Practical use of lichens. Economic importance and use of lichen communities Why lichens are useful for humans

A lichen is an organism that includes a fungus and a green algae. In total, there are about twenty thousand species of lichens, which differ in size, shape, color and other characteristics. Based on their morphological characteristics, these organisms are divided into:

fruticose lichens.

Their sizes can range from a couple of millimeters to 30-50 cm. They resemble bushes, erect or hanging, and can be highly branched or unbranched.

One of the types of organisms in question are bearded lichens. They have a peculiar shape, reminiscent of a hanging human beard. Their thallus can reach half a meter in size.

crustose lichens;

This category of organisms includes crowded lecidea, varied lecanora, etc. Their body is a crust of varying thickness. In diameter it ranges from a couple of millimeters to 20-30 cm.

leaf lichens;

The lamellar, leaf-shaped body of this kind of lichen is located horizontally on the substrate. As a rule, it has a round outline, which may change with age. The upper part of the organisms in question differs in color from the lower surface.

Lichens can grow everywhere: on the surface of mountains, stones, the bark of trees, shrubs, and soil. There are also non-attached, that is, nomadic forms of organisms.

Harvesting and storage of lichens

The lichen thallus is used for medicinal purposes. Organisms that are not damaged by rot, rust and pests are used for harvesting. They are carefully cut off or scraped off, washed, and debris removed. Lichens are dried in special dryers, outdoors, in a ventilated area. It should be stored in a canvas, paper bag in a dry place.

Use in everyday life

Some types of lichens act as food for livestock and wildlife. In addition, the organisms in question are used in perfumery; various types of dyes for wool and silk are produced from them. Their main color is dark blue. By adding acetic acid, you can get purple, red, yellow tones.

Composition and medicinal properties of lichens

1. Lichens contain antibiotic substances that have different effects on bacteria and inflammatory processes. That is, lichens have anti-inflammatory and antimicrobial effects.
2. Preparations prepared on the basis of these organisms are used to treat boils, staphylococcal, streptococcal infections, lupus erythematosus and other skin diseases. They are also used to eliminate varicose veins and trophic ulcers.
3. Lichens relieve inflammation, relieve a number of gynecological diseases, and quickly heal burns.
4. A decoction of lichen is recommended for use by people who have tuberculosis, catarrh, and colds. It has a therapeutic and tonic effect.
5. Parmelia lichen is used for severe coughs, acute colitis, tuberculosis, and gastrointestinal diseases. It has a calming effect on the mucous membrane of the respiratory tract and acts as a general strengthening drug. Parmelia decoction is used externally to wash purulent wounds and ulcers (it heals them quickly).
6. Medicines made from bearded lichen have antimicrobial, anti-inflammatory, expectorant, wound-healing, and antiviral effects. They normalize the functioning of the immune system.
7. Fruticose lichens (cladonia palmate, usnea longissimum, pale ocher alectoria) are prescribed for the treatment of influenza, stomach and colds.
8. Clumped lecidia and a variety of lecanora should be used to get rid of purulent wounds and severe cough.
9. Reindeer moss lichen has a laxative, choleretic, wound healing, antimicrobial, anti-inflammatory effect. From these crushed organisms, mucus is obtained, which helps to increase the production of gastric juice and normalizes the functioning of the gastrointestinal tract. They are also used for diarrhea and constipation, tuberculosis, whooping cough, and chronic bronchitis.

The use of lichens in folk medicine

Let's look at some recipes for preparing medicinal compositions based on lichens.

A decoction of reindeer moss that normalizes the functioning of the stomach and intestines

Grind the raw materials and pour boiling water or hot milk over it (for 1 tablespoon of lichen you need to take 500 ml of liquid). Cook the composition in a water bath for 5-7 minutes. After this, it should sit for 0.5 hours. After straining, drink the product in a third of a glass.

Reindeer moss extract, which has a laxative effect

Pour crushed moss (100 g) with cold water (1 l), leave for 24 hours, strain. Then cook in a water bath until the volume of liquid is reduced by half. The product should be taken 3 times a day, 30 minutes before meals. Duration of treatment – ​​2 weeks.

