Ministry of Education and Science of the Russian Federation
Branch of the Federal State Autonomous Educational Institution
higher professional education
"Russian State Vocational Pedagogical University"
in Sovietsky
Department of Professional and Pedagogical Education
Test
by discipline
"Ecology"
Option number 17
Completed by: Kalinin A.N.
Checked by: Kryukova N. S.
Soviet 2011
Table of contents
Task number 1
3
Task number 2
8
Task number 3
12
LIST OF SOURCES USED
20
Task number 1: 18. The concept of an ecosystem (biogeocenosis). Structure and examples of ecosystems. Distinctive features of natural and artificial ecosystems.
Biogeocenosis is a system that includes a community of living organisms and a closely related set of abiotic environmental factors within the same territory, interconnected by the circulation of substances and the flow of energy. It is a sustainable self-regulating ecological system in which organic components (animals, plants) are inextricably linked with inorganic ones (water, soil). Examples: pine forest, mountain valley. The doctrine of biogeocenosis was developed by Vladimir Sukachev in 1940. In foreign literature - little used. Previously, it was also widely used in German scientific literature.A similar concept is an ecosystem - a system consisting of interconnected communities of organisms of different species and their habitat. Ecosystem is a broader concept referring to any such system. Biogeocenosis, in turn, is a class of ecosystems, an ecosystem that occupies a certain area of \u200b\u200bland and includes the main components of the environment - soil, subsoil, vegetation, and the surface layer of the atmosphere. Aquatic ecosystems are not biogeocenoses, most artificial ecosystems. Thus, every biogeocenosis is an ecosystem, but not every ecosystem is a biogeocenosis. To characterize biogeocenosis, two close concepts are used: biotope and ecotope (factors of inanimate nature: climate, soil). A biotope is a set of abiotic factors within the territory occupied by a biogeocenosis. An ecotope is a biotope that is affected by organisms from other biogeocenoses. The content of the ecological term "biogeocenosis" is identical to the physical and geographical term facies.
Properties of biogeocenosis:
- natural, historical system
a system capable of self-regulation and maintaining its composition at a certain constant level
the circulation of substances
an open system for the input and output of energy, the main source of which is the Sun
- Species composition - the number of species living in biogeocenosis.
Species diversity - the number of species living in a biogeocenosis per unit area or volume.
- Biomass - the number of organisms of biogeocenosis, expressed in units of mass. Most often, biomass is divided into:
- producer biomass
- consumer biomass
decomposer biomass
Productivity
Sustainability
Ability to self-regulate
An ecosystem can be divided into two components - biotic and abiotic. Biotic is divided into autotrophic (organisms that receive primary energy for existence from photo- and chemosynthesis or producers) and heterotrophic (organisms that receive energy from the processes of oxidation of organic matter - consumers and decomposers) components that form the trophic structure of the ecosystem.
The only source of energy for the existence of an ecosystem and the maintenance of various processes in it are producers that absorb the energy of the sun (heat, chemical bonds) with an efficiency of 0.1 - 1%, rarely 3 - 4.5% of the initial amount. Autotrophs represent the first trophic level of an ecosystem. Subsequent trophic levels of the ecosystem are formed due to consumers (2nd, 3rd, 4th and subsequent levels) and are closed by decomposers that convert inanimate organic matter into a mineral form (abiotic component), which can be assimilated by an autotrophic element.
The main components of the ecosystem:
From the point of view of the structure in the ecosystem, there are:
- climate regime, which determines temperature, humidity, lighting regime and other physical characteristics of the environment;
inorganic substances included in the cycle;
organic compounds that link the biotic and abiotic parts in the cycle of matter and energy;
producers - organisms that create primary products;
macroconsumers, or phagotrophs, are heterotrophs that eat other organisms or large particles of organic matter;
microconsumers (saprotrophs) - heterotrophs, mainly fungi and bacteria, which destroy dead organic matter, mineralizing it, thereby returning it to the cycle;
- biophages - organisms that eat other living organisms,
saprophages - organisms that eat dead organic matter.
All these components are interconnected in space and time and form a single structural and functional system.
An example of an ecosystem is a pond with plants, fish, invertebrates, microorganisms that make up the living component of the system, a biocenosis living in it. A pond as an ecosystem is characterized by bottom sediments of a certain composition, chemical composition (ionic composition, concentration of dissolved gases) and physical parameters (water transparency, trend of annual temperature changes), as well as certain indicators of biological productivity, the trophic status of the reservoir and the specific conditions of this reservoir. Another example of an ecological system is a deciduous forest in central Russia with a certain composition of forest litter, soil characteristic of this type of forests and a stable plant community, and, as a result, with strictly defined microclimate indicators (temperature, humidity, light) and corresponding to such environmental conditions. complex of animal organisms.
Artificial ecosystems are ecosystems created by man, for example, agrocenoses, natural economic systems or the Biosphere.
