Young spruce undergrowth standing separately is called. Trees in the life of the ancient Slavs. Age structure as an indicator of the state of adolescence

Let us imagine a forest capable of bearing fruit. The crowns of the trees are closed into a dense canopy. Silence and twilight. Somewhere high above, seeds are ripening. And so they ripened and fell to the ground. Some of them, finding themselves in favorable conditions, sprouted. So he appeared in the forest forest regrowth- young generation of trees.

What conditions do they find themselves in? The conditions are not very favorable. There is not enough light, there is not enough space for the roots, everything is already occupied by the roots of large trees. But we have to survive, to win.

Young generation of the forest

Young generation of the forest, replacing the old one, is important for renewal. Naturally, existing in harsh conditions, with a lack of light and a constant lack of nutrients in the soil, the undergrowth does not look good. A common feature of adolescence is severe depression. Here is an example of such oppression. Spruce undergrowth, only one and a half meters high, can have a fairly respectable age - 60 and even 80 years. Over the same years, fellow juveniles, grown from the same seeds somewhere in a nursery or near a forest, can reach a height of 15 meters. It is very difficult for a teenager to exist. But he nevertheless adapts to the living conditions under the maternal canopy and patiently waits for changes in his living conditions.

It depends on your luck: either the mature trees will die or the young trees will die. It also happens that people interfere in this fight by choosing ripe trees for their needs. The regrowth then recovers and subsequently becomes new forest.

Particularly tenacious spruce undergrowth. In a depressed state, he sometimes lives almost half of his life, up to 180 years. One cannot help but admire his vitality and boundless adaptability, which, however, is understandable.

You have to be very careful with teenagers.. Without knowing his specific growth, driven by the most noble motives - to give him freedom, we can nevertheless destroy him. Living in dim light and suddenly receiving the long-awaited freedom from inexperienced hands, he unexpectedly dies. As they say, a teenager is “scared” of light. The needles quickly turn yellow and fall off, because they are adapted to a different mode of operation, to different living conditions. On the other hand, a teenager suddenly exposed to freedom may die of thirst. Not because there is not enough moisture in the soil. Maybe there is even more of it there, but with its poorly developed roots and needles the undergrowth cannot quench its thirst,

What's the matter? But the fact is that previously, under the mother’s canopy in a humid atmosphere, the young shoots had enough moisture. Now the wind has begun to blow around, the physiological evaporation of the undergrowth has increased, and the pitiful crown and root system are unable to supply the tree with a sufficient amount of moisture.

Of course, earlier parent trees oppressed and suppressed young growth, but at the same time they protected them from the wind and from frost, to which young spruce, fir, oak, and beech are so sensitive; protected from excessive solar radiation and created a soft, humid atmosphere.

This word is “puppeteer”, which is explained quite simply. Everything associated with the word “doll” is associated with something small associated with the younger generation, so a word has been chosen for “children.”

A little information about the “teenager”:

The word "teenager" itself denotes a generation young trees that have grown either in the forest itself under the canopy of older trees, or in an empty place - these can be cut down or burnt areas.

Based on their age, undergrowth trees are classified as young trees.

The practical significance of “undergrowth” is quite significant: it is areas with young trees that can become the basis of a new forest area.

People have long understood the importance of such “undergrowth” for the conservation of forests. Therefore, in addition to natural areas with young trees, you can also find artificial ones, that is, specially planted ones; more often, combined ones are found. Experts evaluate the quality indicators, species, density of existing natural regrowth in terms of the number of trees per certain unit of area and plant new specimens, bringing the density of plantings to the established optimal norm and thereby laying the foundation for new tiers of the forest.

In addition to monitoring undergrowth, forestry specialists use a number of practical measures to promote the proper formation of the forest, for example, various types of felling, which have their own purpose and specificity.

480 rub. | 150 UAH | $7.5 ", MOUSEOFF, FGCOLOR, "#FFFFCC",BGCOLOR, "#393939");" onMouseOut="return nd();"> Dissertation - 480 RUR, delivery 10 minutes, around the clock, seven days a week and holidays

Gutal Marko Milivojevic. Viability and structure of spruce undergrowth under the canopy of tree stands and in clearings: dissertation... Candidate of Agricultural Sciences: 06.03.02 / Gutal Marko Milivoevich; [Place of defense: St. Petersburg State Forestry University named after S.M. Kirov http://spbftu.ru/science/sovet/D21222002/dis02/].- St. Petersburg, 2015.- 180 p.

