environmental factors that affect the phytocenotic process.

The establishment of associations is, first of all, a generalization, a selection of common and essential features, but not a characteristic or description of it. It should be considered as a type of plant community.

Association Criteria:

One and the same tiered addition, i.e. number and nature of tiers

Similar tiling

The same feeds must be edifiers and dominants in the respective tiers

Similar composition and ratio of the role of species of different ecological affiliation

Similar course of seasonal variability

Similar year-to-year changes

Similar course of age-related changes

Similar vitality of the main components

More or less similar responses to the same impact.

The names of associations are composed of the generic name of the dominant (condominant) and subdominant.

association group. Associations are grouped. One group includes associations that differ in the composition of one of the tiers. Groups of associations form a natural ecological series, reflecting changes in trophicity, moisture content, and soil aeration.

The formation is distinguished by one common feature - the dominant. The name of the group-associations are combined into a formation. Formation is the basic unit of middle rank. Its importance is great in forest typological studies, forestry activities and vegetation mapping.

Formation groups. One group includes all formations, the dominants of which belong to the same life form.

Formation class. One class includes all groups of formations, the dominants of which belong to close life forms.

Vegetation type is the largest subdivision of vegetation cover. Types are distinguished by morphological or ecological-morphological characteristics. One type of vegetation includes all formations whose associations in the dominant layer are composed of the same biomorph.

Vegetation types are zonal, azonal and extrazonal. Zonal vegetation occupies leveled watershed spaces with well-drained soils of medium mechanical composition (sandy loam, loam).

The azonal type of vegetation develops in places where the vegetation cover is more determined by soil conditions than by climate.

Certain areas of herbaceous vegetation are close to extrazonal.

Forest vegetation.

The study of phytocenoses is studied from the forest - the main zonal type of vegetation. A forest is a community, or such a combination of woody plants, in which they mutually influence each other, thereby giving rise to a number of new phenomena that are not characteristic of equally growing trees. The forest is the basis of the green cover of the Earth, the main component of the geographical landscape. It has a decisive influence on the hydrological regime of rivers and reservoirs, protects the soil from erosion, affects the chemical composition of the atmosphere, is a habitat for wild animals and birds, and is of great sanitary, hygienic and aesthetic importance.

4.1 Species structure of forest phytocenosis

Table 4.1 Species structure of forest phytocenosis

Conclusions: when studying the method of laying raunkiers on a trial plot, the vegetation of a forest phytocenosis was studied. The bulk of the vegetation is bilberry (31.6%) and winding pike (17.25%), lingonberries, meadow maryannik and common heather were found with single species. The projective moss cover was 70%, and was represented by one species - Hylocomium proliferum.

4.2 Spatial structure of forest phytocenosis.

The tier is the main structural unit of the vertical composition of the biocenosis. A tier is a layer of biocenosis, which is formed by a group of plants of the same height, this concept:

1. morphological (the layer is formed by the life forms of plants - the more complex the life forms, the more complex the structure)

2. ecological (the tier is composed of species of different groups - the tendency of alignment in the tier)

3. phytocoenotic - this is a layer of the community, saturated with life, which plays an important functional role in the system. All living things are subject to layering.

The composition of the 1st tier includes pine, spruce and birch.

The average age of plants is about 50 years.

The average stand height is 25-28 m.

The average diameter of a pine trunk is 40.6 cm.

The maximum diameter is 60 cm.

Crown density -0.5.

The 2nd tier is represented by: trembling poplar, birch, mountain ash, pine, pedunculate oak.

3 tiers are herbs and shrubs. The composition of the 3rd tier includes: blueberries, lingonberries, heather, reed reed, meadow maryannik, raspberries (juvenile), winding meadow, cat's foot, bark, mosses.

The division of plants into tiers allows each plant to occupy its own ecological niche and reduce competition between species. The spatial structure provides species diversity in the biocenosis.

4.3 Ecological structure of forest phytocenosis

Table 4.2 Ecological structure of forest phytocenosis

Conclusion: During the internship, we analyzed the vegetation of the forest phytocenosis in terms of life forms, relation to light, moisture and soil trophicity. In the blueberry pine forest, we found and described 5 plants. Of these, most are shrubs (60%) and 40% herbs. The most common plants in relation to light are shade-tolerant (60% of the total), shade-loving and light-loving plants were the most rare (20% each). In relation to soil moisture during the study of forest phytocenosis, mesophytes were most common (80% of plants), xeromesophytes were rare (20%). In relation to soil trophicity, oligotrophs (80%) and megatrophs (20%) were most frequently encountered.