Biological diversity of its form properties and value. What is biological diversity? Importance of biodiversity conservation

LECTURE 2

TOPIC: Modern concepts of biological diversity

PLAN:

1. The concept of biodiversity.

2. Importance of biodiversity.

2.1. The Significance of Biodiversity for the Biosphere.

2.2. The value of biodiversity for humans.

2.2.1. practical value.

2.2.2. Aesthetic value of biodiversity.

3. Biology of wildlife conservation.

4. Biodiversity is the basis of life on Earth.

5. Structure and levels of biodiversity.

5.1. genetic diversity.

5.2. species diversity.

5.3. Diversity of ecosystems.

6. Quantitative indicators of biodiversity.

6.1. Accounting for biodiversity.

6.2. Biodiversity and "species richness".

6.3. Measurement of biological diversity.

7. Natural resource potential of Russia.

1. The concept of biodiversity

The idea of biological diversity as a unique property of living nature and its role in the preservation of life on Earth has become an integral part of modern views on the relationship between nature and society. For the first time, the phrase "biological diversity" was used by G. Bates (1892) in his work "Naturalist in the Amazon", who observed about 700 species of butterflies during an hour-long excursion.

The concept of "biodiversity" came into wide scientific use in 1972 at the UN Stockholm Conference on the Environment, where ecologists managed to convince the political leaders of the countries of the world community that the protection of wildlife should be a priority in any human activity on Earth.

Twenty years later, in 1992, in Rio de Janeiro, during the UN Conference on Environment and Development, the Convention on Biological Diversity was adopted, which was signed by more than 180 countries, including Russia. Active implementation of the Convention on Biodiversity in Russia began after its ratification by the State Duma in 1995. At the federal level, a number of environmental laws were adopted, and in 1996, by Decree of the President of the Russian Federation, the “Concept of the transition of the Russian Federation to sustainable development” was approved, which considers the conservation of biodiversity as one of the most important directions for the development of Russia. Russia, like other countries that have signed and ratified the Convention on Biological Diversity, does not act alone. The Global Environment Facility (GEF) project for the conservation of biodiversity in Russia, funded by the International Bank for Reconstruction and Development, started in December 1996. Since then, the National Strategy for Biodiversity Conservation of Russia has been developed and adopted in 2001, mechanisms for biodiversity conservation are being developed, national parks and nature reserves are being supported, and measures are being taken to conserve biodiversity and improve the environmental situation in various regions. The GEF project and the National Strategy, along with other projects on biodiversity conservation, provide for the development and implementation of educational programs as priority areas.

2. Importance of biodiversity

2.1. Importance of biodiversity for the biosphere

The principle of human interaction with the planet's biodiversity can be illustrated by considering the scale of human influence on natural systems and the role that biodiversity plays in sustaining life on Earth. The main condition for maintaining life on Earth is the ability of the biosphere to create and maintain a balance between its constituent ecosystems. Ecosystems of a lower rank must be territorially balanced within the biosphere. In other words, the Earth should have the required number of tundras, forests, deserts, etc. - as biomes, and inside the tundra biome, optimal tundra should be preserved, and inside the coniferous forest biome - optimal forest cover. And so on to the smallest ecosystems like meadows, forests, lakes, etc.

The functioning of the planet as a whole and its climatic balance is due to the interaction of the cycles of water, carbon, nitrogen, phosphorus and other substances driven by the energy of ecosystems. Vegetation cover is the most important factor in preventing erosion, preserving the arable layer of the earth, ensuring infiltration and replenishing groundwater reserves. Without a sufficient level of biodiversity of wetland ecosystems, it is impossible to prevent eutrophication of water bodies, and a high level of species diversity of animals is a guarantee of the stability of any ecosystem and the biosphere as a whole.

Millions of species of animals and plants support the conditions necessary for the continuation of life on Earth. Perhaps a smaller number of species could provide these conditions, but what is it, this sufficient number of species? Nobody knows. It also does not know the line beyond which, with the reduction of biodiversity, irreversible destruction of ecosystems will begin and life will be brought to the brink of existence. When biodiversity is destroyed, there are no reliable ways to compensate for the loss.

2.2. The importance of biodiversity to humans

2.2.1. Practical value

A pragmatic view of biodiversity allows us to see it as an inexhaustible source of biological resources. Biological resources provide us with all kinds of products: food, fibers for making clothes, dyes, synthetic substances, medicines, etc. They are the basis of most human activities, and the state of the world economy largely depends on them. Microorganisms, which play a vital role in many ecosystems, have contributed to the progress of food production.