Introduction

1 Problem status 9

1.1 General information about spruce phytocenoses 9

1.2 Spruce juvenile 11

1.2.1 Features of the age structure of spruce undergrowth 12

1.2.2 Features of the light regime under the canopy of spruce forests 16

1.2.3 Viability of spruce undergrowth 22

1.2.4 Number of spruce undergrowth 25

1.2.5 Influence of forest type on spruce regrowth 27

1.2.6 Features of the development of spruce undergrowth under the canopy 30

1.2.7 Influence of vegetation of lower tiers on spruce regrowth 33

1.2.8 The influence of economic activities on spruce juveniles 35

2 Research program and methodology 39

2.1 Research program 39

2.2 Study of forest phytocenosis by structural elements 40

2.2.1 Determination of the main characteristics of the forest stand 40

2.2.2 Accounting for teenagers 41

2.2.3 Accounting for undergrowth and living ground cover 46

2.2.4 Determination of biometric indicators of needles 49

2.3 Research objects 51

2.4 Scope of work performed 51

3 Dynamics of the condition of spruce undergrowth under the canopy .

3.1 Dynamics of the vital state of spruce undergrowth based on the results of long-term studies 53

3.2 Patterns of changes in the viability of spruce undergrowth in connection with the type of forest 69

3.3 Influence of the maternal canopy on the dynamics of the state and structure of spruce undergrowth

3.4 Relationship between the viability of spruce undergrowth and the value of average growth over a period of 3, 5 and 10 years.

3.5 Age structure as an indicator of the state of adolescence 86

3.6 Structure according to the height of undergrowth as an indicator of condition 89

3.7 Comparative analysis of the state and structure of spruce undergrowth in the spruce forests of the Lisinsky and Kartashevsky forest districts 93

4 The influence of economic activities on the number and viability of spruce undergrowth

4.1 The influence of thinning on the dynamics of viability of spruce undergrowth 105

4.2 Thinning the undergrowth - as a measure to promote the natural regeneration of spruce 122

5 Dynamics of the state of spruce undergrowth in the felling area 127

5.1 Features of the structure and condition of spruce undergrowth 127

5.2 Dependence of the dynamics of the state of spruce undergrowth on the recency of felling 134

6 Biometric characteristics of needles as an indicator of the viability of spruce undergrowth

6.1 Biometric indicators of needles under the canopy and in cuttings 140

6.2 Biometric indicators of needles of viable and non-viable spruce undergrowth.

Bibliography

Features of the light regime under the canopy of spruce forests

Spruce is one of the main forest-forming species in the Russian Federation, occupying fourth place in terms of area, second only to larch, pine and birch. Spruce grows from the tundra to the forest-steppe, but it is in the taiga zone that its forest-forming and edificatory role is most manifested. The genus spruce (Picea Dietr.) belongs to the pine family (Pinacea Lindl.). Individual representatives of the spruce genus date back to the Cretaceous period, that is, 100-120 million years ago, when they had one common habitat on the Eurasian continent (Pravdin, 1975).

Norway spruce or common spruce (Picea abies (L.) Karst.) is widespread in northeastern Europe, where it forms continuous forests. In Western Europe, coniferous forests are not a zonal vegetation type, and vertical differentiation occurs there. The northern border of the range in Russia coincides with the forest border, and the southern border reaches the black earth zone.

Norway spruce is a tree of the first size with a straight trunk, a cone-shaped crown and not strictly whorled branching. The maximum height reaches 35-40 meters in flat conditions, and in the mountains there are specimens up to 50 m high. The oldest known tree was 468 years old. However, age over 300 years is very rare, and in the zone of coniferous-deciduous forests it decreases to 120-150 (180) years (Kazimirov, 1983).

Norway spruce is characterized by relatively high plasticity of the root system, capable of adapting to various soil conditions. The root system is most often superficial, but on well-drained soils relatively deep vertical branches often develop (Shubin, 1973). The trunk of the Norway spruce is full wood, covered with relatively thin green-brown, brown or gray bark. The bark of the common spruce is smooth, but with age it becomes scaly and furrowed.

Growth buds are small - from 4 to 6 millimeters, ovoid-conical, red with dry scales. Reproductive buds are larger and reach 7-10 millimeters.

The needles of the common spruce are tetrahedral, sharp, dark green, hard, shiny, up to 10-30 mm long and 1-2 millimeters thick. It stays on shoots for 5-10 years and falls throughout the year, but most intensively from October to May.

Norway spruce blooms in May–June. The cones ripen in the fall of the following year after flowering, the seeds fall in late winter and early spring of the following year. Male spikelets of elongated cylindrical shape are located on the shoots of the previous year. The cones are spindle-shaped, cylindrical, 6 to 16 cm long and 2.5 to 4 centimeters in diameter, located at the ends of the branches. Young cones are light green, dark purple or pinkish, while mature ones take on a different shade of light brown or red-brown. Mature cones contain from 100 to 200 seed scales on the stem. Seed scales are lignified, obovate, entire, finely serrated along the upper edge, notched. Each seed scale contains 2 seed cavities (Kazimirov, 1983). The seeds of the common spruce are brown in color, relatively small, 3 to 5 millimeters long. Weight of 1000 seeds is from 3 to 9 grams. Seed germination varies from 30 to 85 percent depending on growing conditions. Growing conditions also determine the presence of repetition of productive years, which occur on average every 4-8 years.

