Introduction

The environmental education of schoolchildren, the formation of a responsible attitude towards nature and the rational use of its resources is the most important problem of our time. One of the forms of environmental education can be school sites, where students acquire the basics of environmental knowledge and conduct systematic research work on topical issues of ecology and biology. This work is dedicated to the significant date of our school, it turns 25 years old. The purpose of our work is to determine the current state of the flora on the territory of the secondary school with. Aikino Ust-Vymsky district of the Komi Republic. To achieve this goal, specific tasks have been identified:

Most fully identify and determine the species composition of the flora on the territory of the school site.

Conduct a taxonomic, systematic, geographical, ecological and biomorphological analysis of vascular plants growing on the school site.

Assess the current state of the flora on the territory of the school site and offer recommendations for its further landscaping and for long-term monitoring.

The scientific significance of our work lies in the fact that on its basis it is possible to conduct monitoring studies to determine the dynamics of development of various phytocenoses in a given area, as well as to environmentally substantiate scientific and practical recommendations for expanding the list of ornamental woody plants enriched with introduced species in the landscaping of villages and schools. . The results of our research will be included in the environmental passport of the school site and are already being used for biology, geography, environmental talks, lectures, games, quizzes and excursions along ecological paths.

Natural conditions of the study area

The climate of our region is temperate continental, with lower total temperatures during the active growing season and a uniform distribution of precipitation. A general idea of ​​the region's climate is provided by the data of climatic factors given in Table 1 based on long-term observations at the Ust-Vymsk meteorological station.

The growing season (the period with an average daily temperature above 5 °C) begins in early May and ends in September. Its average duration is 100–120 days, which is compensated by the presence of a long daylight hours. The sum of active temperatures above 10°C in this region is 1200–1400°C (Geographic Atlas…, 1994). According to the amount of precipitation, the study area is classified as excessively humid (Atlas…, 1997).

On average, 500-600 mm of precipitation falls per year, a large number of days with precipitation is typical (204 days per year). The amount of precipitation (522 mm) exceeds their annual evaporation (352 mm). More than 56% of the annual precipitation falls during the growing season, which has a positive effect on plant growth.

Air humidity averages 79% per year. Its lowest indicators fall in the spring and summer months, the highest - in autumn and winter (Isachenko, 1995). The average depth of soil freezing is 98 cm. The average dates of river freeze-up are November 10–15;

According to soil zoning, the study area is included in the Vychegdo-Luzsky region of typical podzolic soils (middle taiga) of the Vychegdo-Mezen geomorphological district. Waterlogged variants develop on peaty-podzolic, gleyed soils to varying degrees, since waterlogging occurs due to a decrease in atmospheric water runoff (Zaboeva, 1973). Soil acidity is strong - pH = 3.6–4.5

Table 1. Data of climatic factors based on long-term observationsUst-Vymsk weather station

Me-sya-tsy

Yu.P. Yudina (1954) the study area belongs to the middle taiga subzone. The study area is included in the Vychegodsko-Sysolsky geobotanical district, the northern boundary of which is the valley of the river. Vychegda. There are few dry meadows, they are very unstable, quickly covered with moss and overgrown with shrubs and forests. Farming from the mainland is partially shifting to the river valleys and to the southern slopes. Meadows in the valley of the lower Vychegda are forb-grass and cereals. The yield of herbs in these meadows is high (3–4 t/ha).

Method of collection and processing of material

Field studies of flora and vegetation on the territory of the school site with. Aikino were performed by us during the summer periods of 2004–2006. To study the flora of this area, the method of specific (elementary) floras (CF), developed by A.I. Tolmachev, was used. (1974). According to this method, the flora was examined throughout the territory of the site. We laid routes throughout the site, during which the species of plants, epiphytic lichens and mosses were identified, obscure species were taken in bouquets, in a herbarium and were determined at school, at home, the Institute of Biology of the KSC Ural Branch of the Russian Academy of Sciences.

The collected material was identified according to the "Flora of the North-East of the European Part of the USSR" (1974–1977). The names of the species are given according to the summary of S.K. Cherepanov (1995). To characterize the flora of the school site, a general list of vascular plants was compiled, the number and percentage of species, genera, families of this flora were determined, and a separate list of the assortment of ornamental woody plants used in school gardening was given with the number and percentage of species, genera, families of this group. The method of biographical coordinates was used to analyze the flora. The analysis of life forms was carried out according to the system of I.G. Serebryakova (1962). The analysis of species according to biotypes of Raunkier, according to their ecological and coenotic confinement was carried out.

Research results and discussion

The territory of the studied school site (3.7 hectares) is located at the address: with. Aikino, st. Central, d. 100 "A". It is covered with vegetation on an area of ​​3.3 hectares. Unlike natural communities, anthropogenic landscapes are characterized by direct human intervention in the habitat of animals and plants. This leads to the formation of a new natural and economic complex. In our case, this complex is a school site.

When analyzing its flora, we found 220 species from 137 genera and 44 families, which is slightly less than half (45%) of the entire flora of the vicinity of the village. Aikino. Spore vascular plants (pine and horsetails) number 8, angiosperms - 212 species (of which 39 are monocots, 173 are dicots). The set of ten leading families turned out to be almost the same as the flora of the taiga zone.

On the territory of the school site, the first 3 places are occupied by the Aster family( Asteraceae ) – 29 (13.2%), bluegrass( Poaceae ) – 22 (10%) and rosés( Rosaceae ) – 17 species (7.7%), and in the flora of the taiga zone this three includes the sedge family (Cyperaceae ), which in our case takes only 11th place. Increased family roleLamiaceae due to a significant number of weed species from the genus Pikulnik (Galeopsis ) .

The ten leading families include 62% of the total species composition, which is typical for the floras of the middle taiga zone and indicates the boreal nature of the flora of the school site. The birth spectrum starts withCarex ( 7) andSalix (6 types). This is common in boreal floras. One third of the families (bindweeds– Convolvulaceae , cyanotic -Polemoniaceae ) and a large number of births (chastukha -Alisma , adoxa - Adoxa ) have only one species each, which indicates a certain depletion and migratory nature of the boreal floras (Tolmachev, 1954).

Features of the flora and vegetation of the Boreal floristic region, which includes the studied territory, are determined by the boreal latitudinal group of species (Martynenko, 1989). It includes more than 70% of vascular plants. Boreal species are forest-forming species (Siberian spruce -Picea obovata , forest pine -Pinus sylvestris ), shrubs (blackcurrant -Ribs nigrum , wild rose May - Rosa majalis ) and herbs (meadow foxtail -Alopecurus pratensis , fence peas -Vicia sepium ).

The second place in terms of species diversity is occupied by a polyzonal group (19%), which includes species widely distributed in several natural zones (common ragwort -Senecio vulgaris , shepherd's bag -Capsella bursa - pastoris ). Economic activities are carried out on the territory of the school, as a result, an increase in the coenotic role of eurytopic polyzonal species is observed. Southern latitudinal groups - nemoral (1 species: folded mannik -Glyceria notata ) and forest-steppe - make up about 7% of the species. The forest-steppe latitudinal group includes species that are usually distributed in grassy communities of the steppe and forest-steppe zones of our country, such as narrow-leaved bluegrass ( Poa angustifolia ), Danish Astragalus (Astragalus danicus ) and others.

A very small group (1.4%) is formed by species of the northern latitudinal groups, the distribution area of ​​which lies in the Arctic and Subarctic - arctoalpine (alpine bluegrass -R oa alpina ) and hypoarctic (philico-leaved willow -Salix phylicifolia and ozhica multicolored -Lusula multiflora ). More than half of the longitudinal groups of the flora of the school site have Eurasian areas (aspen -Populus tremula , meadow geranium -Geranium pratense ), the second place (23.6%) in this indicator is occupied by the Holarctic (circumpolar) group (black sedge -Carex Nigra , field violet -Viola arvensis ). A significant proportion (15.4%) of the flora is made up of species with European ranges, many of which play a significant role in the composition of forests (grey alder -Alnus incana , drooping birch -Betula pendula ) and meadow (giant fescue -Festuca gigantea , awnless rump -Bromopsis inermis ) communities.