Modern medicine is showing a keen interest in biological resources in the hope of obtaining new treatments for diseases. The greater the diversity of living beings, the greater the opportunity for discovery of new drugs; and the history of medicine provides excellent examples of this possibility. Potentially, any species may have commercial value or be used in medicine. About 40% of all known drugs currently used in medicine contain substances found in wild plants.

In agriculture, the genetic diversity of crop plants is of great importance for the development of pest control methods. The centers of origin of cultivated plants are the places where, in due time, man first introduced into culture many of today's traditional species. In these areas, there is a clear connection between agricultural plants and their wild relatives. Many wild ancestral species and varieties of modern cultivated plants grow here. Farmers are showing increasing interest in the genetic diversity of crops. Knowledge of the centers of such diversity makes it possible to develop methods for increasing the productivity of agricultural crops and increasing their adaptability to changing environmental conditions.

Biodiversity is also of great importance for recreation. Beautiful landscapes, diverse ecosystems rich in species are the most important condition for the development of tourism and recreation. The rapid expansion of this type of activity is often the main source of income for the local population. Often, individual species of animals and plants become the object of increased interest.

2.2.2. Aesthetic value of biodiversity

For most people, the word "biodiversity" has a positive connotation. At the same time, images of a tropical rain forest, a coral reef, a glade covered with forbs, where a wealth of animal and plant species create positive emotions, arise in the imagination. Often even a single fragment of nature, such as, for example, a wine hawk moth that feeds on the nectar of flowering fireweed at night in flight, leaves an indelible impression. The beauty inherent in biodiversity is a source of inspiration. Genuine works of art rarely do without images of animals and plants, whether it be scarabs and snakes on the necklace of Queen Cleopatra or a lion made of colored tiles on the "Sacred Way" in Babylon. The ideas of paradise, embodied in the painting "Paradise" by Jan Brueghel the Elder (), are associated with a rich variety of different species of animals and plants.

Without aesthetic pleasure, many of our hobbies would lose their meaning, whether it be sport fishing, hunting, hiking or bird watching. People have a need to contemplate beautiful landscapes. Yet the aesthetic value of biodiversity is more than simply admiring a beautiful landscape. What would happen to a person, his mood, his worldview, if instead of a beautiful lake or a patch of pine forest, he saw around him only heaps of garbage or a landscape distorted by rude interference? But with what love the authors describe the amazing pictures of the nature of the Dniester floodplains (quoted from the materials of the journal Vesti SOES, No. 2, 2001): “The mouth area is peculiar and unique in its wealth, its special beauty. Here, on the White Lake, fields of white lilies, relic water chestnuts are still preserved, vast territories are covered with yellow water lilies. The sacred ibises of Ancient Egypt still fly here, the sound of swan wings is heard, mint blossoms, forests are full of familiar and unexpected aromas, the music of birdsong ... ” Apparently, the aesthetic side of the perception of biodiversity is not just enjoying the beauty of individual landscapes; rather, it is an organic need inherent in every person, since the perception of various forms of life objectively improves the quality of life.

3. Biology of wildlife conservation

Conservation biology is a multidisciplinary science that has developed in response to the crisis in which biodiversity finds itself today.

Biology of wildlife conservation- a scientific discipline based on the theory and practice of species conservation, the creation of new protected areas, the protection of existing national parks. Its activities will determine the form in which species and biological communities will be preserved on the planet for the future.

It brings together people and knowledge from different fields and aims to overcome the biodiversity crisis.

The biology of wildlife conservation has three goals: first, to study and describe the diversity of wildlife; secondly, to identify and assess the impact of human activities on species, communities and ecosystems; and thirdly, to explore practical interdisciplinary approaches to the protection and restoration of biological diversity.

4. Biodiversity is the basis of life on Earth

Conservation of biological diversity is the central task of the biology of wildlife conservation. As defined by the World Wide Fund for Nature (1989), biodiversity- it is "the whole variety of life forms on earth, millions of species of plants, animals, microorganisms with their sets of genes and complex ecosystems that form 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 which are also 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 array 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” to it, for example, through flood control, soil erosion protection, air and water filtration.

5. Structure and levels of biodiversity

At each level of biological diversity - genetic, species and community (ecosystem) diversity - experts study the mechanisms that change or maintain diversity.

5.1. genetic diversity

Genetic diversity is the amount of genetic information contained in the genes of organisms that inhabit the Earth.

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.

