Species diversity environment definition. Life on Earth and its diversity

Biodiversity as a key factor in sustainable development

Biological diversity is the diversity of all forms of living organisms and the systems of which these organisms are part. The concept of biological diversity refers to different levels of organization of living things - molecular-genetic, population-species, taxonomic (from "taxonomy" - systematics) and cenotic (from "cenosis" - community). Each subsequent of these levels includes the previous one.
Biological diversity forms the biota of the Earth, represented both by the totality of organisms and species, and by the structure of their distribution among communities (biocenoses) and by the communities themselves as the main structural units of the biosphere.

Importance of biological diversity

Biological diversity was formed as a result of the interaction between the biosphere and the geographic envelopes of the Earth - the hydrosphere, atmosphere and the earth's crust (lithosphere), the composition of which, in turn, is largely determined by the biota. It was the biota that at one time caused the transition of a reducing atmosphere into an oxidizing one, which gave impetus to the evolutionary process and the emergence of new forms of life.

As life conquered the planet, living beings became increasingly important as a factor in the transformation of matter and energy. The effectiveness of these processes, without which life on Earth is already unthinkable, is determined by biological diversity - the functional specialization of various species and the distribution of their roles in communities.

The stability factors of biological communities themselves (as well as any other complex systems) are duplication (in this case duplication of ecological niches occupied by different organisms) and redundancy of structural elements. These factors in natural conditions are provided by biological diversity - as a rule, the removal of any one species does not lead to the destruction of the ecosystem, because functional relationships are maintained at the expense of other species.

Biological diversity also determines such an important property of life as the maintenance of certain climatic environmental conditions suitable for life. First of all - the temperature range that ensures the stay of water in a liquid state. According to modern cosmogonic concepts, there are no physical barriers between the climatic conditions of the Earth and neighboring planets - Mars and Venus, where life is impossible. The transition of the Earth's climate to the climate of any of these planets can take place in a fairly short period of time - about 10 thousand years. However, for almost 4 billion years of the history of life on Earth, this has not happened due to the fact that albedo, the greenhouse effect and other important characteristics of the climate are under the control of the global biota. In support of this concept, we present three typical examples.

Emissions of inorganic carbon from the earth's interior into the atmosphere are compensated by the deposition of this element in the composition of organic compounds, in sedimentary rocks, so that the CO 2 content in the atmosphere remains at a relatively constant level for hundreds of millions of years.

The quantitative ratio in the ocean of carbon, nitrogen, phosphorus and oxygen atoms that make up various compounds coincides with the ratio of these elements in living matter, which indicates that their concentration is due to the activity of biota.

In the water cycle on land, biota also plays a dominant role: 2/3 of precipitation is determined by transpiration - the evaporation of water from the surface of plants.

Finally, we should not forget that living organisms provide us with food and clothing, building materials, medicinal substances and, importantly, spiritual food. Species of wild plants and animals are an exhaustible, irreplaceable resource, a repository of an invaluable genetic fund, of all the possibilities of using which we sometimes do not even suspect.

In the second half of the XX century. Humanity is faced with a contradiction between growing economic needs and the inability of the biosphere to meet these needs. The riches of nature, the possibilities of its self-healing turned out to be not unlimited.

The elimination of this contradiction is possible only within the framework of the so-called sustainable development human society based on the satisfaction of our economic needs within the economic capacity of the biosphere, those. within limits that do not entail irreversible changes in the natural environment. Otherwise, the reduction of biological diversity can really develop into an ecological catastrophe that threatens our very existence on Earth.

What we know about biotic regulation of the environment allows us to conclude that this limit has already been surpassed, but irreversible changes in the biosphere have not yet occurred, and humanity retains a chance to return to the area of permissible influences.

To reduce the degree of pressure on nature and in the future to comply with the permissible level is the only way for us to survive. At the same time, we are talking not so much about reducing environmental pollution, but about preserving natural ecosystems, preserving biological diversity as the main regulator of the sustainability of the biosphere. After all, our civilization, using a huge number of technologies that destroy ecosystems, has not offered, in fact, anything that could replace natural regulatory processes. And it is obvious that humanity will not have time to learn how to somehow regulate the state of the environment by technical means in the time that we have left before the start of catastrophic changes in the biosphere. So the only chance to eliminate a more than real threat to the vital interests of future generations is to clear the way for the stabilizing action of natural forces themselves.

State of biological diversity on the planet and in Russia

Currently, the biological diversity of the planet is impoverished due to the following reasons.

1. Direct destruction of ecological systems - uprooting, burning and cutting down forests, plowing steppes, draining swamps and floodplain reservoirs, as well as building up natural biotopes with settlements, industrial enterprises, laying highways ... Anthroposystems arise in place of natural ecosystems. With such an impact, both ecosystem and species diversity are simultaneously destroyed.

2. Transformation of original ecosystems under the influence of anthropogenic influences - changes in forest types under the influence of felling (the emergence of anthropogenic forest successions) and silvicultural work, artificial afforestation of open spaces, the creation of semi-natural agrolandscapes (agrobiocenoses), an increase in pastures depleted under the influence of overgrazing ... Transformed ecosystems are usually depleted in terms of species.

To be continued

It is based on species diversity. It includes millions of species of animals, plants, microorganisms living on our planet. However, biodiversity also covers the totality of natural ecosystems that are composed of these species. Thus, biodiversity should be understood as the diversity of organisms and their natural combinations. On the basis of biodiversity, the structural and functional organization of the biosphere and its constituent ecosystems is created, which determines their stability and resistance to external influences.

Exist three main types of biodiversity:

genetic, reflecting intraspecific diversity and due to the variability of individuals;
species, reflecting the diversity of living organisms (plants, animals, fungi and microorganisms);
ecosystem diversity, encompassing differences between ecosystem types, habitats and ecological processes. The diversity of ecosystems is noted not only in terms of structural and functional components, but also in terms of scale - from the biocenosis to the biosphere.

All types of biological diversity are interrelated: genetic diversity ensures species diversity; the diversity of ecosystems and landscapes creates conditions for the formation of new species; an increase in species diversity increases the overall genetic potential of living organisms in the biosphere. Each species contributes to diversity, and from this point of view, there are no useless or harmful species.