Icelandic moss decoction used for bronchitis

Finely chopped raw materials (1 tbsp) pour milk (250 ml), boil for 30 minutes, strain. Drink the decoction hot before going to bed.

Icelandic moss decoction used for whooping cough

Dry Icelandic moss (1 tbsp) pour cold water (500 ml), bring to a boil, strain, let the mixture cool. You should drink it in small sips a day, dividing it into 10-12 doses.

Icelandic moss decoction taken for tuberculosis

Pour moss (2 tbsp) with water (250 ml), bring to a boil, remove the slabs and filter. After the product has cooled, it should be taken a couple of sips twice - three times a day.

A remedy based on Icelandic moss, used for stomach and duodenal ulcers

Mix Icelandic moss with flax seeds and marshmallow root in equal parts. Pour a few tablespoons of the resulting mixture with water (500 ml), leave for five hours, boil for 5-7 minutes. After allowing the mixture to cool, strain it. Take a third of a glass of the decoction 0.5 hours before meals 5-6 times a day.

Parmelia decoction to help relieve cough

Pour dry parmelia (1 tbsp) with water (1 l), cook in a water bath (after the liquid boils - 2 hours). Drink the mixture warm 30 minutes before meals (80 ml three times a day). It should be stored in the refrigerator.

Parmelia-based compresses used for purulent wounds and ulcers

Dry lichen (5 tbsp) pour water (500 ml). Having brought the composition to a boil, cook it for another 25-30 minutes over high heat, then let it brew at room temperature (the product must cool). After straining the decoction, apply it to the affected areas.

Contraindications

The composition should not be used by persons with individual intolerance, pregnant and lactating women, and children.

USING LICHENS FOR FOOD

During the Soviet-Finnish war of 1939-1940. A large landing party was landed in the rear of the Finnish army, whose task included sabotage behind enemy lines, destruction of communications, and reconnaissance. It was assumed that the landing party could easily provide themselves with food by hunting animals, fishing, and birds. However, the organizers of this operation did not take into account that the northern nature would not be able to withstand such a load and a significant part of the large (over a thousand people) landing party died of starvation.

During the expedition of the English polar explorer John Franklin, its participants suffered great hardships due to lack of food. They ate the leather of belts and boots, and also tried lichens. However, they did not know how to get rid of the bitter lichen acids and therefore some members of the expedition were poisoned. Later they noticed that the Indians mainly ate the species Umbilicaria mullenbergii and began collecting this type of lichen.

There are known cases when pilots who crashed in the tundra died of hunger, while they practically walked “on food”: lichens, which form the basis moss, quite edible. To do this, it is necessary to thoroughly soak the collected lichen thalli in a solution of soda or potash (potassium carbonate and sodium are contained in the ash), preferably for 2-3 days, rinse thoroughly, periodically changing the water and cook until a brew is formed, slightly reminiscent of jelly. Such jelly is not very nutritious, but in the absence of other food it can maintain strength and prevent you from dying of hunger.

It is assumed that lichens served " manna from heaven" for the ancient Jews. When Moses led the children of Israel through the desert, they began to murmur against their guide, saying that they had nothing to eat. The Old Testament says that the Lord said to Moses: “I heard the murmur of the children of Israel; tell them: “In the evening you will eat meat, and in the morning you will be filled with bread, and you will know that I am the Lord your God.” In the evening the quails flew in and covered the entire camp. In the morning, everyone saw dew around the camp, and when the dew evaporated, grains similar to frost remained on the surface of the desert. This was heavenly bread from the Lord for all the people. The Israelis called this bread "manna" and it tasted like cakes with honey.

If everything is clear about quails, then what “manna” is is still unknown. The most common belief is that it is a free-living nomadic lichen, common in desert areas. Now it is difficult to determine what was meant by “heavenly manna”, whether it was plant gum, mushrooms or insect pupae. According to scientists, in ancient times the Sinai Peninsula was not a bare desert, but was a land overgrown with tamarisk trees. In the desert regions of Asia and North Africa, some species of lichens from the genus Aspicilia form a thick crust on stones, which often falls off and the fallen particles of lichen thalli are carried by the wind, accumulating in the depressions. One person can collect up to 6 kilograms of lichens per day, despite the fact that lichens are very light. Pounded lichen thalli slightly resemble flour, and unleavened cakes baked from such flour are quite edible. The thalli of Aspicilia edible contain up to 60% calcium oxalate, which must be removed before eating lichens.

