What are the common characteristics of all conifers? Seed plants

Natalia Dudareva, landscape construction engineer:

In autumn (and sometimes in May) any pines turn yellow - common, mountain, black, cedar and others. It’s easy to understand whether a tree is dying or whether it is feeling great despite its yellowness.

The expression: “Conifers are evergreens” is just a figure of speech. In fact, they periodically change their needles - and this is an absolutely normal process. Only, unlike deciduous trees, they do this not annually, but approximately once every 2-4 years. This means that a needle “born” this year will remain green from 1 to 4 years. If the tree is doing well, it will change its needles less often, and if it has just been transplanted or has experienced other stress, it will change more often.

Let's go from the top

Looking at a pine branch from the top to the base, it is very easy to see how it grew. You can calculate how old it is by looking at the places where the side branches branch off from the main branch - the so-called whorls. From the top to the nearest whorl - the growth of this year, then - last year, the year before, and so on. And literally everything depends on where yellowness appears!

On healthy pine branches, the youngest needles (i.e., the current year's growth) are always green. In addition, at the tip of each shoot there should be a bud (or several buds). On the outside they are covered with gray-brown scales and resin, but on the inside, if they are broken, they are green and fresh. The larger and “fattier” the buds are, the better the tree feels.

If everything is exactly like this for your pine tree, great. On the contrary, if the needles turn yellow precisely at the ends of the shoots, and the buds dry out, this is a very bad sign: either a separate branch or the entire tree dies.

The needles on the growths of the previous (second) year of pine, as a rule, should also be green. But if it begins to die, this is simply a sign that the tree is weakened for some reason and is shedding “ballast”, which is not able to feed the roots. Next year, it is advisable to water such a pine tree on time and properly, and in the spring feed it with complex fertilizer for conifers. But she's not going to die, don't worry!

If the needles of the year before last turn yellow, this is completely normal. But if it suddenly remains green, your pine tree feels just fine and thus thanks you for your good care.

What about pests and diseases?

And one last thing. Take a closer look at the needles themselves. Suspicious objects such as flakes of white wool, cobwebs, black sooty deposits or rusty specks may indicate the presence of pests or the most common diseases of conifers. They are moderately dangerous and can be controlled with systemic insecticides and fungicides. But with one exception.

Carefully inspect the trunks and thick branches of the pine trees, especially near the whorls. Are there any holes on them, is there so-called drill flour under these holes - tiny brown shavings, is the bark falling off? If there is, the tree is most likely doomed to die, even though its shoots are alive and well. After all, these signs indicate the presence, perhaps, of the dangerous pest conifers - bark beetle. Such a spruce or pine tree must be cut down immediately and the bark must be removed from the log so that it does not become a breeding ground for new hordes of beetles.

On a nice summer day! Majestic coniferous trees with widely spread branches creating a cozy shade will not leave any lover of forest walks indifferent.

Coniferous plants are not only companions for a pleasant forest walk, but also full members of the plant community. Often, when passing by, people don’t even think about how much interesting things can be learned about this class of trees.

It's no secret that a person learns a significant part of the information about the world around him while sitting at his school desk. How is it being built now? educational process when children study the class coniferous plants?

What are conifers? How are they classified? modern science? How do children who are mastering the basic general education program of primary school get to know each other? general education with the conifer class? Answers to these questions, many other interesting facts, as well as beautiful photographs await the reader in the article.

What plants are called conifers?

Most people of all ages, religions, nationalities and political beliefs know that trees are divided into coniferous and deciduous. WITH deciduous trees all clear. They have leaves that form foliage. Branches with foliage, in turn, form the crown of trees. Particularly sophisticated people even know that the leaves of trees and plants participate in the process of photosynthesis, providing the planet Earth with oxygen and processing carbon dioxide.

But what about coniferous plants? Why are they called that? Can they, like their leafy counterparts, participate in the production of oxygen? Let's figure it out.

The name of the class "coniferous" comes from the word called modified leaves of plants that have an elongated narrow shape and a pointed end. If you interact unsuccessfully with tree needles, you can even puncture your hand or seriously damage your eyes.

Conifers are vascular plants. This means that the transport of nutrients and moisture within the tree occurs through a vascular system.

The next sign is woody. It should be understood as the presence of wood on a tree trunk. All are perennial.