Norway spruce is a species that grows over a relatively large area, in different soil and climatic conditions. As a result, Norway spruce is distinguished by high intraspecific polymorphism (in the type of branching, color of cones, crown structure, phenology, etc.), and therefore by the presence of a large number of ecotypes. In relation to air temperature, the common spruce is thermophilic, but at the same time it is a cold-resistant species, growing in a zone of temperate and cool climates with an average annual temperature of -2.9 to +7.4 degrees and the temperature of the warmest month of the year from +10 to +20 degrees (Chertovskoy, 1978). The distribution range of Norway spruce ranges from 370 to 1600 mm of precipitation per year.

The issue of soil moisture is closely related to its aeration. Although common spruce is capable of growing in conditions of excess moisture, good productivity should be expected only in cases where there is running water. On damp soils, spruce falls out at a speed of 6-7 meters per second, and on fresh and dry soils it can withstand wind flows at a speed of 15 meters per second. Wind speeds of more than 20 meters per second cause a massive fall.

The most intensive growth of common spruce occurs on sandy and loamy soils, underlain at a depth of 1-1.5 meters by clays or loams. It should be noted that there are no strict rules for the requirements for soil composition and mechanical composition as such, since the requirements of spruce for soil are of a zonal nature. Norway spruce has a high tolerance threshold to soil acidity and is able to grow at pH fluctuations from 3.5 to 7.0. Norway spruce is relatively demanding in terms of mineral nutrition (Kazimirov, 1983).

Accounting for undergrowth and living ground cover

The heterogeneity of the qualitative and quantitative characteristics of adolescents is expressed, first of all, through the concept of adolescent viability. The viability of adolescents according to the Encyclopedia of Forestry (2006) is the ability of the younger generation of maternal adolescents to exist and function in changing environmental conditions.

Many researchers, such as I.I. Gusev (1998), M.V. Nikonov (2001), V.V. Goroshkov (2003), V.A. Alekseev (2004), V.A. Alexeyev (1997) and others noted that the study of the qualitative parameters of spruce forests, by and large, comes down to studying the condition of the stands.

The state of the tree stand is a consequence of the complex processes and stages through which the plant passes from its primordium and seed formation to its transition to the dominant tier. This long process of plant metamorphosis requires division into various stages, each of which must be studied in a separate order.

Thus, it can be stated that relatively little attention is paid to the concept of vitality and state of the undergrowth (Pisarenko, 1977; Alekseev, 1978; Kalinin, 1985; Pugachevsky, 1992; Gryazkin, 2000, 2001; Grigoriev, 2008).

Most researchers claim that there is a sufficient amount of viable spruce undergrowth under the canopy of mature forest stands, but most often the interdependence of the state of the undergrowth and its spatial distribution with the characteristics of the maternal tree stand is not revealed.

There are also researchers who do not claim that under the canopy of the maternal tree stand there should be viable undergrowth capable of fully replacing the mother tree stand in the future (Pisarenko, 1977; Alekseev, 1978; Pugachevsky, 1992).

Fluctuations in height and group distribution of spruce undergrowth allowed some authors to argue that spruce undergrowth as a whole is not capable of providing preliminary regeneration under the condition of intensive logging operations (Moilanen, 2000).

Another study by Vargas de Bedemar (1846) established that the number of trunks sharply decreases with age, and that of the sprouted seedlings, in the process of natural selection and differentiation, only about 5 percent are preserved to the age of ripeness.

The process of differentiation is most pronounced in the “youth” of the planting, where the oppressed classes are distinguished to the greatest extent by status, and gradually takes over the “old age”. According to G.F. Morozov, who refers to earlier works by Ya.S. Medvedev (1910) in this direction, a common feature of undergrowth growing in a plantation is depression. Evidence of this is the fact that at the age of 60-80 years, spruce undergrowth under a canopy very often does not exceed 1-1.5 m, while spruce undergrowth in the wild at the same age reaches a height of 10-15 meters.

However, G.F. Morozov (1904) notes that the productivity and productivity of individual specimens of undergrowth can change for the better, as soon as the environmental conditions change. All specimens of undergrowth, of varying degrees of depression, differ from undergrowth in the wild in the morphological characteristics of the vegetative organs, incl. fewer buds, a different crown shape, a poorly developed root system, and so on. Such morphological changes in spruce, such as the formation of an umbrella-shaped crown developing in a horizontal direction, are an adaptation of the plant to the most efficient use of the “scarce” light penetrating to the undergrowth. Studying cross-sections of the stems of spruce undergrowth growing in the conditions of the Leningrad District (Okhtinskaya Dacha), G.F. Morozov noted that in some specimens the annual layers were densely closed at the initial stage of life (which indicates the degree of oppression of the plant), and then sharply expanded as a result of some forestry measures (in particular thinning), changing environmental conditions.