Genetic diversity in a population is determined both by the number of genes with more than one allele (so-called polymorphic genes) and by the number of alleles for each polymorphic gene. The existence of a polymorphic gene leads to the appearance in the population of heterozygous individuals receiving different alleles of the gene from their parents. Genetic variation allows species to adapt to environmental changes, such as rising temperatures or a new disease outbreak. In general, it has been found that rare species have less genetic diversity than widespread ones, and, accordingly, they are more susceptible to the threat of extinction when environmental conditions change.

5.2. Species 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 morphological definition of a species is commonly used in taxonomy, that is, taxonomic biologists who specialize in identifying new species and classifying species. The biological definition of a species is commonly used in evolutionary biology, because it is based more on measurable genetic relationships than on any subjectively distinguishable physical traits. However, in practice, it is rather difficult to use the biological definition of a species, since this requires knowledge of the ability of individuals to interbreed with each other, and this, as a rule, is difficult to access information. As a result, practical biologists were forced to learn to distinguish species by their appearance, sometimes calling them "morphospecies" or similar terms, until taxonomists assigned official Latin names to them.

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.

It is difficult to write clear, effective laws to protect a species if it is not entirely clear how to accurately identify it. Therefore, a lot of work still needs to be done to systematize and classify all the species that exist in the world. Systematists have described only 10–30% of the world's species, and many may become extinct before they are described. To solve this problem as soon as possible, many taxonomists must be trained, especially for work in the tropics abounding in species.

The difficulties associated with the description of species new to science force us to be cautious in assessing their total abundance. The number of species of animals and plants known to science has increased from 11,000 in the time of C. Linnaeus to 2 million today and continues to grow. Scientists constantly describe and name new species of animals, plants and microorganisms. No one can give an exact number of species living on our planet, but it is known that the number of animal species significantly exceeds the number of plant, fungal and bacterial species. It is also known that insects are leading among animals in terms of the number of recorded species. Their diversity is such that in terms of the number of species they surpass not only all other animals, but also plants and microorganisms combined. In the plant kingdom, angiosperms, or flowering plants, confidently hold the palm.

5.3. Ecosystem Diversity

Ecosystem diversity refers to the different habitats, biotic communities, and ecological processes in the biosphere, and the vast diversity of habitats and processes within an ecosystem.

Quantitative indicators of biodiversity in ecosystems vary greatly depending on the influence of various factors. It should be noted that the biocenosis includes not only species that constantly live in the ecosystem, but also species that spend only part of their life cycle in it (for example, mosquito larvae, dragonflies).

The species composition and, in general, the diversity of the biocenosis can only be described at a certain point in time, since the species richness changes as a result of the processes of immigration and elimination of species that continuously occur in the biocenosis.

The time factor is taken into account to some extent in environmental monitoring services. Thus, in particular, hydrobiological monitoring programs in Russia require mandatory analysis in different seasons of the year and assessment of the state of water bodies based on data obtained in spring, summer and autumn.

At each moment of time, the biocenosis has a certain species richness.

One of the components of the natural environment is the relief of the earth's surface, which exists in its continuous variability at the border of three natural shells, or spheres, of our planet - the earth's crust, or lithosphere, atmosphere and hydrosphere. The earth's surface with its relief - picturesque or harsh mountains, vast plains, along which rivers smoothly meander, dunes and sandy ridges of deserts, high-mountain glaciers - is the arena of life, one of the main components of the biosphere.

The more diverse the environmental conditions in a given region, the more time organisms have at their disposal for evolutionary transformations, the more diverse their species composition is here. The relief and geological structure can create a variety of conditions within areas with a uniform climate. In hilly terrain, its slope and exposure determine the temperature and moisture content of the soil. On steep slopes, the soil drains well, which often leads to a lack of moisture for plants, although in nearby lowland areas the soil is saturated with moisture. In arid areas, in floodplains and along riverbeds, one can often see well-developed forest communities, in sharp contrast with the surrounding desert vegetation. On the warm and dry slopes of the south-facing hillsides, different tree species grow than on the cold and humid north. The hilly terrain is often associated with the beauty of the landscape, which means that rich and diverse communities coexist here. The picturesque landscape is always admirable. This is one of the reasons why the mountains or the shores of favorite reservoirs serve as a place of mass pilgrimage for nature lovers.

Every landscape on the globe undergoes changes under the influence of climatic conditions. The plant world has a huge influence on them. Landscapes in all their diversity have been formed over many millennia and as a result of human activity. They are constantly changing due to the constant search for efficient forms of land use and mining. Man builds cities and builds roads. Thus, landscapes are composed of a number of natural and cultural elements. They embody the collective memory of nature and those who inhabit it, forming a complex element of the environment.