Convention on Biological Diversity

In accordance with the 1992 Convention on Biological Diversity, to which 181 states are parties as of August 14, 2001, their governments have committed themselves to conserve biological diversity, use its components in a sustainable manner and equally share the benefits arising from the use of genetic resources. Despite this, the planet's biodiversity is being irreversibly lost at an alarming rate as a result of large scale deforestation and deforestation; the predatory scale of harvesting plants; indiscriminate use of pesticides and other persistent pesticides; drainage and backfilling of swamps; destruction of coral reefs and mangroves; the use of predatory fishing methods; climate change; water pollution; the transformation of untouched natural areas into agricultural land and urban areas.

In the capital of Malaysia - Kuala Lumpur in February 2004, under the auspices of the UN, the Seventh Conference of the Parties to the Convention on Biological Diversity was held. More than 2 thousand representatives from over 180 countries of the world took part in it. The conference discussed issues of protecting the environment and endangered species, exploring the possibility of creating a special network that would help the population of developing countries protect their heritage.

Director General of the UN Environment Program K. Toepfer stated at the forum that after 2000 about 60,000 biological species disappear annually on the planet, and this number is steadily growing.

Biodiversity characterizes the process of real evolution, which takes place at many levels of organization of the living. According to scientists, the total number of species of living beings is from 5 to 30 million. Of these, no more than 2.0 million are currently described. Thus, since the time of Linnaeus, who tried to create a classification of living organisms, the number of animal and plant species known to science , increased from 11 thousand to 2 million.

Animals are one of the leading components of the Earth's ecological systems. At present, a little more than 1 million species of animals are known (described) to science, which is about half of all that exist on the planet. The main groups of organisms and their abundance (number of species, thousand) are presented as follows:

The biological diversity of species is maximum among insects and higher plants. According to experts, the total number of organisms of all life forms ranges between 10 and 100 million. These millions of species of animals and plants support the conditions necessary for the continuation of life on Earth.

In 1982, the American researcher T. Erwin published an article that caused a heated controversy. He argued that more than 30 million species of arthropods, mostly insects, can live in tropical forests. The basis for such a bold conclusion was his estimate of the number of insect species specifically associated with only one species of trees from the legume family (Luehea seemanni) in the rainforest of Panama. Using insecticide fumigation on tree crowns and collecting all the fallen arthropods on a plastic sheet stretched below, Erwin counted the total number of beetle species (he believed that many of them were unknown to science) and came to the conclusion that the tree serves as a food plant for only 136 of them. Having made a number of assumptions, he calculated that the number of species of all arthropods associated with one type of tree (including those living on earth) reaches 600. Since there are about 50 thousand tree species in the tropics, it is easy to calculate that there were 30 million of them. Thus, with the species already known to science (about 1 million), this amounted to 31 million! Some entomologists were rather skeptical about Erwin's calculations: accepting his logic, one would expect that most insects in the tropics should belong to new species, but in fact they are not so common.

Recently, this hypothesis was tested by the Czech scientist V. Novotny (Institute of Entomology of the Czech Academy of Sciences) together with colleagues from the USA, Panama, Sweden and the Czech Republic.

Surveying a patch of lowland tropical rainforest in New Guinea for several years, scientists collected insects from the leaves of 51 plant species, including 13 species of the genus Ficus and four species of the genus Psychotria. In total, more than 50 thousand insects belonging to 935 species were collected, among which beetles, caterpillars of butterflies (lepidoptera) and orthoptera prevailed. In addition, the researchers grew caterpillars on different plants, trying to bring them to the chrysalis.

An analysis of this extensive material showed that, per one food species, there are 7.9 species of beetles, 13.3 of butterflies, and 2.9 of orthoptera. Thus, the idea of the extreme prevalence of stenophagy in the tropics turns out to be nothing more than a myth. Novotny and his colleagues also calculated how many species of insects could be associated with host plants at the genus level, and then calculated the total number of arthropod species: there were about 4.9 million of them, not 31 million, as Erwin had assumed.

Importance of biodiversity conservation

Biodiversity is the main source of satisfaction for many and serves as the basis for their adaptation to changing environmental conditions. The practical value of biodiversity lies in the fact that it is essentially an inexhaustible source of biological resources. These are, first of all, food products, medicines, sources of raw materials for clothing, production of building materials, etc. Biodiversity is of great importance for the organization of human recreation.

We know very little about the beneficial properties of most organisms. In the asset of mankind, for example, there are only about 150 species of cultivated plants that are widely used, and out of 265 thousand species of all plant organisms, only 5 thousand have ever been cultivated by man. To an even lesser extent, the diversity of microorganisms and fungi is taken into account.

Currently, there are about 65 thousand species of mushrooms. And how many of them does a person use?

Natural vegetation is the main base for obtaining medicines, with the help of which mankind got rid of many diseases. So, for example, if the cinchona tree (Chinchona), which gives quinine, was not found in the selva on the eastern slopes of the Andes, the inhabitants of the tropics, subtropics and many inhabitants of the temperate zones would be doomed to suffer from malaria. The appearance of synthetic analogues of this drug became possible only thanks to a detailed study of the original. Mexican yam, belonging to the genus Dioscorea, is a source of diosgenin, which is used in the production of cortisone and hydrocortisone.

Trying to change natural conditions, man came into conflict with the forces of natural self-regulation. One of the results of this conflict has been the decline in the biological diversity of natural ecosystems. Currently, the number of species on Earth is rapidly decreasing. Up to 10 animal species disappear daily and 1 plant species disappears weekly. The death of one plant species leads to the destruction of about 30 species of small animals (primarily insects and roundworms - nematodes) associated with it in the process of feeding. In the next 20-30 years, humanity may lose about 1 million species. This will be a serious blow to the integrity and stability of our natural environment.

The reduction of biodiversity occupies a special place among the main environmental problems of our time. There is a massive destruction of natural ecosystems and the disappearance of many species of living organisms. Natural ecosystems have been completely changed or destroyed on a fifth of the land. Since 1600, 484 animal species and 654 plant species have been recorded extinct.

Species are distributed unevenly over the surface of the planet. Species diversity in natural habitats is highest in the tropical zone and decreases with increasing latitude. The richest ecosystems in terms of species diversity are tropical rainforests, which occupy about 7% of the planet's surface and contain more than 90% of all species. Coral reefs and Mediterranean ecosystems are also rich in species diversity.