The spruce undergrowth, abruptly finding itself in an open space, also dies from excessive physiological evaporation due to the fact that in open areas this process occurs with greater activity, to which the undergrowth growing under the canopy is not adapted. Most often, this teenager dies as a result of a sharp change in the situation, but, as G. F. Morozov noted, in some cases, after a long struggle, he begins to recover and survives. The ability of a young plant to survive in such circumstances is determined by a number of factors, such as the degree of its oppression, the degree of severity of changes in environmental conditions, and, of course, biotic and abiotic factors affecting the growth and development of the plant.

Individual specimens of undergrowth often vary greatly within the same massif in such a way that one specimen of undergrowth, marked before felling as nonviable, recovered, while another remained in the category of nonviable. Spruce regrowth, formed on fertile soils under the canopy of birch or pine, often does not respond to the removal of the upper tier, because did not experience light deficiency even in its presence (Cajander, 1934, Vaartaja, 1952). After a buffer period of adaptation, the height growth of undergrowth increases many times, but small undergrowth requires more time for the functional restructuring of vegetative organs (Koistinen and Valkonen, 1993).

Indirect confirmation of the fact of the expressed ability of spruce undergrowth to change the category of condition for the better was given by P. Mikola (1966), noting that a significant part of rejected spruce forests (based on the state of undergrowth), in the process of forest inventory in Finland, was later recognized as suitable for forest growing.

Age structure as an indicator of the state of adolescence

Depending on the structure of the planting, from 3 to 17 percent of photosynthetic active radiation can penetrate under the canopy of spruce forests. It should also be noted that as edaphic conditions worsen, the degree of absorption of this radiation decreases (Alekseev, 1975).

The average illumination in the lower tiers of spruce forests in blueberry forest types most often does not exceed 10%, and this, in turn, on average provides the minimum energy for annual growth, which ranges from 4 to 8 cm (Chertovskoy, 1978).

Research in the Leningrad region, conducted under the direction of A.V. Gryazkina (2001) show that the relative illumination on the soil surface under the canopy of tree stands is 0.3-2.1% of the total, and this is not enough for the successful growth and development of the young generation of spruce. These experimental studies showed that the annual growth of the young generation of spruce increases from 5 to 25 cm with an increase in light penetrating under the canopy from 10 to 40%.

Viable spruce undergrowth in the overwhelming majority of cases grows only in the windows of the canopy of a spruce stand, since in the windows the spruce undergrowth does not experience a lack of light, and besides, the intensity of root competition there is much lower than in the near-trunk part of the stand (Melekhov, 1972).

V.N. Sukachev (1953) argued that the death of undergrowth is largely determined by root competition of mother trees, and only then by light deficiency. He supported this statement by the fact that in the very early stages of a teenager’s life (the first 2 years) “there is a strong decline of spruce regardless of the light.” Authors such as E.V. Maksimov (1971), V.G. Chertovsky (1978), A.V. Gryazkin (2001), K.S. Bobkova (2009) and others question such assumptions.

According to E.V. Maksimov (1971), undergrowth becomes unviable when illumination is from 4 to 8% of full. Viable undergrowth is formed in the gaps between the crowns of mature trees, where illumination averages 8-20%, and is characterized by light needles and a well-developed root system. In other words, viable undergrowth is confined to gaps in the canopy, and strongly suppressed undergrowth is located in the zone of dense closure of the upper tiers (Bobkova, 2009).

V.G. Chertovskoy (1978) also claims that light has a decisive influence on the viability of spruce. According to his arguments, in medium-density stands, viable spruce regrowth usually accounts for more than 50-60% of the total. In tightly closed spruce forests, nonviable undergrowth predominates.

Research in the Leningrad region showed that the lighting regime, i.e. The canopy closeness determines the proportion of viable undergrowth. When the canopy density is 0.5-0.6, undergrowth with a height of more than 1 m predominates. In this case, the proportion of viable undergrowth exceeds 80%. When the density is 0.9 or more (relative illumination less than 10%), viable undergrowth is most often absent (Gryazkin, 2001).

However, other environmental factors should not be underestimated, such as soil structure, soil moisture, and temperature conditions (Rysin, 1970; Pugachevsky, 1983; Haners, 2002).

Although spruce is a shade-tolerant species, spruce undergrowth in high-density plantings still experiences great difficulties in low light conditions. As a result, the quality characteristics of undergrowth in dense plantations are noticeably worse compared to undergrowth growing in medium-density and low-density plantations (Vyalykh, 1988).

As the spruce tree grows and develops, the threshold of tolerance to low light decreases. Already at the age of nine years, the need for light in spruce trees increases sharply (Afanasyev, 1962).

The size, age and condition of the undergrowth depend on the density of forest stands. Most mature and overmature coniferous plantations are characterized by different ages (Pugachevsky, 1992). The largest number of juvenile specimens is found at a density of 0.6-0.7 (Atrokhin, 1985, Kasimov, 1967). These data are confirmed by the research of A.V. Gryazkina (2001), who showed that “optimal conditions for the formation of viable undergrowth with a population of 3-5 thousand individuals/ha are formed under the canopy of tree stands with a density of 0.6-0.7.”