During the war between Russia and Persia in 1829, a large area around one of the cities, besieged by Russian troops, whose inhabitants were on the verge of starvation, was suddenly covered with lichens carried by the wind. These lichens were eaten by people and sheep. It was also Aspicilia esculenta. However, the lichens did not help the Persians, the army of General Paskevich defeated the army of the crown Persian prince Abbas Mirza, took Erivan and Tavrits, and the war ended with the signing of the Turkmanchay Treaty, according to which Shah Fet-Ali ceded the Erivan and Nakhichevan provinces to Russia and paid 20 million rubles in indemnity and gave Russian subjects important trade advantages. Russian soldiers met Aspicilia edible later, when in 1885 the troops of General Komarov defeated the Afghans near Kushka.

Pancakes: 250 g lichen flour, 250 g wheat flour, 3 glasses of water or milk, 2-3 eggs, 1 tablespoon sugar, 0.5 teaspoon each salt, soda and acid. If there is no acid, then instead of water you can use sour milk, and dilute the soda in water and pour it into the dough before baking. Mix eggs with 3 glasses of warm water, add salt, sugar and soda, then add flour and stir well so that the dough is free of lumps. Dilute citric acid in water, pour into the prepared dough, stir and immediately bake pancakes.

Cookie: 1 cup each of lichen and wheat flour, 3 tablespoons of sugar, 2 eggs, 2 tablespoons of sour cream, 0.5 teaspoon of soda. Beat the eggs into a bowl, add sugar and stir with a wooden spoon, gradually adding melted butter, and then add cold sour cream. Put baking soda mixed with a small amount of flour, add the rest of the flour and knead the dough. Roll out the resulting dough into a thin layer, brush its entire surface with egg yolk, cut out circles from the dough using a glass, place them on a greased baking sheet and bake in the oven.

Kissel: 3 cups crushed Cetraria, 2 cups berries (raspberries, cranberries, lingonberries), 0.5 cups granulated sugar, 1 liter of water. Boil the washed Cetraria for 2 hours. Strain the broth, add berry juice and sugar. Boil. Serve hot or cold.

Jelly: concentrated Cetraria decoction (1 kg of lichen per 1 liter of water), salt to taste and pour boiled mushrooms over it. Once cooled, serve with horseradish, mustard, pepper and vinegar.

On our website you can read others popular science articles on lichenology Doctor of Biological Sciences A.V. Pchyolkina: 1) The simplest methods of lichenological examinations, 2) The use of lichens and algae in environmental monitoring and bioindication studies, 3) Popular lichenology: introduction and table of contents (history of the study of lichens, life forms of lichens, components of lichens, how lichens reproduce, where lichens are distributed, the main factors affecting lichens, what substances lichens produce, the relationship of lichens with other organisms, the use of lichens for food, the use of lichens for embalming, lichen paint, lichens - indicators of pollution, the use of lichens for dating historical objects, how to identify lichens, basic terms used in identifying lichens, chemical reagents used in identifying lichens).

Our original teaching materials on mushrooms and lichens of Russia: In our at non-commercial prices(at production cost) Can purchase the following teaching materials

The economic importance of lichens in human life is great. Firstly, these are the most important food plants. Lichens serve as the main food for reindeer - animals that play a large role in the life of the peoples of the Far North.

The basis of reindeer food is reindeer moss or moss - 3 types of bushy lichens: alpine cladonia, forest cladonia and deer cladonia. In total, deer use up to 50 species for food.

The nutritional value of lichens is determined by the high content of carbohydrates, which are well digested and absorbed by deer. However, a small amount of vitamins and a lack of ash and protein substances make lice feed incomplete. Epiphytic lichens are also eaten by other animals, for example, squirrels, voles, etc. In northern countries, some lichens, especially Icelandic Cetraria, were widely used as additional food for livestock. This lichen was also used as an additional product when baking bread, especially in Iceland. Humans use other lichens for food. For example, in Japan, one of the delicacies is the foliose lichen edible umbilicaria.