Business card coniferous plants are that they are evergreen. Yes, some of them shed their leaves (for example, larch) once a year. Some plants, at the same time, change their “wardrobe” once every fifty years.

Another unique feature of conifers is the presence of a cone in which the seeds ripen. The cone plays a key role in the reproduction of these plants. Scientists have proven that some representatives of the Coniferous department can retain seeds in their cones for decades.

Most representatives of conifers have a straight trunk and branches going from it to different sides. A characteristic feature of many plants of this class are whorls - peculiar rings formed by branches extending from the main trunk of the tree. Counting the number of whorls on a tree trunk is one way to determine the age of a tree. Each ring of whorls corresponds to one year that has passed in the life of the tree. The straight trunk in the vast majority of cases ends with a pronounced crown.

An interesting feature of gymnosperms of the Coniferous class is that many of them begin to dry out from the crown. This is explained by the peculiar supply of nutrients along the tree trunk. Such problems with conifers can arise due to poor ecology. Another common cause is damage to the tree's root system or bark.

Conifer roots

Also unique. Most often, most of them retain the main root throughout their lives. Smaller roots extend from it, running almost along the surface of the earth. This arrangement of the root system is an advantage and disadvantage of such trees. On the one hand, in this way the plant can collect more nutrients due to a larger area of ​​soil coverage by the root system. On the other hand, such a structure of roots makes conifers extremely vulnerable to forest fires. It is not uncommon for entire hectares of forest to stand dead because the fire, which destroyed the small undergrowth, also destroyed the roots of the trees.

What kind of needles are there?

The length of the needles may vary depending on the specific tree species. Some specimens have giant needles, the length of which can reach up to thirty centimeters (for example, Engelmann pine). The smallest needles can reach a length of only three to six millimeters.

The needles of trees of the Coniferous class also differ in their hardness. Some species, such as larch, have soft and delicate needles, which are simply impossible to get damaged. Spruce trees, on the contrary, have tough needles that, if the circumstances are unfortunate, can even pierce clothing and human skin.

The needles of certain tree species are abundantly covered with special wax. This was done by prudent nature in order to protect the plant from excessive ultraviolet rays, which are destructive to it.

Young and mature needles also differ from each other. Young leaf-like organs of coniferous trees are softer than older ones. Old needles become rough to the touch. This is due to the fact that the special pores of the needles, which are responsible for the “breathing” of the plant, gradually become larger and begin to be felt to the touch.

Beneficial substances contained in needles

The needles of most plants of the Coniferous class have a sour taste (especially spruce needles) and are tart. This is due to the presence of a significant amount of amino acids there. When chewing the needles, a pulp is formed that does not disintegrate in the mouth. It is not recommended to constantly use pine needles for food, although they are not poisonous.

On the contrary, needles are often used for medicinal purposes. This is done due to the rich range of substances contained in it. Tree needles contain a lot of vitamins (vitamin C, vitamin P, vitamin K, as well as iron, cobalt and manganese).

Needles are one of the most popular sources of carotene (a substance found in large quantities in carrots). Its content reaches from one hundred fifty to three hundred milligrams per kilogram of needles.

How long ago did conifers appear on Earth?

Coniferous plants are very ancient. Perhaps even the most ancient of the higher plants on planet Earth.

Exhibits removed from the ground by archaeologists and paleobotanists are subjected to radiocarbon dating studies to determine the most accurate age of the fossil. As a result of such procedures, it was established that individual representatives of the Coniferous class existed on our planet already three hundred million years ago. Think about these numbers - three hundred million years ago! At this ancient time, there was not even a hint of man in nature, and the planet was inhabited by huge dinosaurs.

The discovery of scientists is of interest. According to research scientific community studying the history of this class of plants, a characteristic feature of ancient conifers was that among them there were many shrubs and even herbaceous plants. Now, unfortunately, most of them have died out, giving way to modern representatives of the Coniferous class.

Today, the vast majority of conifers are trees covered with durable bark and without herbaceous fibers.

Place of conifers in plant taxonomy

Each class of plants is systematized by scientists into a single system. Plants that have needles instead of foliage are no exception.

Conifers are quite simple and understandable. If we give a simple classification of conifers, it will look like this: eukaryotes, plants, conifers.

Domain Eukaryotes include organisms that have a cellular structure. In addition to plants, the records also include animals, fungi, protists and chromists.