NOT. Dekatov (1931) argued that the main prerequisite for the appearance of viable spruce regrowth in the sorrel forest type is that the completeness of the maternal canopy is in the range of 0.3-0.6.

Viability, and therefore growth in height, is largely determined by the density of the planting, as evidenced by the research of A.V. Gryazkina (2001). According to these studies, the increase in non-viable undergrowth in sorrel spruce forests with a relative stand density of 0.6 is the same as the increase in viable undergrowth when the sorrel spruce forest density is 0.7-0.8.

In blueberry-type spruce forests, with increasing stand density, the average height of undergrowth decreases and this dependence is close to a linear relationship (Gryazkin, 2001).

Research by N.I. Kazimirova (1983) showed that in lichen spruce forests with a density of 0.3-0.5, spruce undergrowth is rare and qualitatively unsatisfactory. The situation is completely different with sorrel forests, and especially with lingonberry and blueberry forest types, where, despite the high density, there is a sufficient amount of undergrowth that is satisfactory in terms of vital condition.

Dependence of the dynamics of the state of spruce undergrowth on the recency of felling

As the relative density of the tree stand increases, the proportion of medium and large viable spruce undergrowth also increases, since competition for light in such a closed canopy most affects the small undergrowth. With a high stand density, the proportion of non-viable small spruce undergrowth is also very large. However, this proportion is significantly larger when the relative density is low, since in such light conditions competition increases, from which small juveniles primarily suffer.

With an increase in the relative density of the forest stand, the share of small non-viable undergrowth changes as follows: at low density, the share of small non-viable undergrowth is greatest, then it falls and reaches a minimum at a density of 0.7, and then increases again with increasing density (Figure 3.40).

The distribution of spruce undergrowth by condition and size categories confirms that the life potential of undergrowth grown in the conditions of the Lisinsky forestry is greater than that of spruce undergrowth in the Kartashevsky forestry. This is especially clearly seen in the altitudinal structure of the undergrowth, since the proportion of medium and large spruce undergrowth is, as a rule, greater at the Lisisinsky sites under similar forest conditions (Figures 3.39-3.40).

The better life potential of spruce undergrowth at the Lisinsky sites is also evidenced by the growth rates of undergrowth, which are shown in Figures 3.41-42. For each age group, regardless of life state, the average height of spruce undergrowth at the Lisinsky sites is greater than the average height of undergrowth grown in the conditions of the Kartashevskoe forestry. This once again confirms the thesis that in relatively less favorable environmental conditions (in terms of soil moisture and fertility - closer to the blueberry type of forest), spruce young trees are more able to demonstrate their competitive abilities. It follows that changes occurring in the canopy as a result of anthropogenic or other impacts give a more positive result in the context of improving the condition of spruce undergrowth in the conditions of Lisinsky rather than Kartashevsky forestry.

1. At each stage of development, the number of undergrowth, as well as the structure in height and age in the experimental plots, change in different directions. However, a certain pattern has been identified: the more the number of undergrowth changes (after fruitful seed years it increases sharply), the more the structure of undergrowth changes in height and age. If, with an increase in the number of undergrowth due to self-seeding, a significant decrease in the average height and average age occurs, then with a decrease in the number as a result of mortality, the average height and average age can increase - if predominantly small undergrowth goes into decline, or decrease - if predominantly large undergrowth goes into decline teenager

2. Over 30 years, the number of undergrowth under the canopy of the sorrel spruce and blueberry spruce forests has changed; in this component of the phytocenosis, the change of generations is continuous - the main part of the older generation goes into decline, and the undergrowth of new generations regularly appears, and first of all, after a bountiful seed harvest.

3. Over three decades, the composition of undergrowth at the observation sites has changed significantly, the share of deciduous trees has increased markedly and reached 31-43% (after cutting). At the beginning of the experiment it did not exceed 10%.

4. In section A of the ecological station, the number of spruce undergrowth increased by 2353 specimens over 30 years, and taking into account the surviving model specimens, the total number of spruce undergrowth by 2013 amounted to 2921 specimens/ha. In 1983 there were a total of 3049 specimens/ha.