About 7% of the flora belongs to the pluriregional (almost cosmopolitan) group, which includes mainly polyzonal weeds (field bindweed -Convolvulus arvensis , Veronica field -Veronica arvensis ) plants that are widely distributed throughout the world. The proximity of our republic to Siberia and historical ties with the Siberian flora have determined here a certain number of Asian (Siberian) species (0.9%) - bristly currant (Ribs hispidulum ) and wild rose (Rosa acicularis ). Near the school, in a flowerbed, from year to year, the only representative of America grows by self-sowing - the amaranth is thrown back (Amaranthus retroflexus ), once introduced with other cultivated flower seeds.

More than half of plant species grow in meadow (54.6%) communities, and one third in weed-ruderal habitats. Abandoned areas of fields and meadows draw attention. Weeds are actively growing here - horsetail (Equisetum arvense ), couch grass (Elytrigia repens ), Sosnovsky's hogweed (Heracleum sosnowskyi ), field sow thistle (Sonchus arvensis ). At one time, dozens of biologists worked on the creation of Sosnovsky's hogweed, combining the best features of several plants. We got an "ideal plant" with a large biomass and energy of seed reproduction, extremely unpretentious.

Now this introduced plant is a problem XXI century. It fills everything around, crowding out other plants. Thus, uncontrolled human impact on nature can lead to detrimental consequences (Orlovskaya et al., 2006). A large number of ruderal species grow in manured areas (dioecious nettle -Urtica dioica , common flaxseed -Linaria vulgaris , curly thistle -Carduus crispus ). More than half of the weeds are adventitious species introduced from the southern regions of our country (Silene noctiflora , Arabis gerardii ).

The forest cenotype (10%) is represented mainly by woody plants - Siberian larch (Larix sibirica ), mountain ash (Sorbus aucuparia ), goat willow (Salix caprea ) and others. The presence of marsh (3.7%) and coastal-water (1.4%) cenotypes is due to insignificant watering in the ravines where springs flow.

The selection of ecological groups of plant species was carried out on the basis of their relationship to the moisture factor (Poplavskaya, 1948; Goryshkina, 1979). Most of the plant species of the school site belong to mesophytes (76.5%), growing in conditions of sufficient moisture (white gauze -Chenopodium album , sorrel sour -Rumex acetosa ).

The second place in terms of the number of species is occupied by plants of dry habitats that can tolerate a significant lack of moisture - xeromesophytes (medium cinquefoil -Potentilla intermedia , rough cornflower -Centaurea scabiosa ) .

The group of hygrophytes includes 10.4% of plant species (bog Belozor –Parnassi palustris , marsh bedstraw -Galium palustre ) that live in humid environments. According to the life forms of Raunkier, hemicryptophytes (60.5%) prevail in the flora of the school site, which is typical for the forest zone, the second place is occupied by therophytes (18.5%), represented mainly by plant species in the anthropogenic disturbed areas of the school.

In the analyzed flora, 90% of the species are herbs, of which 67.3% are perennials, among which rhizomatous (32.7%) and taproot (15%) plants predominate. In the former, this ensures their stable fixation in the territory and good distribution even with a weakened seed renewal due to intensive vegetative reproductionCirsium setosum , coltsfoot -Tussilago farfara ). A significant proportion of one- and two-year-olds (19.1%) are mainly anthropochoreous species (medium chickweed -Stellaria media , mountaineer bird -Polygonum aviculare ). They take an active part in open groups and in the overgrowth of disturbed areas.

The set of tree life forms on the school plot is not rich - 10%. A large area is occupied by lawns and flower beds (91%), and trees and shrubs - only 0.5 ha. In the course of our research, 33 species of woody plants (of which 12 are introduced) from 22 genera and 9 families were identified. Of the ornamental tree species, the most typical are fluffy birches (Betula pubescens ) and warty (B . R endula ) and many species of willows, as well as from introduced species - balsam poplar (Rohr ulus balsamifera ) and yellow locust (Caragana arborescens ).

The systematic composition of woody plants is variegated. The largest number of species are represented by the Rosaceae families (Rosaceae ) – 10 (30%) and willow (Salicaceae ) – 8 (24%). In the Red Book of the Republic of Kazakhstan (1998), the elderberry is listed (Sambucus racemosa ), which is very rare in the southern forests of our republic and is used in the landscaping of our village and school. The Komi Republic has 74% of the forested area (Government Report…, 2005), but the species composition of woody plants is poor, represented by only 101 species (Flora of the North-East…, 1974–77), of which only 45 are suitable for landscaping.

In this work, 21 species of woody plants from the local flora, used in landscaping the school site, are identified. The most promising ecological and geographical areas for attracting woody and shrubby plants are: the European part of Russia, North America, East Asia, and the Far East (Skupchenko et al., 2003).

The list is made up of 29 species of woody plants, taking into account fruiting or successful vegetative propagation, seedlings of which can be purchased at the arboretum of the Institute of Biology of the KSC Ural Branch of the Russian Academy of Sciences or the nurseries of the Aikinsky and Chernamsky forestries. List of species of woody plants recommended for landscaping p. aikino

Acer ginnala Maxim .

Berberis amurensis Rurp .

Cotoneaster integerrimus Medic .

Crataegus chlorosarca Maxim .

Crataegus curvicepala Lindl.

Crataegus dahurica Koehne

Crataegus submolis Sarg.

Euonymus europaeus L.

Euonymus verrucosus Scop.

Fraxinus pensyvanica Marsh.

Malus cerasifera Spacy.

Malus prunifolia (Willd.) Borckh.

Malus purpurea (Barbier) Rehhd.

Padus maackii (Rupr.) Kom.

Philadelphus coronarius L.

Philadelphus coronarius 'Luteus'

Picea pungens Enggelm.

Ribes alpium L.

Salix alba L.

Sorbaria sorbifolia (L.) A. Br.

Sorbus sambucifolia Roem.

Spirea beauverdiana Schneid.

Spirea beauverdiana Schneid. x billiardii Hering.

Spirea chamaedryfolia L.

Spirea trilobata L.

Syringa amurensis Rupr.

Syringa josikaea Jacq. Fil.

Syringa wolfii Schneid.

Swida alba "Argenteo -; line-height: 150%"> It should be noted that some woody plants (hawthorn, wild rose, birch, Tatar maple, Siberian larch) have a well-developed dust-retaining property and gas resistance (poplar, bird cherry), so they are used in plantings to reduce environmental pollution.

On the territory of the school site, we identified 24 species of epiphytic lichens from 18 genera and from 7 families, and according to life forms - 4 fruticose, 11 foliose and 9 scale. Nitrophilic lichens are very abundant among the foliose ones: stellate fiscia (R hyscia stellaris ) and gray-blue (Ph . aipolia ), xanthoria wall (Xanthoria parietina ) and scale: scoliciosporum chlorococcal (Scoliciosporum chlorococcum ).

Bushy forms are noted - grooved ramalina (Ramalina sinensis ), bryoria (Bryoria sp . ), sleeping hard (Usnea hirta ) and evernia plum (Evernia prunastri ) is depressed. Also, 3 types of epiphytic moss were identified - Pilesia multiflorum (Pylaisiella polyantha ( Hedw .) Graut - seven.Hypnaceae), leskea polycarpous (Lescea polyocarpa Hedw . - seven. Lescaceae ), orthotrichum is beautiful (Orthotrichum speciosum Ness in Sturm - seven. Orthotrichaceae ), which grow well at the base and on the north side of the trunks of old deciduous trees in settlements.

conclusions

1. In the flora of the school site with. Aikino, Ust-Vymsky district, 220 species from 137 genera and 44 families were identified, which is slightly less than half (45%) of the entire flora of the vicinity of the village. Aikino, as well as 24 species of epiphytic lichens from 18 genera and 7 families, and 3 species of mosses.

2. Ecological and biological analysis of the school plot showed the predominance of species of the boreal Eurasian element and the advantage of mesophilic herbaceous rhizomatous perennials of the meadow coenotype.

3. 33 species of woody plants from 22 genera and 9 families used in landscaping the school site have been identified.

4. It is necessary to use an extended list of landscaping assortment of woody plants, proposed by the staff of the Institute of Biology of the KSC Ural Branch of the Russian Academy of Sciences and the creation of long-term monitoring on the territory of the school site with. Aikino Ust-Vymsky district to continue research work.

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The concept of flora

Flora is a collection of plant species that live in a particular area. We can talk about the flora of a particular region, region, country, or some physical-geographical region (for example, the flora of Siberia, the flora of Europe, the flora of the Omsk region, etc.). Often, flora also means a list of plants noted in a given territory.

