Introduction
1. Suksessia
1.1 Types of Sucessions
1.3 Process Suksessia
2. Change ecosystems
Conclusion
Bibliography
Introduction
Environmental Sukessia is the process of gradual change in the composition, structure and functions of ecosystems under the influence of an external or internal factor.
Restoration of the violated equilibrium ecosystem passes through well-defined stages.
The ecosystem can be derived from the equilibrium state in many ways. It is mainly a fire, flood or drought. After such a violation of equilibrium, the new ecosystem restores itself, and this process is regular and repeated in a variety of situations. What happens in the disturbed ecosystem? At the disorder, certain types and the entire ecosystem are developing in such a way that the procedure for the emergence of these species is the same for similar violations and similar ranges. In this consistent change of some species, the essence of the ecological sukcession is.
However, there is another model that explains the Socsessia mechanism as follows: the views of each previous community are displaced only by consistent competition, inhibiting and "resisting" the implementation of subsequent species.
Nevertheless, this theory considers only competitive relations between the species, not describing the entire picture of the ecosystem as a whole. Of course, such processes go, but the competitive displacement of previous species is possible precisely because of the transformation of them biotope.
Thus, both models describe different aspects of the process and are true at the same time. As the suscession row is progressing, there is an increasing involvement of biogenic elements into the ecosystems in the ecosystems, possibly the relative circuit inside the ecosystem of flows of such biogenic elements as nitrogen and calcium (one of the most movable biogenles).
Therefore, in the terminal stage, when most of the biogenes are involved in the circulation, the ecosystems are more independent of the external receipt of these items. To study the Sukcess process, various mathematical models are used, including stochastic nature.
1. Suksessia
1.1 Types of Sucessions
Any ecosystem, adapting to changes in the external environment, is in the state of the dynamics. This dynamics may concern both individual units of ecosystems (organisms, populations, trophic groups) and the system as a whole. At the same time, the dynamic may be connected, on the one hand, with adaptation to factors that are external to the ecosystem, and on the other to the factors that create and modify the ecosystem itself.
These changes in some cases can to be repeated to some extent, in others they have a unidirectional, progressive nature and determine the development of the ecosystem in a certain direction.
Primary Sukcessions.
Under the primary is usually understood by Suksessia, the development of which begins on initiallylifeless substrate. The course of the primary Sukessia will consider on the example of terrestrial ecosystems. If you take areas of the earth's surface, such as abandoned sandy careers, in various geographic areas (in forest, steppe zones or among tropical forests, etc.), then for all these objects such regularities will be characteristic as:
· Settlement by alive organisms
· Increased their species diversity
· Gradual soil enrichment with organic matter
· Increasing their fertility
· Strengthening bonds between different types or trophic groups of organisms
· Reducing the number of free environmental niches
· Gradual formation of increasingly complex biocenoses and ecosystems
· Increase their productivity.
Smaller types of organisms, especially vegetable, while, as a rule, are replaced by larger, the processes of substances of substances are intensified, etc.
In each case, it is possible to distinguish the consecutive stages of succersions, under which the change of one ecosystems by others is understood, and the sucessional rows ends relatively little changing ecosystems. They are called climax (Greek. Climax - staircase), indigenous or nodal
The flow of primary succeings takes place in several stages.
For example, in the forest area: dry lifeless substrate - lichen-- MA - annual dissection - cereals and perennial grass-- shrubs - trees of the 1st generation-- the trees of the 2nd generation; In the steppe zone, Suksessia is completed at the stage of herbs, etc.
Secondary Sukcessions.
The term "secondary succement" refers to communities that develop on the site of the already essential ranee of the formed community. In places where economic dealers of people do not interfere with the relationship between organisms, there is a climax community, which can exist indefinitely for a long time - as long as any impact of the outside (plowing of land, cutting the forest, fire, volcanic eruption, flood) will not break His natural structure. In case of destroying the community, Suksessia begins in it - a slow process of restoring the initial state. Examples of secondary sucessions: overgrowth of the abandoned field, meadows, gary or cutting. Secondary Succession lasts several decades. It begins with the fact that annual herbaceous plants appear on the liberated area of \u200b\u200bthe soil. These are typical weeds: dandelion, odds, mother-and-stepmother and others. Their advantage is that they quickly grow and produce seeds adapted to spread to distant distances with wind or animals. However, after two or three years, there are competitors - perennial herbs, and then shrubs and trees, primarily aspen. These breed shadow the earth, and their extensive root systems are taken from the soil all the moisture, so the seedlings of species, the first on the field, it becomes difficult to grow. However, the Suksessia does not stop at this; Sosina appears for Osin; And the last - slowly growing shadowed rocks, such as spruce or oak. After a hundred years, this community is restored in this area, which was at the site of the field to the attention of the forest and plowing of the Earth.
1.2 Succession action mechanisms
Assistance.
The pioneering species that appeared in the new ecosystem facilitate the following settlement. For example, after the departure of the glacier, lichens and some plants with surface roots appear first - that is, species that can survive on fruitless, poor nutrients soil. As these plants die, the layer of soil occurs, which makes it possible to root late sukcession species. Similarly, early trees give a shadow and asylum for the sprouts of late Socsession trees.
Cutting.
Sometimes pioneer species create conditions complicating or at all make it impossible to appear late succeed plants. When new surfaces appear near the ocean (for example, as a result of the construction of concrete piers or waveness), they quickly turn the pioneer species of algae, and other plant species are simply displaced. This displacement occurs very easily, since the pioneer view is reproduced extremely quickly and soon covers all available surfaces, without leaving space for subsequent species. An example of active containment is the appearance of Gorchaka, an Asian plant spreading through the American West. Gorchak largely larsing the soil in which it grows, which makes it unsuitable for many wild herbs.
Coexistence.
Finally, pioneering species may not have any impact on subsequent plants at all - nor useful or harmful. In particular, this happens if different types use different resources and grow independently of each other (see Differential Use of Resources).