5. Over three decades, under the canopy of the blueberry spruce and sorrel spruce forests, the share of undergrowth that moved from the “nonviable” category to the “viable” category was 9% in section A, 11% in section B and 8% in section C, i.e. on average about 10%. Based on the total number of undergrowth on the experimental plot of 3-4 thousand/ha, this proportion is significant and deserves attention when carrying out accounting work when assessing the success of natural regeneration of spruce in the indicated forest types. 103 6. From the category “viable” to the category “non-viable” over the specified period of time, from 19 to 24% moved, and immediately from the category “viable” to the category “dry” (bypassing the category “non-viable”) - from 7 to 11%. 7. Of the total amount of growing undergrowth in section A (1613 specimens), 1150 specimens of undergrowth of different heights and different ages were lost, i.e. about 72%. In section B – 60%, and in section C – 61%. 8. During observations, the proportion of dry undergrowth increased with increasing height and age of the model specimens. If in 1983-1989. it accounted for 6.3-8.0% of the total amount, then by 2013 dry undergrowth already accounted for from 15 (blueberry spruce forest) to 18-19% (sorrel spruce forest). 9. Of the total number of certified undergrowth in section A, 127 specimens became trees of oversized size, i.e. 7.3%. Of these, the majority (4.1%) are those specimens that moved in different years from the “non-viable” category to the “viable” category. 10. Repeated recording of the same specimens of spruce undergrowth over a long period of time allows us to indicate the main reasons for transitions from the “non-viable” category to the “viable” category. 11. Changes in the structure of undergrowth in height and age, fluctuations in numbers are a dynamic process in which two mutually opposite processes are simultaneously combined: the decline and arrival of new generations of undergrowth. 12. Transitions of adolescents from one category of condition to another, as a rule, occur more often among small adolescents. The younger the teenager is, the more likely a positive transition is. If during the first 6 years of observation, about 3% of specimens moved from the “VF” category to the “F” category. (with the average age of a teenager being 19 years), then after 20 years - less than 1%, and after 30 years - only 0.2%. 13. The dynamics of the state of undergrowth is also expressed by forest type. The transition of non-viable undergrowth to the “viable” category is more likely in the blueberry spruce forest than in the sorrel spruce forest.

TEENAGE

Young trees that appear naturally in the forest are called undergrowth. They grew from seeds that fell on the surface of the soil. However, not every tree is classified as undergrowth, but only relatively large ones - from one to several meters in height. Smaller trees are called seedlings or self-seeding.

Undergrowth, as we know, does not form a separate layer in the forest. However, it is located mostly at the level of the undergrowth, although sometimes higher. Individual specimens of undergrowth can vary greatly in height - from short to relatively large.

There is almost always some amount of undergrowth in the forest. Sometimes there is a lot of it, sometimes there is little. And it is often located in small clusters, clumps. This happens especially often in an old spruce forest. When you come across such a clump in the forest, you notice that it develops in a small clearing, where there are no trees. The abundance of undergrowth is explained by the fact that there is a lot of light in the clearing. And this favors the emergence and development of young trees. Outside the clearing (where there is little light), young trees are much less common.

Small clusters are also formed by oak undergrowth. But this is noticeable in the case when mature oaks are found in the forest alone among the total mass of other trees, for example, birches and spruces. The arrangement of young oak trees in groups is due to the fact that acorns do not spread to the sides, but fall directly under the mother tree. Sometimes young oak trees can be found in the forest very far from the mother trees. But they do not grow in groups, but one at a time, since they grew from acorns brought by a jay. The bird stores acorns, hiding them in moss or litter, but then does not find many of them. These acorns give rise to young trees located very far from adult fruit-bearing oaks.

In order for regrowth of a particular tree species to appear in the forest, a number of conditions are necessary. It is important, first of all, that the soil receives seeds and, moreover, benign ones that are capable of germinating. There must, of course, be favorable conditions for their germination. And then certain conditions are required for the survival of the seedlings and their subsequent normal growth. If some link is missing in this chain of conditions, then the undergrowth does not appear. This happens, for example, when conditions for seed germination are unfavorable. Imagine that some small seeds fell on a thick layer of litter. They will first begin to germinate, but then die. Weak roots of seedlings will not be able to break through the litter and penetrate into the mineral layers of the soil, from where plants take water and nutrients. Or another example. In some area of ​​the forest there is too little light for the normal development of undergrowth. Shoots appear, but then die from shading. They do not survive to the teenage stage.

In the forest, only a very small proportion of seeds that fall to the ground give rise to seedlings. The vast majority of seeds die. The reasons for this are different (destruction by animals, decay, etc.). But even if seedlings have appeared, not all of them subsequently turn into regrowth. A lot can interfere with this. It is not surprising that our trees produce huge quantities of seeds (for example, birch many millions on one hectare). After all, only with such a strange, at first glance, extravagance is it possible to leave offspring.

In a forest, it often happens that one species dominates in the tree layer, and a completely different species dominates in the undergrowth. Pay attention to many of our pine forests that are quite old. There is absolutely no pine undergrowth here, but spruce undergrowth is very abundant. Often young fir trees form dense thickets over a large area in a pine forest. Young pine trees are absent here for the reason that they are very light-loving and cannot withstand the shading that is created in the forest. In nature, pine regrowth usually appears en masse only in open places, for example, on fires, abandoned arable lands, etc.

The same discrepancy between mature trees and young trees can be observed in many birch forests located in the taiga zone. Birch grows in the upper tier of the forest, and beneath it there is dense, abundant spruce growth.