The floras of different territories differ significantly in the number of their constituent species. This is primarily due to the size of the territory. The larger it is, the larger, as a rule, the number of species. Comparing approximately the same size parts of the land in terms of the number of plant species growing on them, poor floras and rich floras are identified.

The flora of tropical countries is the richest in species; as you move away from the equatorial region, the number of species decreases rapidly. The richest is the flora of Southeast Asia with the archipelago of the Sunda Islands - more than 45 thousand plant species. In second place in terms of wealth is the flora of tropical America (the Amazon basin with Brazil) - about 40 thousand species. The flora of the Arctic is one of the poorest, there are a little over 600 species, the flora of the Sahara Desert is even poorer - about 500 species.

The richness of the flora is also determined by the diversity of natural conditions within the territory. The more diverse the environmental conditions, the more opportunities for the existence of various plants, the richer the flora. Therefore, the floras of mountain systems are, as a rule, richer than the plain floras. Thus, the flora of the Caucasus has more than 6,000 species, and on the vast plain of the middle zone of the European part of Russia, only about 2,300 species are found.

The richness of the flora can also be due to historical reasons. Older floras, which are many millions of years old, tend to be particularly rich in species. Plants that died out in other areas due to climate change, glaciation, etc. could be preserved here. Such ancient floras are found, for example, in the Far East and Western Transcaucasia. Young floras formed relatively recently are much poorer in species.

Significant differences in systematic composition are observed between the floras of different territories. In countries with a temperate climate, as a rule, the families of Asteraceae, legumes, Rosaceae, grasses, sedges and cruciferous plants predominate. In arid regions, various representatives of the haze are very common. Tropical floras are rich in representatives of orchids, euphorbia, madder, legumes, and cereals. In the savannahs and steppes, cereals take the first place.

flora elements

Arctic - a group of species whose ranges are located in the Far North, in the continental tundra zone and on the Arctic islands. It breaks up into a number of more fractional elements, for example, Western Arctic and Eastern Arctic. On the other hand, some arctic species have parts of their ranges (disjunctions) in the Caucasus, Altai, etc., so one can speak of an arctic-caucasian, arctic-alpine, etc. element.

Northern (or boreal) - a group of species with ranges located mainly within the northern parts of the forest region, namely in the area of ​​\u200b\u200bconiferous forests. Here, too, there are further subdivisions: Euroboreal - only in the European part, Sibboreal in Siberia, etc.

Central European - a group of species with ranges in Central Europe, entering the eastern segments of their ranges into the western part of the Union, in some cases even reaching beyond the Urals.

Basically, this group, which is more thermophilic than the previous one, is distributed in the area of ​​broad-leaved forests.

Examples: common oak (reaches the Urals), sharp-leaved maple (as well as field and Tatar maples), ash, hornbeam, beech, winter oak (Quercus petraea), such herbaceous species inherent in broad-leaved forests as hoof, Peter's cross (Lathraea squamaria ), lungwort (Pulmonaria officinalis, etc. Lungwort area.

Atlantic - found in the western regions of the European part of the USSR. This element is most strongly represented on the territory of the Atlantic coastal parts of Europe. Some species are more advanced to the east. Among the plants growing on our territory, we can mention lobelia (Lobelia Dortmanna), waxwort (Myrica Gale).

Pontic - a group of species mainly of the southern Russian steppes, but also found in the Romanian and Hungarian steppes (if the species are found mainly in the Hungarian steppes, then this is a Pannonian element). This includes numerous species of our steppe spaces: Adonis (Adonis vernalis), Chistets (Stachys recta), purple mullein (Verbascum phoeniceum), yellow scabiosa (Scabiosa ochroleuca), steppe cherry (Cerasus fruticosa), broom (Cytisus ruthenicus), etc. The Pannonian element is very weakly represented in our country. Area of ​​the adonis.

Sarmatian - combines species occupying the territory between the southern steppes and coniferous forests in the north, without going far to the west, beyond the western borders of the Union. These species are less thermophilic in comparison with Pontic ones. A few examples: peas (Vicia pisiformis), hill violet (Viola collina), sandy astragalus (Astragalus arenarius) (and partly Southern Siberia); these are generally steppe species. It is better, in order to avoid confusion, to speak here of the North Kazakhstani element).

Mediterranean - a group of species distributed in dry areas surrounding the Mediterranean Sea, and in the east growing on the coasts of the Black Sea - in the Crimea and the Caucasus (also in the Caspian regions). Trees and shrubs with evergreen leathery leaves and dry-loving herbs. Examples: strawberry tree (Arbutus andrachne), boxwood (Buxus sempervirens), sumac (Rhus coriaria), wild jasmine (Jasminum fruticans), etc. Some authors also include Near East and Central Asian elements in the Mediterranean element. Boxwood area.

Anterior Asian. This includes species that have a range in the countries of Western Asia - from the borders of Iran in the east to the shores of the Mediterranean Sea. Basically, these are plants of dry mountainous countries. It breaks up into a number of elements of a narrower meaning, of which we note Iranian, which generally coincides with the Iranian Highlands and extends into our borders in Transcaucasia. 9. Central Asian - confined to Central Asia, to its large mountain ranges (Tien Shan, Pamir-Alai, Tarbagatai, Altai). It is very complex and breaks down into a number of more fractional elements.

Turan - unites a group of species whose ranges are mainly associated with the deserts of the Turan lowland of Central Asia. Desert character element. In basic terms, this is the Aral-Caspian element of some authors, which, however, is usually understood somewhat more broadly. A typical Turanian element is a group of Central Asian desert polynyas (Artemisia). Range of white wormwood.

Manchurian - a group of species that has the main area of ​​\u200b\u200bthe range in Manchuria and enters the southern parts of the Far East Territory. A number of broad-leaved trees and shrubs: Manchurian walnut (Juglans manshurica, Fig. 108), Manchurian aralia (Aralia manshurica), velvet tree (Phellodendron amurense, various-leaved hazel (Corylus heterophylla), etc.

Elements of the flora of the Caucasus. Especially for the Caucasus, you can specify some more geographical elements, spatially more limited. Caucasian - consists of species associated with their ranges with the Greater Caucasus; this includes Caucasian endemics (forest and alpine). Colchis - a group of species that have their range in the Colchis province of the Caucasus, that is, in Western Transcaucasia (Adzharia, Abkhazia and more northerly coast). Species forest, limestone, mountain-meadow. Most of the elements are ancient in their genesis (tertiary): pontic oak (Quercus pontica), rhododendron (Rhododendron Smirnowii), birch (Betula Medwedewii) and others. Hyrcanian - species occupying the extreme southeast of the Caucasus, but the main mass of species is concentrated abroad in northern Iran. Ancient tertiary elements (mainly forest species): Parrotia persica, honey locust (Gleditschia caspia), silk locust (Albizzia julibrissin), genus Danae, etc.

floristic saturation phytogenic swamp

The concept of floristic richness and floristic saturation

The floristic composition is the complete set of plant species found within a particular plant community.

The floristic composition is the most important constitutional feature, which largely determines the structure and functions of the community. This is a very informative sign that speaks about the ecological conditions in which the community is located, about its history, the degree and nature of its disturbance, etc.

The floristic composition is characterized by a number of indicators.

The first is species richness, that is, the total number of species characteristic of a phytocenosis. This indicator can vary from 1 (monodominant single-species communities) to 1000 or more species (some tropical forests). According to the witty remark of R. Margalef (Margalef, 1994), in any case, species richness can be placed between two extreme situations: the Noah's Ark model - there are a lot of species, but each is represented by only one pair of individuals, and the "Petri dish" - microbiological culture , which represents a huge number of individuals of the same species. Species richness is the simplest measure of alpha diversity, that is, biotic diversity at the phytocoenosis level.

With all the interest in the indicator of the degree of species richness, it is obvious that its use in comparative analytical constructions is in many cases incorrect. So, for example, in terms of species richness, a small swamp and a patch of tropical forest are incomparable. Therefore, in geobotany, the indicator of species saturation is much more often used - the number of species per unit area. But here it should be noted that in order to determine the species saturation of a phytocenosis, it is necessary in any case to know its species richness.

If species richness is identified using square or round areas of increasing size inscribed into each other, then, as a rule, with an increase in the area of ​​​​the accounting unit, the number of species identified in the phytocenosis will increase. If we build a curve from the obtained values, then it will quite well reflect the dependence of the increase in the number of species on the size of the accounting area. As a rule, such a curve will initially rise sharply upwards, and then gradually transition to a plateau. The beginning of the transition to the plateau will show that the vast majority of species in the phytocenosis have already been identified on a site of this size. As a rule, the richer in species the phytocenosis, the smaller the size of the area at which the curve goes to the plateau.