6. Quantitative indicators of biodiversity

6.1. Biodiversity Accounting

Ecosystem-level diversity inventories are often carried out using aerial or satellite photography. This makes it possible to form a complete picture of the diversity of ecosystems and landscape features, as well as to draw preliminary conclusions about possible species diversity. For a more accurate assessment of diversity at the species level, it is necessary to determine species richness, that is, accounting for all species found in a given area (number of species, for comparison, referred to a given area). However, it is obvious that the larger the territory, the greater the number of species the researcher will be able to register, therefore, when assessing species richness, it is necessary to take into account the frequency of occurrence of species. So, on an area of 4 m2, 35 species of vascular plants grow on a carefully groomed pasture. The same number of species can be found in the same virgin area, but if we narrow the search area to 1 m2, we will be able to register only 25 plant species, since many species are less common here. On an abandoned pasture, many vascular plants disappear, so the level of species richness here is lower than in a virgin meadow.

Attempts to describe the structure of a complex natural community with a single indicator, such as species richness, are untenable due to the loss of valuable information about the rarity of some species and the commonness of others. The index (indicator) of species diversity takes into account both the total number of species in the community and the ratio of the abundance of different species. It is calculated by determining for each species the proportion of its individuals in the total number of individuals in the community.

Measuring diversity at the genetic level is more difficult. For this purpose, external hereditary traits of species are traditionally used. Based on these features, discrete groupings of individuals are distinguished within a species. This kind of individual variability is called polymorphism. For example, on the elytra of ladybugs there are pigment patterns that are characteristic of each individual. This species is widely distributed, it is found in Siberia, China, on the Korean Peninsula, in Japan. Black beetles predominate in Western and Central Siberia, and further to the east the population becomes more polymorphic, with yellow beetles with black spots increasingly common.

6.2. Biodiversity and "Species Richness"

Any biodiversity conservation strategy requires a clear 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.

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.

The lack of complete collections makes it difficult to judge reliably the number of species found in marine environments. The marine environment has become a kind of frontier of our knowledge of biological diversity. So, a completely new group of animals, Loricifera, was first described in 1983 in samples taken at great depths. Another new group of small creatures, the Cycliophora, found in the mouth region of the Norwegian lobster, was first described in 1995. In 1999, the world's largest bacterium, the size of a fruit fly's eye, was discovered off the coast of Namibia. Undoubtedly, many more undescribed marine species are waiting in the wings.

Until now, along with individual species, completely new biological communities have been discovered, especially in extremely remote or hard-to-reach places for humans. Special study methods have made it possible to identify such unusual communities, primarily in deep seas and in the forest canopy:

Diverse communities of animals, primarily insects, adapted to life in the crowns of tropical trees; they have virtually no connection to the ground. In order to penetrate the forest canopy, in recent years, scientists have installed observation towers in the forests and stretched hanging paths in the crowns.

At the bottom of the deep seas, which are still poorly understood due to technical difficulties in transporting equipment and people under high water pressure, there are unique communities of bacteria and animals that have formed near deep-sea geothermal sources. Previously unknown active bacteria have been found even in five hundred meters of marine sediments, where they undoubtedly play an important chemical and energetic role in this complex ecosystem.

Thanks to modern drilling projects below the surface of the Earth, down to a depth of 2.8 km, various communities of bacteria have been found, with a density of up to 100 million bacteria per g of rock. The chemical activity of these communities is being actively studied in connection with the search for new compounds that could potentially be used to destroy toxic substances, as well as to answer the question of the possibility of life on other planets.

Species "richness" of different climatic and geographical zones is very different.

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.

Coral reefs are also a wonderful place for the concentration of species. Colonies of tiny animals called polyps build large coral ecosystems comparable in complexity and biodiversity to tropical rainforests. The world's largest coral reef - the Great Barrier Reef - off the east coast of Australia covers an area of about 349 thousand km2. About 300 coral species, 1500 fish species, 4000 shellfish species and 5 turtle species have been found on the Great Barrier Reef and provides nesting sites for 252 bird species. The Great Barrier Reef is home to about 8% of all fish species in the world fauna, although it accounts for only 0.1% of the total ocean surface area.

The state of species richness also depends on the local features of the topography, climate, environment and geological age of the area. In terrestrial communities, species richness usually increases with decreasing altitude, increasing solar radiation, and increasing precipitation. Species richness is usually higher in areas with complex topography, which can provide genetic isolation and, consequently, local adaptation and specialization. For example, a sedentary species living on isolated mountain peaks may evolve over time into several different species, each adapted to specific conditions in the highlands. In areas that are highly geologically complex, a variety of well-defined soil conditions are created, and, accordingly, diverse communities are formed, adapted to a particular type of soil. In the temperate zone, great floristic richness is characteristic of the southwestern part of Australia, South Africa and other areas with a Mediterranean climate type with its mild, wet winters and hot, dry summers. The species richness of shrub and herb communities is due here to a combination of significant geological age and complex terrain. In the open ocean, the greatest species richness is formed where different currents meet, but the boundaries of these areas, as a rule, are unstable in time.