Artificial ecosystems have the same set of components as natural ones: producers, consumers and decomposers, but there are significant differences in the redistribution of matter and energy flows. In particular, human-created ecosystems differ from natural ones in the following ways:
- a smaller number of species and the predominance of organisms of one or more species (low evenness of species);
low stability and strong dependence on the energy introduced into the system by a person;
short food chains due to the small number of species;
an open cycle of substances due to the withdrawal of the crop (community products) by man, while natural processes, on the contrary, tend to include as much of the crop as possible in the cycle.
Task number 2: 61. The concept of "natural resources". Classification of natural resources according to their exhaustibility and renewability. conditionality of such a classification.
Natural resources is one of the most commonly used concepts in the literature. In the Concise Geographical Encyclopedia, this term refers to “...elements of nature used in the national economy, which are the means of existence of human society: soil cover, useful wild plants, animals, minerals, water (for water supply, irrigation, industry, energy, transport ), favorable climatic conditions (mainly heat and moisture), wind energy”.Natural resources - spatio-temporal category; their volume is different in different regions of the globe and at different stages of the socio-economic development of society. Bodies and phenomena of nature act as a certain resource in the event that they are needed. But the needs, in turn, appear and expand as the technical possibilities for the development of natural resources develop.
When taking into account the reserves of natural resources and the volumes of their possible economic withdrawal, they use the concept of the depletion of reserves. A. Mints proposed to call the classification according to this criterion ecological. All natural resources are depleted into two groups: exhaustible and inexhaustible.
1. Exhaustible resources. They are formed in the earth's crust or landscape sphere, but the volumes and rates of their formation are measured on the geological time scale. At the same time, the need for such resources on the part of production or for the organization of favorable living conditions for human society significantly exceeds the volumes and rates of natural replenishment. As a result, depletion of natural resource reserves inevitably occurs. The exhaustible group includes resources with different rates and volumes of formation. This allows them to be further differentiated. Based on the intensity and speed of natural formation, resources are divided into subgroups:
1. Non-renewable, which include:
a) all types of mineral resources or minerals. As is known, they are constantly formed in the bowels of the earth's crust as a result of a continuously ongoing process of ore formation, but the scale of their accumulation is so insignificant, and the formation rates are measured in many tens and hundreds of millions of years (for example, the age of coal is more than 350 million years), which is practically they cannot be taken into account in economic calculations. The development of mineral raw materials takes place on a historical time scale and is characterized by ever-increasing volumes of withdrawal. In this regard, all mineral resources are considered as not only exhaustible, but also non-renewable.
b) Land resources in their natural form are the material basis on which the life of human society takes place. The morphological structure of the surface (i.e., relief) significantly affects economic activity and the possibility of developing the territory. Once disturbed lands (for example, by quarries) during large-scale industrial or civil construction, they are no longer restored in their natural form.
2. Renewable resources to which belong:
a) plant resources and
b) the animal world.
Both of them are restored quite quickly, and the volumes of natural renewal are well and accurately calculated. Therefore, when organizing the economic use of accumulated timber reserves in forests, herbage in meadows or pastures, and hunting for wild animals within the limits not exceeding the annual renewal, it is possible to completely avoid the depletion of resources.
3. Relatively renewable. Although some resources are restored in historical periods of time, their renewable volumes are much less than the volumes of economic consumption. That is why these types of resources are very vulnerable and require particularly careful human control. Relatively renewable resources also include very scarce natural resources:
a) productive arable soils;
b) forests with stands of mature age;
c) water resources in the regional aspect.
The fact of the practical inexhaustibility of water resources on a planetary scale is well known. However, fresh water reserves are unevenly concentrated on the surface of the land, and there is a shortage of water suitable for use in water management systems over vast areas. Arid and subarid areas are particularly affected by water shortages, where irrational water consumption (for example, water withdrawal in excess of the amount of natural replenishment of free water) is accompanied by a rapid and often catastrophic depletion of water resources. Therefore, it is necessary to accurately record the amount of allowable withdrawal of water resources by region.
2 Inexhaustible resources. Among the bodies and natural phenomena of resource significance, there are those that are practically inexhaustible. These include climatic and water resources.
A) climatic resources. The most stringent climate requirements are imposed by agriculture, recreational and forestry, industrial and civil construction, etc. Usually, climate resources are understood as the reserves of heat and moisture that a particular area or region has. Since these resources are formed in certain links of the thermal and water cycles, constantly operating over the planet as a whole and over its individual regions, the reserves of heat and moisture can be considered as inexhaustible within certain quantitative limits, precisely established for each region.
