The meaning of the word tai in Dahl's dictionary. Clear cutting of forest plantations
Man and the taiga... This problem, even if we limit ourselves to the Siberian region, is so broad and multifaceted that it is difficult to cover all its aspects at once. But let’s try to trace—in a very, of course, schematic form—at least how the relationship between man and the taiga developed.
On the banks of the Yenisei and Amur, Lena and Olekma, archaeologists have been studying rock paintings by artists of the distant past for many years. Hunter, animals, fish - this is the main motive of the found “writings”. The taiga has fed man for centuries, demanding from him (or nurturing in him?) strength, courage, perseverance, courage. The natives of Siberia, like the Russian old-timers, had unwritten rules for taiga environmental management: “the pot is the measure.” Don't take more than you need now for food...
This kind of “balance” between the taiga and man, where the role of the strong belonged to the taiga, was preserved for centuries. Even in V. Dahl’s dictionary (19th century!) you can read the following definition: “Taiga is vast continuous forests, an impenetrable primordial wilderness, where there is no habitation...”
Subsequent times, especially ours, have made great adjustments to this definition. Everyone knows today about Siberian oil and Siberian hydropower, about new fields discovered in the taiga, new roads and cities built in the once “primordial wilderness”. Taiga seemed to switch positions with the man armed modern science and technology. The danger of conflict between taiga nature and human activity began to arise. Polluted rivers, dug up, wounded earth, reserved forest falling under the saw of a careless business executive - much has been written and said about this. But no, no, you will also find in print a motif from the recent past - a man at war with the taiga, “conquering” it. “In place of the taiga wilderness grew...” New route, new village- let them stand among pine trees, and not among logging residues and burnt areas. The taiga is our great national treasure; it must be protected and not thoughtlessly squandered. There is an opinion that nature supposedly “recedes before culture.” This is wrong. It is not nature that retreats before creative activity, but rather the purely consumerist attitude towards it...
V.I. Lenin considered the basis of conservation natural resources their rational operation.
Nature conservation has today become a matter of national importance, and it is already bringing beneficial results. Science and practice are looking for ways to achieve a “conscious balance” between man and the taiga, this unique natural complex. Scientists have calculated that on each hectare of the taiga zone, plants, using only about one percent of incoming solar energy, create approximately 60 centners of plant mass per year; animals transform plant tissue into zoomass, the amount of which in the taiga zone averages 170 kilograms per hectare. Taiga - everything that this capacious word unites - is essentially a gigantic factory created by nature for converting solar energy into earthly wealth.
There is no doubt that with the development of industry and with the growth of urbanization, the importance of biological taiga resources will increase.
Everyone is concerned today about the present and future of the Siberian taiga...
F. Shtilmark, game biologist
Clear cuttings
Clear cutting is the simultaneous felling of all trees in a naturally demarcated forest area. To ensure natural regeneration of the planting in the clear-cut area, a portion of it can be left standing. ripe trees and, in addition, well-growing undergrowth of the main breeds.
The area allocated in nature for felling is called cutting area. A cutting area in which all the trees have already been cut down is called clearing. When establishing cutting areas, the following circumstances must be taken into account: 1) the width and area of the cutting area, 2) the direction of felling, 3) the direction of cutting areas, 4) the period of adjoining cutting areas and 5) the method of joining cutting areas to each other.
The width and area of the cutting area are of great silvicultural importance. The width of the cutting area determines the conditions of its environment, the conditions for seeding and development of seedlings of tree species on it. Logging areas up to 100 m wide are considered narrow, from 100 to 250 m - medium, over 250 m - wide 1. The length of the cutting area (the axis of the cutting area) is usually equal to the side of the forest block and is 500 - 1,000 m. In different forests climatic zones For the main tree species in the USSR, the following width of clear cutting areas is accepted (Table 29).