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.

The number of freshwater insects in tropical forests is 3-6 times greater than in temperate forests. Tropical forests contain the largest number of mammal species on Earth per unit area. In the tropical rainforests of Latin America, 40-100 species of trees are found per hectare, while in the east of North America there are 10-30 species.

In the marine environment, the same pattern of distribution is observed as on land. Thus, the number of ascidian species in the Arctic barely exceeds 100, while in the tropics it is more than 600.

6.3. Measuring biodiversity

In addition to the closest definition of biological diversity for most biologists, as the number of species living in a certain area, there are many other definitions related to the diversity of biological communities at different hierarchical levels of their organization and at different geographical scales. These definitions are used to test the theory that increased diversity at different levels leads to increased stability, productivity, and community resilience to alien species invasion. The number of species in a single community is usually described as species richness or alpha diversity and is used to compare biodiversity across different geographic regions or biological communities.

When evaluating alpha diversity, two factors are taken into account: species richness and evenness of species abundances(uniform distribution of species according to their abundance in the community).

Beta diversity characterizes the degree of differences or similarities between habitats or samples in terms of their species composition, and sometimes also the abundance of species. The term was introduced by Whittaker in 1960. One common approach to establishing beta diversity is to estimate changes in species diversity along an environmental gradient. Another way to determine it is to compare the species composition of different communities. The fewer common species in communities or at different points on the gradient, the higher the beta diversity. This path is used in any studies that consider the degree of differences in the species composition of samples, habitats or communities. Together with measures of assessing the internal diversity of habitats, beta diversity can be used to get an idea of the overall diversity and conditions of a given area. Beta diversity is high if, for example, the species composition of moss communities is significantly different in alpine meadows of adjacent peaks, but beta diversity is low if most of the same species occupy the entire alpine meadow belt.

For beta-diversity, similarity indicators based on diversity measures (Whittaker measure, measure, Cody, etc.), similarity indicators, community indices are characteristic.

Gamma diversity is applicable over large geographic scales; it takes into account the number of species in a large area or continent.

An important measure of alpha diversity is the species richness index (Margalef species richness index, Menhinik species richness index, etc.).

The main potential applications of diversity indices are conservation and monitoring. The use of diversity assessments in these areas is based on two assumptions: 1) species-rich communities are more stable than species-poor ones; 2) the level of pollution is associated with a decrease in diversity and a change in the nature of species abundance. At the same time, indicators of species richness are usually used in nature protection, and indices and models of species abundance are used in environmental monitoring.

Diversity indicators are used in environmental studies for a variety of purposes. They were successfully used in the works of MacArthur and his followers in the study of bird competition, saturation, and the degree of overlap of their ecological niches. The dependence of bird diversity on the diversity of some habitat elements and other environmental factors was elucidated.

Jacobs in 1975 summarized the results of many studies of the influence of environmental factors on the diversity of communities and established the following.

1. Spatial heterogeneity increases diversity.

2. Temperature heterogeneity can decrease or increase diversity depending on the severity of the climate and other factors.

3. Stressful environmental conditions are usually negatively associated with diversity.

4. With an increase in competition in a relatively short period of time, diversity may decrease, but if it is present for a period sufficient for evolutionary transformations to occur (speciation), diversity may increase.

5. Enemies act like competition, their effect on variety depends on the intensity of their impact, duration, and the influence of enemies on competition among victims.

6. The influence of the intensity of energy flow through the community and the amount of food resources can be very important, but the extent and direction of their influence on diversity depends on many other factors.

During the period of succession, processes of different directions can occur with a change in diversity.

Diversity indicators are used when comparing the population of different stations, the seasonal dynamics of communities, for the ecological assessment of various species, the nature of their distribution in different habitats, for measuring the degree of food specialization of species and the diversity of the food ration of a species. Diversity indicators are also successfully used in assessing the pollution of water bodies and territories, in particular, when comparing sites in the pollution gradient of terrestrial ecosystems.

7. Natural resource potential of Russia.

Russia has a unique recreational potential. The country has an extensive system of specially protected natural areas both of national and global importance, including nature reserves, national and natural parks, sanctuaries, natural monuments, etc. The total area of all types of specially protected natural areas in Russia at the beginning of 2005 amounted to 230 million hectares, or 13% of the country's territory.