B) Water resources of the planet. The earth has a colossal volume of water - about 1.5 billion cubic meters. km. However, 98% of this volume is made up of salty waters of the World Ocean, and only 28 million cubic meters. km - fresh water. Since technologies for desalination of salty sea waters are already known, the waters of the World Ocean and salt lakes can be considered as potential water resources, the use of which is quite possible in the future. Subject to the principles of rational water use, these resources can be considered as inexhaustible. However, if these principles are violated, the situation can sharply worsen, and even on a planetary scale, there may be a shortage of clean fresh water. In the meantime, the natural environment annually "gives" humanity 10 times more water than it needs to meet a wide variety of needs.
Any classification of natural resources today is rather conditional, because at each stage of knowledge of environmental laws they will change taking into account the possibilities of scientific and technological progress and socio-economic development.
Task number 3: 81. Objects and subjects of environmental law. Environmental harm. Legal liability for environmental offenses.
According to Art. 9 of the Constitution of the Russian Federation, land and other natural resources are used and protected in the Russian Federation as the basis of life and activity of the peoples living in the respective territory. The state guarantees the protection of the environmental rights of man and citizen. Consequently, one of the participants in environmental legal relations (subject) is the state represented by its competent authority.Another subject of environmental relations is a legal entity or an individual acting on the natural environment for the purpose of its consumption, use, reproduction or protection. These entities include citizens, including foreign ones, and business entities.
Economic entities are understood as enterprises, institutions, organizations that affect the natural environment, as well as citizens engaged in entrepreneurial activities, or citizens engaged in general or special nature management.
In relation to environmental legal relations, state bodies act as holders of authority for management and control in the field of environmental protection. They determine the procedure and conditions for the use and protection of the natural environment, its individual objects.
Business entities, citizens, including foreign legal entities and individuals, are required to comply with environmental regulations.
The objects of environmental legal relations are the objects of environmental protection from pollution, depletion, degradation, damage, destruction and other negative impacts of economic and other activities. Such objects include: lands, bowels, soils; surface and ground waters; forests and other vegetation, animals and other organisms and their genetic fund; atmospheric air, the ozone layer of the atmosphere and near-Earth space.
As a matter of priority, natural ecological systems, natural landscapes and natural complexes that have not been subjected to anthropogenic impact are subject to protection.
The nature of the object of legal relations, its features determine the rights and obligations that are vested in the subject of legal relations. In the presence of, say, such an object of legal relations as nature reserves, prohibitive norms prevail in the composition of legal relations; in the economic use of land, priority is given to preventive, permissive measures.
Speaking about the concept of environmental harm, it should be borne in mind that the object of encroachment in this case is the stability of the environment and natural resource potential, as well as the right of everyone guaranteed by Article 42 of the Constitution of the Russian Federation to a favorable environment.
The consequences of violating the rules of environmental protection in the course of work (Article 246 of the Criminal Code of the Russian Federation) should be understood as a significant deterioration in the quality of the environment or the state of its objects, the elimination of which requires a long time and large financial and material costs; destruction of individual objects; land degradation and other negative changes in the environment that impede its conservation and lawful use.
Significant environmental damage is characterized by the occurrence of diseases and the death of aquatic animals and plants, other animals and vegetation on the banks of water bodies, the destruction of fish stocks, spawning and feeding areas; mass death of birds and animals, including aquatic ones, in a certain area, in which the mortality rate exceeds the average by three or more times; ecological value of the damaged territory or lost natural object, destroyed animals and trees and shrubs; a change in the radioactive background to values that pose a danger to human health and life, the genetic fund of animals and plants; the level of land degradation, etc.
The creation of a threat of causing significant harm to human health or the environment (part 1 of article 247 of the Criminal Code of the Russian Federation) implies the occurrence of such a situation or such circumstances that would entail harmful consequences provided for by law, if they were not interrupted by timely measures taken or other circumstances beyond the control of from the will of the harmer.
In this case, the threat implies the presence of a specific danger of actual harm to human health or the environment.
Violation of legal environmental requirements entails the application of legal liability measures.
Legal liability is understood as a system of coercive measures applied to violators of environmental legislation in order to punish those responsible, suppress and prevent offenses, and restore violated rights. One of the properties of legal responsibility is that it has a state coercive character, expressed in the right of the state to impose on the relevant subjects the obligation to bear adverse consequences. Adverse consequences of a personal, property, organizational and other nature are called sanctions. The most common sanctions provided for committing environmental offenses are administrative and criminal fines, seizure of tools of illegal activity and illegally obtained products, imposition of the obligation to compensate for the damage caused.
Legal liability for environmental offenses occurs when there are legal and factual grounds, which include:
- a rule that prohibits behavior or action, or a rule that obliges one or another action to be taken;
- the fact of non-compliance with the requirements of the law, i.e. existence of an offense;
- causal relationship between the committed action and the resulting consequences.