In order to characterize the floristic composition of the phytocenosis as fully as possible, all plants are first rewritten, standing at one point on the boundary of the described area. After all plants are marked, including the most inconspicuous ones visible from the observation point, they slowly move along the border, recording new plants that have not yet been included in the list. Bypassing the entire area. make its intersection diagonally, continuing to enter the plants. This recording method ensures the completeness of the list and saves the described area from trampling by the researcher.

With a single account of the species composition, it is usually impossible to obtain a complete list of species characterizing the phytocenosis. Some species have a short growing season, resting the rest of the year as seeds or underground organs; other species begin their development late and do not fall into the lists compiled during the spring description of the phytocenosis. Therefore, in order to obtain more complete information about the floristic composition of the community, it is necessary to compile lists of plants two or three times during the growing season.

Characteristics of the flora of the world

A section of the earth's surface with its inherent relief, the surface layer of the atmosphere, surface and groundwater, soils, communities of flora and fauna, naturally interconnected, is called a natural territorial complex (NTC). The same concept is also called "geosystem". The ecosystem, which is the main concept of environmental science, is a combination of living organisms and their environment in interaction based on metabolism and directed energy flows: These concepts are very similar in content: in all three concepts, we are talking about a certain territory of the earth's surface. Geosystems, or PTC, mean areas of the earth's surface at various levels that are in regular relationships, from the smallest - facies - to the global - geographical shell. Ecosystems refer to spatial units of various sizes inhabited by organisms characterized by species composition, abundance and biomass, patterns of distribution and seasonal dynamics. The ecosystem of the highest rank is the biosphere. The biosphere and the geographic shell are almost identical concepts. In ecology and geography, not only global units coincide, like the biosphere and the geographical shell, but also others - of a lower rank: as concepts that are close in meaning, but different in form. For example, "facies" in landscape science and "zone" in physical geography are very close in meaning to both biological and ecological terms - "biocenosis" and "biome".

In ecology, biological organisms, their relationship with the environment, species composition, biomass and energy exchange are put in the forefront, since living organisms are distinguished by bio-geochemical activity. Especially green plants, which, as a result of the process of photosynthesis, continuously exchanging substances and energy with non-living components of nature, create primary organic products. In nature, only green plants convert solar energy into biochemical energy and accumulate it. Due to such accumulated energy of green plants, life exists and is preserved on Earth. Animals feed on organic substances that are synthesized by plants, thanks to which they continue their kind. Living organisms that provide continuous metabolism and energy flows form the basis of an ecosystem. In it, the most important component is the plant environment, which affects the soil, wildlife and microorganisms. The state of vegetation determines the nature of biogeocenoses, their morphological and functional structure.
In solving environmental problems, an important role is played by the preservation of the natural state of green plants, land areas and species diversity in the process of human economic activity. The reduction in the annual production of green plants has a negative effect on the biochemical cycle of substances and energy flows, on maintaining the ecological balance in the ecosystem. And negative results cannot but affect a person's life. The ecological situation among animal organisms is in direct connection with the ecological state of vegetation.

For mankind, the plant world is the most important component of the habitat, the main source of food, medicinal and technical raw materials, building material. Vegetation is the main basis of animal husbandry. Cultivated plants are also grown in order to improve the human environment, as well as to increase soil fertility, protect them from water and wind erosion, to fix loose sands, etc.

However, vegetation as one of the components of the natural-territorial complex is quite vulnerable and has low resistance to external influences. In the hierarchical system of the natural-territorial complex, vegetation is in a dependent position on a number of components. Of the PTC components, the most stable is the lithological link, i.e. geological structure and relief. Air mass is also one of the stable components of PTC. After them is the water component, then the soil, and then only the vegetation. Altering any of the above components will result in a violation of the botanical component. If the relief is disturbed, the soil is washed away, the water regime is changed, then there can be no question of preserving natural vegetation. But, if other components of nature have not undergone changes, then it is possible to preserve and restore the plant environment.

The animal world is also an important part of the biosphere. Animals are the most vulnerable component of the NTC - the main consumer of primary organic products created by plants, which provide the cycle of chemical elements in the biosphere.

In soil fertility and weathering of rocks, the role of animals is great. Animal organisms in the composition of the soil, such as earthworms, various beetles, spiders, microorganisms, digging rodents, constantly mix the soil, loosening it, increasing pores and voids in it, contribute to the penetration of air into the soil and, together with the remains of dead plants and animals, increase its fertility. . Small insects provide pollination of plants, thus creating the possibility of quantitative reproduction. By transferring the seeds of some plants from place to place, they contribute to their spread. Animals improve pastures to a certain extent, and only their excessive numbers within a limited area can lead to deterioration of the soil cover.

Animals play an important role in people's lives. They provide us with food, serve as a raw material base for industry. Wild animals are the source of the genetic fund for animal husbandry. At the present stage, people are trying to domesticate different types of wild animals in order, for example, to use their valuable fur.
Some species of animals cause serious damage to the economy, and people try to reduce such losses.

The fauna, together with the flora, is the most important component of the ecosystem, a factor that determines its current state. Ecological situations on the ground are determined by the state in which people, animals and plants are.).
The animal world, as one of the components of the natural-territorial complex, is the most vulnerable, especially susceptible to external influences, including those resulting from human economic activity, and has the least stability. This component is dependent on all other PTC components. In the hierarchical series of the geosystem, it occupies the last step, because the influence of human economic activity primarily affects it, leading to a sharp increase in the number of some species, a reduction in others, or the complete disappearance of others. The animal world is the most affected of all components of the NTC from human economic activity.

Floristic division of the Earth

An attempt at floristic zoning of the earth's landmasses was made as early as the first half of the 19th century. Floristic zoning can be based on various principles. In particular, it is possible to single out individual regions depending on the richness of species, the features of the systematic composition, the presence or absence of certain elements of the flora.

However, most often the land area of ​​the globe is divided into a series of mutually subordinate areas, or phytochorios (from the Greek phyton - plant and horos - space), identified on the basis of similarities and differences in the systematic composition of their floras. As new data accumulates, they are repeatedly refined. A significant contribution to the zoning of the Earth according to the composition of floras was made by the Russian botanist A. L. Takhtadzhyan in his book Floristic Regions of the Earth (1978). An analysis of the ranges and the identification of the geographical and genetic elements of a given flora are essential in determining the boundaries of phytochorios.

Where the composition of the main elements of the flora changes, one flora is replaced by another. In works on floristic zoning, the distribution of endemics in the floras is especially important.

Endemics are species (plants) that are not found anywhere except in a given territory. Endemism is a broader concept, since endemic species can, for larger areas, constitute both endemic genera and even endemic families. The degree of endemism is very different for different areas. Flora of isolated oceanic islands is highly endemic. So, for the flora of the Hawaiian Islands, 82% of endemics are indicated, for the flora of the Galapagos Islands - more than 50, in the aboriginal part of the flora of New Zealand - 82%. Of the mainland floras, the flora of Australia, a continent that has long been isolated from other significant land areas, is the most isolated.

Here, out of 12 thousand species, more than 9 thousand are endemic. But the number of endemic families here is still less than in East and Southeast Asia. Among endemics, botanists try to distinguish between paleoendemics and neoendemics. Paleoendemics are of ancient origin. These are, as a rule, systematically isolated taxa. The number of paleoendemics to a greater extent determines the originality and antiquity of the flora. Neoendemics most often include species, less often genera, which have arisen relatively recently and have not yet had time to spread widely. Especially a lot of neoendemics in mountain ranges. A large number of neoendemics indicates active speciation processes and the relative youth of the main core of the flora. The centers of modern diversity of certain taxa are primarily associated with the abundance of neoendemics.

Floristic kingdoms

Floristic kingdoms (regions) of the globe, historically formed on certain parts of the Earth's surface, are the largest associations of related floras. Isolation F. c. substantiated primarily by paleogeographic (beginning mostly from the Cretaceous period), as well as modern soil and climatic factors. In each F. c. there are complexes of endemic families and genera of plants, the origin and distribution of which during a long geological history proceeded within its boundaries. F. c. subdivided into subordinate floristic units of a lower rank (floristic regions, provinces, districts, districts, etc.). Although in the division of the earth's surface into F. c. (or areas) by different authors there are discrepancies, in its fundamental basis it is uniform (see Floristic zoning).