The most traditional form of territorial nature protection, which is of priority importance for the conservation of biological diversity, are state nature reserves. The system of state reserves, as standards of undisturbed natural areas, is the subject of well-deserved pride of domestic science and the environmental movement. The network of reserves has been created for nine decades: the first reserve - "Barguzinsky" - was created in 1916, the hundred and first - "Kologrivsky Forest" - in 2006. The total area of reserves is 1.6% of the country's territory.

The state system of national parks of the Russian Federation began to take shape relatively recently: the first national park - Sochi - was established in 1983. As of January 1, 2005, there were 35 national parks in the country, occupying 0.41% of the country's area.

In recent decades, the number and total area of nature reserves and national parks have increased significantly. Of the country's 101 reserves, 27 have the international status of biosphere reserves, 11 are under the jurisdiction of the Convention on the Protection of Cultural and Natural Heritage. Three national parks also have the status of UNESCO Biosphere Reserves.

An independent category of protected areas is represented by botanical gardens and dendrological parks. Currently, the Council of Botanical Gardens of Russia unites over 100 botanical gardens and dendrological parks of various departmental affiliations. Their total area is about 8 thousand hectares, and the number of visitors exceeds 1 million people a year.

The natural resources of Russia (land, water, mineral, forest, biological, as well as recreational and climatic) make a significant contribution to the conservation strategic security of the country, make it possible to meet the needs of the economy, including maintaining a high level of exports of raw materials.

To the share of industries and activities directly related to the natural resource complex - electric power, fuel, mining, forestry, woodworking and pulp and paper industries, ferrous and non-ferrous metallurgy, production of building materials, agriculture and water management, fishing, forestry, geological exploration , geodesy, hydrometeorology - according to expert estimates, now accounts for more than 30% of the country's GDP. Including non-renewable natural resources (extraction of minerals and their processing), the volume of GDP is about 20%. Taking into account intersectoral relations, that is, the main consuming and providing industries, as well as the sphere of intermediary services, these estimates should be increased.

The use, restoration and protection of natural resources continue to serve as a source of livelihood for a significant part of the country's population, both directly employed and their families. For example, only in industries directly related to the natural resource complex, approximately every fifth person from the economically active population of the country is employed. Taking into account related industries and activities, as well as family members, this figure increases several times.

In absolute terms, the total value of natural resources varies, according to various organizations and expert estimates, depending on the principles and methods of calculation used, from several hundred trillion to several quadrillion rubles in current prices.

In 1999–2002 Within the framework of the State Statistics Committee of Russia, with the involvement of employees of other departments and scientific departments, the available estimates of various components of the country's national wealth were analyzed. Specific statistical data prepared by specialists from various departments (organizations) and published in domestic publications were studied. As part of the natural resource component, a large (absolute) part of the cost value falls on mineral reserves.

The above estimates reflect the results of one of the stages of a long-term and theoretically and practically complex work on a comprehensive assessment of Russia's national wealth and the role of natural (tangible non-produced) assets in it. The results of the calculations are far from unambiguous and are largely due to the lack of an acceptable unified methodology for assessing the natural resource component of Russia's national wealth.

Summarizing indicative data obtained by the Institute of Economics of the Russian Academy of Sciences according to the methodology of the World Bank specialists make it possible to evaluate Russian natural resources in comparison with other countries (due to the complexity of economic assessment, water, recreational and most of the biological resources are not taken into account). These data also show that if the natural capital of most countries is dominated by land and forests, and mineral resources make up a fifth or sixth part, then in Russia the contribution of minerals is about two thirds.

The materials of this section testify to the unique nature and resource endowment of Russia. However, to a large extent, this explains the low efficiency of the use of natural resources and the economy as a whole, traditionally oriented towards an unlimited national resource base. Specific costs of natural resources and produced pollution per unit of final product in Russia are extremely high compared to economically developed countries. For example, the energy intensity of units of final products in Russia is 2–3 times higher, the cost of forest resources for the production of 1 ton of paper is 4–6 times higher. In addition, over the past 10 years, due to a decrease in technological discipline, there has been a significant increase in the energy and resource intensity of manufactured products (by 20–60%). Energy consumption per unit of GDP increased by 25%, water intensity - by 20%. Specific emissions of sulfur oxides, which lead to acid rain and ecosystem degradation, are 20 times higher in Russia than in Japan and Norway, and about 6–7 times higher than in Germany and France. Greenhouse gas emissions exceed those of developed countries by 3–4 times.