Environmental offenses are actions or omissions that intentionally or recklessly violate the norms of environmental law. An action or inaction is recognized as an environmental offense if it is environmentally significant. Environmentally significant behavior means the mandatory use of natural objects that are the subject of encroachment, and the focus on such a change in the state of the environment that is prohibited by law. Thus, an environmental offense differs from other offenses in that the subject of the encroachment of actions or inactions prohibited by law is the environment or its individual components in their legal sense.
For the commission of environmental offenses, the application of measures of criminal, administrative, civil and disciplinary liability is envisaged. Legal regulation in the field of criminal and civil liability, in accordance with Art. 71 of the Constitution of Russia, is within the jurisdiction of the Russian Federation. Accordingly, at the level of the subjects of the Russian Federation, laws or other regulatory legal acts establishing these measures of responsibility for environmental offenses cannot be adopted. At the same time, in accordance with Art. 72 of the Constitution of the Russian Federation, administrative legislation is the joint jurisdiction of the Russian Federation and the constituent entities of the Russian Federation.
Criminal liability for environmental crime is provided for by the Criminal Code of the Russian Federation. In ch. 26 of this Code "Ecological crimes", 17 elements of criminal offenses are defined. These include illegal harvesting of aquatic animals and plants, illegal hunting, violation of the legislation of the Russian Federation on the continental shelf and the exclusive economic zone, violation of the rules for the protection and use of subsoil, illegal forest management, destruction or damage to forests, pollution of water bodies and atmospheric air, sea pollution harmful substances, violation of the regime of specially protected natural areas and natural objects, violation of the rules for handling environmentally hazardous substances and waste, etc.
Penal sanctions, deprivation of the right to occupy certain positions or the right to engage in certain activities, deprivation or restriction of liberty are applied for the commission of criminal offenses. Criminal fines are calculated in multiples of the minimum wage and range from 50 to 700 times the minimum wage. The subjects of criminal liability can only be individuals - citizens and officials, whose criminal liability may be different for the same offense. A criminal fine in the amount of 500 to 700 times the minimum wage is provided for illegal hunting with aggravating circumstances using one's official position. The most severe punishment in the form of 8 years in prison is established for the deliberate destruction or damage of forests by arson, violation of the rules with environmentally hazardous substances, which negligently caused the death of a person or mass disease of people. In appropriate cases, along with fines, confiscation of illegally obtained and instruments of environmental crime is carried out. The application of criminal liability measures does not relieve the offender from the obligation to compensate for the environmental damage caused to citizens, organizations, the state
Criminal sanctions are applied by a court decision, which is preceded by investigative actions by law enforcement agencies.
Administrative responsibility for environmental offenses is applied for the commission of unlawful acts, which, in comparison with a criminal offense, are characterized by a lesser degree of public danger. Measures of administrative responsibility are applied by specially authorized state bodies in the field of environmental protection, sanitary and epidemiological supervision bodies, administrative commissions on the basis of decisions to impose a fine. Decisions on the imposition of an administrative fine may be appealed to the court.
One of the most common penalties applied to citizens, officials or organizations for environmental offenses is a fine based on the officially established minimum wage. The payment of a fine does not release the perpetrators from the obligation to compensate for the harm caused by the offense.
A feature of the legal regulation of administrative liability for environmental offenses is that administrative liability is established by several federal laws - the Law "On Environmental Protection", the Code of Administrative Offenses of the Russian Federation, the Land Code, the Law "On Specially Protected Natural Territories", etc.
etc.................
All living organisms do not live on Earth in isolation from each other, but form communities. Everything in them is interconnected, both living organisms and such formation in nature is called an ecosystem that lives according to its own specific laws and has specific features and qualities that we will try to get acquainted with.
The concept of an ecosystem
There is such a science as ecology, which studies But these relationships can only be carried out within the framework of a certain ecosystem and occur not spontaneously and chaotically, but according to certain laws.
There are different types of ecosystems, but all of them are a collection of living organisms that interact with each other and with the environment through the exchange of substances, energy and information. That is why the ecosystem remains stable and sustainable over a long period of time.
Ecosystem classification
Despite the great diversity of ecosystems, they are all open, without which their existence would be impossible. The types of ecosystems are different, and the classification may be different. If we keep in mind the origin, then ecosystems are:
- natural or natural. In them, all interaction is carried out without the direct participation of a person. They, in turn, are divided into:
- Ecosystems that are completely dependent on solar energy.
- Systems that receive energy from both the sun and other sources.
2. Artificial ecosystems. Created by human hands, and can only exist with his participation. They are also divided into:
- Agro-ecosystems, that is, those that are associated with human activities.
- Technoecosystems appear in connection with the industrial activities of people.
- urban ecosystems.
Another classification distinguishes the following types of natural ecosystems:
1. Ground:
- Rainforests.
- Desert with grassy and shrubby vegetation.
- Savannah.
- Steppes.
- Deciduous forest.
- Tundra.
2. Freshwater ecosystems:
- stagnant reservoirs
- Flowing waters (rivers, streams).