The vast Holarctic floristic kingdom (or the Holarctic region) occupies the entire extratropical space of the North. hemisphere, in the south to the Cape Verde Islands, sowing. parts of the Sahara and Arabia, the coast of the Persian Gulf, south. slopes of the Hindu Kush and the Himalayas, the extreme south of China, in the North. America - to sowing. parts of the Mexican Highlands and the shores of the Gulf of Mexico.

Historically, the floras of the Holarctic are associated with the ancient Paleogene-Neogene arcto-tertiary floristic complex, its derivatives, with Amer. Madro-tertiary floras. Relations with tropical flora proper have long been limited to the vast Tethys basin, whose isolating role opposed the similarity of climatic conditions in the south of the Holarctic with tropical ones proper. Flora of the Holarctic F. c. it is highly differentiated, which makes it subdivide it into a number of floristic regions: Arctic - has poor floras with a predominance of such families as cereals, sedge, cruciferous, clove, Compositae, etc .; Boreal - characterized by the dominance of coniferous trees, cereals, sedge, composite flowers are distinguished by the number of species; the Central European region is characterized by the dominance of deciduous tree species (temperate forests), an abundance of cereals, composites, rosaceae, and other groups common to the Holarctic; Mediterranean - richly represented by Compositae, papilionaceous, cereals, cruciferous, labial, carnation, umbellate (flora is highly differentiated in space, progressive endemism is pronounced); Central Asian - relatively poor flora, similar to the Mediterranean, Boreal and East Asian; East Asian preserved many features of the Arcto-Paleogene-Neogene species in combination with the development of progressive endemism; California (Sonoran) and Appalachian - the basis of the flora are relics of the Paleogene-Neogene and Madro-Paleogene-Neogene complexes with elements of progressive endemism.

The paleotropic floristic kingdom (or the Paleotropical region) occupies the space to the south from the Holarctic floristic kingdom (in the Eastern Hemisphere) to the subtropics of South Africa, together with the islands of the Indian and Pacific oceans. The flora is rich and highly differentiated. The leading position is occupied by pantropical families, which are characterized by division into territories of the Old and New Worlds (for example, palm trees and orchids); madder, euphorbiaceae, palms, orchids, melastomas, aroids, mulberries, laurels, and a number of tubular groups are widespread. Cosmopolitan families and species are represented by grasses, legumes, Asteraceae, and others. There are few endemic families - dipterocarps, pandanaceae, and some others. The species composition of floras is rich, especially in areas dominated by forest vegetation. The richness and differentiation of floras make it possible to single out regions in the paleotropical realm: Sahara-Sind, Sudano-Zambezian, Guinea-Congo, Kalahari, Cape, Madagascar, Hindustan, Indochinese, Malay, Papuan, Hawaiian, Polynesian.

The Neotropical floristic kingdom (or the Neotropical region) occupies the space of the New World from the South. California and the Bahamas to 41° S. sh. The flora is characterized by the mass presence of cosmopolitan (orchids, Asteraceae, legumes, cereals, etc.) and pantropical (palms, myrtle, euphorbia, madder, etc.) families. The families of cacti, bromeliads, and others are endemic. Changes in the richness of floras mainly depend on climatic conditions (wet and hot forest regions of the equatorial zone, rich in species composition, change when moving to subtropical latitudes and when climbing mountains). The following areas are distinguished: Caribbean, Orinoco, Amazonian, Brazilian, Laplata, Andean.

The southern floristic kingdom occupies mainland Australia and about. Tasmania, New Zealand with adjoining islands, extreme south South. America, the subantarctic islands and Antarctica. The flora of Australia is the most peculiar - myrtle (in particular, eucalyptus), protea, mimosa, epacrid, buzz, restia, casuarina, etc. There are Australian (a number of botanists consider it as a floristic kingdom), New Zealand, New Caledonian and Magellano-Antarctic regions.

Phytogenic factors, their classification and characteristics

In the domestic literature, the most common classification of the forms of relationships between plants according to V. N. Sukachev (Table.

Table The main forms of relationships between plants (according to V. N. Sukachev, N. V. Dylis et al., 1964).

Direct (contact) interactions between plants

An example of mechanical interaction is damage to spruce and pine in mixed forests from the whipping action of birch. Swaying from the wind, the thin branches of the birch injure the needles of the spruce, knocking down the light young needles. This is very noticeable in winter, when the birch branches are leafless.

Mutual pressure and adhesion of trunks often has a negative effect on plants. However, such contacts are more common in the underground sphere, where large masses of roots are closely intertwined in small volumes of soil. The types of contacts can be different - from a simple clutch to a strong fusion. Thus, the overgrowth of vines turns out to be detrimental to the life of many tropical forest trees, often leading to breaking off branches under their weight and drying out of the trunks as a result of the squeezing action of climbing stems or roots. It is no coincidence that some creepers are called "stranglers" (Fig. 1).

Rice. 1 Liana plants: 1 - strangler ficus; 2 - dodder; 3 - curly honeysuckle (according to N. M. Chernova et al., 1995)

According to scientists, about 10% of all plant species lead an epiphytic lifestyle. Tropical forests are richest in epiphytes. These include many species of bromeliads, orchids (Fig. 2).

Rice. 2 Epiphytic orchid with aerial roots: A - general view; B - cross section of the air root with the outer layer of the suction tissue (1) (according to V. L. Komarov, 1949)

The ecological meaning of epiphytism consists in a kind of adaptation to the light regime in dense tropical forests: the ability to get out to the light in the upper tiers of the forest without large expenditures of substances for growth. The very origin of the epiphytic way of life is associated with the struggle of plants for light. The evolution of many epiphytes has gone so far that they have already lost the ability to grow outside the plant substrate, that is, they are obligate epiphytes. However, there are species that can grow in the soil under greenhouse conditions.

A characteristic example of close symbiosis, or mutualism between plants, is the cohabitation of algae and fungus, which form a special integral lichen organism (Fig. 3).

Rice. 3. Cladonia lichen (according to N. M. Chernova et al., 1995)

Another example of symbiosis is the cohabitation of higher plants with bacteria, the so-called bacteriotrophy. Symbiosis with nodule nitrogen-fixing bacteria is widespread among legumes (93% of the studied species) and mimosa (87%). Thus, bacteria from the genus Rhizobium, living in nodules on the roots of leguminous plants, are provided with food (sugar) and habitat, and plants receive from them the available form of nitrogen in return (Fig. 5).

Rice. 5 Nodules on the roots of leguminous plants: A - red clover; B beans; B - soybeans; G - lupine (according to A.P. Shennikov, 1950).

There is a symbiosis of the mycelium of the fungus with the root of a higher plant, or mycorrhiza formation. Such plants are called mycotrophic, or mycotrophs. Settling on the roots of plants, the hyphae of the fungus provide the higher plant with an enormous suction capacity. The surface of contact between root cells and hyphae in ectotrophic mycorrhiza is 10–14 times larger than the surface of contact with the soil of bare root cells, while the suction surface of the root due to root hairs increases the root surface only 2–5 times. Of the 3425 species of vascular plants studied in our country, mycorrhiza was found in 79%.

As an example of the symbiosis of fungi with insects, one can cite the symbiosis of the fungus Septobasidium with the worm insect from Coccidae, which gives a new symbiotic formation - varnishes, which, as a single organism, is introduced into culture by man.

A separate group of plants with heterotrophic nutrition is saprophytes - species that use organic matter of dead organisms as a carbon source. In the biological cycle, this important link, which decomposes organic residues and converts complex compounds into simpler ones, is mainly represented by fungi, actinomycetes, and bacteria. They are found among flowering plants in representatives of the wintergreen, orchid, and other families. Examples of flowering plants that have completely lost chlorophyll and switched to food with ready-made organic substances are saprophytes of coniferous forests - common podelnik (Monotropahypopitis), leafless chin (Epipogonaphylluon). Among mosses and ferns, saprophytes are rare.

The fusion of roots of closely growing trees (of the same species or related species) also refers to direct physiological contacts between plants. The phenomenon is not so rare in nature. In dense plantations of Piceaflies spruce, about 30% of all trees grow together with their roots. It has been established that between intergrown trees there is an exchange through the roots in the form of the transfer of nutrients and water. Depending on the degree of difference or similarity in the needs of the fused partners, relations between them are not excluded, both of a competitive nature in the form of the interception of substances by a more developed and stronger tree, and symbiotic.