Efficient use of the natural resource potential should serve as the basis for the steady transformation of the economy of our country in the national interest, the shift of the economic base from nature-exploiting industries in the direction of deep processing of raw materials and materials, high-tech industries, the service sector, etc.

The natural resource block remains the central factor in the development of the state in the near future.

To achieve the goals of sustainable nature management, it is necessary to:

- to carry out an economic, and above all cadastral, assessment of the totality of natural resources on the territory of the country;

- to determine the rights and rules for the use of natural objects;

- creatively use foreign experience in legislative, economic and environmental aspects of the use of natural potential;

– to develop systems of modern economic and legal mechanisms for nature management.

QUESTIONS FOR SELF-CHECKING

1. Who and when first used the phrase "biological diversity"?

2. When and where did the concept of “biodiversity” come into wide scientific use?

3. What is the Convention on Biological Diversity?

4. The value of biodiversity for the biosphere and man.

5. What special science deals with the study of biological diversity?

6. Define the concept of "biological diversity".

7. What levels of biological diversity do you know?

8. What are the methods of accounting for biodiversity?

9. What determines the state of "species richness"?

10. How is biodiversity assessed?

11. Describe alpha, beta and gamma diversity.

12. What is the applied value of the assessment of biological diversity?

LECTURE № 6,7

SOIL ECOLOGY

SUBJECT:

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 ensure the 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 in 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 in a depressed state for some time 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 got 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.

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 in a depressed state for some time 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 sharper the fluctuations in their numbers, 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.

The biological diversity of the planet includes the genetic intraspecific, species and diversity of ecosystems. Genetic diversity is due to the diversity of traits and properties in individuals of the same species, an example is the many varieties of herbaceous bluebell - more than 300 species and subspecies of woodpecker - about 210 (Fig. 1).

Fig.1 Genetic diversity of bluebell and woodpecker

Species diversity is the variety of species of animals, plants, fungi, lichens and bacteria. According to the results of research by biologists published in the journal PLoS Biology for 2011, the number of described living organisms on the planet is approximately 1.7 million, and the total number of species is estimated at approximately 8.7 million. It is noted that 86% have yet to be discovered. land dwellers and 91% of ocean dwellers. Biologists estimate that a full description of unknown species will require at least 480 years of enhanced research. Thus, the total number of species on the planet will not be known for a long time. The biological diversity of ecosystems depends on natural and climatic conditions, ecosystems are distinguished by structure and functions, in scale from microbiogeocenosis to the biosphere (Fig. 2).

Fig.2 Biological diversity of natural terrestrial and aquatic ecosystems

Biological diversity is the main natural resource of the planet, which provides an opportunity for sustainable development and is of great ecological, social, aesthetic and economic importance. Our planet can be represented as a complex multicellular organism that, through biological diversity, supports the self-organization of the biosphere, which is expressed in its restoration, resistance to negative natural and anthropogenic influences. Biodiversity allows you to regulate water flows, control erosion, form soils, perform climate-forming functions, and much more.

The genetic intraspecific, species and diversity of ecosystems are interconnected. Genetic diversity ensures species diversity, the diversity of natural ecosystems and landscapes creates conditions for the formation of new species, and an increase in species diversity increases the overall gene pool of the planet's biosphere. Therefore, each specific species contributes to biological diversity and cannot be without (with) beneficial or harmful. Each individual species will perform certain functions in any ecological system, and the loss of any animal or plant leads to an imbalance in the ecosystem. And the more species die out for a non-natural reason, the greater the imbalance. In confirmation of this, we can cite the words of the domestic scientist Nikolai Viktorovich Levashov, that "... the ecological system is nothing more than a balance between all forms and types of living organisms and their habitat ...". One cannot but agree with these words.

The distribution of species over the surface of the planet is uneven, and their biological diversity in natural ecosystems is greatest in tropical rainforests, which occupy 7% of the planet's surface and contain up to 70-80% of all animals and plants known to science. This is not surprising, since tropical forests are rich in plants, which provide a huge number of ecological niches and, as a result, high species diversity. At the initial stages of the formation of the ecological system of the planet and up to the present day, a natural process of the emergence and disappearance of species has occurred and continues to occur. The extinction of some species was compensated by the emergence of new species. This process was carried out without human intervention for a very long time. This fact is confirmed by the fact that in different geological epochs there was a process of extinction and emergence of species, which we can judge from the found fossils, imprints and traces of life activity (Fig. 3).