- Swamps.
3. Marine ecosystems:
- Ocean.
- continental shelf.
- Fishing areas.
- Mouths of rivers, bays.
- Deep water rift zones.
Regardless of the classification, one can see the diversity of ecosystem species, which is characterized by its set of life forms and numerical composition.
Distinguishing features of an ecosystem
The concept of an ecosystem can be attributed to both natural formations and artificially created by man. If we talk about natural, then they are characterized by the following features:
- In any ecosystem, the essential elements are living organisms and abiotic environmental factors.
- In any ecosystem, there is a closed cycle from the production of organic substances to their decomposition into inorganic components.
- The interaction of species in ecosystems ensures stability and self-regulation.
The entire surrounding world is represented by various ecosystems, which are based on living matter with a certain structure.
Biotic structure of an ecosystem
Even if ecosystems differ in species diversity, abundance of living organisms, their life forms, the biotic structure in any of them is still the same.
Any types of ecosystems include the same components; without their presence, the functioning of the system is simply impossible.
- Producers.
- Consumers of the second order.
- Reducers.
The first group of organisms includes all plants that are capable of the process of photosynthesis. They produce organic matter. This group also includes chemotrophs, which form organic compounds. But only for this they use not solar energy, but the energy of chemical compounds.
Consumers include all organisms that need organic matter from outside to build their bodies. This includes all herbivorous organisms, predators and omnivores.
Decomposers, which include bacteria, fungi, convert the remains of plants and animals into inorganic compounds suitable for use by living organisms.
Functioning of ecosystems
The largest biological system is the biosphere, which, in turn, consists of individual components. You can make the following chain: species-population-ecosystem. The smallest unit in an ecosystem is the species. In each biogeocenosis, their number can vary from several tens to hundreds and thousands.
Regardless of the number of individuals and individual species in any ecosystem, there is a constant exchange of matter and energy not only among themselves, but also with the environment.
If we talk about the exchange of energy, then it is quite possible to apply the laws of physics. The first law of thermodynamics states that energy does not disappear without a trace. It only changes from one species to another. According to the second law, in a closed system, energy can only increase.
If physical laws are applied to ecosystems, then we can come to the conclusion that they support their vital activity due to the presence of solar energy, which organisms are able not only to capture, but also to transform, use, and then release into the environment.
Energy is transferred from one trophic level to another; during the transfer, one type of energy is converted into another. Part of it, of course, is lost in the form of heat.
Whatever types of natural ecosystems exist, such laws operate absolutely in each.
Ecosystem structure
If we consider any ecosystem, then we can definitely see in it that various categories, for example, producers, consumers and decomposers, are always represented by a whole set of species. Nature provides that if something suddenly happens to one of the species, then the ecosystem will not die from this, it can always be successfully replaced by another. This explains the stability of natural ecosystems.
A large variety of species in the ecosystem, diversity ensures the stability of all processes that take place within the community.
In addition, any system has its own laws, which all living organisms obey. Based on this, several structures can be distinguished within the biogeocenosis:
Any structure is necessarily present in any ecosystem, but it can differ significantly. For example, if we compare the biogeocenosis of the desert and the rainforest, the difference is visible to the naked eye.
artificial ecosystems
Such systems are created by human hands. Despite the fact that in them, as in natural ones, all components of the biotic structure are necessarily present, there are still significant differences. Among them are the following:
- Agrocenoses are characterized by poor species composition. Only those plants grow there that man grows. But nature takes its toll, and always, for example, on a wheat field you can see cornflowers, daisies, various arthropods settle. In some systems, even birds have time to build a nest on the ground and hatch chicks.
- If a person does not take care of this ecosystem, then cultivated plants will not withstand competition with their wild relatives.
- Agrocenoses also exist due to the additional energy that a person brings, for example, by applying fertilizers.
- Since the grown biomass of plants is withdrawn along with the harvest, the soil is depleted in nutrients. Therefore, for further existence, again, the intervention of a person who will have to fertilize in order to grow the next crop is necessary.
It can be concluded that artificial ecosystems do not belong to sustainable and self-regulating systems. If a person stops caring for them, they will not survive. Gradually, wild species will displace cultivated plants, and the agrocenosis will be destroyed.
For example, an artificial ecosystem of three types of organisms can easily be created at home. If you put an aquarium, pour water into it, place a few branches of elodea and settle two fish, here you have an artificial system ready. Even such a simple one cannot exist without human intervention.
The value of ecosystems in nature
Globally speaking, all living organisms are distributed across ecosystems, so their importance is difficult to underestimate.
- All ecosystems are interconnected by the circulation of substances that can migrate from one system to another.
- Due to the presence of ecosystems in nature, biological diversity is preserved.
- All the resources that we draw from nature are given to us by ecosystems: clean water, air,
Any ecosystem is very easy to destroy, especially given the capabilities of man.