Biodiversity provides genetic resources for agriculture, constitutes the biological basis for world food security and is a necessary condition for the existence of mankind. A number of wild plants related to crops are very important for the economy at the national and global levels. For example, Ethiopian varieties of Californian barley provide protection against disease-causing viruses worth $160 million. USA per year. Genetic disease resistance achieved with wild wheat varieties in Turkey is estimated at $50 million.

There are many reasons for the need to preserve biodiversity: the need for biological resources to meet the needs of mankind (food, materials, medicines, etc.), ethical and aesthetic aspects, etc. However, the main reason is that biodiversity plays a leading role in ensuring the sustainability of ecosystems and the biosphere as a whole (absorption of pollution, stabilization of the climate, provision of conditions suitable for life). Biodiversity performs a regulatory function in the implementation of all biogeochemical, climatic and other processes on Earth. Each species, no matter how insignificant it may seem, makes a certain contribution to ensuring the sustainability of not only its local ecosystem, but also the biosphere as a whole.

As the anthropogenic impact on nature intensifies, leading to the depletion of biological diversity, the study of the organization of specific communities and ecosystems, as well as the analysis of changes in their diversity, becomes an urgent need. In 1992, the UN Conference on Environment and Development was held in Rio de Janeiro (Brazil). The Convention on Biological Diversity was signed by representatives of most of the world's states.

In the Convention, "biological diversity" refers to the variability of living organisms from all sources, including terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part; this concept includes diversity within species, between species, and ecosystem diversity.

The goal of the Convention on Biological Diversity was formulated as follows: "the conservation of biological diversity, the sustainable use of its components and the equitable distribution of income from the use of genetic resources."

In addition to the Convention, a Program of Action for the 21st Century was adopted. It recommends directing the activities of mankind primarily to identify the state of biodiversity and potential threats to it in each of the countries that recognize the values proclaimed at this conference.

Today it is obvious that the preservation of the diversity of living organisms and biological systems on Earth is a necessary condition for human survival and the sustainable development of civilization.

Biodiversity- short for "biological diversity" - means the diversity of living organisms in all its manifestations: from genes to the biosphere. The issues of study, use and conservation of biodiversity began to receive much attention after the signing by many states of the Convention on Biological Diversity (UN Conference on Environment and Development, Rio de Janeiro, 1992).

There are three main type of biodiversity:

- genetic diversity, reflecting intraspecific diversity and due to the variability of individuals;

- species diversity, reflecting the diversity of living organisms (plants, animals, fungi and microorganisms). At present, about 1.7 million species have been described, although their total number, according to some estimates, is up to 50 million;

- diversity of ecosystems covers differences between ecosystem types, habitat diversity and ecological processes. They note the diversity of ecosystems not only in terms of structural and functional components, but also in terms of scale - from microbiogeocenosis to the biosphere;

All types of biological diversity interconnected: Genetic diversity ensures species diversity. The diversity of ecosystems and landscapes creates conditions for the formation of new species. An increase in species diversity increases the overall genetic potential of the living organisms of the Biosphere. Each species contributes to diversity - from this point of view, there are no useless and harmful species.

Distribution species on the surface of the planet unevenly. Species diversity in natural habitats is highest in the tropical zone and decreases with increasing latitude. The richest ecosystems in species diversity are tropical rainforests, which occupy about 7% of the planet's surface and contain more than 90% of all species.

In the geological history of the Earth in the biosphere, there has been a constant emergence and extinction of species All species have a finite lifetime. The extinction was compensated by the emergence of new species, and as a result, the total number of species in the biosphere increased. The extinction of species is a natural process of evolution that occurs without human intervention.

Currently, under the influence of anthropogenic factors, there is reduction biological diversity due to the elimination (extinction, destruction) of species. In the last century, under the influence of human activity, the rate of extinction of species has exceeded the natural rate by many times (according to some estimates, 40,000 times). There is an irreversible and uncompensated destruction of the unique gene pool of the planet.

Elimination of species as a result of human activities can occur in two directions- direct extermination (hunting, fishing) and indirect (habitat destruction, disturbance of trophic interactions). Overfishing is the most obvious direct cause of the direct decline of species, but it has a much lesser impact on extinction than indirect causes of habitat change (eg, chemical pollution of a river or deforestation).

Diversity of biotic cover, or biodiversity, is one of the factors for the optimal functioning of ecosystems and the biosphere as a whole. Biodiversity ensures the resilience of ecosystems to external stresses and maintains a dynamic balance in them. The living from the non-living, first of all, differs by several orders of magnitude in its great diversity and the ability not only to preserve this diversity, but also to significantly increase it in the course of evolution. In general, the evolution of life on Earth can be considered as a process of structuring the biosphere, a process of increasing the diversity of living organisms, forms and levels of their organization, a process of the emergence of mechanisms that ensure the stability of living systems and ecosystems in the constantly changing conditions of our planet. It is the ability of ecosystems to maintain balance, using the hereditary information of living organisms for this, that makes the biosphere as a whole and local ecosystems material-energy systems in the full sense.

In this photo we see many types of plants growing together in a meadow in the floodplain of the river. Budyumkan in the southeast of the Chita region. Why did nature need so many species in one meadow? This is what this lecture is about.

Russian geobotanist L.G. Ramensky in 1910 he formulated the principle of ecological individuality of species - a principle that is the key to understanding the role of biodiversity in the biosphere. We see that many species live together in each ecosystem at the same time, but we rarely think about the ecological meaning of this. Ecological individuality plant species living in the same plant community in the same ecosystem allows the community to quickly rebuild when external conditions change. For example, in a dry summer in this ecosystem, the main role in ensuring the biological cycle is played by individuals of species A, which are more adapted to life with a moisture deficit. In a wet year, individuals of species A are not at their optimum and cannot provide a biological cycle in the changed conditions. In this year, individuals of species B begin to play the main role in ensuring the biological cycle in this ecosystem. The third year turned out to be cooler; under these conditions, neither species A nor species B can ensure the full use of the ecological potential of this ecosystem. But the ecosystem is rapidly rebuilding, as it contains individuals of species B, which do not need warm weather and photosynthesize well at low temperatures.