1.3 Sukcesssessia process.
The process of Sukezia, according to F. Clementis, consists of several stages:
1) the emergence of the site unoccupied;
2) migration on it of various organisms or their adventures;
3) their suggestions in this area;
4) Competitions of them between themselves and displacing certain species;
5) transformation by living organisms of habitat, gradual stabilization of conditions and relationships.
Currently, almost all available life is the surface of the sushi is occupied by various communities, and therefore the occurrence of the parts free of living beings has a local character. These are either places released as a result of adjuncing glaciers, retreating water riva in water bodies, collaps, erosion, etc., or the resulting human activity, for example, the removal of large masses of deep rocks during the development of minerals.
Relief, plant seeds, animal penetration on the liberated plot have most of the random nature and depend on what kinds are in the surrounding biotopes. Only those ecological valences of which correspond to this complex of abiotic conditions are coming from among the species in new habitat. The prisoners gradually occupy the entire new biotop, entering into competition with each other. As a result, there is a restructuring of the species composition and quantitative ratios of various forms. In parallel, the process of converting the very habitat under the influence of the developing community is underway. The process is completed by the formation of a more or less stable system with a balanced type of biological circulation.
Sukcessions of any scale and rank are characterized by a number of common patterns, many of which are extremely important for human practical activities.
succession ecosystem organism Abiotic
2. Change ecosystems
Causes of shift ecosystems. Watching the same biogeocenosis, you can see how its appearance changes noticeably during the year. The steppe, scorched at the end of the summer, does not look like the same steppe in spring, colorful from flowering tulips, irises, primulous, crocuses. Winter forest dressed in snowy "caps", absolutely not like the autumn, painted in orange, yellow, crimson paints. The appearance of a meadow changes as different herbs bloom in the spring and summer. At the same time, in addition to seasonal changes, many years of change occur in ecosystems.
Despite the fact that the ecosystem is a stable, self-regulating system, it is typical of development. Under the development of any system understand the irreversible qualitative change, which is usually accompanied by quantitative changes. Thus, in the process of developing an ecosystem, simple communities are substituted in it more complex, with a rich species composition, with complex spatial and trophic structures. That is, the basis of the development of the ecosystem is the change of communities (plant, animals, mushroom, microbiological), which are included in the bioscenosis of this ecosystem.
The development and change of communities can be observed on moles that overgrow, replacing a number of consecutive stages, several years. The exposure of the soil formed as a result of the fall in old trees is restored for more - dozens of years. Large cutting of forests or sections after frying requires for recovery of 100-200 years.
The change of natural communities can be under the influence of biotic abiotic factors and man.
2.1 Change of ecosystems under the influence of livelihoods of organisms
The change of communities under the influence of the vital activity of organisms lasts hundreds and thousands of years. The main role in these processes plants play plants.
An example of the change of community under the influence of the vital activity of organisms can be the process of bonding reservoirs. Most lakes gradually merge and decrease in size. At the bottom of the reservoir, the remains of aqueous and coastal plants and animals accumulate, the soil particles, washed off from the slopes. Gradually, a thick layer of Slah is formed on the bottom. As Lake Melets, his shores will overgrow with reed and cane, then by the seeds. Organic residues accumulate even faster, form peat deposits. Many plants and animals are replaced by species whose representatives are more adapted for life in new conditions. Over time, a different community - swamp is formed on the site of the lake. But this change the communities does not stop. Unpretentious shrubs and trees can appear on the swamp, and ultimately the swamp can change the forest.
Thus, the change of communities is because as a result of changes in the species composition of communities of plants, animals, fungi, microorganisms gradually changes the habitat and conditions are created favorable for habitat of other species.
It is noted that the process of changing communities tends to end the stage of the mature community: with a rich species composition, branched food networks, the ability to self-regulation. As a result, a steady ecosystem is formed - in relative equilibrium with the medium.
2.2 Changing ecosystems under the influence of human activity
Changing communities under the influence of human activity. If the change of communities under the influence of the vital activity of the organisms themselves is a gradual and long-term process, covering the period in dozens, hundreds and even thousands of years, the change of communities (underlying the exchange of ecosystems) caused by the human activity, occurs quickly for several years.
The rapid (hoppy) development of ecosystems is often accompanied by a reduction in their species diversity, a slowdown in the processes of self-regulation and stability. As a result, such ecosystems form a simplified type community, with a poor species structure. For example, the disintegrating steppes man turns into arable land, the floodplain meadows are filled with reservoirs. Thus, the decay of virgin lands in the second half of the twentieth century led to the destruction of natural steppe ecosystems in Kazakhstan and in the south of Russia. As a result, many types of insects, mammals, various types of herbs disappeared.
Large load is experiencing suburban forests due to the mass visits to their people. Due to the drawing of grass, the ground organs of plants are injured, the soil is compacted, it is damaged. As a result, the forest is waiting, brightened. Teleboy and shadowish herbs are replaced by light-minded characteristic of meadow ecosystems.
Cattle rearranges changes meadow and steppe ecosystems: those herbs that are not eaten by animals (wormwood, thistle) are widely applied, the abundance of feed cereals is reduced. Many plants do not have time to bloom and give seeds. As a result, the species diversity of the ecosystem is reduced, its structure, food networks are simplified.
The reservoirs also experience anthropogenic effects. If it falls in wastewaters, fertilizers with fields, household waste, then oxygen dissolved in water is spent on their oxidation. As a result, the species diversity is reduced, various aquatic plants (salvia floating, amphoushell's horsepower) are replaced by a rich, algae - bleachalen, "bloom of water" occurs. Valuable fishing fish are replaced by little value, mollusks disappear, many types of insects. A rich aqueous ecosystem turns into an ecosystem of the reservoir.