Ecosystems and man
Since the appearance of man, his influence on nature has increased every year. Developing, man imagined himself the king of nature, began without hesitation to destroy plants and animals, destroy natural ecosystems, thereby began to cut the branch on which he himself sits.
By interfering with centuries-old ecosystems and violating the laws of the existence of organisms, man has led to the fact that all ecologists of the world are already shouting with one voice that the world has come. human intervention in its laws. It's time to stop and think that any kind of ecosystems were formed for centuries, long before the appearance of man, and perfectly existed without him. Can humanity live without nature? The answer suggests itself.
Unlike a natural ecosystem, an artificial ecosystem is characterized. Write your answer in numbers without spaces.
1) a wide variety of species
2) diverse supply chains
3) open circulation of substances
4) the predominance of one or two species
5) the influence of the anthropogenic factor
6) closed circulation of substances
Explanation.
Differences of agrocenoses from natural biogeocenoses. Between natural and artificial biogeocenoses, along with similarities, there are also big differences that are important to take into account in agricultural practice.
The first difference is in the different direction of selection. In natural ecosystems, there is natural selection that rejects non-competitive species and forms of organisms and their communities in the ecosystem and thereby ensures its main property - sustainability. In agrocenoses, mainly artificial selection operates, directed by man primarily to maximize the yield of agricultural crops. For this reason, the ecological stability of agrocenoses is low. They are not capable of self-regulation and self-renewal, they are subject to the threat of death during the mass reproduction of pests or pathogens. Therefore, without human participation, his tireless attention and active intervention in their lives, agrocenoses of grain and vegetable crops exist for no more than a year, perennial grasses - 3-4 years, fruit crops - 20-30 years. Then they disintegrate or die.
The second difference is in the source of energy used. For natural biogeocenosis, the only source of energy is the Sun. At the same time, agrocenoses, in addition to solar energy, receive additional energy that a person spent on the production of fertilizers, chemicals against weeds, pests and diseases, on irrigation or drainage of land, etc. Without such additional energy consumption, the long-term existence of agrocenoses is almost impossible .
The third difference is that the species diversity of living organisms is sharply reduced in agroecosystems. One or several species (varieties) of plants are usually cultivated in the fields, which leads to a significant depletion of the species composition of animals, fungi, and bacteria. In addition, the biological uniformity of cultivated plant varieties occupying large areas (sometimes tens of thousands of hectares) is often the main reason for their mass destruction by specialized insects (for example, the Colorado potato beetle) or damage by pathogens (powdery hummock, rust, smut fungi, late blight and etc.).
The fourth difference is the different balance of nutrients. In a natural biogeocenosis, the primary production of plants (yield) is consumed in numerous food chains (networks) and is again returned to the biological cycle system in the form of carbon dioxide, water and mineral nutrition elements.
In the agrocenosis, such a cycle of elements is sharply disturbed, since a person removes a significant part of them with the harvest. Therefore, in order to compensate for their losses and, consequently, to increase the yield of cultivated plants, it is necessary to constantly apply fertilizers to the soil.
Thus, in comparison with natural biogeocenoses, agrocenoses have a limited species composition of plants and animals, are not capable of self-renewal and self-regulation, are subject to the threat of death as a result of mass reproduction of pests or pathogens, and require tireless human activity to maintain them.
Under the numbers 3, 4, 5 - characterizes agrocenosis; 1, 2, 6 - natural biogeocenosis.
Answer: 345.
artificial ecosystems
Lecture number 6. artificial ecosystems
Natural and artificial ecosystems
In the biosphere, in addition to natural biogeocenoses and ecosystems, there are communities artificially created by human economic activity - anthropogenic ecosystems.
natural ecosystems differ in significant species diversity, exist for a long time, they are capable of self-regulation, have great stability, stability. The biomass and nutrients created in them remain and are used within the biocenoses, enriching their resources.
artificial ecosystems - agrocenoses (fields of wheat, potatoes, vegetable gardens, farms with adjacent pastures, fish ponds, etc.) make up a small part of the land surface, but provide about 90% of food energy.
The development of agriculture since ancient times has been accompanied by the complete destruction of the vegetation cover over large areas in order to make room for a small number of human-selected species that are most suitable for food.
However, initially human activity in an agricultural society fit into the biochemical cycle and did not change the flow of energy in the biosphere. In modern agricultural production, the use of synthesized energy in the mechanical processing of the land, the use of fertilizers and pesticides has increased dramatically. This disrupts the overall energy balance of the biosphere, which can lead to unpredictable consequences.