Each species of living organisms can exist in a certain range of values of external factors. Outside these values, individuals of the species die. In the diagram, we see the limits of endurance (limits of tolerance) of the species according to one of the factors. Within these limits, thereoptimum zone, the most favorable for the species, and two zones of oppression. Rule L.G. Ramensky on the ecological individuality of species argues that the limits of endurance and optimum zones for different species living together do not coincide.

In nature, we find a lot of factors or mechanisms that provide and maintain a high species diversity of local ecosystems. First of all, such factors include excessive reproduction and overproduction of seeds and fruits. In nature, seeds and fruits are produced hundreds and thousands of times more than is necessary to make up for the natural loss due to premature death and dying of old age.

Thanks to adaptations for distributing fruits and seeds over long distances, the rudiments of new plants fall not only on those areas that are favorable for their growth now, but also on those areas whose conditions are unfavorable for the growth and development of individuals of these species. Nevertheless, these seeds germinate here, exist for some time in a depressed state and die. This happens as long as environmental conditions are stable. But if the conditions change, then the seedlings of species that were previously doomed to death begin to grow and develop here, going through a full cycle of their ontogenetic (individual) development. Ecologists say that in nature there is powerful pressure of diversity of life to all local ecosystems.

General land cover gene pool– its flora-local ecosystems of this region are used most fully due to the pressure of biodiversity. At the same time, local ecosystems in terms of species become richer. During their formation and rearrangement, the ecological selection of suitable components is carried out from a larger number of applicants whose diagerms have found their way into a given habitat. Thus, the probability of forming an ecologically optimal plant community increases.

Thus, the stability factor of a local ecosystem is not only the diversity of species living in this local ecosystem, but also the diversity of species in neighboring ecosystems, from which the introduction of diagerms (seeds and spores) is possible. This applies not only to plants that lead an attached lifestyle, but even more so to animals that can move from one local ecosystem to another. Many animal individuals, not belonging specifically to any of the local ecosystems (biogeocenoses), nevertheless play an important ecological role and participate in ensuring the biological cycle in several ecosystems at once. Moreover, they can alienate biomass in one local ecosystem, and throw out excrement in another, stimulating the growth and development of plants in this second local ecosystem. Sometimes such a transfer of matter and energy from one ecosystem to another can be extremely powerful. This flow connects completely different ecosystems.

Diversity of species and diversity of life forms or ecobiomorph are not the same thing. I will demonstrate this with an example. In the meadow, species, genera and families of plants can live 2-3 times more than in the dark coniferous forest. However, in terms of ecobiomorphs and synusia, it turns out that the biodiversity of the dark coniferous forest as an ecosystem is much higher than the biodiversity of the meadow as an ecosystem. In the meadow, we have 2-3 classes of ecobiomorphs, and in the dark coniferous forest, 8-10 classes. There are many species in the meadow, but all of them belong either to the ecobiomorph class of perennial mesophytic summer-green grasses, or to the class of annual grasses, or to the class of green mosses. In the forest, different classes of ecobiomorphs are: dark coniferous trees, deciduous trees, deciduous shrubs, deciduous shrubs, perennial mesophytic summer green grasses, green mosses, epigeic lichens, epiphytic lichens.

The biodiversity of organisms in the biosphere is not limited to the diversity of taxa and the diversity of ecobiomorphs of living organisms. For example, we can get into an area that is entirely occupied by one local elemental ecosystem - a raised swamp, or a damp alder forest at the mouth of a large river. In another area on the same territory, we will meet at least 10-15 types of local elementary ecosystems. Ecosystems of coniferous-broad-leaved forests at the bottom of river valleys are regularly replaced here by ecosystems of cedar-oak mixed-shrub forests on the southern gentle slopes of mountains, larch-oak mixed-grass forests on the northern gentle slopes of mountains, spruce-fir forests in the upper part of the northern steep slopes of mountains and ecosystems steppe meadows and clump vegetation on the steep southern slopes of the mountains. It is easy to understand what is intra-landscape diversity of ecosystems determined not only by the diversity of their constituent species and ecobiomorphs, but also variety of ecological landscape background associated primarily with the diversity of landforms, the diversity of soils and their underlying rocks.

The processes of extinction of species in the biosphere are compensated by the processes of speciation. If the balance of these two processes is upset in favor of extinction, then the Earth will most likely face the fate of Venus - that is, an atmosphere of carbon dioxide and water vapor, a surface temperature of about +200 degrees Celsius, evaporated oceans and seas. Life on a protein basis in such conditions, of course, is simply impossible. Having become a powerful geological force, humanity must take responsibility not only for the future of its children and grandchildren, but also for the future of the entire biosphere. And this future will largely depend on how far the process of extinction of species in the Earth's biosphere lags behind the process of formation of new species.

For the accounting species that are on the verge of extinction, many countries create Red Books - lists of rare and endangered species of living organisms. To preserve and maintain biological diversity, specially protected natural areas are created - protected areas (reserves, national parks, etc.), genetic data banks. The preservation of an individual species is possible only if its habitat with the entire complex of species included in it, as well as climatic, geophysical and other conditions, is protected. A special role is played by the conservation of environment-forming species (edificatory species), which form the internal environment of the ecosystem. The creation of protected areas is aimed at protecting not only individual species, but also entire complexes and landscapes.

Reserves also serve to evaluate and monitoring state of biodiversity. There is no unified system for monitoring the state of biodiversity in Russia today. The most complete and permanent control over changes in biodiversity components is carried out in reserves. Every year, reserves prepare reports on the state of ecosystems ("Chronicles of Nature") - summaries of data on the state of protected areas, protected populations of plants and animals. Some reserves have been keeping "Chronicles of Nature" for more than 50 years, which include continuous series of data on the number of animals, biological diversity, ecosystem dynamics, as well as data on climate observations.

Part of the reserves of Russia (18) is part of the international network of biosphere reserves, specially created to monitor the state of biodiversity, climatic, biogeochemical and other processes on the scale of the Biosphere.

reasons need conservation biodiversity many: the need for biological resources to meet the needs of mankind (food, materials, medicines, etc.), ethical and aesthetic aspects (life is valuable in itself), etc. However, the main reason for the conservation of biodiversity is that it plays a leading role in ensuring the sustainability of ecosystems and the Biosphere as a whole (absorption of pollution, climate stabilization, provision of conditions suitable for life). Biodiversity performs a regulatory function in the implementation of all biogeochemical, climatic and other processes on Earth. Each species, no matter how insignificant it may seem, contributes to ensuring the sustainability of not only the “native” local ecosystem, but the Biosphere as a whole.