The form of connections in the form of predation has a certain meaning. Predation is widespread not only between animals, but also between plants and animals. Thus, a number of insectivorous plants (dew, nepenthes) are classified as predators (Fig. 6).

Rice. 6 Predatory sundew plant (according to E. A. Kriksunov et al., 1995)

Indirect transbiotic relationships between plants (through animals and microorganisms). An important ecological role of animals in the life of plants is their participation in the processes of pollination, seed and fruit dispersal. Pollination of plants by insects, called entomophily, contributed to the development of a number of adaptations in both plants and insects. Let us name here such interesting adaptations of entomophilous flowers - patterns that form "travel threads" to nectaries and stamens, often visible only in ultraviolet rays accessible to insects; difference in color of flowers before and after pollination; synchronization of the diurnal rhythms of opening of the corolla and stamens, ensuring the unmistakable hit of the stigma on the body of the insect, and from it on the stigma of another flower, etc. (Fig. 7).

Rice. 7 Insect on a flower (according to N.M. Chernova et al., 1995)

The diverse and complex structure of flowers (different shapes of petals, their symmetrical or asymmetrical arrangement, the presence of certain inflorescences), called heterostyly, are all adaptations to the body structure and behavior of strictly specific insects. For example, flowers of wild carrot (Daucuscarota), cumin (Carumcarvi), pollinated by ants, flowers of Asarumeuropaeum, pollinated by ants and, accordingly, do not rise from under the forest floor.

Birds also take part in the pollination of plants. Pollination of plants with the help of birds, or ornithophily, is widespread in the tropical and subtropical regions of the southern hemisphere. About 2,000 species of birds are known here, which pollinate flowers when looking for nectar or catching insects hiding in their corollas. Among them, the most famous pollinators are nectaries (Africa, Australia, South Asia) and hummingbirds (South America). The flowers of ornithophilous plants are large, brightly colored. The dominant color is bright red, which is most attractive to hummingbirds and other birds. In some ornithophilous flowers, there are special protective devices that prevent nectar from spilling out when the flower moves.

Pollination of plants by mammals, or zoogamy, is less common. For the most part, zoogamy is noted in Australia, in the forests of Africa and South America. For example, Australian shrubs of the genus Driandra are pollinated by kangaroos, who willingly drink their abundant nectar, passing from flower to flower.

The distribution of seeds, fruits, spores of plants with the help of animals is called zoochory. Among plants whose seeds and fruits are carried by animals, in turn, there are epizoochoric, endozoochoric and synzoochoric. Epizoochoric plants in most open habitats have seeds and fruits with all kinds of devices for fixing and holding animals on the surface of the body (outgrowths, hooks, trailers, etc.), for example, large and cobwebbed burdock, common Velcro, etc.

In the shrub layer of forests, where many birds live, endozoochoric plant species predominate. Their fruits are edible or attractive to birds with bright coloring or juicy pericarp. It should be noted that the seeds of many endozoochoric plants increase their germination capacity, and sometimes the ability to germinate only after passing through the food tract of the animal - many Araliaceae, Sievers' apple tree (Malussieversu), etc.

Animals do not eat edible fruits and seeds of oak, Siberian pine immediately, but take them away and put them in stock. At the same time, a significant part of them is lost and, under favorable conditions, gives rise to new plants. This distribution of seeds and fruits is called synzoochory.

Microorganisms often act as plants in indirect transbiotic relationships. The rhizosphere of the roots of many trees, for example, oak, greatly changes the soil environment, especially its composition, acidity, and thus creates favorable conditions for the settlement of various microorganisms there, primarily bacteria, such as Azotobacterchroocoteum, Tricholomelegnorum, Pseudomonassp. These bacteria, having settled here, feed on the secretions of oak roots and organic residues created by the hyphae of mycorrhiza-forming fungi. Bacteria, living next to oak roots, serve as a kind of "defensive line" from the penetration of pathogenic fungi into the roots. This biological barrier is created with the help of antibiotics secreted by bacteria. The colonization of bacteria in the oak rhizosphere immediately has a positive effect on the condition of plants, especially young ones.

Indirect transabiotic relationships between plants (environment-forming influences, competition, allelopathy). Changing the environment by plants is the most universal and widespread type of relationships between plants during their coexistence. When one or another plant species or group of plant species in C, as a result of its life activity, greatly changes the main environmental factors in quantitative and qualitative terms in such a way that other species of the community have to live in conditions that differ significantly from the zonal complex of physical environmental factors, this indicates environment-forming role, environment-forming influence of the first type in relation to the others. One of them is mutual influences through changes in microclimate factors (for example, the weakening of solar radiation inside the vegetation cover, its depletion in photosynthetically active rays, changes in the seasonal rhythm of illumination, etc.). Some plants also affect others through a change in the temperature regime of the air, its humidity, wind speed, carbon dioxide content, etc.

Another way for plants to interact in communities is through the ground layer of dead plant residues, which in the meadows and steppes are called rags, grassy decay or "steppe felt", and in the forest - litter. This layer (sometimes several centimeters thick) makes it difficult for seeds and spores to penetrate the soil. Seeds germinating in (or on) a layer of rags often die from drying out before the roots of the seedlings reach the soil. For seeds that have fallen into the soil and germinate, ground residues can be a serious mechanical obstacle on the way of sprouts to light. Interactions between plants are also possible through the decay products of plant residues contained in the litter, which inhibit or, conversely, stimulate plant growth. Thus, fresh spruce or beech litter contains substances that inhibit the germination of spruce and pine, and in places with poor rainfall and weak washing of the litter, the natural renewal of tree species can be inhibited. Water extracts from forest litter also have a negative effect on the growth of many steppe grasses.

An essential way of mutual influence of plants is the interaction through chemical secretions. Plants release various chemicals into the environment (air, water, soil) in the process of guttation, secretion of nectar, essential oils, resins, etc.; when mineral salts are washed out by rainwater, leaves, for example, of trees, lose potassium, sodium, magnesium and other ions; in the course of metabolism (root secretions) gaseous substances emitted by aboveground organs - unsaturated hydrocarbons, ethylene, hydrogen, etc .; when the integrity of tissues and organs is violated, plants emit volatile substances, the so-called phytoncides, and substances from dead parts of plants (Fig. 8).

Released compounds are necessary for plants, but with the development of a large plant body surface, their loss is just as inevitable as transpiration.

The chemical secretions of plants can serve as one way of interaction between plants in a community, exerting either a toxic or stimulating effect on organisms.

Rice. 8 The influence of one plant on another (according to A. M. Grodzinsky, 1965): 1 - miasmins; 2 - volatile substances; 3 - phytogenic substances; 4 - active intravital discharge; 5 - passive intravital discharge; 6 - post-mortem discharge; 7 - processing by heterotrophic organisms

Such chemical interactions are called allelopathy. As an example, we can mention the secretions of beet seedlings, which inhibit the germination of cockle (Agrostemmagithago) seeds. Chickpeas (Cicerarietinum) have an overwhelming effect on potatoes, corn, sunflowers, tomatoes and other crops, beans - on the growth of spring wheat; root secretions of couch grass (Agropyronrepens) and brome (Bromusinermis) - on other herbaceous plants growing near them and even trees. As an extreme form of allelopathy or the impossibility of the existence of one or another species in the presence of another as a result of environmental intoxication, it is called amensalism. Amensalism corresponds to direct competition, antibiosis and antagonism. Thus, thanks to the release of toxic substances by the roots, the hawkweed (Hieraciumpilosella) from the Compositae family displaces other annual plants and often forms pure thickets over fairly large areas. Many fungi and bacteria synthesize antibiotics that inhibit the growth of other bacteria. Amensalism is widespread in the aquatic environment.

In different plant species, the degree of impact on the environment and thus on the life of the inhabitants is not the same in accordance with the characteristics of their morphology, biology, seasonal development, etc. Plants that most actively and deeply transform the environment and determine the conditions of existence for other cohabitants are called edificators. There are strong and weak edifiers. Strong edificators include spruce (strong shading, soil depletion in nutrients, etc.), sphagnum mosses (moisture retention and the creation of excess moisture, an increase in acidity, a special temperature regime, etc.). Weak edificators are deciduous species with an openwork crown (birch, ash), plants of the herbaceous cover of forests.