The next level of classification is the kingdom. Conifers belong to the kingdom of Plants, as they answer all inherent characteristics. This includes the presence of a dense cellulose cell membrane, growth throughout life, the process of photosynthesis, and maintaining an attached lifestyle (they do not move independently).

Kingdoms are divided into divisions. The department we are interested in - Gymnosperms of the Coniferous class - is included here. It got its name because the plants included in this department do not have a seed coat.

Departments are divided into classes. The department of gymnosperms includes the classes Ginkgoaceae (the only representative is Ginkgo biloba), Cycadaceae, Gnetaceae, and finally Conifers. There were two other classes of gymnosperms - Bennettite and seed ferns, but today they are considered extinct.

How are conifers classified?

The Coniferous class, in turn, is also divided into several smaller classification levels. Let's look at the main ones.

A class in botany is conventionally divided into subclasses. The plant class Conifers is divided into the subclass Cordaitaceae (now extinct) and the subclass Conifers. Yes, that's not a typo. The names of the class and subclass are the same.

The subclass of conifers includes 6 (according to other classifications 7) plant families. They all form one order - Conifers (Pines). These include Pine, Araucariaceae, Cypress, Taxodiaceae, Podocarpaceae and Yew plants.

Each family is divided into genera, in which specific species are already distinguished. For example, let’s classify a plant, starting with class. For example, Scots pine. Class - Conifers. Subclass - Conifers. Order - Coniferous (Pine). Family - Pine. Rod - Pine. Species: Scots pine. Any coniferous plant lends itself to a similar classification.

Variety of species

In total, in the classification of plants there are from six hundred to six hundred and fifty species of the coniferous class. Their characteristics are similar in many ways, but they also have differences. Let's take a closer look at the coniferous trees often found in Russia!

One of the most common plants in Russian latitudes is spruce. This genus of plants is characterized by a high trunk and a lush, cone-shaped beautiful crown. A special property of this tree is the ability to live almost forever - the spruce is able to take living roots from a dead tree. There are more than thirty species of this gorgeous plant on the globe.

Pine is also very common in our country. Researchers have recorded more than a hundred species of pine trees, the vast majority of which grow in the northern hemisphere of the Earth. Feature pine trees - high resin content. If you go up and hug a tree, then with a high degree of probability your clothes will have to be cleaned.

The next representative of conifers found in Russia is larch. This tree exceeds forty meters in height and lives up to four hundred years. The peculiarity of larch is the shedding of needles on winter time. The tree's needles are soft and very pleasant to the touch.

Types of conifers depending on size and growth rate

In the scientific community, one of the classification systems for conifers is classification based on the annual growth of the tree. There are five types. The “fastest” plants add fifteen to twenty centimeters per year. The “slowest” are three to five centimeters.

World record holders

Interesting fact: Coniferous trees are “world champions in all categories.”

In the “Oldest Tree” category, Old Tikko, a pine tree in the mountains of Sweden, took the first step of the podium. According to the most conservative estimates of biologists, the age of the tree is more than nine and a half thousand years. The secret of Tikko's longevity is that he managed to take down living roots from a tree burned in a fire. These roots serve the owner to this day. By the way, second and third places are also occupied by representatives of the coniferous class. The age of these trees exceeds five thousand years, and they grew when there were no presidents, no kings, no Roman and Greek emperors, or most of the Egyptian pharaohs.

The tallest tree in the world is the Hyperion sequoia. A powerful tree with a straight trunk rises one hundred and fifteen meters above American forests. The height of the giant is comparable to a building of forty floors.

The most massive tree is also a conifer. "General Sherman" - a sequoiadendron from a national park in California - weighs a total of about two million kilograms. According to the calculations of practical Americans, up to forty houses with five rooms in each of them can be built from its wood. The second largest tree in the world is the "General Grant". This sequoiadendron is declared a US national shrine and a monument to fallen soldiers.

The place of conifers in the primary school educational program

With the entry into force of the federal state educational standard for primary general education, the school curriculum was also revised. The subject in which children get acquainted with living nature is called " The world". Children are allocated two hours a week to study it.

As part of their study of the subject “The World Around us”, the children get acquainted with coniferous trees. At the end of mastering the primary general education program, teachers often resort to a form of knowledge testing such as the “Coniferous Forest” dictation. In 4th grade, children know tree species and are able to talk about them. Another important evaluation criterion is determining the type of plant.