There are quite a few cases when a person violated the species structure of the ecosystem as a result of new species in it. So, at the beginning of the XIX century. Australia from America was delivered a cactus empmunication to create spiny hedges on pastures. He spread so much that he began to form the appearance of many communities, ousting the usual types of plants, led to a change in a number of ecosystems. By the middle of the twentieth century. Australia could turn into a continent of solid prickly thickets, but this did not happen due to the cactus fire brought to the mainland, the caterpillars of which he eaten the nip. After the number of cactus managed to adjust with the help of caterpillars, the violated ecosystems were gradually recovered.
If the impact of a person who caused the change of communities is stopped, then, as a rule, the natural process of self-healing ecosystem begins. Plants continue to play a leading role in it. So, on pastures after stopping grazing, tall herbs appear, in the forest - typical forest plants, the lake is cleaned from the dominance of single-celled algae and blinkers, fish, mollusks, crustaceans reappear in it.
If the species and trophic ecosystem structures are simplified so much that the process of its self-healing can no longer be happening, then the person is again forced to interfere with this natural community, but now with good goals: herbs are seeded on pastures, new trees are seeded in the forest, the reservoirs are cleaned and launched There young fish.
Interesting experience used in the Stavropol Territory: There are already unproductive pastures of hay, scattering it on the surface. The hay contains the seeds of the entire complex of plant species of the steppe ecosystem. Three - four years, this site becomes closer to the natural steppe.
The ecosystem is capable of self-healing only with partial disorders. Therefore, the influence of man's economic activity should not exceed the threshold, after which the ecosystem cannot carry out the processes of self-regulation. For this, the impact of man on the ecosystems is normalized: determine how much livestock can be kept on 1 hectare of pastures, how many vacationers can visit the suburban forest park, make the total amount of wastewater with what the water ecosystem can be neutralized.
2.3 Change of ecosystems under the influence of abiotic factors
Changing ecosystems under the influence of abiotic factors. The development and change of ecosystems has great influence and have sharp climate change, fluctuations in solar activity, population processes, volcanic eruptions. These factors are called abiotic - the factors of inanimate nature. They violate the stability of the habitat of living organisms.
Consider examples of changing ecosystems under the influence of climate change. In the history of the development of life on Earth, the climate changed repeatedly. In warm periods, when a large amount of precipitation dropped out, species with increased requirements for warmth and moisture prevailed in ecosystems. Wet tropical forests spread on the planet. Significant raising sushi as a result of tectonic processes led to the development of a arid climate. As a result, ecosystem changes were shown on a large part of the Earth: the forests were replaced by savannahs, deserts, the desert arose. New ecosystems were characterized by another complex of species, possessed a different species, spatial, trophic structure.
3. Examples of Ecosystem Succession
Conclusion
Ecosystems are dynamic, they are constantly changing in accordance with the daily and seasonal rhythms of changes in abiotic factors, with fluctuations in the amount of precipitation and temperature mode in different years, under the influence of the vital activity of animals or the death of large plants. All these changes are reversible, and any state of the ecosystem that can be observed with such changes, sooner or later repeats again.
However, in addition to cyclic (flowing in a circle) changes, irreversible changes in ecosystems occur, under which the composition of the species and (or) its productivity and biomass is changed. Such changes are called environmental subsecessions. Sukcessions ecosystems are also very diverse and occur under the influence of the vital activity of their biota (for example, when overgrown with rocks or lakes) or under the influence of external factors, as a rule, related to human activity (grazing, pulpating, intensifying in water, rich in nutrition elements, etc. d.).
If the influence of the external factor stops (the pasture leaves an excess cattle, new portions of pollutants will not fall in the reservoir, the suburban forest will be landscaped, and vacationers will walk on special tracks), then the Suksessia caused by this factor. And then instead of her will begin another, restorative succement. Moreover, the process will proceed by itself, approximately the same as the cliff bump succement. The pasture will be restored by grass, water will be cleaned in the reservoir and green and diatoms of algae will again come to the change of cyanobacteria, the composition of the plant-macrophytes, fish, amphibians, etc. will be restored.
Also "by themselves" ecosystems are restored after violations, when as a result of a fire, cutting down of the forest, plowing steppe, etc. The entire ecosystem or a significant part of the species that are included in it are destroyed.
On a fire or deforestation, the forest grows gradually, the steppe is restored on the abandoned passage, etc. However, the recovery process may permanently delay, if there are no sites nearby, from which the reviving ecosystem can make up plant and animal species.
Each ecosystem simultaneously proceeds several options for changes, reversible and irreversible. Therefore, it is difficult to study their dynamics.
Bibliography
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2. Akimova T.V. Ecology. Man-economics-Biota-Wednesday: Textbook for university students / TA Akimova, V.V. Khaskin; 2nd ed., Pererab. and supplemented. - M.: Uniti, 2009.- 556 p. Recommended by the Ministry of Europe. RF as a textbook for university students.
3. ODUM Y. Ecology TT 1.2. World, 2006.
4. General ecology. Lazutkin Yu.S., Somin V.A. (AltGTU; 2007, 134С.)
5. Handojina E.K, Gerasimova N.A., Handojina AV .. Ecological foundations of environmental management, M., "Forum", 2007.
Forest fires as the process of degradation of natural ecosystems under the influence of human activity. Definition and classification of sukcessions, the concept of forest climax communities. Dynamic rows of restoration of pine forests after fires in Kandalaksha Bay.
course work, added 01.05.2011
The zonal nature of the leading abiotic and biotic factors of the fuels of water ecosystems. The toxicity of pollutants and the characteristics of the toxicor consistance of freshwater biocenoses. Environmental role of fisheries MPC for pollutants.