Another area of ​​practical application of lichens is medicine.

Lichens are still used in folk medicine. In the mid-20th century, the healing properties of lichens began to be rightly associated with lichen acids. Lichen acids are complex organic compounds with a very diverse structure. Their molecules are built from carbon, oxygen and hydrogen atoms. Most of these compounds are not soluble in water, but dissolve in acetone, chloroform, ether, etc. Many lichen acids are colorless, but there are also colored compounds. In the thallus, lichen acids are located on the walls of fungal hyphae. Lichen usnic acid is a broad-spectrum antibiotic. Modern studies of the chemical composition of the thallus have shown that Icelandic cetraria contains up to 70-80% carbohydrates, mainly “lichen starch” - lichenin and prolichenin, as well as sugar (glucose and galactose), 0.5-3% proteins, 1-2% fats , 1% wax, about 3% gum, about 3% pigments and 3 to 5% lichen acids. Lichen acids can regulate enzyme activity. It is the acids that give lichen its bitter taste and determine its tonic and antibiotic properties. Modern research has shown that, for example, protolichesterolic and lichesteric acids exhibit high antimicrobial activity against staphylococci, streptococci and some other microorganisms. Thanks to these features, Icelandic cetraria is used as a medicinal product in modern medicine. It is widely used as a proven folk remedy: decoctions are prepared from the lichen to treat catarrhs ​​and colds, jellies against diarrhea, and it is also used as a bitter for therapeutic purposes. Icelandic cetraria is also used as a folk remedy in the treatment of tuberculosis.

German scientists obtained the first antibiotic drug from lichens called “|Evosin”. In the late 40s, a new medical drug was obtained at the Botanical Institute of the USSR Academy of Sciences - the sodium salt of usnic acid, or “Vinan”.

Lichens are also widely used as raw materials for the perfume industry. It has long been known that some of them contain aromatic substances and essential oils. In ancient times in Egypt and later, in the 15th-18th centuries, powders were obtained from dry lichens, which were then used to make powders, in particular powders for wigs. Currently, extracts of these lichens are used in perfumery.

Evernia plum has acquired the greatest importance as a raw material for the perfume industry. From this lichen a resinoid is obtained - a concentrated alcoholic extract that looks like a thick, dark-colored liquid. Resinoid is an aromatic substance; it is used in perfume factories as an aromatic beginning for some types of perfumes. In addition, it has the property of an odor fixative, and perfumers in some cases use it to make perfumes last longer.

Since ancient times, lichens have served as raw materials for dyes. Dyes were used to dye wool and silk. The main color of dyes obtained from lichen substances is dark blue. But the addition of acetic acid, alum, etc., will give purple, red and yellow tones. It is important that paints made from lichens have particularly warm and deep tones, although they are unstable in relation to light.

Lichens can be found almost everywhere, even in Antarctica. This group of living organisms has been a mystery to scientists for a long time; even now there is no consensus on their systematic position. Some believe that they should be classified as a plant kingdom, while others believe that they should be classified as fungi. Next, we will consider the types of lichens, the features of their structure, their significance in nature and for humans.

General characteristics of lichens

Lichens are a lower group of organisms that consist of a fungus and algae that are in symbiosis with each other. The first are most often representatives of phycomycetes, ascomycetes or basidiomycetes, and the second organism is green or blue-green algae. There is mutually beneficial cohabitation between these two representatives of the living world.

Lichens, regardless of the variety, are not green in color; most often they can be gray, brown, yellow, orange or even black. This depends on the pigments, as well as the color of the lichen acids.

Distinctive features of lichens

This interesting group of organisms is distinguished by the following features:

• The cohabitation of two organisms in a lichen is not accidental; it is determined by historical development.
• Unlike plants or animals, this organism has a specific external and internal structure.
• The physiological processes occurring in fungi and algae differ significantly from those in free-living organisms.
• Biochemical processes also have their own distinctive features: as a result of vital activity, secondary metabolic products are formed that are not characteristic of any group of living organisms.
• A special method of reproduction.
• Attitude to environmental factors.