Under favorable conditions, the undergrowth eventually turns into mature trees. And these trees of natural origin are more valuable from a biological point of view than those grown artificially (by sowing seeds or planting seedlings). Trees that have grown from undergrowth are best adapted to local natural conditions and are most resistant to a variety of adverse environmental influences. In addition, these are the strongest specimens that have survived the harsh competition that is always observed between trees in the forest, especially at a younger age.

So, undergrowth is one of the important components of the forest plant community. Under favorable conditions, young trees can replace old, dead trees. This is exactly what happened in nature for many centuries and millennia, when the forest was little affected by humans. But even now, in some cases, it is possible to use undergrowth for the natural restoration of cleared forest or individual large trees. Of course, only when the young trees are sufficiently numerous and well developed.

Our story about forest plant communities has come to an end. You could see that all tiers of the forest, all groups of plants and, finally, individual plants in the forest are closely related to each other and, to one degree or another, influence each other. Each plant occupies a specific place in the forest and plays one or another role in the life of the forest.

There are many remarkable features in the structure and life of forest plants. They will be discussed further. But to make the story more consistent and clear, we divided the material into separate chapters. Each chapter looks at plants from a different perspective. One chapter talks about interesting structural features, another - reproduction, the third - development, etc. So, let's get acquainted with some of the little secrets of plants living in the forest.

But first, a few more words. The book consists of separate short stories, unique biological sketches. These stories will talk about a variety of forest inhabitants - trees and shrubs, herbs and shrubs, mosses and lichens. It will also be said about some mushrooms. According to the latest ideas, mushrooms are not classified as plants, but are classified as a special kingdom of nature. But the greatest attention will, naturally, be paid to trees - the most important, dominant plants in the forest.

It should also be noted that our story will concern not only plants as a whole, but also their individual organs - both aboveground and underground. We will get acquainted with the interesting biological secrets of flowers and fruits, leaves and seeds, stems and rhizomes, bark and wood. In this case, attention will be paid mainly to large external signs that are clearly visible to the naked eye. Only here and there we will have to touch a little on the internal, anatomical structure of plants. But here we will try to show how different microscopic features are reflected in external signs - in what is noticeable to the naked eye.

And one last thing. The division adopted in the book into separate chapters devoted to certain characteristics of forest plants (structure, development, reproduction) is, of course, conditional. This was done only for convenience of presentation, for some ordering of the material presented. There are no sharp demarcations between these chapters. It is difficult to draw, for example, a clear boundary between structural features and reproduction. The same material can be placed with almost equal rights in either one or the other chapter. For example, the story about the special structure of pine and spruce seeds, which allows them to rotate very quickly in the air when falling from a tree, concerns both structure and reproduction. In the book, this material is placed in a chapter devoted to the structure of plants. But this is just an arbitrary decision of the author, which I hope the reader will forgive him, just like some other similar decisions.

The spruce forest is a classic setting for many folk tales. In it you can meet Baba Yaga and Little Red Riding Hood. This forest is home to many animals, it is mossy and always green. But spruce is not only an element of a fairy tale and the New Year, this tree grows quickly and is of great importance for the country’s economy and wildlife.

Meaning

The spruce forest is an abode of birds and animals, insects and bacteria. For a person, this is an opportunity to have a great time and relax, pick berries and mushrooms, and medicinal herbs. And for industry, forest is about 30% of the volume of all wood, from which not only furniture is made, but also ethyl alcohol and charcoal.

Peculiarities

The spruce forest is always shaded, but this does not prevent the trees from growing well. The crown of spruce trees is characterized by a single layer, which allows each branch to break through to the light.

An integral part of forests are berries, mushrooms and moss. Spruce prefers moist soil, groundwater, and is difficult to tolerate drought. If the soil is fertile, then spruce forests, which are not only of natural origin, can displace pine trees. They are often created artificially, since they grow much faster than deciduous trees, and therefore are of great value to the country’s economy.

Spruce blossom

Female representatives of spruce trees form small cones, which then decorate the trees. The males have elongated catkins on their branches, with pollen scattered by the tree in May. The cone is fully ripened in October, when the squirrels begin to stock up on food for the winter.

Kinds

There are five main groups of spruce forests:

• greengrowers;
• long-haulers;
• complex;
• sphagnum;
• marsh-grass.

The group of green spruce forests includes three types of forest:

• Spruce-sorrel forest. The soil in such forests is sandy and loamy, well drained. The soil is fertile due to the ground cover of wood sorrel and oxalis, which grow only in spruce forests. Groups of spruce oxalis forests are found mainly at higher elevations.
• Spruce-blueberry grows most often in the plains. The soil is less fertile and more humid; blueberries and green moss are most comfortable here.
• Spruce-lingonberry grows at higher elevations. The soil is not highly fertile, mostly sandy and dry sandy loam. Despite the low soil productivity, there are a lot of lingonberries in such forests.

This group of forests of spruce trees retains the entire occupied area and is quickly renewed.

Dolgomoshniki are more often found in the northern regions of our country. The soil is predominantly with excess moisture, and the forest, in addition to conifers, includes birch trees. Forest productivity is low. It is worth noting the presence of blueberries, horsetail and cuckoo flax.