How is this topic taught at the beginning of training?

In the 1st grade, first-graders begin to study coniferous trees from the simplest. The teacher usually asks the children about their personal experience. Have any children been in the forest? What did they see there?

At the same time, it is very important to motivate the child to learn and create an educational situation. For the sake of achieving the teacher’s cherished goal primary classes often resort to various tricks: either they will place a letter from the Old Man Lesovich on their desk with an invitation to visit the Magic Forest, or they will be transported together with the class to unknown paths in Baba Yaga’s mortar. The main thing is that the child has interested eyes.

Study of conifers by second graders

In the subject "The World around us" 2nd grade studies coniferous plants in more detail. The children begin to get acquainted with the most common families and learn to distinguish their characteristic features from photographs. As part of the study of coniferous forests in 2nd grade, the teacher is also tasked with instilling in children a careful and caring attitude towards nature.

To create educational situations, the technique of asking riddles is often used, which is very effective in elementary schools. In 2nd grade, children can ask many different interesting riddles about coniferous plants. For example, "On New Year Everyone is happy with her, even though her outfit is prickly" (answer - spruce). This method achieves two results at once: the child’s attention is concentrated and an educational situation arises.

The system authored by Zankov is especially popular in elementary schools. Conifers and flowering plants Grade 2 is studied using interactive techniques. The class teacher often asks children to prepare reports on given topics. After preparing a report, you must present it in front of the class to convey the information to other children. Important point- teach children to listen to others, be able to formulate and ask good and interest Ask, keep the discussion going. This approach instills in students the ability to speak in front of an audience and communication skills. Children learn to argue and defend their position, and to advantageously present the results of their work.

Conifers and flowering plants for grade 2 are an excellent opportunity to distribute reports about various types such plants. The entire lesson can be structured according to this principle, and it will be highly effective.

Leonid Vladimirovich Zankov is a Russian psychologist who proposed a unique training system in the mid-nineties. The hallmark of the system is its humanitarian nature and the personal development of children. Working according to such a system requires high skill and professionalism from the teacher.

What new things will children learn about conifers in the third year of study?

In grade 3, coniferous plants also continue to be studied. Children get to know them in more detail, touch on representatives of conifers in their region, and study the characteristics and features of some species. The teacher begins to build with the students the simplest food chains in which conifers are involved.

As current control knowledge of students, teachers often conduct simple tests for grade 3 on coniferous trees. This method allows you to quickly assess the class’s mastery of the material covered, identify children who have poorly mastered the information, and focus on working with them. extra attention.

At the final stage of primary school

In the 4th grade, when children complete their mastery of the basic educational program primary general education, more complex methods of working with children are used. One of these methods can be called project activities. The essence is the distribution (or choice at will) among students or groups of students of topics for developing a project. This approach allows not only to develop the individual qualities of children, but also to teach them to work in a team, which is very important. After preparing the project, as with reports, they are defended.

Conclusion

Now the reader has discovered new facts about gymnosperms of the Coniferous class, which will help him take a fresh look at conifers when he encounters them, and classify them according to the generally accepted system. It is important to treat these plants with care, since, being evergreen, they all year round produce oxygen and absorb carbon dioxide. Thanks to conifers, the air on our planet is becoming cleaner.

Conifers are the most important representatives of the gymnosperm subdivision. They are characterized by monopodial branching and open arrangement of ovules on macrosporophylls, or seed scales; sometimes the ovules sit at the ends of the shoots. The coniferous class includes 7 families. The most important families for our country are: Pine (Pinaceae), Yew (Tachaseae) and Cypress (Cupressaceae). The pine family includes four genera of tree species growing wild in the USSR: pine (Pinus), larch (Larix), spruce (Picea) and fir (Abies), and among the introduced ones - the genus Pseudotzuga.

In most species of conifers, the leaves (needles) are needle-shaped, linear or scale-like; they persist on plants for several years. In the genus larch, the needles fall off annually and develop again in the spring.

Conifers have “flowers” ​​in the form of spikelets and cones. Male (anther) spikelets and female cones are formed at the ends of shoots or in the axils of leaves (needles). Stamens with two, less often with big amount anthers. Pollen has two air sacs, allowing it to spread in the air over considerable distances. Sometimes there are no air sacs (in larch), and pollen travels a short distance from the crown. Female cones - with numerous megasporophylls (seed scales), incorrectly called carpels, sometimes several, less often without them. The ovary is absent. Therefore, there is no real fruit. In species that do not form cones (yew), the ovule sits at the end of the shoot, and the seeds are surrounded by a fleshy periosperm.