Fig. 3 Fossils of ammonites and shells of bivalve mollusks that lived on the planet about 150 million years ago, in the Jurassic period

However, at present, under the influence of human factors, there is a reduction in biological diversity. This became especially noticeable in the 20th century, when, under the influence of human activity, the rate of extinction of species exceeded the natural rate, which led to the destruction of the genetic potential of the biosphere of our planet. The main reasons for the reduction of the biodiversity of the planet can be considered hunting and fishing, forest fires (up to 90% of fires happen due to human fault), destruction and change of habitats (construction of roads, power lines, dishonest construction of residential complexes, deforestation, etc.) , pollution of natural components with chemicals, the introduction of alien species into unusual ecosystems, the selective use of natural resources, the introduction of GMO crops in agriculture (when pollinated by insects, genetically modified plants spread, which leads to the displacement of natural plant species from the ecosystem) and many other reasons . In confirmation of the above reasons, we can cite some facts of violations of natural ecosystems, which, unfortunately, are a huge number. So, on April 20, 2010, the largest man-made disaster occurred in the Gulf of Mexico, caused by an explosion on the Deepwater Horizon oil platform at the Macondo field (USA). As a result of this accident, about 5 million barrels of oil spilled into the Gulf of Mexico in 152 days, resulting in an oil slick with a total area of 75 thousand square kilometers (Fig. 4) . This is, according to the most conservative estimates, how much actually spilled out is unknown.

The environmental consequences for the ecosystem of the bay and coastal areas are difficult to assess, since oil pollution disrupts natural processes, changes the habitats of all types of living organisms, and accumulates in biomass. Petroleum products have a long decay period and rather quickly cover the water surface with a layer of oil film, which prevents the access of air and light. As of November 2, 2010, 6814 dead animals were collected as a result of the accident. But these are only the first losses, how many animals and plants have died and will die when toxic substances enter the food chain is unknown. It is also unknown how such a man-made disaster will affect other regions of the planet. The natural ecosystem of the Gulf of Mexico and its coasts is capable of self-restoration, but this process can drag on for many years.

Another reason for the reduction of biological diversity is deforestation for the construction of roads, housing, agricultural land, etc. As a confirming fact, we can cite the construction of a high-speed highway Moscow - St. Petersburg through the Khimki forest. The Khimki forest was the largest undivided natural complex, which was part of the forest-park protective belt of Moscow and the Moscow region, and made it possible to maintain high biological diversity (Fig. 5). In addition, it served as the most important regulator of atmospheric air purity, a recreational natural complex for more than half a million residents of nearby settlements, capable of providing a favorable environment for living.

Fig. 5 Khimki forest before the construction of a high-speed highway

As a result of the construction of the high-speed highway, the Khimki forest park suffered irreparable environmental damage, which is expressed in the destruction of the only corridor that runs along the floodplain of the river. Klyazma and connecting the Khimki forest with neighboring forests (Fig. 6).

Rice. 6 Construction of a high-speed road through the Khimki forest

The migration routes of such animals as elk, wild boar, badger and other organisms have been disrupted, which will eventually lead to their disappearance from the Khimki forest. The construction of the road further led to the fragmentation of the forest, which will further increase the adverse edge effects on natural ecosystems (chemical pollution, the impact of acoustic noise, the collapse of forest walls adjacent to the highway, etc.) (Fig. 7). Unfortunately, there are a huge number of such examples throughout the country and around the world, and all together this causes irreparable environmental damage to biological diversity.

The fact of biodiversity reduction is also confirmed by (c) studies, which can be found in the works and. According to a report by the World Wildlife Fund, the total biodiversity of the planet has declined by approximately 28% since 1970. Considering that a huge number of living organisms have not yet been described and the fact that only known species were taken into account in the assessment of biodiversity, it can be assumed that biodiversity loss is mainly occurring at the regional level. However, if a person continues to develop in a technocratic and consumer way and does not take real actions to change the situation, then there is a real threat to global biodiversity, and, as a result, the possible death of civilization. The decrease in the diversity of life leads to a decrease in the maintenance of the functions of the biosphere in its natural state. Ignorance and denial of the laws of nature often leads to the misconception that the loss of one species of animal or plant in nature is interchangeable. Yes, this is so, if it is caused by the natural course of the evolution of living matter. However, today "intelligent" human activity has begun to predominate. I would like to recall one of the laws of ecology of the American ecologist Barry Commoner: "Everything is connected with everything." The law shows the integrity of the ecological system from the living organisms that form it and the environment. I would like to finish my little reflection with the words of the Bulgarian aphorist Veselin Georgiev: “Take care of nature in yourself, and not yourself in nature.”

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.

Biota also plays a dominant role in the water cycle on land: 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 continue 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 transport 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