SOIL ECOLOGY

LECTURE № 8,9,10

SUBJECT:

Ecological functions of soils. Biochemical transformation of the upper layers of the lithosphere. Transformation of surface waters into groundwater and participation in the formation of river runoff. Regulation of the gas regime of the atmosphere . Ecological function of soils. Participation of soils in the formation of the geochemical flow of elements.

The soil cover forms one of the geophysical shells of the Earth - the pedosphere. The main geospheric functions of the soil as a natural body are due to the position of the soil at the junction of animate and inanimate nature. And the main one is the provision of life on Earth. It is in the soil that terrestrial plants take root, small animals, a huge mass of microorganisms live in it. As a result of soil formation, it is in the soil that water and mineral nutrition elements that are vital for organisms are concentrated in the forms of chemical compounds available to them. Thus, soil is a condition for the existence of life, but at the same time soil is a consequence of life on Earth.

The global functions of soils in the biosphere are based on the following fundamental qualities. First, the soil serves as a habitat and physical support for a huge number of organisms; secondly, the soil is a necessary, irreplaceable link and regulator of biogeochemical cycles; practically, the cycles of all nutrients are carried out through the soil.

Biological diversity (biodiversity) is a concept that refers to the diversity of life on Earth and all existing natural systems. Biodiversity is recognized as one of the foundations of human life. The role of biodiversity is enormous - from stabilizing the earth's climate and restoring soil fertility to providing people with products and services, which allows us to maintain the well-being of society, and, in fact, allows life to exist on Earth.

The diversity of living organisms around us is very significant, and the level of knowledge about it is still not great. Today, science knows (described and received scientific names) about 1.75 million species, but it is estimated that at least 14 million species may exist on our planet.

Russia has significant biodiversity, while the unique feature of our country is the presence of large underdeveloped natural areas, where most of the ecological processes retain their natural character. Russia owns 25% of all virgin forests on the planet. In Russia, there are 11,500 species of wild plants, 320 species of mammals, 732 species of birds, 269 species of freshwater fish, and about 130,000 species of invertebrates. There are many endemics, species living only on the territory of our country. Our forests make up 22% of all forests in the world.

It is the topic "The role of diversity in wildlife" that this essay is devoted to.

1.

It is obvious to any of us that we are all different and that the world around us is diverse. However, not everyone would think to ask a seemingly simple question - why is this so? Why do we need diversity and what role does it play in everyday life?

And if you think about it seriously, it turns out that:

Diversity is progress, development, evolution. Something new can only be obtained from different things - atoms, thoughts, ideas, cultures, genotypes, technologies. If everything around is the same, then where does the new come from? Imagine that our Universe consists only of identical atoms (for example, hydrogen) - how could you and I be born at the same time?

Diversity is sustainability. It is the mutual and coordinated actions of components with different functions that give any complex system the ability to resist external influences. A system of identical elements is like pebbles on a beach - it is stable only until the next incoming wave.

Diversity is life. And we live in a series of generations solely due to the fact that we all have different genotypes. It is no coincidence that from time immemorial all religions of the world have imposed the strictest taboo on marriages with close relatives. This preserved the genetic diversity of the population, without which there is a direct path to degeneration and disappearance from the face of the earth.

If we now imagine that diversity has disappeared in the world, then with it we will lose:

A) the ability to develop;

B) stability;

c) life itself.

Creepy picture, isn't it?

That is, having asked a seemingly naive question, we come to an unexpected conclusion for many: variety - determining factor in the existence of all life on our planet.

Mankind, which imagines itself to be the "kings of nature", easily, without hesitation, wipes off the face of the earth "objectionable" species to us. We destroy entire species of plants and animals - completely, irrevocably, forever. We are destroying natural diversity and at the same time investing huge sums in cloning - the artificial creation of identical individuals ... And we call this biotechnology, the science of the future, with which we associate all hopes for further existence. What are the prospects for such an existence is clear from the previous paragraph - do not be lazy, re-read it again ...

At one time, we felt on ourselves both the “only true doctrine”, and the “society of universal equality”, and at the cost of millions of lives we were like “in a single ranks” ... In the socio-economic sphere, life has taught us to appreciate diversity, but is it necessary to go through even more ordeals to learn to appreciate biological diversity?

Biodiversity is defined by the World Wide Fund for Nature (1989) as “the entire diversity of life forms on earth, the millions of species of plants, animals, micro-organisms with their gene sets, and the complex ecosystems that make up wildlife”. Therefore, biodiversity should be considered at three levels. Biological diversity at the species level covers the entire range of species on Earth from bacteria and protozoa to the kingdom of multicellular plants, animals and fungi. On a smaller scale, biological diversity includes the genetic diversity of species, both from geographically distant populations and from individuals within the same population. Biological diversity also includes the diversity of biological communities, species, ecosystems formed by communities and the interactions between these levels For the continuous survival of species and natural communities, all levels of biological diversity are necessary, all of them are important for humans. Species diversity demonstrates the richness of evolutionary and ecological adaptations of species to different environments. Species diversity serves as a source of diverse natural resources for humans. For example, tropical rainforests, with their richest variety of species, produce a remarkable variety of plant and animal products that can be used for food, construction, and medicine. Genetic diversity is necessary for any species to maintain reproductive viability, resistance to diseases, and the ability to adapt to changing conditions. The genetic diversity of domestic animals and cultivated plants is especially valuable to those working on breeding programs to maintain and improve modern agricultural species.

Community-level diversity is the collective response of species to different environmental conditions. The biological communities found in deserts, steppes, forests and floodlands maintain the continuity of the normal functioning of the ecosystem by providing “maintenance” for example through flood control, soil erosion protection, air and water filtration.