Competition is distinguished as a special form of transbiotic relationships between plants. These are those mutual or unilateral negative influences that arise on the basis of the use of energy and food resources of the habitat. Plant life is strongly influenced by competition for soil moisture (especially pronounced in areas with insufficient moisture) and competition for soil nutrients, more noticeable on poor soils. An example of competition is the relationship between meadow foxtail (Alopecuruspratensis) and fescue (Festucasulcata). Fescue can grow in moist soil, but does not grow in the foxtail meadow community due to suppression by the shade-tolerant and fast growing foxtail. In the formation of fescue or foxtail phytocenosis, it is not soil moisture that is decisive, but the competitive relationship between fescue and foxtail. In drier habitats, the fescue drowns out the foxtail, and in wet meadows, the foxtail emerges victorious.

Interspecific competition manifests itself in plants in the same way as intraspecific competition (morphological changes, reduced fertility, abundance, etc.). The dominant species gradually crowds out or greatly reduces its viability.

The fiercest competition, often with unforeseen consequences, occurs when new plant species are introduced into communities without taking into account already established relationships.

The concept of the swamp

A swamp is an area of ​​the earth's surface characterized by abundant stagnant or weakly flowing moistening of the upper horizons of soil and soil, on which specific marsh vegetation grows, adapted to conditions of abundant moisture and lack of oxygen in the soil.

If the thickness of the deposited peat is such that the roots of the main mass of plants reach the underlying mineral soil, then in this case the excessively moistened land areas are referred to as wetlands or swamps in the initial stage of their development.

The task of hydrology includes the study of the hydrological (and especially water) regime of swamps both in the initial stages of their formation (wetlands and swampy water bodies) and in subsequent phases of development (bog massifs).

The division of wetlands into wetlands and marshes is largely a reflection of differences in vegetation composition. Purely marsh forms of plant groups do not appear simultaneously with the beginning of the swamping process. As long as the thickness of the peat is small and the root systems of the main plant species do not break away from the mineral soil underlying the peat, the vegetation cover includes plants characteristic of both bog and non-bog habitats.

Due to the fact that the condition that determines the existence of certain plant associations in overmoistened territories is primarily the water regime, the indicated difference between wetlands and swamps in the subsequent stage of their development also has a hydrological significance. In addition to defining a swamp as a hydrological object, there are definitions in which a swamp is considered as an object of peat extraction, that is, from the point of view of the presence or absence of fuel reserves in it.

Ways of swamp formation

There are three main stages in the development of swamps.

First stage.

Lakes are natural reservoirs in land depressions (hollows), filled within the lake bowl (lake bed) with heterogeneous water masses and not having a one-sided slope. Lake basins are divided by origin into tectonic, glacial, river (oxbow lakes), seaside (lagoons, estuaries), sinkholes (karst, thermokarst), volcanic (in the craters of extinct volcanoes), dammed, artificial (reservoirs, ponds). According to the water balance, lakes are divided into waste and non-drainage; according to the chemical composition of water - into fresh and mineral.

This is not unimportant, since a huge amount of minerals is delivered to the lakes by groundwater or aboveground waters, and organic matter (plus minerals) is brought with coastal washout waters and springs (ground type of nutrition).

Mineralization of water, saturation of water with inorganic (mineral) substances, which are in the form of both ions and colloids.

In the process of vital activity of plants and animals, a substance called sapropel, organic silts, consisting mainly of organic substances and the remains of aquatic organisms, is formed at the bottom of lakes. Sapropel is used as fertilizer. Plants along the shore of the reservoir (trees, shrubs) correspond to the types found in the area. But aquatic and wetland plants (reeds, reeds, water lilies, pondweeds) are already starting to do their job.

At this stage, representatives of fish, fish-like, mollusks, etc. are still noticeable. You can also see plankton, which reproduces especially abundantly during the spring mixing of water, when its temperature promotes reproduction processes, and the amount of oxygen reaches its highest mark (oxygen dissolved in water).

Dokturovsky V.S. wrote: “From the edges of the shores of the lake, wetland vegetation gradually moves towards the middle of the reservoirs ... leaving in their center only a small lake, which is surrounded by peat instead of shores with mineral soil ...”

Second stage of development.

A layer of lowland peat is formed here (it unites 24 species), the predominance of marsh plants. The boundaries of peat and sapropel coincide. Atmospheric feeding maintains a weak runoff from the banks and contributes to waterlogging by replenishing the upper layer with water. Evaporation processes are negligible compared to the process of water inflow from the soil and the atmosphere.

The flow of water from the ground can be partially disturbed, but more often the constant prevails. This process contributes to the growth of the swamp, which gradually increases its volume. But the volume is due to the growth of peat, which in turn is the main reason for the increase in the volume of the swamp.

Peat formation occurs within the peat layer. This layer is located at the top (0.2 -0.7 m) of the peat deposit.

With a high standing of water, anaerobic conditions arise and decomposition processes slow down.

Third stage.

At this stage of development, the type of swamp is fully formed, that is, we can already determine what kind of swamp it is: lowland, transitional or upland. Let's take a swamp as an example. So, before us is a formed lowland swamp. The layer of low-lying peat accumulated during the growth of the marsh landscape is quite high. Vegetation cover is widely represented by marsh plants described above. Representatives of trees - spruce and birch, spread over the surface of the swamp. The layer of sapropel is significantly increased. There is a boundary between peat and sapropel with interpenetration. Atmospheric nutrition brings oxygen and contributes to the waterlogging of territories. The flow of water from the soil in some cases supports, while in others it contributes to an increase in the volume of the swamp. Evaporation processes are slowed down. A continuous vegetation cover retains moisture. Growth processes prevail over decomposition processes. And in this sense, the swamps in terms of productivity (its relation to decomposition processes) are in one of the first places.

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presentation, added 11/10/2012


The influence of animals and insects on the change in the composition of the forest stand. Biotic factors and the forest. Ecological system. Rational use and protection of animals. Direct and indirect human impact on animals. Protection of rare and endangered animal species.

abstract, added 05/31/2012


Soil as a habitat and the main edaphic factors, assessment of its role and importance in the life of living organisms. The distribution of animals in the soil, the ratio of plants to it. The role of microorganisms, plants and animals in soil-forming processes.

term paper, added 02/04/2014


Terrestrial and cosmic factors of plant life. Solar radiation as the main source of light for plants. Photosynthetically and physiologically active radiation and its significance. Influence of illumination intensity. The importance of heat and air in plant life.

presentation, added 02/01/2014


Types and role of plastids in plant life. The value of bast, wood fibers. Methods of nutrition and reproduction of mushrooms. Life cycle of Scotch pine. Characteristics of the aster family. Influence of climatic factors on the distribution of vegetation by zones.

control work, added 11/03/2009


The concept and distinctive features of the formation of oligotrophic swamps. Common characteristic features in the structure of plants common in their territories. Methodology for the study of the main phytocenoses of the oligotrophic type, their properties and ecological significance.

Although flora, by definition, is understood full the species composition of plants growing in any territory, in reality, only a part of the species that have been identified in this territory always appears in the floristic lists. A rare researcher dares to include in the list all plant species, among which, in this case, both avascular (bryophyte) and vascular plants should be represented. Due to the objectively limited possibilities of the researcher, he has to focus primarily on taxa (systematic groups) in which he considers himself a specialist. Another kind of restrictions arise when the researcher is especially interested in some ecological groups, for example, a group of coastal aquatic plants, which, of course, does not limit the flora of the entire territory of a district or region. A more rigorous and correct name for the lists of species that are limited in various circumstances occurring in the study area - partial floras.

It is not customary to include plant species cultivated by humans in the flora, just as it is not customary to include in it species that ended up in a given territory as a result of accidental unintentional introduction. Such species, as a rule, are poorly adapted to unusual local conditions and do not form stable populations. A special attitude to "naturalizants" - species that, being accidentally introduced ( adventitious) or specially introduced, naturalized, renewed in the place where they appeared, regardless of the person. Such species with appropriate marks are included in the flora along with naturally occurring, aboriginal types.

Inventory of flora always involves identifying it ecological and taxonomic structure.