The concept of "productivity of ecosystems", its types, classification of ecosystems on productivity. Four consecutive steps (or stages) of the production of organic matter. Species and saturation of biocenosis. Environmental standardization.
examination, added 09/27/2009
Natural factors defining geoecological regime. Changes in the level of the Caspian Sea for a certain historical time. Environmental destabilization of the natural environment. Sukcessions of plant communities under the influence of natural, anthropogenic factors.
thesis, added 11.09.2012
Extreme environmental and environmental disaster zones. Environmental Suksessia, concept of climax systems. Biotic environmental factors, ecosystem study methods. Rationing of EMF and ionizing radiation, environmental control.
examination, added 19.07.2010
The complexity of natural biocenoses. First of all, they are characterized by species diversity and population density. Their biomass and biological productivity. The ratio of these indicators. Environmental Sukessia, concept and characteristics of the flow.
abstract, added 08.07.2010
The concept of the biosphere, its components. Distribution scheme of living organisms in the biosphere. Pollution by Ecosystems by wastewater. Prevailing pollutants of aquatic ecosystems by industries. Principles of state environmental impact assessment.
examination, added 08/06/2013
The nitrogen cycle is a number of closed interrelated paths, for which nitrogen circulates in the earth's biosphere. The cycle of transformation of solar energy into carbohydrates is the so-called Calvin cycle. Milankovich cycles. Hypothesis of a gas-pepped cloud. Environmental Sukecession.
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Changes in ecosystems, the concept of biological rhythms. The concept of sukcession, classification. Tasks of protective forest expectation. Eutrophication of water bodies under the influence of man's economic activity. Phytoplankton's life cycle and eutrophic lakes.
examination, added 01.12.2010
Consideration of the principles of the theory of Bari Commonor, the laws of the minimum, the need, the pyramids of the energy, the concepts of the succement (consistent change of community by the influence of time), biocenosis, tolerance, the resistance of the medium, the stability of the natural community.
Environmental Suksessia
One of the main achievements of the ecology was the discovery that not only organisms and types, but also ecosystems develop. Communities are continuously changed. Some organisms die, others come to them to shift. Energy and nutrients pass through a community endless stream.
Concept and species, 2018.
Community change sequence (ecosystems, biocenoses) on the same territorycalled sukessia.
In determining the ecological sukcession, three points should be taken into account.
First, the Suksessia occurs under the influence of the community, i.e. biotic component of the ecosystem.
In second place, Sukzesia is defined and can be predicted (to foresee).
The third aspect is that the culmination of the succement is the occurrence of a stabilized ecosystem, in which the energy flow unit accounts for maximum biomass and the maximum number of interspecific interactions.
The final stage of Sukzizia is called the climax community.
Traditionally, the Sukcession process is illustrated by the example of the overgrowth of a small reservoir in the forest (Fig. 34). The surface parts of the coastal herbal vegetation plants are dying annually, thereby decreasing the area of \u200b\u200bpond pond mirror.
Gradually, there are conditions favorable for the development of more powerful coastal plant species, such as willow. By rooting, Iva begins to pump out the water from the pond, having an existence of an existence. As a result, ϶vva is replaced by small rocks of trees: birch, hazel.
Concept and species, 2018.
The area of \u200b\u200bthe pond mirror continues to decrease, the moisture content of the soil decreases, forest soil begins to form. The petty trees are replaced by broader, oaks, limes are gradually appearing, and various shrubs and grassy plants are developing under their crowns. The conditions for the introduction of coniferous trees in the community are gradually being created. As a result of redundant receipt - together with the organic - in the reservoir of biogenic chemical elements, mainly nitrogen and phosphorus, occurs''''''''''' water: single-cell algae multiplied in huge quantities. There is a 'resumption of lake ecosystems - their eutrophication.
Demunning algae, together with the phoraminifers, falling 'late''' on the bottom, which leads to a decrease in the pond depth. As a result, a forest is formed on the place of the reservoir, which is actually not different from the one who surrounded the reservoir several decades ago. Under certain external conditions, the lake turns into a peat swamp, which is a stable ecosystem of a climax type.
There is a very large number of classifications of Suksessions.
Depending on the causes of the Suksessia distinguish
· exodynamice (from the Greek word of the ECCO - Outside) Suksessia caused by external factors in relation to this ecosystem
· endodynamic (from the Greek word Endon - inside) Suksessia caused by internal mechanisms of the ecosystem
Exodynamicsukcessions may be caused by climate change, lowering the level of groundwater, the rise in the level of the world ocean, etc. Such shifts can last centuries and millennia. They are mainly due to the action of the ecosystem adaptation mechanisms to the external environmental factors, which in turn are based on the mechanisms of adaptation of living organisms of the ecosystem.
Endodynamic Sukcessions are given by special laws, the mechanisms of which are still in many ways incomprehensible. It is known that on any, even an absolutely lifeless, substrate type of sand dunes or hardened lava, life flourished sooner or later. With this form of life, more precisely, the types of communities, in this space consistently replaced by each other, gradually becoming more complicated and increasing the species diversity, forming the so-called sucessional series, consisting of consecutive stages noting the change of one community to others.
The sucessional series ends with the stage of maturity, on which the ecosystem varies very little. Ecosystems at the current stage are called climax (from the Greek Words of the Climax - Staircase).
The duration of the Suksessia from the origin of the ecosystem to the Klimaks stage can be up to hundreds and even up to thousands of years. Such a long duration is mainly connected with the need to accumulate nutrients in the substrate.
There is another kind of sukcession classifications.
It should be distinguished autotrophic and heterotrophic Sukcessions. All autotrophic succias flow in ecosystems, where the central link is vegetation (phytocenosis).
The dynamics of heterotrophs is entirely subject to the dynamics of autotrophic - the change of animal communities depends on the change of plant communities. Avtrophic Sukcessions can last theoretically forever, as they constantly fueled the energy of the Sun.
IN heterotrophic successeys Only animals (heterotrophs, consversions) are involved. In this process, both dead plants may also be involved, for example, fallen trees, stumps, etc., which are usually a source of energy for heterotrophic succement.
Heterotrophic Suksessia implies the mandatory presence of a certain reserve of energy accumulated in the organic matter. It ends with the exhaustion of the energy resource, that is, after a complete decomposition of the source substrate. After the ecosystem ceases to exist. Thus, the concept of climax is not defined for it. In contrast to biogeocenoses, such ecosystems are mortal.
