biological diversity. Concept and definition

What is biological diversity?

Conservation of biological diversity is the central task of the biology of wildlife conservation. 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

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 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” to it, for example, through flood control, soil erosion protection, air and water filtration.

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.

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.

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.

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.

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 (read, in the biosphere) 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.

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.

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.

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; if adverse conditions occur, 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.

Species diversity and life form diversity 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.

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 Russia's biodiversity, 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 biodiversity conservation projects, 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 must have the required number of tundras, forests, deserts, etc. - as biomes, and inside the tundra biome, optimal tundra must 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 rainforest, 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.

5. Structure and levels of biodiversity

At each level of biological diversity - genetic, species and community diversity (ecosystem), specialists 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, which 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, i.e. taxonomy 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 species of plants, fungi and bacteria. 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 that contrast sharply 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 that lives on isolated mountain peaks may evolve over time into several different species, each adapted to specific mountain conditions. 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?

BIOLOGICAL DIVERSITY

What is biological diversity? Why is it important? And why should we support it? In the most general sense, biodiversity refers to the "diversity of life". This concept covers the genetic diversity of different species and higher taxonomic units (families, classes, phyla, etc.) as well as the diversity of habitats and ecosystems. Because "biological diversity" is too broad, there is no rigorous definition; it all depends on the specific area in which it is used. In practice, biological diversity means, first of all, the diversity of species.

Biodiversity means much more than just having different forms of life. It not only determined the directions of applied research, but also acquired the status of a special assessment: it is good when there is biological diversity, and it is necessary to support it in every possible way, since the lack of diversity is bad. In environmental protection measures, priority is now given not so much to the conservation of individual (typical) species, but to the preservation of the entire diversity of the ecosystem. Many arguments have been put forward in favor of this, starting with the assertion that the diversity of life is valuable in itself and we have a moral and ethical responsibility for its preservation, and ending with the usual anthropocentric pragmatism - a person makes full use of the biological diversity of ecosystems (see article " Ecosystem") for their economic needs, such as the development of drugs for cancer or the development of ecotourism.

How to preserve biodiversity? One approach is to focus efforts primarily on maintaining and conserving the best of the many ecosystems available. Another proposes to take care primarily of "hot spots", that is, areas of greatest concentration of representatives of rare species that are threatened with extinction. Carrying out a complex of protective measures in "hot spots", you can save more rare species than in other regions.

See also the articles "Gradient of latitudinal diversity", "Environmental protection", "Ecological redundancy", "Ecosystem".

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From the book Anthropology and Concepts of Biology author Kurchanov Nikolai Anatolievich

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From the book Biological Chemistry author Lelevich Vladimir Valeryanovich

20. Variety of criminal activities Guiteau has a very long list of violations of the law: murder, fraud, theft, battery, robbery, threatening with a weapon, illegal possession of a weapon, forgery, failure to appear in court while on bail, assaulting a representative of the law

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A variety of organic compounds Although organic molecules make up less than 1% of all cell molecules (99% of the molecules are water), they determine the course of basic biochemical processes. Found in the cell as small organic compounds

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Chapter 10 Biological oxidation Living organisms from the point of view of thermodynamics are open systems. An exchange of energy is possible between the system and the environment, which occurs in accordance with the laws of thermodynamics. Every organic

Introduction

The diversity of life has long been a subject of study. The first systems of living nature, known, for example, from the works of Aristotle (384-322 BC), already belong to the analysis of this phenomenon. The scientific and methodological basis for describing biodiversity was created by K. Liney for his "System of Nature". And then there was the accumulation of knowledge.

And in the last decade, the term "biodiversity" has become extraordinarily popular. Since the signing of the Convention on Biological Diversity in 1992 by many states, this word has been constantly heard in government resolutions, documents of state and public organizations, and in the media. Scientific research has proven that a sufficient level of natural diversity on our planet is a necessary condition for the normal functioning of ecosystems and the biosphere as a whole. At present, biological diversity is considered as the main parameter characterizing the state of supraorganismal systems. In a number of countries, it is the characteristic of biological diversity that acts as the basis for the environmental policy of the state, which seeks to preserve its biological resources in order to ensure sustainable economic development.

Biodiversity conservation is discussed at the global, national, and regional levels. However, the meaning of this word is not understood by everyone correctly. Why is biodiversity given such attention, what role does it play in the life of people and the planet, how it changes, what threatens it and what needs to be done to conserve it - my work is devoted to answering these questions.

The aim of the work was to study the methods and assessments of biodiversity

During the work, the following tasks were set:

1) consider the concept of "biodiversity";

2) identify the features of biodiversity;

3) study the methods and assessments of biodiversity.

The object of the study was biological diversity as a variety of natural ecosystems on the globe.

The subject of the study was the current state of biological diversity.

biological environmental policy

Biodiversity

The concept of biodiversity

The phrase "biological diversity", as noted by N.V. Lebedev and D.A. Krivolutsky, was first used by G. Bates in 1892 in the famous work "Naturalist in the Amazon", when he described his impressions of meeting with seven hundred species of butterflies during an hour-long excursion. The term "biodiversity" entered into wide scientific use in 1972 after the UN Stockholm Conference on the Environment, when environmentalists managed to convince the political leaders of the countries of the world community that the protection of wildlife is a priority task for any country.