All these features confuse scientists and do not allow them to determine a permanent systematic position.

Varieties of lichens

This group of organisms is often called the “pioneers” of land, since they can settle in completely lifeless places. There are three types of lichens:

1. Scale lichens. They got their name from their shape, similar to scale.
2. Foliaceous lichens. They look like one large leaf blade, hence the name.
3. Fruticose lichens resemble a small bush.

Let's look at the features of each type in more detail.

Description of crustose lichens

Almost 80% of all lichens are crustose. In their shape they look like a crust or a thin film, firmly fused with the substrate. Depending on their habitat, crustose lichens are divided into:

Due to its special appearance, this group of lichens can be completely invisible and blend in with the environment. The structure of crustose lichens is unique, so they are easy to distinguish from other species. But the internal structure of almost all is the same, but more on that later.

Habitats of crustose lichens

We have already looked at how crustose lichens got their name, but the question arises: do the habitats differ? The answer can be given in the negative, because they can be found in almost every latitude. These organisms are amazingly able to adapt to absolutely any conditions.

Crustaceous types of lichens are distributed throughout the planet. Depending on the substrate, one or another species predominates. For example, in the Arctic you cannot find species that are common in the taiga, and vice versa. There is a connection to a certain type of soil: some lichens prefer clay, while others feel comfortable on bare rocks.

But among the great diversity of this group of organisms, you can find species that live almost everywhere.

Features of foliose lichens

The thallus of this species looks like medium-sized scales or plates, attached to the substrate using a bunch of fungal hyphae. The simplest thallus resembles a rounded leaf blade, which can reach 10-20 cm in diameter. With this structure, the thallus is called monophyllous. If there are several plates, then polyphilic.

A distinctive feature of this type of lichen is the difference in the structure and color of the lower and upper parts. There are nomadic forms.

"Bearded" lichens

Bushy lichens received this name for their thallus, consisting of branched filaments that grow together with the substrate and grow in different directions. The thallus resembles a hanging bush; there are also upright forms.

The dimensions of the smallest representatives do not exceed a few millimeters, and the largest specimens reach 30-50 cm. In tundra conditions, lichens can develop attachment organs, with the help of which organisms protect themselves from being torn off from the substrate in strong winds.

Internal structure of lichens

Almost all types of lichens have the same internal structure. Anatomically, two types are distinguished:

It should be noted that those lichens that belong to crustaceans do not have a lower layer, and the hyphae of the core directly grow together with the substrate.

Feeding features of lichens

Both organisms living in symbiosis take part in the feeding process. Fungal hyphae actively absorb water and minerals dissolved in it, and algae cells have chloroplasts, which means they synthesize organic substances as a result of photosynthesis.

We can say that hyphae play the role of the root system, extracting moisture, and algae perform the function of leaves. Since for the most part lichens settle on lifeless substrates, they absorb moisture over their entire surface; not only rainwater, but also fog and dew are suitable for these purposes.

For normal growth and functioning, lichens, like plants, require nitrogen. If green algae are present as a phycobiont, then nitrogen compounds are extracted from solutions when the thallus is saturated with moisture. It’s easier for lichens, which have blue-green algae; they are able to extract nitrogen from the air.

Reproduction of lichens

Regardless of the variety, all lichens reproduce in the following ways:

Considering that these organisms grow very slowly, we can conclude that the reproduction process is quite long.

Ecological role of lichens

The importance of this group of organisms on the planet is quite great. They are directly involved in the process of soil formation. They are the first to settle in lifeless places and enrich them for the growth of other species.

Lichens do not require a special substrate to function; they can cover barren territory, preparing it for plant life. This is explained by the fact that in the process of life, lichens secrete special acids that contribute to the weathering of rocks and enrichment with oxygen.

Settling on bare rocks, they feel absolutely comfortable there and gradually create favorable conditions for other species. Some small animals are able to change their color to match the color of lichens, thus camouflaging and using them for protection from predators.

The importance of lichens in the biosphere

Currently, more than 26 thousand species of lichens are known. They are distributed almost everywhere, but surprisingly they can serve as an indicator of air purity.