Examples of heterotrophic succement are changes in the communities on the corpse of the animal (the changes occurs in about this order: bacteria - ants - muggy-dawn, beetles, leberbwing, blades); on a pile of manure (or litter); On the rest lying on the ground fruit - an apple, for example.
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The most prolonged heterotrophic sukzesia is observed on the trunk of a large fallen tree.
So in heterotrophic Suksessia There is no climax stage.
Heterotrophic Suksessia is well associated with society depending on the fossil fuel. The speaker of the heterotrophic succement is described by the curve with a rapid increase in the number of organisms until some maximum is achieved, then the number of organisms gradually decreases as the energy resource exhausted. Some sustainable state (climax) cannot succeed. Such society quickly progresses, but nevertheless it is initially doomed to extinct.
We already "removed cream" from most deposits. Further exploitation over time will require all major energy investments. Therefore, the efficiency of mining will be steadily falling. At the same time, the viability of civilization built on a heterotrophic sukcession, if, of course, there will be no catastrophic changes even earlier. Therefore, we are a huge amount of effort to search for new energy sources. But even if we learn to manage thermonuclear synthesis, it does not change our destructive entity.
Depending on the initial conditions, the Sukcession is divided into
- primary(When the organisms are mastering empty areas that have never been settled before) and
- secondary(The process proceeds in places that have already been populated, but lost their inhabitants as a result, for example, glaciation or human activity).
Primary Suksessia - The process of development and shift ecosystems on unknown sections beginning with their colonization.
The classic example of the primary succement is the development of the community on the cooled lava or ash in the zone of the volcano, on the rocks and stones. Originally appear lichens, enriching the surface with nitrogen.
Concept and species, 2018.
After some time, Mai begin to develop in the biotope. After till, the grass grows together with Mka, then fine trees. It is not difficult to notice that all this time in the ecosystem develops soil, making it possible to grow all the more complex organisms.
Secondary Suksessia It arises where Biocenosis has previously existed, but it was destroyed as a result of natural or anthropogenic factors.
For example, the secondary succement begins on the flooring sites, on abandoned fathers, in abandoned villages, after natural cataclysms: floods, tsunami, forest windscreen, earthquakes. Special sound acquires a study of pyrogenic (arising from fires) of successions, since with the development of human society the share of fires arising from human fault increases.
Secondary Suksessia ends with the stable stage of the community after 150-250. years, A. primary lasts near 1000 years.
4.2.1 Climaxy Ecosystem.
Sukcessia is completed by the stage, when all types of ecosystem, multiplying, retain a relatively constant number and its further change does not occur. Such an equilibrium condition is called the climax, and the ecosystem is climax. In different abiotic conditions, unequal climatic ecosystems are formed. In the hot and wet climate, it will be a rain tropical forest, in a dry and hot-desert. The main biomes of the Earth are the climax ecosystems of the corresponding geographic areas.
Yelnik - this is the last climax stage of the development of the ecosystem in the climatic conditions of the north, i.e., already indigenous biocenosis (Fig. 33).
Fig. 33. Consecutive Sukcessions in the formation of the fry.
Initially, the so-called pioneer species, such as lichen and cortical algae) settle on a lifeless substrate. For 5-10 years, they are somewhat enriching the substrate with nutrients, forming soil routines. Next, on these still poor soils, herbs are settled, even more enriching the soil. After 15 years from the beginning of the Skcession, the first shrubs are settled for a lifeless space, which are gradually displaced by deciduous lightwood trees, more often in Birch and Osinoi, which are characterized by rapid growth.
Concept and species, 2018.
To the 50th age in the young deciduous forest, the strongest trees are highlighted, which shad out a weaker piglet, which dies, giving the opportunity to settle under the canopy of the deciduous forest fir. Spruce more shadowed, under the protection of deciduous trees, it gradually catchies them in growth, retavating their living space. Somewhere to 70 years, the ecosystem reaches the stage of mixed fir-deciduous forest. Deciduous trees have been time to be aware of the time, and gradually spruce goes to the first tier, shading and serving all deciduous vegetation. By the age of 90, this ecosystem reaches the climax stage, for which the almost complete lack of deciduous trees is characterized, the spruce becomes the dominant edifier, forming a particularly lifetime inhabiting this ecosystem of the community.
the law of thermodynamics is called the law of preserving the structure of the biosphere).
Environmental Succession is the concept and types. Classification and features of the category "Ecological Sukcession" 2017-2018.
The relatively long existence of biocenosis in one place (pine or fir forest, low swamp) changes the biotop (the place where biocenosis exists) so that it becomes unsuitable for the existence of some species, but suitable for the introduction or development of others. As a result, another biocenosis is gradually developing in this biotope, more adapted to new environmental conditions. Such a multiple change of one biocenosis is called sukessia.
Suksessia (from Lat. Successio - continuity, inheritance) is a gradual, irreversible, directed by the change of one biocenosis by others on the same territory under the influence of natural factors or human impact.
The term "Suksessia" for the first time used the French botanist de Luke in 1806 to designate the shift of vegetation.
Examples of Suksessia are gradual overgrowing of bulk sands, stony stamps, shames, settling with vegetable and animal organisms of abandoned agricultural land (Pashnya), deposits, cutting, etc. The former fields are quickly covered with a variety of annual plants. Seeds of woody breeds fall here: pine, spruce, birch, aspen. They are easily and over long distances are spread by wind and animals. In weakly-dressed soil, the seeds begin to germinate. In the most favorable position there are light-loving fine breeds (birch, aspen).
The classic example of the Sukcessia is to oversee the lake or river old man and turning it first in the swamp, and then, after a long period of time, in forest biocenosis. Initially, the water surface of the melette is delayed from all sides of the splavor, the deadly parts of the plants are lowered onto the bottom. Gradually, the water mirror is delayed. This process will last a few decades, and then on the site of the lake or the old man, the upper peat swamp is formed. Even later, the swamp will gradually begin to overcome wood vegetation, most likely the pine. After a period of time, the processes of peat formation on the site of the former reservoir will lead to the creation of excessive moistening and to the death of the forest. Finally, a new swamp will appear, but already excellent because it was before.