Most coniferous seeds have wings, which facilitates the dispersal of seeds over considerable distances. However, species with wingless seeds are known (cedar pines), the distributors of which are birds and some animals. Coniferous seeds ripen in the fall in the year of flowering or in the second, less often, third year after flowering. In some species, seeds spill out of the cones soon after they ripen, but in most species they remain in the cones until the spring of next year, and then gradually spill out of the cones.

The germination rate of seeds in many species is usually high and, if properly stored, lasts for several years. The embryo usually has from 2 to 15 cotyledons.

Coniferous wood, excluding primary wood, is without vessels and consists of tracheids. The growth layers (rings) are clearly visible.

Value coniferous species growing in our forests is exceptionally large. Coniferous forests occupy about 77% of the total forested area Soviet Union. They provide the most valuable for many industries National economy timber and many other forest products.

Cossack juniper (J. sabina L.) Cone berries with a diameter of 5-7 mm, mature brown-black, with a bluish bloom, ripen in the fall in the second year after flowering. Undemanding to soil. Grows on sands and rocky mountain slopes. Frost-resistant. Very light-loving and drought-resistant. It has great soil protection and agroforestry significance. It has long been used to consolidate loose sand in Central Asia. Wood can be used for fuel. Propagated by seeds, layering and cuttings. Since needles, branches and cone berries contain essential poisonous oil, growing Cossack juniper in public parks and gardens is not recommended.

Genus Thuja (Thuja Tourn.)

A genus of trees and shrubs of the thuja subfamily with scale-like, cross-opposite needles and flat, flattened shoots. Male spikelets are apical, small, round, located in the axils of the needles. Female spikelets are terminal, each scale, except the upper pair, with 1-2 ovules. The cones are small, up to 10 mm long, elongated oval, with 3-6 pairs of scales arranged crosswise, ripen in the fall in the year of flowering and fall off after the seeds open and fly out. The seeds are small, oval, dipterous. Shoots with two cotyledons. The primary needles are needle-shaped. Propagated by seeds, in garden culture and cuttings. Tolerates haircuts well.

Most prosperous group of plants forms seeds. These plants apparently descended from extinct seed ferns and their close relatives. The taxonomy and main characteristics of seed plants are summarized in the table.

The table discusses two main seed plant groups- gymnosperms and . The latter are often called flowering plants. In gymnosperms, ovules (and subsequently seeds) are located on the surface of special scaly leaves called megasporophylls or seed scales. These scales are collected in cones. In angiosperms, the ovules, and therefore the seeds, are enclosed in special structures, i.e. better protected.

Division Coniferophyta. Conifers. Signs of conifers.

Basic characters of Coniferophyta summarized in the table.

Conifers (gymnosperms) - a thriving group of plants distributed throughout to the globe; they account for approximately one third of all forests on the planet. These are trees and shrubs, mostly evergreen with needle-shaped leaves. The overwhelming number of species live in high latitudes and spread northward further than all other trees.

Conifers have great economic importance as “soft wood”, used not only for the production of timber and lumber, but also for the production of resin, turpentine and wood pulp. Conifers include pines, larches (with leaves that fall in winter), fir, spruce and cedar. A typical representative of conifers is Scots pine (Pinus syl-vestris).

Conifers are common throughout central and northern Europe, former USSR And North America. It was introduced into Great Britain, but grows naturally only in Scotland. This beautiful, stately tree, up to 36 m tall, with its characteristic peeling pinkish or yellowish-brown bark, is grown for both ornamental purposes and for lumber and timber.

Pines most often grow on sandy or poor mountain soils, and therefore root system they usually spread out in the surface layers of the soil and are heavily branched. The appearance of the pine is shown in Fig. 2.39.

Every year from whorls of lateral buds a new whorl of branches grows at the top of the trunk. The characteristic conical appearance of pine and other conifers is due to the fact that whorls of shorter (younger) branches at the top are gradually replaced by increasingly longer (older) ones. With age, the lower branches die and fall off; therefore, the crown of old trees usually remains only at the top.