These organisms are quite sensitive to pollution, so in large cities near roads and factories you will hardly find lichens. They simply do not survive there and die. It should be noted that crustose lichens are the most resistant to poor natural conditions.

Lichens also take a direct part in the cycle of substances in the biosphere. Since they belong to autoheterotrophic organisms, they easily accumulate the energy of sunlight and create organic substances. Participate in the process of decomposition of organic matter.

Together with bacteria, fungi and algae, lichens create favorable conditions for higher plants and animals. Settling in trees, these symbiotic organisms cause virtually no harm, since they do not penetrate deep into living tissues. In a way, they can even be called protectors, because a plant covered with lichens is less susceptible to attacks by pathogenic fungi; lichen acids suppress the growth of wood-destroying fungi.

But there is also a downside: if the lichens grow too much and cover almost the entire tree, they cover the lentils, disrupting gas exchange. And this is an excellent refuge for insect pests. For this reason, it is better to control the growth of lichens on fruit trees and clean the wood.

The role of lichens for humans

We cannot ignore the question of the role of lichens in human life. There are several areas where they are widely used:

Lichens do not cause any harm to human economic activity.

To summarize all that has been said, we can say that such inconspicuous and amazing organisms exist next to us. Despite their small size, their benefits are enormous, for all living organisms, including humans.

In the north, lichens are valuable food for animals, for example, Icelandic moss (Cetraria islandica), reindeer moss (Cladonia sp., etc.).

Lichens are used for human food, especially in China and Japan. It is believed that the biblical manna from heaven is nothing more than thalli of crustacean lichen growing in the mountains, edible aspicilia (Aspicilia esculenta), blown by the wind. This lichen constituted a significant part of the diet of the tribes inhabiting the deserts. There is information about the use of lichens for food by Egyptians, Indians, and residents of northern countries.

The use of lichens for medicinal purposes dates back to the Middle Ages. In folk medicine, they used and are currently using, for example, lobaria (Lobaria pulmonaria), Icelandic cetraria (Cetraria islandica) for the treatment of pulmonary diseases. Many biologically active substances, in particular antibiotics, have been found in lichens. Some antimicrobial drugs based on usnic acid have been developed.

Fabric dyes and litmus were obtained from lichens. In the perfume industry, lichen substances are used to impart longevity to perfumes.

Based on the size of the lichen thallus, knowing the annual growth, one can determine the age of the substrate on which they live (from several decades to several thousand years).

Lichens are sensitive to atmospheric pollution, especially fluorine, sulfur and nitrogen oxides, so they are used as an indicator of the state of the environment. There is a method for determining the cleanliness of the environment - lichen indication. It was found that in ecologically unfavorable areas, bushy lichens first disappear, then some foliose and crustacean lichens.

The negative significance of lichens is that, settling on sculptures and architectural monuments, they destroy them.

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Lichenometry. Due to the fact that lichens live for a long time and grow at a constant rate, they can be used to determine the age of the rock (glacial retreat or the time of construction of a new building) (lichenometry).

How do people use lichens?

Most often, yellow lichens of the genus Rhizocarpon are used for this purpose. Thus, in 1965, using this method, the average age of monuments on Easter Island was determined (almost 500 years). This method, however, is not always accurate due to the disproportionate growth of the lichen and is not indisputable, and therefore should only be used when radiocarbon dating cannot be resorted to.

The Lichens department belongs to the kingdom of Mushrooms. The anatomy and physiology of these organisms attracts attention. Lichens are called “pioneers of vegetation.” Indeed, lichens are the first to settle on bare, barren rocks, where no higher plants can exist; they thrive on tree bark, fences, stones, poor soil, in the hot desert and in the harsh conditions of the Arctic and Antarctic. In Antarctica, where only 2 species of higher plants are found, 350 species live.

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Lichens is a group of living organisms that combines the characteristics of two other groups: mushrooms and algae. The body of the lichen is presented thallus. Depending on the shape of the thallus, the following are divided: types of lichens:

1. Crustose lichens- look like a thin film of different colors on trees, stones, walls, etc.
2. Foliose lichens have the shape of a small plate raised above the surface on which they grow.
3. Fruticose lichens have a bush-like thallus and can settle on the soil and bark of trees.