Together with the change in vegetation, the animal world of the territory subject to Suksessia is changing. For an old man or lake typical water invertebrates, fish, waterfowl, amphibious, some mammals - ondatra, mink. The result of Sukzizia is a sphagnum pine. Now there are other birds and mammals here - a deaf, partridge, elk, bear, hare.
Any new habitat is the naked sandy bank of the river, frozen the lava of an extinct volcano, a puddle after the rain - immediately turns out to be a hundred-speculation with new species. The nature of developing vegetation depends on the properties of the substrate. The newly settling organisms gradually change the habitat, for example, shadow the surface or change its humidity. The consequence of such a change in the medium is the development of new species-resistant species and the displacement of the previous ones. Over time, a new biocenosis is formed with significantly different from the initial species.
Initially, changes occur quickly. Then the speed of the succement is reduced. Birch shoots form a thick piglet, which shads the soil, and even if the seeds of ate sprout together with a birch of birch, being in very unfavorable conditions, far behind the birch. Light birch - a serious competitor for ate. In addition, the specific biological features of birch gives it advantages in growth. Berezu is called the "pioneer of the forest", the pioneer rock, since it is almost always the first to settle on the disturbed lands and has a wide range of adaptability.
Birches at the age of 2 - 3 years can reach a height of 100 - 120 cm, while the Christmas tree at the same age is barely reaching up to 10 cm. Gradually, by 8 - 10 years, birchs form a sustainable birch plant with a height of up to 10 - 12 m. Under the developing A canopy of birch begins to grow up and fir, forming a teen in varying degrees of degree. Changes occur in the lower, herbian - shrub tier. Gradually, as birch crowns are closed, light-minded species characteristic of the initial stages of the Sukzesia begin to disappear and inferior place to the shadowish.
Changes relate to the animal component of biocenosis. At the first stages, May Khrushchi, birch spin, then numerous birds - a championship, Slavka, foam, small mammals - earthrook, mole, hedgehog. Changing the lighting conditions begins to affect young Christmas trees that accelerate their growth. If in the early stages of the Suksessia, the growth of the Christmas tree was 1 - 3 cm per year, then after 10-15 years it already reaches 40 - 60 cm. Somewhere by 50 years, spruce catches the birch in growth, and a mixed ero-birbean ancient is formed. Animals appear hares, forest waters and mice, proteins. Sukcession processes are also noticeable among birds: in such a forest, the hoists fall on the caterpillars.
Mixed Elovo - Birch Forest gradually replaced by Elov. A fir distilts in the growth of birch, creates a significant shadow, and birch, without preparing competition, gradually falls out of the stand.
Thus, a suczission occurs, at which the birch first, and then mixed Elovo - the birch forest is replaced by a clean yelnik. The natural process of changing Bereznyak Yelanik lasts more than 100 years. That is why the process of Suksessia is sometimes called century shift .
If the development of communities is on newly formed, previously not populated habitats (substrates), where the vegetation was absent - on the sand dunes, frozen lava flows, rocks that were exposed as a result of erosion or the retreat of ice, then such a succias is called primary.
As an example of the primary sukcession, the process of settling the newly formed sand dunes can be given, where the vegetation was previously absent. Here, perennial plants are in charge, capable of carrying arid conditions, such as drossing creeping. It is rooted and multiplied by the sand, strengthens the surface of the dune and enriches the sand with organic substances. The physical conditions of the medium in close proximity to the perennial herbs are changed. Following the perennials, annuals appear. Their growth and development often contribute to the enrichment of the substrate with organic material, so that conditions are gradually created, suitable for growing plants such as Iva, Toloknyanka, a chamber. These plants are preceded by the appearance of pine seedlings, which are fixed here and, growing, after a lot of generations form pine forests on the sand dunes.
If there was vegetation on a certain locality, but for some reason it was destroyed, then its natural recovery is called secondary sukessia . Such successes may result in, for example, partial destruction of forests, hurricane, volcanic eruption, an earthquake, either by fire. Restoration of forest biocenosis after such catastrophic effects occurs for a long time.
An example of the secondary succement is the formation of peat swamps when the lake is overgrown. The change in vegetation in the swamp begins with the fact that the edges of the reservoir will overgrow with aquatic plants. The moisture types of plants (reed, reed, SCO) begin to grow close to the coast with a solid carpet. Gradually, a more or less dense layer of vegetation is created on the surface of the water. Memorial remains of plants accumulate at the bottom of the reservoir. Due to the small amount of oxygen in the stagnation of plants, the plants are slowly decomposed and gradually turn into peat. The formation of marsh biocenosis begins. Sphagnum mosses appear, on a solid carpet of which the cranberries, a richness, blueberry grow. Sosens can settle here, forming a rare pig. Over time, the ecosystem of the rolling swamps is formed.
Most of the succeings observed at present anthropogenic , those. They occur as a result of human impact on natural ecosystems. This is a grazing of livestock, cutting forests, the emergence of foci of fire, disintegration of land, soil flooding, desertification, etc.
Ecological Succession (lat. Sukcedo - follow) - this is a sequential change in the time of biocenoses, i.e. the natural communities of a certain section of the earth's surface.
1. Sukzesia is an ordered process of consistent change of natural communities associated with a change in their species structure and processes occurring in the community.
2. It occurs as a result of changes in the physical environment, firstly, under the action of the very developing community. Secondly, Sukzesia proceeds under the influence of changes in external factors: humidity, temperature, precipitation, soil composition, solar radiation.
3. The climax of a stabilized ecosystem is the culmination of the Suksessia, the effectiveness of the energy transformation into biomass is maximum and when the maximum possible number of types and populations of flora and fauna, as well as connections between them: food (trophic), territorial (topical), etc.
Sukcessions with replacement of vegetation can be primary and secondary.