1 (IN forest areas with accumulated significant reserves of mature wood, for the purpose of extensive mechanization of timber harvesting and removal, which requires significant capital expenditures over a long period, so-called concentrated cutting areas are established, the width of which exceeds 250 m, and the area of cutting areas can be 1,000 hectares or more. Concentrated cutting areas are unfavorable for natural regeneration, the seedlings on them are killed by frost and sunburn, the soil becomes waterlogged or, on the contrary, dries out, becomes sod and becomes infected with the larvae of the cockchafer)
The width of the cutting areas depends on the method of their renewal. Regeneration is called subsequent if it occurs in clear-cutting areas after cutting down all the trees. IN coniferous forests and in plantations of hard deciduous trees (oak, ash), subsequent natural regeneration occurs through the fall of seeds. When calculating for subsequent natural seed regeneration, the width of cutting areas in such forests is assumed to be 50 - 100 m. Copper regeneration does not depend on the width of cutting areas. Therefore, for plantations regenerated by soft deciduous trees (birch, aspen, alder), the width of the cutting area can be increased to 500 m. On the contrary, in forests protective value, in dry pine forests southern part European plain USSR, in oak seed plantations on chernozem and chestnut soils of the southeast, in forests located along gullies and canyons, as well as on steep slopes, in plantations on loose sand and similar locations, narrow cutting areas with a width of 50 m or less 1 . With artificial resumption of felling, the width of cutting areas can be increased.
1 (In sparsely forested areas, when clear-cutting along the forest border, which is adjacent to open areas and gardens, leave a strip of forest 100 m wide untouched. If the area of the forest being cut down is adjacent to railways, highways and dirt roads of national importance, then the strip of forest left is expanded to 250 m)
The cutting direction is the direction in which the cutting areas follow each other. When establishing cutting areas, it is important to protect the forest wall that opens during felling from windfall and to ensure that seeds from this forest wall reach the felling areas. Therefore, the direction in which felling is carried out is set against the prevailing winds.
In the northwestern, western and central parts of the European plain of the USSR, winds prevail, blowing predominantly from west to east. Therefore, in these parts of our country, cutting areas are laid one after another in the opposite direction the prevailing winds, i.e. from east to west; this will be the cutting direction.
In the forests of the southern and southeastern parts of the European Plain of the USSR, the greatest danger to the resumption of felling is overheating by the sun. On hot days in such clearings, the soil dries out greatly, and planted seedlings, self-seeding and growth of tree species die. It is important to protect the largest clearing area with a forest wall from the south. Therefore, in the forests of the southern and southeastern parts of the European Plain of the USSR, the direction of felling is taken from north to south. Plantings on damp and wet soils especially suffer from the wrong direction of felling, where, due to the superficial location of the root system of trees, windfall, which constantly occurs in spruce forests, intensifies.
Logging areas, as a rule, have the shape of a narrow and long rectangle, and the width of the rectangle, i.e., the narrow side of the cutting area, coincides with the direction of felling. Therefore, the long side of the cutting area (axis of the cutting area) is perpendicular to the cutting direction. Thus, the direction of the cutting area is the direction of its long side, which is perpendicular to the direction of felling. The long side of the cutting area is located parallel to the clearing of the block network of the forest dacha.
Logging is resumed more successfully if the planting is felled before a year of abundant seed harvest. Therefore, it is necessary that the new cutting area be adjacent to the already cut down cutting area in accordance with the years of increased fruiting of the plantings. The number of years after which a new cutting area adjoins a previously established one is called the adjacency period. In pine, spruce and oak forests in the western and southwestern parts of the European Plain of the USSR, the period of contiguity of cutting areas is assumed to be 2 - 3 years, and in forests of the same species in the southern and south-eastern parts of the USSR, the period of contiguity of cutting areas is extended to 4 - 6 years . During the regeneration of birch, aspen and alder plantations, the period for joining cutting areas is set at one year. In the case of artificial resumption of felling, the period of closure of cutting areas does not matter.
After clear cutting of forests, the clearings are quickly covered with grass and sod, which poses serious obstacles to their natural regeneration (Fig. 162). For better seeding of cleared areas, healthy, stable trees with well-developed crowns, the length of which is 1/3 - 1/2 the height of the trunks, are left in clear-cut areas. Such trees are called seed trees (Fig. 163). Several years before the clear felling of the plantation, the seed plants are prepared for abundant fruiting by removing neighboring trees; When logging areas are allocated or earlier, they are branded.