The ecological structure of the flora is characterized by the spectrum of life forms - the percentage ratio of the number of species representing different life forms. Although quite a lot of classifications of plant life forms have been developed in science, not all of them are used to the same extent to establish the ecological structure of the flora. In this regard, the classification of K. Raunkjer turned out to be the most successful and therefore popular. Based on it, a global ecological spectrum was built for the entire flora of vascular plants of the globe. This is what is usually used as a standard for comparison with the spectra of specific floras. It was found that the floras of vascular plants from different regions of the Earth and different biomes naturally differ in the spectrum of life forms. If in humid tropical forests (hylaea) phanerophyte trees, woody lianas and epiphytes prevail, then in dry subtropics, with a significant participation of phanerophyte shrubs, herbs still prevail, but in some regions cryptophytes, and in others (in the area of ​​ephemeral deserts) - terophytes. In the floras of a temperate and moderately warm humid climate, a sharp predominance of perennial grasses (hemicryptophytes and cryptophytes) was noted.

The characteristic of the ecological structure of the flora can also include the ratio in it relic and progressive elements.

To relic elements include species for which the conditions of existence on the territory of the flora seem to be unfavorable, due to which the number of their populations decreases and the range is reduced. A sign of relictness, even with a more or less stable existence of a species in the territory of the flora, can be considered its narrow local distribution in its territory with a low number of populations. As opposed to relic progressive elements and with a narrow local distribution are found massively, and the number of their populations increases. Both the relict and progressive components of the flora are represented in it by a small number of species. The equilibrium with environmental conditions, in which most species of flora exist, does not imply either a steady decrease or a steady increase in abundance, and the occurrence of such species in the flora area remains stable. They can be distinguished in a special conservative flora element. The most widespread species that inhabited a variety of habitats, stably occurring in certain phytocenoses and usually playing a significant role in their composition, can be attributed to active types. The group of active species corresponds to some of the progressive and some of the conservative species.

The main indicator that reflects taxonomic structure flora, we can consider the distribution of its constituent species according to higher taxa and, first of all, families.

The result of a comparison of the richest in species, the so-called leading, families allows you to rank these families in descending order of the number of species. The number of families taken for comparison of floras can be different, but, as a rule, biogeographers are limited to ten, the composition and relative position of which gives out the specifics of floras of different climatic zones (see Table 1).

Leading Families are distinguished only by the number of flora species included in them, but neither the number of populations or individuals of these species, nor their occurrence, nor their role in the composition of the vegetation cover are taken into account.

The taxonomic structure of floras provides good material for their comparison, if the difficulties mentioned above with a number of taxa that are problematic for science are overcome. For example, the family Compositae or Asteraceae, which appears in the characteristics of three of the four climatic zones given in the table, is known for a number of apomictic genera. If, again, we assign the rank of species to microspecies and recognize the existence of 15–20 species instead of one variable species of dandelion, which is not indisputable, then this will certainly affect the position of the family among the leading ones and move it up. One could use the number of genera in them to identify and rank the leading families, but this technique has not yet become generally accepted.

Table 1. Leading families of flowering plants, arranged in descending order of the number of species, as an indicator of differences in the taxonomic structure of floras in different climatic zones

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flora refers to the totality of plant species found in a given area.

Geographical elements and floristic areas:

1) Arctic element -(dwarf birch, cloudberry).

2) North or boreal element - in the area of ​​coniferous forests. Note. boreal species - spruce, pine, northern linnaea.

3) Central European element - avg. European (oak, maple, ash, beech, hornbeam and herbaceous species, inherent in broad-leaved forests - hoof, Peter's cross, lungwort, etc.).

4) Atlantic element - gr. in. with ranges to the west. regions of the European part of Russia (lobelia, waxwort).

5)Pontic element - gr. in., South Russian. steppes, but meetings. in Romanian and Hungarian. steppes (spring adonis, chistets, purple mullein, broom).

6)Mediterranean element - gr. c., distribution in dry areas, encirclement. the Mediterranean Sea, and in the east growing in the Crimea and the Caucasus. It is mostly evergreen..trees and handicrafts. - earthlings. tree, boxwood, myrtle.

7) Central Asian element- gr. in with habitats along the mountain ranges of Central Asia, Tien Shan, Pamir-Alay, Altai (walnut, juniper, eremurus, irises)

8) Turan element- gr. in. with an area in the Turan lowland of Central Asia. This is an element of a desert character, typical representatives are sagebrush.

9) Manchurian element - gr. in. with an area in Manchuria (Manchurian walnut, Manchurian aralia, various-leaved hazel).

1) Holarctic kingdom. Occupied all of Europe and Asia (without Hindustan and Indochina), the North. America, China and Japan, i.e. occupy. the entire Arctic, temperate and subtropical latitudes to the Tropic of Cancer. Common features of the Golar flora. kingdoms speak to the mainland, once beings. in place of Europe, Asia and North America.

2) Paleotropic kingdom. Occupied tropical Africa, subtropical South Africa to the Cape Province, Arabia, Hindustan and Indochina, Indonesia, the Philippine Islands, the islands of Polynesia and Melanesia, Northern Australia. The similarity of their floras suggests that once these territories were also in the general massif.

3) Neotropical kingdom. Occupied big part of Mexico, Central America up to 40° south latitude and the Pacific Islands.

4) the Australian kingdom. Occupied Australia and Tasmania. Of the 12 thousand species, 9 thousand are endemic.

5) Cape kingdom. Occupied Cape province of South Africa.

6) Holantarctic kingdom. Occupied the southern tip of South America, Tierra del Fuego and the Antarctic islands.

111) Ecotypes of plants in relation to various abiotic factors. Features of their morphological and anatomical structure and habitat (xerophytes, mesophytes, hygrophytes, hydrophytes; sciophytes, heliophytes, etc.)

Plants in relation to water are divided into two groups:

ü aquatic plants- constantly living in water;

ü land plants- land

A. Schimper and E. Warming proposed to divide plants in relation to water into 3 groups:

· hydrophytes - plants of aquatic and excessively humid habitats;

· xerophytes - plants of dry habitats with high drought resistance are divided into:

ü succulents

ü sclerophytes

· mesophytes - plants living in average (sufficient) conditions of moisture.

A little later, a group hygrophytes .

hydrophytes - hydro- water and phyton- plant.

In a narrow sense of the term hydrophytes they name only those plants that live in water in a semi-submerged state (that is, they have underwater and above-water parts).

Xerophytes- terrestrial plants adapted to life with a significant permanent or temporary lack of moisture in the soil and / or in the air. (gr. xeros- dry and phyton- plant)

Sclerophytes- plants with hard shoots, relatively small leaves, sometimes covered with dense pubescence or a waxy layer (Greek. scleros- hard and phyton- plant)

succulents- plants that accumulate water in succulent fleshy stems and leaves. (lat. succulentus- juicy).

Mesophytes- land plants that prefer conditions of moderate moisture (gr. mesos- average, phyton- grow-e)

Hygrophytes- terrestrial plants living in conditions of high environmental humidity (in damp forests, swamps, etc.). Hygrophytes are characterized by delicate stems and leaves, a poorly developed root system. They wilt easily with a lack of water. (gr. hygros- wet and phyton- plant).

In relation to light, there are:

· Heliophytes – light loving plants. leaves are smaller and landmark. so as to reduce the dose of radiation during the daytime; the leaf surface is shiny.

· Sciophytes – shade loving plants. to get the maximum amount of incident radiation. The leaf cells are large, the system of intercellular spaces is well developed, the stomata are large, located only on the underside of the leaf.

· Hemisciophytes – shade tolerant plants

112) Life forms of plants and their classification according to Raunkier.

Classif. K. Raunkner(1905, 1907), based on posit. kidney resume. in relation to the surface soil in unfavorable. conditions (in winter or during a dry period) and the nature of the protective kidney covers.

Raunkier highlights the trace. 5 types of women's f.:

phanerophytes- plants in which buds and terminal shoots, intended for experiencing an unfavorable period, are located high above the ground (trees, shrubs, woody vines, epiphytes).

chamephites- low plants with buds, located. no higher than 20-30 cm above the ground and often hibernating under the snow (shrubs, dwarf shrubs, some perennial grasses = the author: dwarf shrubs, passive chamefites, active chamefites and cushion plants).

hemicryptophytes- herbaceous perennials. rast., the shoots of which at the beginning of an unfavorable period die off to the level of the soil, therefore, during this period, only the lower parts of the plants remain alive, protected by the ground and dead leaves of the plant. It is they who carry the buds intended for the formation of shoots of the next season with leaves and flowers.

cryptophytes- buds are hidden underground (rhizomatous, tuberous, bulbous geophytes) or under water (hydrophytes);

terophytes- annuals - plants that survive the unfavorable season exclusively in the form of seeds.