Primary Suksessia begins on the site, which before that was not busy in any community, on the deprived of the places, for example, on a bare rock, sand, frozen lava, cliffs, rivers, bulk sands, etc. When settling such sections of living organisms Impaired changing habitats and replace each other. The main role belongs to the accumulation of dead vegetable residues or decomposition products, which depends on both the nature of vegetation and the complex of destroyers of the dead plant mass - animals, fungi and microorganisms. The soil profile is gradually formed, the hydrological mode of the site, its microclimate changes. Such succisions in the geobotanic are called eco -nets, as they lead to the transformation of the very habitat.
Secondary sukzesias are replacement shifts. They start in the event that in the already established communities partially violated the established interconnection of organisms, for example, the vegetation of one or more tiers is removed. That is, the previous community is removed, for example, on an abandoned field, cutting down the forest, as a result of a fire, plowing, etc. It proceeds faster than primary, since there are already some organisms or their primitives.
Examples of Suksessions are a gradual overgrowth of bulk sands, stony places, bellows, settling with vegetable and animal organisms of abandoned agricultural land (Pashnya), deposits, cutting, etc. The former fields are quickly covered with a variety of annual plants. Seeds of woody breeds fall here: pine, spruce, birch, aspen. They are easily and over long distances are spread by wind and animals. In weakly-dressed soil, the seeds begin to germinate. In the most favorable position there are light-loving fine breeds (birch, aspen).
The classic example of the Sukcessia is to oversee the lake or river old man and turning it first in the swamp, and then, after a long period of time, in forest biocenosis. Initially, the water surface of the melette is delayed from all sides of the splavor, the deadly parts of the plants are lowered onto the bottom. Gradually, the water mirror is delayed. This process will last a few decades, and then on the site of the lake or the old man, the upper peat swamp is formed. Even later, the swamp will gradually begin to overcome wood vegetation, most likely the pine. After a period of time, the processes of torforming on the site of the former water branch will lead to the creation of excessive moistening and to the death of the forest. Finally, a new swamp will appear, but already different from what was before.
Suksessia (from lat. Successio. - continuity, inheritance) - the process of community self-development. At the heart of Suksessia lies incomplete biological circulation in this community. Each living organism as a result of vital activity changes around itself a medium that is made of part of the substances from it and saturately by the products of metabolism. With a more or less long existence of populations, they change their environment in an unfavorable side and as a result turn out to be displaced populations of other species, for which caused by the transformations of the medium turn out to be environmentally friendly
. During the Succession based on competitive interactions of species, there is a gradual formation of more stable combinations corresponding to specific abiotic environmental conditions.
The consistent row is gradually and naturally replacing each other in the communities Sukcessions called Sukcession series.
Sukcessions in nature have different scales. The hierarchy in the organization of communities is also manifested in the hierarchy of sucessional processes: larger conversion of ecosystems are made up of smaller. Even in stable ecosystems with a well-adjusted circulation of substances, many local sucessional shifts that support the complex internal structure of communities are constantly carried out.
Two main types of Sukezsessions are distinguished: 1) with the participation of both the autotrophic and heterotrophic population; 2) with only heterotrophs.
Sukcession with replacement of vegetation can be primary; They begin on devoid of places, and secondary - reducing (Fig. 8.7). Currently, almost all available life is the surface of the sushi is occupied by various communities and therefore the emergence of areas free from living beings has a local character.
Fig. 8.7. Secondary Succession of the Siberian Dark Conifer (Fir-Cedar Taiga) after a devastating forest fire: the numbers in rectangles are oscillations in the duration of the phases of the secondary succement (in brackets are the deadline for their end). Biomass and biological productivity are randomly shown (curves reflect the qualitative and quantitative side of the process)
Sukcessions of any scale and rank are characterized by a whole near common patterns Many of which are extremely important for human practical. In any congestion series, the rates of occurring changes are gradually slowed down and ended with the formation of a stable stage - Climix Community. From energy items Suksessia - Such an unstable state of the community, which is characterized by the inequality of two indicators: the total productivity and energy spending of the entire system on maintaining metabolism.
During the Sukcession, the general biomass of the community first increases, but then the pace of this increase decreases, and at the KMIMAKS stage of the biomass system is stabilized.
When removing an excess of pure products from ecosystems at the beginning of the succement of rows, only the speed of the Sukessia decreases. Interference in stable, climax systems, with a large complete strength consuming energy on "their" needs, inevitably causes violations of the current equilibrium in this ecosystem.
So far, the violations do not exceed the reductive ability of the ecosystem (the principle is followed Le chaitor) It can return to the initial state. This is used, for example, with the rational planning of logging. But if the influence intensity goes beyond the scope of these possibilities, the initially stable, rich in the species community gradually degrades by replacing the other.
Final cutting on local areas with leaving part of the territory under the indigenous types of forest vegetation causes accelerated succements, the initial phytocenoses is restored for a relatively short period - several decades.
Thus, the community cannot simultaneously combine two opposite properties: to be highly stable and give a large output of pure products that could be withdrawn without harm for the community itself.
The relatively long existence of biocenosis in one place (pine or fir forest, low swamp) changes the biotop (the place where biocenosis exists) so that it becomes unsuitable for the existence of some species, but suitable for the introduction or development of others. As a result, another biocenosis is gradually developing in this biotope, more adapted to new environmental conditions. Such a multiple change of alone biocenoses is called SuCsessia.
Suksessia (from Lat. Successio - continuity, inheritance) is a gradual, irreversible, directed by the change of one biocenosis by others on the same territory under the influence of natural factors or human impact.
The term "Suksessia" for the first time used the French botanist de Luke in 1806 to designate the shift of vegetation. This is one of the key terms of modern ecology.