Comparison of natural and simplified anthropogenic ecosystems
(according to Miller, 1993)
| Natural ecosystem (bog, meadow, forest) | Anthropogenic ecosystem (field, plant, house) |
| Receives, transforms, accumulates solar energy | Consumes energy from fossil and nuclear fuels |
| Produces oxygen and consumes carbon dioxide | Consumes oxygen and produces carbon dioxide when fossil fuels are burned |
| Forms fertile soil | Depletes or poses a threat to fertile soils |
| Accumulates, purifies and gradually consumes water | Uses a lot of water, pollutes it |
| Creates habitats for various types of wildlife | Destroys the habitats of many species of wildlife |
| Filters and disinfects pollutants and waste free of charge | Produces pollutants and waste that must be decontaminated at the expense of the public |
| Possesses the ability of self-preservation and self-healing | Requires high costs for constant maintenance and restoration |
artificial ecosystems
Agroecosystems
Agroecosystem(from the Greek agros - field) - a biotic community created and regularly maintained by man in order to obtain agricultural products. Usually includes the totality of organisms that live on agricultural land.
Agroecosystems include fields, orchards, vegetable gardens, vineyards, large livestock complexes with adjacent artificial pastures.
A characteristic feature of agroecosystems is low ecological reliability, but high productivity of one (several) species or varieties of cultivated plants or animals. Their main difference from natural ecosystems is their simplified structure and depleted species composition.
Agroecosystems are different from natural ecosystems a number of features:
1. The variety of living organisms in them is sharply reduced to obtain the highest possible production.
On a rye or wheat field, in addition to a cereal monoculture, only a few types of weeds can be found. In a natural meadow, biological diversity is much higher, but biological productivity is many times inferior to a sown field.
Artificial regulation of the number of pests is, for the most part, a necessary condition for maintaining agroecosystems. Therefore, in agricultural practice, powerful means are used to suppress the number of undesirable species: pesticides, herbicides, etc. The environmental consequences of these actions lead, however, to a number of undesirable effects, in addition to those for which they are applied.
2. Species of agricultural plants and animals in agroecosystems are obtained as a result of artificial rather than natural selection, and cannot withstand the struggle for existence with wild species without human support.
As a result, there is a sharp narrowing of the genetic base of agricultural crops, which are extremely sensitive to the mass reproduction of pests and diseases.
3. Agro-ecosystems are more open, matter and energy are withdrawn from them with crops, livestock products, and also as a result of soil destruction.
In natural biocenoses, the primary production of plants is consumed in numerous food chains and again returned to the biological cycle in the form of carbon dioxide, water and mineral nutrients.
Due to the constant harvesting and disruption of soil formation processes, with long-term cultivation of monoculture on cultivated lands, soil fertility gradually decreases. This position in ecology is called law of diminishing returns .
Thus, for prudent and rational agriculture, it is necessary to take into account the depletion of soil resources and preserve soil fertility with the help of improved agricultural technology, rational crop rotation and other methods.
The change of vegetation cover in agroecosystems does not occur naturally, but at the will of man, which is not always well reflected in the quality of abiotic factors included in it. This is especially true for soil fertility.
Main difference agroecosystems from natural ecosystems - getting extra energy for normal operation.
Supplementary refers to any type of energy that is added to agroecosystems. This can be the muscular strength of a person or animals, various types of fuel for the operation of agricultural machines, fertilizers, pesticides, pesticides, additional lighting, etc. The concept of "additional energy" also includes new breeds of domestic animals and varieties of cultivated plants introduced into the structure of agroecosystems.
It should be noted that agroecosystems - highly unstable communities. They are not capable of self-healing and self-regulation, they are subject to the threat of death from the mass reproduction of pests or diseases.
The reason for the instability is that agrocenoses are composed of one (monoculture) or less often a maximum of 2–3 species. That is why any disease, any pest can destroy the agrocenosis. However, a person consciously goes to simplify the structure of agrocenosis in order to obtain the maximum yield of products. Agrocenoses, to a much greater extent than natural cenoses (forest, meadow, pastures), are subject to erosion, leaching, salinization and pest invasion. Without human participation, agrocenoses of grain and vegetable crops exist for no more than a year, berry plants - 3-4, fruit crops - 20-30 years. Then they disintegrate or die.
The advantage of agrocenoses before natural ecosystems is the production of food necessary for humans and great opportunities to increase productivity. However, they are realized only with constant concern for the fertility of the earth, providing plants with moisture, protecting cultural populations, varieties and breeds of plants and animals from the adverse effects of natural flora and fauna.
All agro-ecosystems of fields, gardens, pasture meadows, kitchen gardens, greenhouses artificially created in agricultural practice are human-supported systems.
In relation to the communities that take shape in agroecosystems, the emphasis is gradually changing in connection with the general development of ecological knowledge. The idea of fragmentation, fragmentation of coenotic connections and the ultimate simplification of agrocenoses is being replaced by an understanding of their complex systemic organization, where a person significantly affects only individual links, and the whole system continues to develop according to natural, natural laws.