Species diversity

At every level of biological diversity - species, genetic and community diversity, experts study the mechanisms that change or maintain diversity. Species diversity includes the entire set of species that live on Earth. There are two main definitions of the concept of species. First: a species is a collection of individuals that differs from other groups in one or another morphological, physiological or biochemical characteristics. This is the morphological definition of the species. Differences in DNA sequences and other molecular markers are increasingly being used to distinguish between species that are virtually identical in appearance (such as bacteria). The second definition of a species is a set of individuals between which there is free interbreeding, but there is no interbreeding with individuals of other groups (the biological definition of a species).

The inability to clearly distinguish one species from another due to the similarity of their characteristics, or the resulting confusion in scientific names, often reduces the effectiveness of species protection efforts.

Only 10–30% of the world's species have now been described by biologists, and many may become extinct before they are described.

Any biodiversity conservation strategy requires a good understanding of how many species there are and how those species are distributed. To date, 1.5 million species have been described. At least twice as many species remain undescribed, mainly insects and other tropical arthropods.

Our knowledge of the number of species is not accurate, since many non-showy animals have not yet come to the attention of taxonomists. For example, small spiders, nematodes, soil fungi and insects living in the crowns of rainforest trees are difficult to study; various currents occur, but the boundaries of these areas are usually unstable over time.

These little-studied groups can number hundreds and thousands, even millions of species. Bacteria are also very poorly studied. Because of the difficulty in growing and identifying them, microbiologists have only been able to identify about 4,000 species of bacteria. However, research conducted in Norway on bacterial DNA analysis shows that more than 4,000 species of bacteria can be present in one gram of soil, and about the same number can be found in marine sediments. Such high diversity, even in small samples, implies the existence of thousands or even millions of as yet undescribed bacterial species. Modern research is trying to determine what is the ratio of the number of widespread species of bacteria compared to regional or narrow local species.

genetic diversity

Genetic intraspecific diversity is often provided by the reproductive behavior of individuals within a population. A population is a group of individuals of the same species that exchange genetic information among themselves and give fertile offspring. A species may include one or more distinct populations. A population can consist of a few individuals or millions.

Individuals within a population are usually genetically distinct from each other. Genetic diversity is due to the fact that individuals have slightly different genes - sections of chromosomes that encode certain proteins. Variants of a gene are known as its alleles. Differences arise from mutations - changes in the DNA that is located on the chromosomes of a particular individual. Alleles of a gene can affect the development and physiology of an individual in different ways. Breeders of plant varieties and animal breeds, by selecting certain gene variants, create high-yielding, pest-resistant species, such as crops (wheat, corn), livestock and poultry.

Diversity of communities and ecosystems

A biological community is defined as a collection of individuals of different species living in a certain area and interacting with each other. Examples of communities are coniferous forests, tall grass prairies, tropical rainforests, coral reefs, deserts. A biological community together with its environment is called an ecosystem. In terrestrial ecosystems, water is evaporated by biological objects from the surface of the Earth and from water surfaces in order to shed again in the form of rain or snow and replenish the terrestrial and aquatic environments. Photosynthetic organisms absorb light energy, which is used by plants for their growth. This energy is absorbed by animals that eat photosynthetic organisms or is released in the form of heat both during the life of organisms and after their death and decomposition.

The physical properties of the environment, especially the annual temperature and precipitation regime, influence the structure and characteristics of the biological community and determine the formation of either a forest, or a meadow, or a desert or swamp. The biological community, in turn, can also change the physical characteristics of the environment. In terrestrial ecosystems, for example, wind speed, humidity, temperature and soil characteristics can be influenced by the plants and animals that live there. In aquatic ecosystems, such physical characteristics as turbulence and transparency of water, its chemical characteristics and depth determine the qualitative and quantitative composition of aquatic communities; and communities such as coral reefs themselves greatly influence the physical properties of the environment. Within a biological community, each species uses a unique set of resources that constitutes its niche. Any niche component can become a limiting factor when it limits the size of a population. For example, populations of bat species with highly specialized environmental requirements that form colonies only in limestone caves may be limited by the number of caves with suitable conditions.

The composition of communities is largely determined by competition and predators. Predators often significantly reduce the number of species - their prey - and may even displace some of them from their usual habitats. When predators are exterminated, the population of their prey can rise to a critical level or even exceed it. Then, after the exhaustion of the limiting resource, the destruction of the population may begin.

The community structure is also determined by symbiotic (in the broadest sense of the word) relationships (including mutualistic ones), in which species are in mutually beneficial relationships. Mutualistic species achieve greater density when living together. Common examples of such mutualism are plants with fleshy fruits and birds that feed on these fruits and spread their seeds; fungi and algae, which together form lichens; plants that give shelter to ants, supplying them with nutrients; coral polyps and the algae that live in them.

Tropical rainforests, coral reefs, vast tropical lakes and deep seas are the most species-rich. The biological diversity is also great in dry tropical regions with their deciduous forests, bush bushes, savannahs, prairies and deserts. In temperate latitudes, shrub-covered territories with a Mediterranean type of climate are distinguished by high rates. They are found in South Africa, southern California and southwestern Australia. Tropical rainforests are primarily characterized by an exceptional diversity of insects. On coral reefs and in deep seas, diversity is due to a much wider range of taxonomic groups. The diversity in the seas is associated with their great age, gigantic areas and the stability of this environment, as well as with the peculiarity of the types of bottom sediments. The remarkable diversity of fish in large tropical lakes and the emergence of unique species on islands is due to evolutionary radiation in isolated productive habitats.

The species diversity of almost all groups of organisms increases towards the tropics. For example, Thailand has 251 species of mammals, while France has only 93, despite the fact that the areas of both countries are approximately the same.

2. DIVERSITY OF LIVING ORGANISMS IS THE BASIS OF THE ORGANIZATION AND STABILITY OF THE BIOSPHERE

The biosphere is a complex outer shell of the Earth, inhabited by organisms that together make up the living substance of the planets. It can be said that the biosphere is an area of active life, covering the lower part of the atmosphere, the upper part of the lithosphere and the hydrosphere.

Huge species diversity. living organisms provides a constant mode of biotic circulation. Each of the organisms enters into specific relationships with the environment and plays its role in the transformation of energy. This has formed certain natural complexes, which have their own specifics depending on environmental conditions in one or another part of the biosphere. Living organisms inhabit the biosphere and are included in one or another biocenosis - spatially limited parts of the biosphere - not in any combination, but form certain communities of species adapted to cohabitation. Such communities are called biocenoses.