   Human use of lichens

   Many bushy lichens can be found in the tundra, mountains and other climatically harsh areas of the planet.

Lichens use vegetative propagation method, using separate sections of the thallus for this. Algae cells and fungal cells in a lichen can reproduce separately.

Lichens are very important for the biosphere. They settle in rocky and sandy areas where there is no soil, and participate in its formation. Lichens also create living conditions for other organisms, including their food.

Humans use lichens to produce dyes, sugar, alcohol and some medicinal substances. Also, lichens are the best indicator of air pollution, since they feed mainly from the air, they die when it is polluted.

Additional materials on the topic: Lichens. General characteristics.

The structure of the cell membrane.

The cell membrane (cytoplasmic membrane) is the surface apparatus of the cell, which performs important functions, and therefore has its own characteristics. The structure of the cell membrane.

Seaweed.

Algae are lower plants that do not have stems, roots or leaves. Seaweed.

Meaning and Use of Lichen

True reindeer moss Cladonia rangiferina in the plant community Corynephorion canescentis

Brown-winged Plover (Pluvialis dominica) nest made from lichen

The role of lichens in the life of animals is especially important in the Far North, where vegetation is sparse; in the winter months they make up about 90% of the diet of deer. Particularly important for deer is moss (reindeer moss) (Cladonia), which they even reach from under the snow cover with the help of their hooves. Moose also use this food source. The ability to consume lichens is due to the presence of the enzyme lichenase.

For many butterfly larvae, such as members of the genus Eilema, lichen serves as a staple food, and their caterpillars feed exclusively on it. In addition, lichen is eaten by invertebrates such as snails, insects and mites, which use it to varying degrees. You can also mention the hay beetles and larvae of Mycobates parmelia with camouflage coloring to match the color of their lichen Xanthoria parietina.

Lichen vegetation is used by many animals as habitat and shelter from predators. Ticks and insects live on them in large quantities; they serve as one of the important habitats for tardigrades. The caterpillars of various moths are colored to match the color of the lichen, while others also imitate its outline.

Many birds use lichens, especially foliose and bushy forms, for nesting, such as the brown-winged plover (Pluvialis dominica), which builds nests on members of the genera Cladonia and Cetraria.

Dish made from edible lichen Bryoria fremontii

Lichens serve as food for domestic animals, for example, reindeer moss (Cladonia) and Iceland moss are traditional food for reindeer.

Medications. Lichens have also been used as a medicinal remedy for a long time, as Theophrastus pointed out. It is known that Lobaria pulmonaria was used in the Middle Ages against pulmonary diseases.

Lichens are used in folk medicine and also contain a wide range of ingredients of pharmaceutical interest. For example, Cetraria islandica is added to cough remedies, and the antibiotic usnic acid, used to treat skin and other diseases, was discovered in Usnea. Polysaccharides (sarcoma-180) are of interest to oncologists.

Lichen indication The lichen Usnea filipendula grows only in places with very high air quality

Lichens are indicator organisms (bioindicators) for determining environmental conditions, in particular air quality (lichen indication). The high sensitivity of lichens to pollution is due to the fact that the interaction of its components is easy to disrupt. From the air or with rain, toxic substances enter the lichen without any obstacles along with nutrients; this happens because lichens do not have any special organs for extracting moisture from the substrate, but absorb it with the entire thallus. Therefore, they are especially vulnerable to air pollution.

The first reports of mass death of lichens in areas of industrialized cities appeared in the second half of the 19th century. The main reason was the increase in sulfur dioxide content in the air. Meanwhile, the use of sulfur filters on industrial equipment and catalytic converters in cars have improved air quality, so that today lichens are common in large cities.

“Passive monitoring” takes into account the frequency of occurrence of lichens in a certain area, which is used to draw conclusions about the air quality there. With “active monitoring”, a specific type of lichen (often Hypogymnia physodes) is observed, which is planted in the place under study, and its quality is judged by the impact of the environment on it (decreased viability, change in color of the talome, death). Lichen indication is intended for long-term studies.