From an ecological point of view, it is extremely dangerous to simplify the natural environment of a person, turning the entire landscape into an agricultural one. The main strategy for creating a highly productive and sustainable landscape should be to preserve and increase its diversity.
Along with the maintenance of highly productive fields, special care should be taken to preserve protected areas that are not subject to anthropogenic impact. Reserves with a rich species diversity are a source of species for communities recovering in successional series.
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| natural ecosystem | Agroecosystem |
| SIMILARITIES: 1. They absorb solar energy (they are open systems). 2. Includes producers, consumers and decomposers. 3. There are food chains inside them. 4. All the factors of evolution (hereditary variability, struggle for existence, natural selection) operate. 5. They have a circulation of substances. | |
| DIFFERENCES: | |
| 1. The species composition of organisms has developed naturally. | 1. The species composition is artificially selected by man. |
| 2. The species composition is varied | 2. The species composition is poor, usually 1-2 species predominate |
| 3. Food chains are long | 3. Food chains are short, one of the links is a person |
| 4.Stable system | 4. The system is unstable, without the help of a person does not exist on its own |
| 5. Organic matter remains inside the system | 5. Organic matter is removed from the system by humans |
| 6. The circulation of substances is natural, closed | 6. The circulation of substances is open, supported by man through the application of fertilizers |
| 7. The only source of energy is the energy of the Sun | 7. In addition to the energy of the Sun, other types of energy are used (the energy of machines, people, electrical, etc.) |
| 8. All factors of evolution are active | 8. The action of evolutionary factors is weakened by man, artificial selection prevails |
Natural ecosystems (biogeocenoses) are the main components of the biosphere. Their diversity and distribution over the earth's surface is of great importance for man, since from them he receives food, substances for treatment, materials for making clothes and housing, raw materials for industrial production, etc.
Human activity, especially in the last century, began to dramatically change the state of natural ecosystems and the biosphere as a whole. As a result, thousands of years of existing ecosystems are being destroyed, and many species of plants and animals are disappearing.
The main human activities that lead to ecosystem change: with construction of cities, roads, dams , d custom of minerals, hunting, fishing, collection of valuable plants , deforestation, plowing of land , burning large amounts of fossil fuels, etc.
Consequences of human activity:
1. Reducing the area of natural ecosystems.
2. Destruction of species habitats, extinction of some species, reduction of biodiversity.
3. Pollution of the atmosphere, oceans.
4. Earth climate change.
5. The deterioration of the health of the world's population.
6. Reduction of natural resources with their growth in consumption.
7. Reduction of habitable territories with the growth of the world's population.
8. Reducing the stability of the biosphere.
Ways to save ecosystems:
1. Application of resource-saving and energy-saving technologies (non-waste technologies, recycling of raw materials).
2. The fight against pollution of the atmosphere, hydrosphere, soil (improvement of cleaning, waste disposal, non-waste technologies, clean energy sources, economic and legal measures - fines, tougher liability, environmental monitoring).
3. Land reclamation, soil erosion control (land restoration after mining, construction, pollution, etc., organization of sanitary protection zones around cities, industrial enterprises)
4. Environmental measures (adoption of laws, Red Books, creation of specially protected natural areas, limitation of fishing, fight against poachers).
5. Birth control (by adopting programs of control, demographic development, laws, contraception).
6. Education of ecological consciousness in people. (rejection of consumer attitude to nature, fostering a caring attitude, a sense of responsibility to future generations)
2. Angiosperms are the dominant group of plants on Earth. Angiosperm classes. Among herbarium specimens or living plants, find angiosperms belonging to different classes. By what signs do you distinguish them?
Department Angiosperms includes plants that form flowers and fruits. They are descended from gymnosperms. Flowering - the largest and highly organized department in the plant kingdom, uniting 250 thousand species out of 350 thousand species of all plants. Compared with gymnosperms, angiosperms have a number of advantages that have allowed them to become the dominant group of plants on Earth. The appearance of the flower ensured more reliable pollination, and the appearance of the fruit ensured the protection of seeds and their distribution. Double fertilization ensures the development of not only a diploid embryo, but also a triploid endosperm (nutrient tissue for the embryo). A variety of adaptations allows you to live in various conditions.
Characteristic features of the department:
1) They have a flower in which the ovules are protected inside the ovary.
2) They form a fruit, inside of which there are seeds, and the seed embryo is protected by both the seed coat and the pericarp.
3) Double fertilization, which results in the formation of a diploid embryo and a triploid endosperm - a nutrient tissue for the development of the embryo.
4) Conductive tissues (vessels and sieve tubes with satellite cells) are well developed.
5) They have a variety of life forms (herbs, trees, shrubs, shrubs and trees), forming multi-tiered biocenoses.
6) They have various adaptations for pollination, seed dispersal, evaporation, feeding, receiving light, etc.
In the department of angiosperms, two classes are distinguished: Dicotyledonous and Monocotyledonous.