The relationship between predator and prey is particularly complex. On the one hand, predators, destroying domestic animals, are subject to extermination. On the other hand, predators are necessary to maintain the ecological balance (“Wolves are the orderlies of the forest”).

An important ecological rule is that the more heterogeneous and complex the biocenoses, the higher the stability, the ability to withstand various external influences. Biocenoses are distinguished by great independence. Some of them persist for a long time, others naturally change. Lakes turn into swamps - peat is being formed, and as a result, a forest grows on the site of the lake.

The process of regular changes in the biocenosis is called succession. Succession is a successive change of some communities of organisms (biocenoses) by others in a certain area of the environment. In a natural course, succession ends with the formation of a stable community stage. In the course of succession, the diversity of the species of organisms that make up the biocenosis increases, as a result of which its stability increases.

The increase in species diversity is due to the fact that each new component of the biocenosis opens up new opportunities for invasion. For example, the appearance of trees allows species living in the subsystem to penetrate into the ecosystem: on the bark, under the bark, building nests on branches, in hollows.

In the course of natural selection, only those types of organisms that can reproduce most successfully in this particular community are inevitably preserved in the composition of the biocenosis. The formation of biocenoses has an essential side: "competition for a place under the sun" between different biocenoses. In this “competition”, only those biocenoses are preserved that are characterized by the most complete division of labor between their members, and, consequently, richer internal biotic connections.

Since each biocenosis includes all the main ecological groups of organisms, it is equal in its capabilities to the biosphere. The biotic cycle within the biocenosis is a kind of reduced model of the Earth's biotic cycle.

Thus:

1. The stability of the biosphere as a whole, its ability to evolve is determined by the fact that it is a system of relatively independent biocenoses. The relationship between them is limited to connections through non-living components of the biosphere: gases, atmosphere, mineral salts, water, etc.

2. The biosphere is a hierarchically built unity, including the following levels of life: individual, population, biocenosis, biogeocenosis. Each of these levels has a relative independence, and only this ensures the possibility of the evolution of the entire large macrosystem.

3. The diversity of life forms, the relative stability of the biosphere as a habitat and the life of individual species create the prerequisites for a morphological process, an important element of which is the improvement of behavioral responses associated with the progressive development of the nervous system. Only those species of organisms have survived that, in the course of the struggle for existence, began to leave offspring, despite the internal restructuring of the biosphere and the variability of cosmic and geological factors.

3. THE PROBLEM OF CONSERVATION OF DIVERSITY IN NATURE AS A FACTOR OF SURVIVAL OF HUMANITY

At the turn of the third millennium, we bitterly state that as a result of anthropogenic pressure, especially in recent decades, the number of plant and animal species is sharply decreasing, their gene pool is depleted, the areas of the most productive ecosystems are shrinking, and environmental health is deteriorating. The constant expansion of the lists of rare and endangered species of biota in new editions of the Red Books is a direct evidence of this. According to some forecasts of leading ornithologists, by the end of the 21st century, every eighth bird species will disappear on our planet.

Awareness of the need to preserve all species from the kingdoms of fungi, plants and animals, as the basis for the existence and well-being of mankind itself, served as a decisive incentive for the development and implementation of a number of major international and national programs, as well as the adoption of fundamental interstate agreements in the field of environmental protection and monitoring, plant and the animal world. After the signing and subsequent ratification by more than 170 states of the International Convention on Biodiversity (1992, Rio de Janeiro), much more attention has been paid to the study, conservation and sustainable use of biological resources in all countries of the world. In accordance with the basic requirements of the Convention on Biological Diversity, which Russia ratified in 1995, it was necessary to provide "scientific support" for decision-making in the field of wildlife conservation in-situ and ex-situ. Everything related to the inventory, assessment of the state, conservation, restoration and rational use of objects of flora and fauna requires a clear scientific justification. For the vast territory of Russia with its landscape diversity, multinational population, various traditions in the use of natural resources, a much more active development of fundamental research is necessary, without which, in principle, it is impossible to carry out an inventory and develop a coordinated strategy for the protection of all categories of biodiversity, at all its hierarchical levels.

The problem of biodiversity conservation is today one of the central problems of ecology, since life itself on Earth is compensated only with a sufficient variety of evolutionary material. It is thanks to biological diversity that the structural and functional organization of ecological systems is created, ensuring their stability over time and resistance to changes in the external environment. According to the figurative definition of Corr. RAS A.F. Alimova: “The whole set of biological sciences studies four main phenomena: life, organism, biosphere and biodiversity. The first three form a series from life (at the base) to the biosphere (above), the fourth penetrates into the first three: without a variety of organic molecules there is no life, without a morphological and functional diversity of cells, tissues, organs, and in unicellular - organelles - there is no organism, without the diversity of organisms, there can be no ecosystems and no biosphere.” In this regard, it seems very logical to study biodiversity not only at the species level, but at the level of populations, communities, and ecosystems. As the anthropogenic impact on nature intensifies, ultimately leading to the depletion of biological diversity, the study of the organization of specific communities and ecosystems, as well as the analysis of changes in their biodiversity, becomes really important. One of the most important causes of biodiversity degradation is the underestimation of its real economic value. Any proposed options for biodiversity conservation are constantly losing competition with forestry and agriculture, the mining industry, since the benefits from these sectors of the economy are visible and tangible, they have a price. Unfortunately, neither the centrally planned economy nor the modern market economy could and cannot correctly determine the true value of nature. At the same time, a group of experts led by Robert Constatz (University of Maryland) identified 17 categories of functions and services of nature, among which were climate regulation, atmospheric gas composition, water resources, soil formation, waste processing, genetic resources, etc. The calculations of these scientists gave a total estimate of these functions of nature at an average of 35 trillion. dollars, which is twice the GNP created by mankind (18 trillion dollars a year). We still do not pay due attention to this area of research to determine the value of biodiversity, which does not allow us to create a reliable economic mechanism for protecting the environment in the republic.