In areas with intensive agriculture, there is a high application of fertilizers, nitrogen compounds from which are distributed with water, making the soil reaction weakly basic. This leads to the extinction of lichen species that prefer acidic soils. Lichens also serve as indicators of the presence of toxic heavy metals in the air that accumulate in tissues, which can ultimately lead to the death of the lichen. Lichens and radioactive substances accumulate. Therefore, they can be used to monitor radioactive fallout after atmospheric nuclear tests.

Lichenometry. Due to the fact that lichens live for a long time and grow at a constant rate, they can be used to determine the age of the rock (glacial retreat or the time of construction of a new building) (lichenometry). Most often, yellow lichens of the genus Rhizocarpon are used for this purpose. Thus, in 1965, using this method, the average age of monuments on Easter Island was determined (almost 500 years). This method, however, is not always accurate due to the disproportionate growth of the lichen and is not indisputable, and therefore should only be used when radiocarbon dating cannot be resorted to.

Dyes For a long time, valuable purple dye was obtained from the littoral lichens of the genus Roccella and the species Pertusaria corallina. Carl Linnaeus mentioned six dye lichens in his “Plantae tinctoriae” (“Colorful Plants”). The dye and chemical indicator litmus is also obtained by extraction from Roccella.

Evernia and Parmelia are used in Scotland and Scandinavia to dye wool and fabric and can be used to achieve particularly pleasing yellow and brown tones. Also interesting is the use of the lichen Xanthoparmelia camtschadalis (incorrect, but often used synonym - Parmelia vagans) by residents of the Lower Volga region for coloring Easter eggs.

Other Uses Poisonous vulpinic acids from Letharia vulpina were previously used as a poison for foxes and wolves.

Some lichens, such as oakmoss (Evernia prunastri) and Pseudevernia furfuracea, produce aromatic substances used in perfumery.

Cladonia stellaris is imported in large quantities from Scandinavia and is used to make model trees or decorative wreaths.

In the history of biology, it often happened that the essence of the organisms studied by scientists was learned much later than the beginning of their use. It was the same with lichens. We find the first information about these organisms in the works of the great ancient scientist Theophrastus (370–285 BC), who described two lichens - usnea and roccellia. Even then, dye for fabrics was obtained from Roccellia, and later they began to extract the well-known indicator for acidity and alkalinity.

Until the end of the 60s of the last century, lichens were considered as ordinary integral plants. They were often called mosses, algae, or simply “the chaos of nature.”

The Lichens department belongs to the kingdom of Mushrooms. The anatomy and physiology of these organisms attracts attention. Lichens are called “pioneers of vegetation.”

Lichens. General characteristics.

Indeed, lichens are the first to settle on bare, barren rocks, where no higher plants can exist; they thrive on tree bark, fences, stones, poor soil, in the hot desert and in the harsh conditions of the Arctic and Antarctic. In Antarctica, where only 2 species of higher plants are found, 350 species live.

Slides, presentations

Control questions:

1. What substances are absorbed by lichens using hyphae?

2. Foliaceous lichens as opposed to crustose lichens

3. Lichen Science

4. Lichens reproduce

5. From what organisms is litmus obtained?

6. What symbiosis forms the body of the lichen?

7. Is lichen a symbiosis?

8. How much do fruticose lichens grow in a year?

9. How do lichens attach to the soil?

10. What is the body of a lichen represented by?

11. How do lichens reproduce vegetatively?

12. What is reindeer moss, or moss?

13. What representatives of lichens do you know?

Literature:

Zvyagintsev D.G., Babieva I.P., Zenova G.M. Soil biology: Textbook. — 3rd ed., rev. and additional - M.: Moscow State University Publishing House, 2005.

Zvyagintsev D.G. Microorganisms and soil. M.: MSU, 1987.

Babeva I.P., Zenova G.M. Soil biology. M.: MSU, 1989. p.336.

Prokaryotes

Purpose of the lecture: to introduce soil prokaryotes and their varieties, their role and significance in the destruction of organic matter and participation in soil fertility

Key words: cyanobacteria and proteobacteria, spirochetes and cytophages, gram-positive bacteria, gram-negative bacteria, mycoplasmas and archaebacteria, bacilli

1 History of the formation of prokaryotes and eukaryotes

2 Cyanobacteria and Proteobacteria