In pine cutting areas, the number of seed trees is 15 - 25 pine trees per 1 hectare. In pine plantations, seed plants are left in those clear-cut areas where there is no danger of windfall. In arid zones, seed plants should not be left where they are unable to protect self-seeding from heat and drought. In spruce plantations, due to the windiness of the spruce, the seed plants are left only on sandy loams, where the spruce takes deeper roots, in the amount of 10 - 15 trees per 1 hectare. In oak plantations, due to the heaviness of acorns, which fall only under the tree crowns, and the phenomena of physiological dryness that cause dry tops of trees, seed plants are not left behind. In birch plantations of high quality, when regrowth is difficult, seed plants are left in the amount of 5 trees per hectare.
When calculating the natural regeneration of clear cutting areas, the state of the undergrowth of the main tree species is taken into account. Successfully growing undergrowth of spruce and oak is of great value if it is located in groups, since after being freed from the maternal canopy, the group undergrowth develops better and is more easily preserved from damage that is inevitable during logging. To preserve valuable undergrowth in clear-cutting areas, the lower branches of trees are cut off before felling. The cutting itself is done in deep snow; harvested timber is transported bypassing the undergrowth, and the burning of logging residues is concentrated in places where there is no undergrowth.
The adjoining of continuous cutting areas to each other can occur in such a way that one cutting area immediately follows another. Such a junction of cutting areas is called direct.
However, in the interests of natural or artificial regeneration, the next cutting area can be laid in the direction of cutting not directly, but through a strip of mature forest, the width of which is part of the width of the cutting area. If this strip of mature forest left between cutting areas is cut down over a 10-year period, then such a junction of cutting areas is called inter-strip. If the felling of the strip of mature forest left between the cutting areas is scheduled for a period greater than a 10-year period, then such a junction of cutting areas is called backstage. Inter-strip and deep-cutting divide the forest into a number of areas with sharply changed water, wind and temperature conditions; the conditions for regeneration during these fellings, compared with the immediate adjacent cutting areas, do not improve, therefore inter-strip and side-by-side cuttings are not recommended.
Cutting areas are designated for each year in different blocks of a forest dacha or in different parts of the same block, in connection with the accepted period of contiguity. A series of cutting areas established in compliance with the direction of felling, the width and direction of the cutting area, the timing and method of joining the cutting areas is called a logging link. Logging links are plotted on the planting plan of the forest dacha, and data on them is included in the felling plan. The initial cutting areas in logging units are called cuts; they can be laid in several blocks of a forest dacha.
In addition to clear cuttings, in which all trees are cut down in the cutting areas (with the exception of the seed trees, which are left in some cases), cuttings are sometimes used in which small trees (with a diameter of up to 12 cm), damaged conifers and all wood are left in the cutting areas. deciduous trees, which is explained by the unprofitability of cutting them down. Such fellings are called conditionally clear fellings.
At clear-cutting sites, resumption is provided for after felling of mature forest; Therefore, clear cuttings are called subsequent regeneration fellings. If fellings are started with the expectation of forest regeneration before the final felling of mature trees, then they are called preliminary regeneration fellings. Preliminary regeneration of cutting areas is important in forests of agricultural and water conservation importance, where the soil should not be exposed from under the forest. “The soil surface of a forest of agronomic importance should never be cleared of the forest canopy,” says Academician. W. R. Williams. When calculating for preliminary renewal, felling of mature stands is carried out gradually.
3.1.1
Clear cutting (forestry)
More than one generation of foresters was brought up on the principle of G.F. Morozova " felling and renewal are synonyms" And nowadays, the forester must always remember that the ultimate goal of final felling should be to replace mature forest with a new generation.
The main comprehensive indicator of the use of clear cuttings is the silvicultural state of the undergrowth. With the same completeness of the upper layer, the viability of the undergrowth may be different. As age increases, the viability and prospects of adolescents decrease.
Clear cuttings for final use with preliminary (natural or artificial) regeneration are significantly different from fellings with subsequent renewal.
RGP with preliminary natural reforestation carried out in areas with tree stands, under the canopy of which there is economically viable undergrowth–valuable species, capable of adapting to dramatically changed conditions and forming a young forest during a single felling of a tree stand. Usually these are areas of the same age, low–and medium-density forest stands of coniferous, hard-leaved and soft-leaved species.
Clear cuttings with preliminary artificial reforestation not found wide application.