The complex spruce forest consists of several subspecies:

• Lime. In addition to spruce, the forests contain linden, aspen, birch and sometimes fir. The land here is quite fertile and well-drained. The ground cover is represented by a huge number of different types of grasses.
• Oak spruce forest. It is considered one of the most highly productive forest species. The forest includes oaks, maple, pine, and aspen. The undergrowth mainly consists of Euonymus verrucosa; the ground cover is characterized by a variety of grasses.

Sphagnum spruce most often appears as a result of waterlogging of the long-gross spruce forest. Characterized by liquid peaty soil. There is no undergrowth in such forests; if it is found, it consists of white alder and black currant. The topsoil layer is represented by sphagnum and

Swampy grassy spruce forest is found near streams and rivers. It is characterized by high productivity and a dense undergrowth of bushes. There is a lot of moss and grass in such forests.

Geography

Spruce forest is widespread in almost all climatic zones of the globe. These trees are found mainly in the taiga, common in Northern Eurasia and North America, closer to the North Pole they gradually turn into the tundra, and closer to the southern latitudes they are found in mixed forest. In tropical climates, conifers grow exclusively in mountainous areas.

In our country, the Urals, Khabarovsk and Primorsky Territories are covered with spruce forests. In the Komi Republic, these trees cover about 34% of the entire territory. In Altai and the Western Siberian part, spruce is mixed with fir. Western Siberia is represented by complex forests. In the Yenisei part of the taiga, spruce trees grow together with cedars. Dark spruce forest is found in central Russia and Primorye, as well as the Carpathians and the Caucasus.

Flora

Due to the large shade in the forests, the flora is not very diverse and is represented by the following types of herbs and shrubs:

• sorrel;
• mine;
• wintergreen;
• blueberry;
• cowberry;
• spiraea;
• dropsy bush;
• cuckoo flax;
• cat's paw

They grow well in low-light areas. Herbaceous plants of the spruce forest are those representatives of the plant world that reproduce vegetatively, that is, through tendrils or roots. Their blooms are usually white or pale pink. This color allows the plants to “stand out” and become noticeable to pollinating insects.

Mushrooms

What forest could there be without mushrooms? Due to the fact that undergrowth is rarely found in spruce forests, and the needles themselves take a long time to rot, the main mushroom harvest occurs in the fall. If we are talking about young animals, where the food was still short, their number and variety is amazing. Most mushrooms are found in spruce forests with sparse plantings or in stripes of mixed types. That is, where there is enough light for the rapid growth of mushrooms.

The most common edible one is white. This mushroom is dense and fleshy, and is practically not affected by worms and larvae. It can grow both in dense spruce forests and on the edges.

If there are aspen and birch trees in the forest, then you can collect boletuses and boletuses. There are always a lot of saffron milk caps in the spruce forests, which grow mainly in groups on the outskirts of the forest. Under the trees themselves there are larger specimens with a yellowish cap.

In spruce forests there are always a lot of russula, which seem to imitate their “big” neighbors in the forest: the caps of these mushrooms have a blue or lilac tint. Russulas grow in large groups and have a pleasant taste and aroma. In the wettest places of the forest, near ponds, you can find yellow milk mushrooms.

There are many inedible mushrooms in pine and spruce forests. These are fly agarics, cobwebs, reddish talkers and thin pigs.

The poorest spruce forests for mushrooms are the same type and old plantings. Most mushrooms are found in swamps and small ponds. A good harvest can be harvested in the mountain plantings of the middle and lower zones.

Animals and insects

Despite the modest species of spruce forests, there are a huge number of ants, worms, shrews and rodents in the old stumps. These are dark shrews.

Depending on the yield of spruce trees, the squirrel population also changes. In winter and spring, hares and moose are found here. In pursuit of prey, wolves wander into spruce forests. In a forest of spruce trees they can create a den for breeding.

A large number of rodents are attracted to the spruce forest by stoats and martens. Also in the deep thickets you can encounter a bear, flying squirrel or lynx.

At the same time, the distribution of animals throughout the forest is uneven. Most representatives of the fauna live where spruce trees do not grow so densely, where there is undergrowth and a relatively high degree of illumination.

Feathered

There are many birds in the spruce forests. In some forests, nesting reaches 350 pairs per 1 square kilometer. Hazel grouse and wood grouse, partridges and black grouse like to settle in green moss forests. Cuckoos, Muscovites and Wrens will likely become rare here. Where the forest is dense, plumes, finches and robins settle. Nests of rattlebirds, wood pipits and warblers are set up on the ground. In sparse and mixed forests there are many jays, woodpeckers, pigeons and willow warblers.

Reptiles and amphibians

Reptiles found in spruce forests include vipers and lizards. You can find these inhabitants in sunny clearings where the grass and bushes are low.

Newts are found in puddles and on the edges of roads. also loves high humidity and shady spruce trees.