Examples of Suksessions are a gradual overgrowth of bulk sands, stony places, bellows, settling with vegetable and animal organisms of abandoned agricultural land (Pashnya), deposits, cutting, etc. The former fields are quickly covered with a variety of annual plants. Seeds of woody breeds fall here: pine, spruce, birch, aspen. They are easily and over long distances are spread by wind and animals. In weakly-dressed soil, the seeds begin to germinate. In the most favorable position there are light-loving fine breeds (birch, aspen).
The classic example of the Sukcessia is to oversee the lake or river old man and turning it first in the swamp, and then, after a long period of time, in forest biocenosis. Initially, the water surface of the melette is delayed from all sides of the splavor, the deadly parts of the plants are lowered onto the bottom. Gradually, the water mirror is delayed. This process will last a few decades, and then on the site of the lake or the old man, the upper peat swamp is formed. Even later, the swamp will gradually begin to overcome wood vegetation, most likely the pine. After a period of time, the processes of torforming on the site of the former water branch will lead to the creation of excessive moistening and to the death of the forest. Finally, a new swamp will appear, but already different from what was before.
Together with the change in vegetation, the animal world of the territory subject to Suksessia is changing. For an old man or lake typical water invertebrates, fish, waterfowl, amphibious, some mammals - ondatra, mink. The result of Sukzizia is a sphagnum pine. Now there are other birds and mammals here - a deaf, partridge, elk, bear, hare.
Any new habitat is the naked sandy bank of the river, frozen the lava of an extinct volcano, a puddle after the rain - immediately turns out to be a hundred-speculation with new species. The nature of developing vegetation depends on the properties of the substrate. The newly settling organisms gradually change the habitat, for example, shadow the surface or change its humidity. The consequence of such a change in the medium is the development of new species-resistant species and the displacement of the previous ones. Over time, a new biocenosis is formed with significantly different from the initial species composition (Fig. 9).
Fig. 9. Environmental Succession on the example of a change of phytocenoses in southern taiga
Initially, changes occur quickly. Then the speed of the succement is reduced. Birch shoots form a thick piglet, which shads the soil, and even if the seeds of ate sprout together with a birch of birch, being in very unfavorable conditions, far behind the birch. Light birch - a serious competitor for ate. In addition, the specific biological features of birch gives it advantages in growth. Berezu is called the "pioneer of the forest", the pioneer rock, since it is almost always the first to settle on the disturbed lands and has a wide range of adaptability.
Birches at the age of 2-3 years can reach a height of 100-10 cm, while the Christmas tree at the same age is barely reaching up to 10 cm. Gradually, by 8-10 years, birchs form a sustainable birch plant with a height of up to 10-12 m. Under the developing A canopy of birch begins to grow up and fir, forming a teen in varying degrees of degree. Changes occur in the lower, herbal-shrub tier. Gradually, as birch crowns are closed, light-minded species characteristic of the initial stages of the Sukzesia begin to disappear and inferior place to the shadowish.
Changes relate to the animal component of biocenosis. At the first stages, May Khrushchi, birch spin, then numerous birds - a championship, Slavka, foam, small mammals - earthrook, mole, hedgehog. Changing the lighting conditions begins to affect young Christmas trees that accelerate their growth. If at the earliest stages of the Suksessia, the growth of the Christmas tree was 1-3 cm per year, then after 10-15 years it already reaches 40-60 cm. Somewhere by 50 years, spruce catches the birch in growth, and a mixed spruce-birbean ancient is formed. Animals appear hares, forest waters and mice, proteins. Sukcession processes are also noticeable among birds: in such a forest, the hoists fall on the caterpillars.
Mixed elo-birch forest is gradually replaced by Elov. A fir distilts in the growth of birch, creates a significant shadow, and birch, without preparing competition, gradually falls out of the stand.
Thus, a suczission occurs, at which the birch first, and then a mixed spruce-birch forest is replaced by clean yelnik. The natural process of changing Bereznyak Yelanik lasts more than 100 years. That is why the Sukcessia process is sometimes called an age-old shift.
If the development of communities is on newly formed, previously not populated habitats (substrates), where the vegetation was absent - on the sand dunes, frozen lava flows, rocks that were exposed as a result of erosion or the retreat of ice, then such a succias is called primary.
As an example of the primary sukcession, the process of settling the newly formed sand dunes can be given, where the vegetation was previously absent. Here, perennial plants are in charge, capable of carrying arid conditions, such as drossing creeping. It is rooted and multiplied by the sand, strengthens the surface of the dune and enriches the sand with organic substances. The physical conditions of the medium in close proximity to the perennial herbs are changed. Following the perennials, annuals appear. Their growth and development often contribute to the enrichment of the substrate with organic material, so that conditions are gradually created, suitable for growing plants such as Iva, Toloknyanka, a chamber. These plants are preceded by the appearance of pine seedlings, which are fixed here and, growing, after a lot of generations form pine forests on the sand dunes.
If there was vegetation on a certain locality, but for some reason it was destroyed, its natural recovery is called secondary Sukessia. Such successes may result in, for example, partial destruction of forests, hurricane, volcanic eruption, an earthquake, either by fire. Restoration of forest biocenosis after such catastrophic effects occurs for a long time.
An example of the secondary succement is the formation of peat swamps when the lake is overgrown. The change in vegetation in the swamp begins with the fact that the edges of the reservoir will overgrow with aquatic plants. Moofly busy plants (reed, reed, SC) begin to grow close to the coast with a solid carpet. Gradually, a more or less dense layer of vegetation is created on the surface of the water. Memorial remains of plants accumulate at the bottom of the reservoir. Due to the small amount of oxygen in the stagnation of plants, the plants are slowly decomposed and gradually turn into peat. The formation of marsh biocenosis begins. Sphagnum mosses appear, on a solid carpet of which the cranberries, a richness, blueberry grow. Sosens can settle here, forming a rare pig. Over time, the ecosystem of the rolling swamps is formed.
Most of the succeings observed at present anthropogenic. They occur as a result of human impact on natural ecosystems. This is a grazing of livestock, cutting forests, the emergence of foci of fire, disintegration of land, soil flooding, desertification, etc.