Among the priority areas of scientific research for the coming decades for the purposes of biodiversity conservation in the European North-East of Russia, the following should be highlighted:

— unification of existing and development of new methods for assessing and inventorying all components of biodiversity;

— creation of computer databases on biodiversity in the context of individual taxa, types of ecosystems, forms of use of biodiversity components, including databases on rare plant and animal species;

– development and implementation of the latest methods of taxonomy in the systematics and diagnostics of plants, animals, fungi and microorganisms;

— continuation of the inventory of the biota of the region, and especially in specially protected natural areas;

— preparation and publication of new regional floristic and faunal summaries, atlases, catalogs, guides, monographs on individual taxa of microorganisms, fungi, lower and higher plants, vertebrates and invertebrates;

— development of methodological foundations for the economic assessment of biodiversity;

— development of scientific bases and technologies for the restoration of biological diversity in anthropogenically disturbed terrestrial, water and soil ecosystems; — preparation of a regional program for the conservation of biodiversity, taking into account the specifics of the diverse conditions of our country.

CONCLUSION

Mankind has recognized the great importance of biological diversity and its components by adopting the Convention on Biological Diversity on June 5, 1992. It has become one of the most massive international conventions; today 187 countries are its members. Russia has been a party to the Convention since 1995. With the adoption of this Convention, a global approach to the conservation and sustainable use of the entire wealth of living organisms on Earth was adopted for the first time. The Convention recognizes the need for a multi-sectoral and integrated approach for the sustainable use and conservation of biodiversity, the special role of the international exchange of information and technology in this area, and the importance of a fair and equitable distribution of benefits derived from the use of biological resources. It is these three components - sustainable use of biodiversity, conservation of biodiversity, equitable distribution of benefits from the use of genetic resources - that make up the "three pillars" of the Convention.

If we look at how things are in the real ecosystems of Primorsky Krai, we will see that in a coniferous-deciduous forest, for example, on a plot of 100 sq. meters grow individuals of 5-6 species of trees, 5-7 species of shrubs, 2-3 species of vines, 20-30 species of herbaceous plants, 10-12 species of mosses and 15-20 species of lichens. All these species are ecologically individual, and in different seasons of the year, in different weather conditions, their photosynthetic activity varies greatly. These species seem to complement each other, making the plant community as a whole ecologically more optimal.

By the number of species of a similar life form, with similar requirements for the external environment, living in one local ecosystem, one can judge how stable the conditions in this ecosystem are. In stable conditions, such species, as a rule, will be less than in unstable conditions. If weather conditions do not change for a number of years, then there is no need for a large number of species. In this case, the species is preserved, which, under these stable conditions, is the most optimal of all possible species of this flora. All the rest are gradually eliminated, unable to withstand competition with it.

Thanks to adaptations for distributing fruits and seeds over long distances, the rudiments of new plants fall not only on those areas that are favorable for their growth now, but also on those areas whose conditions are unfavorable for the growth and development of individuals of these species. Nevertheless, these seeds germinate here, exist for some time in a depressed state and die. This happens as long as environmental conditions are stable. But if the conditions change, then the seedlings of species that were previously doomed to death begin to grow and develop here, going through a full cycle of their ontogenetic (individual) development. Ecologists say that in nature (read, in the biosphere) there is powerful pressure of diversity of life to all local ecosystems.

This graph (Willy, 1966) shows how the number of hare (curve 1) and the number of lynx (curve 2) change synchronously in one of the ecosystems. As the number of hare increases, with some delay, the number of lynx begins to grow. By increasing its numbers, the lynx has a depressing effect on the hare population. At the same time, the number of hare is reduced, lynxes cannot provide themselves with food and leave this ecosystem, or die. The press from the side of the lynx decreases and the number of the hare increases. The fewer species of predators and species of herbivorous animals in the ecosystem, the more sharp fluctuations in their numbers are, the more difficult it is for the ecosystem to maintain its balance. With a large number of prey species and predator species (see the previous diagram), fluctuations in numbers have a much smaller amplitude.

For example, migratory fish, accumulating their biomass in the sea, go to spawn in the upper reaches of rivers and streams, where after spawning they die and become food for a large number of animal species (bears, wolves, many mustelid species, many bird species, not to mention hordes of invertebrates). These animals feed on fish and discard their excrement in terrestrial ecosystems. Thus, the substance from the sea migrates to land deep into the mainland and is assimilated by plants and included in new chains of the biological cycle.

Stop entering the rivers of the Far East to spawn salmon, and in 5-10 years you will see how much the population of most animal species will change. The number of animal species will change, and, as a result, rearrangements in the vegetation cover will begin. The decrease in the number of predatory species of animals will lead to an increase in the number of herbivores. Having quickly undermined their food base, herbivorous animals will begin to die, and epizootics will spread among them. The number of herbivorous animals will decrease, and there will be no one to spread the seeds of some species and eat the biomass of other plant species. In a word, with the cessation of entry into the rivers of red fish in the Far East, a series of restructurings will begin in all parts of ecological systems that are hundreds and even thousands of kilometers away from the sea.

And these graphs (G.F. Gause, 1975) show how in one ecosystem the number of shoe ciliates (single-celled animal) (curve 1) and predatory ciliates feeding on shoe ciliates (curve 2) changes. The two upper graphs - the ecosystem is closed and limited in space: a - the ciliate shoe has no shelter; b - the shoe infusoria has a shelter. The lower graphs (c) show that the ecosystem is open; in the event of unfavorable conditions, both species can hide or go to another system. With the onset of favorable conditions, both species may return.

Unfortunately, ecologists are not yet able to model the behavior of real ecosystems in the face of changes in certain environmental factors. And the point here is not only the extreme complexity of ecological systems and the lack of sufficient information about their composition. There is no theory in ecology that would allow such modeling. In this regard, with a powerful impact on ecosystems, great care is required and following the rule: “Before you have an impact on the ecosystem and bring it out of balance, measure it seven times” and ... do not cut off - refuse this impact. The 20th century has convinced us that protecting natural ecosystems by keeping them in balance is much more reasonable than redesigning these ecosystems in an attempt to optimize them.

It should be said that in order to maintain balance in local ecosystems and for their biogeochemical optimization, it is important not taxonomic diversity in itself according to the principle “the more species, the better”, but functional variety, or a variety of ecobiomorphs. A measure of the functional diversity of an ecosystem is the number of ecobiomorphs and synusia of plants, animals, fungi, and microorganisms. measure taxonomic diversity is the number of species, genera, families and other higher taxa.