Biological diversity is the totality of all biological species and biotic communities formed and developing in different habitats (terrestrial, soil, marine, freshwater). This is the basis for maintaining the life-supporting functions of the biosphere and human existence. National and global problems of biodiversity conservation cannot be realized without fundamental research in this area. Russia, with its vast territory, where the main diversity of ecosystems and species diversity of Northern Eurasia is preserved, needs the development of special studies aimed at inventorying, assessing the state of biodiversity, developing a system for monitoring it, as well as developing principles and methods for the conservation of natural biosystems.

According to the definition given by the World Wildlife Fund, biodiversity 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." With such a broad understanding of biodiversity, it is advisable to structure it in accordance with the levels of organization of living matter: population, species, community (a set of organisms of one taxonomic group in homogeneous conditions), biocenosis (a set of communities; biocenosis and environmental conditions are an ecosystem), territorial units of a larger rank - landscape, region, biosphere.

The biological diversity of the biosphere includes the diversity of all types of living beings inhabiting the biosphere, the diversity of genes that form the gene pool of any population of each species, as well as the diversity of biosphere ecosystems in various natural zones. The amazing diversity of life on Earth is not just the result of the adaptation of each species to specific environmental conditions, but also the most important mechanism for ensuring the stability of the biosphere. Only a few species in the ecosystem have a significant abundance, high biomass and productivity. Such species are called dominant. Rare or few species have low numbers and biomass. As a rule, dominant species are responsible for the main energy flow and are the main environment-formers that strongly influence the living conditions of other species. Few species constitute, as it were, a reserve, and when various external conditions change, they can become part of the dominant species or take their place. Rare species basically create species diversity. When characterizing diversity, such indicators as species richness and evenness of the distribution of individuals are taken into account. Species richness is expressed as the ratio of the total number of species to the total number of individuals or to a unit area. For example, 100 individuals live in two communities under equal conditions. But in the first, these 100 individuals are distributed among ten species, and in the second, among three species. In the example above, the first community has a richer species diversity than the second. Let us assume that both in the first and in the second community there are 100 individuals and 10 species. But in the first community, individuals are distributed between species by 10 in each, and in the second, one species has 82 individuals, and the rest by 2. As in the first example, the first community will have a greater evenness of the distribution of individuals than the second.

The total number of currently known species is about 2.5 million, and almost 1.5 million of them are insects, another 300 thousand are flowering plants. There are about as many other animals as there are flowering plants. A little more than 30 thousand algae are known, fungi - about 70 thousand, bacteria - less than 6 thousand, viruses - about a thousand. Mammals - no more than 4 thousand, fish - 40 thousand, birds - 8400, amphibians - 4000, reptiles - 8000, mollusks - 130000, protozoa - 36000, various worms - 35000 species.

About 80% of biodiversity is terrestrial species (land-air and soil life environments) and only 20% are aquatic life environments, which is quite understandable: the diversity of environmental conditions in water bodies is lower than on land. 74% of biological diversity is associated with the tropical belt. 24% - with temperate latitudes and only 2% - with polar regions.

As rainforests disappear catastrophically under pressure from plantations of hevea, bananas and other highly profitable tropical crops, as well as as sources of valuable timber, much of the biodiversity of these ecosystems may die without scientific names. This is a depressing prospect, and so far the efforts of the global environmental community have not yielded any tangible result in the conservation of tropical forests. The lack of complete collections also makes it impossible to reliably judge the number of species living in marine environments, which have become "... a kind of frontier of our knowledge of biological diversity." In recent years, completely new groups of animals have been discovered in marine environments.

To date, the biodiversity of the planet has not been fully identified. According to forecasts, the total number of species of organisms living on Earth is at least 5 million (and according to some forecasts - 15, 30 and even 150 million). The least studied are the following systematic groups: viruses, bacteria, nematodes, crustaceans, unicellular, algae. Mollusks, fungi, arachnids and insects are also insufficiently studied. Only vascular plants, mammals, birds, fish, reptiles, and amphibians have been well studied.

Microbiologists have learned to identify less than 4,000 species of bacteria, but studies on the analysis of bacterial DNA performed in Norway have shown that more than 4,000 species of bacteria live in 1 gram of soil. The same high diversity of bacteria is predicted in samples of marine bottom sediments. The number of bacterial species that are not described is in the millions.

The number of species of living organisms living in marine environments is far from being completely revealed. "The marine environment has become a kind of frontier of our knowledge of biological diversity." New groups of marine animals of high taxonomic rank are constantly being identified. Communities of organisms unknown to science in recent years have been identified in the canopy of tropical forests (insects), in geothermal oases of the sea depths (bacteria and animals), in the earth's depths (bacteria at a depth of about 3 km).

The number of described species is indicated by the shaded parts of the bars.

Portal for the student. Self-training

What is biological diversity?

Introduction

Biodiversity

The concept of biodiversity

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