Clear cuttings with subsequent natural renewal carried out in groups of forest types where there is no undergrowth under the canopy and its appearance is problematic without human help. In this case, simultaneously with cutting down the tree stand, special measures are taken to promote forest regeneration (partial removal of litter, mineralization of the soil surface and its loosening, etc.), which ensures the regeneration of the target species. Basically, these are indigenous complex pine and spruce forests, oak groves and other types of forests where there is great competition with herbaceous vegetation, there is a high probability of regeneration of undesirable tree species (soft-leaved) or in the absence of sources of natural forest regeneration.
Due to significant silvicultural differences in clear cuttings of preliminary and subsequent renewal, at one time the following were distinguished: narrow–average – and wide cuttings.
According to the “Rules...” the clear-cutting system in the forests of the Republic of Belarus allows the use of:
Clear-cutting strip fellings with a cutting area width of up to 100 m with direct, less often inter-strip or side-by-side abutment;
Solid –precinct (or precinct) felling when felling individual taxation areas of up to 5.0 hectares in coniferous and hard-leaved forests and up to 10.0 hectares in soft-leaved forest stands.
Clear cuttings are carried out mainly in forests of group II. In forests of group I, clear felling is allowed:
In overmature, decaying plantings;
In plantations damaged by fires, pests, fungal diseases with progressive drying out of trees;
In low-density plantings;
In plantations where clear cuttings cannot be carried out due to the high danger of windfall;
In mature plantations, where it is impossible to ensure natural regeneration of the target species.
The felling method is established for each specific area (taxation area, cutting area), taking into account, as noted above, forest conditions, composition, structure and current state planting, the presence of undergrowth or a second layer, the method of reforestation and the target species of the future planting, as well as the wind resistance of the remaining part of the tree stand and adjacent plantings. The cutting down of some plantings should not significantly affect the increase in the danger of windfalls for other remaining plantings. Otherwise, other cutting methods are used, and narrower (up to 50 m) cutting areas are allocated. Plantings that are not resistant to wind blows include spruce and aspen forests with a height of more than 23 m, pine and birch forests with a height of more than 25 m, growing on soils of normal moisture, as well as tree stands with a significant admixture of spruce (30-50 percent), with a height of more than 21 m on soils with increased moisture content. hydration.
The main organizational and technical elements (OTE) of clear-cutting are:
The width and shape of the cutting area, its area;
Cutting direction;
Direction of cutting area;
Method of joining cutting areas;
Deadline for joining cutting areas;
Technology of logging operations;
Method of cleaning cutting areas;
Reforestation activities.
The width and shape of the cutting area, its area. The width of the cutting area is the length of the cutting area along the short side. It is determined by the distance at which a sufficient number of seeds flies from the forest walls. They also take into account the influence of forest walls on changes in microclimatic and soil conditions, the degree of sodding of the felled area and the possibility of an undesirable change in species. It should be noted that when designing new methods of mechanized logging, the forester, first of all, strives to preserve the preliminary renewal of the main species.
The “Rules...” provide for the possible width of cutting areas (from 50 to 100 m) depending on the group of forests (Appendix P).
In a block with a side of 1 km in forests of group II with a cutting area width of up to 100 m, two cuttings are allowed, i.e. cutting areas of one year. If the quarter is smaller, one cut is allowed.
The shape of the cutting area is usually rectangular, and for small areas (up to 5 hectares in hardwood plantations, up to 10 hectares in coniferous forests and up to 25 hectares in softwood forests) it can correspond to the configuration of the plot.
The area of cutting areas in group I forests for coniferous and hard-leaved trees is no more than 3 hectares and soft-leaved trees - no more than 5 hectares, and for group II forests - 5 and 10 hectares, respectively.
Cutting direction. The cutting direction is the direction in which the cutting areas are located one after the other. It always chooses to face the main danger (wind, water flow, erosion, etc.). In the conditions of the republic, the most dangerous are the western and northern–westerly winds, prevailing during the most dangerous times of the year in terms of wind blows. The cutting direction is the main one, and then, depending on it, the cutting direction is set.
Direction of the cutting area. This is the direction of the long side of the cutting area in relation to the parts of the world. It should facilitate seeding of the cutting area from the forest walls and provide more favorable conditions for seed germination, rooting of seedlings and further growth and development of self-seeding. The direction of the cutting area is always perpendicular to the direction of felling.
Method of joining cutting areas. This is the order of spatial placement of one cutting area relative to another. The abutment can be direct, interstriated, rocker and staggered. At direct At the junction, each subsequent cutting area is located next to the previous one. This is the most common method to ensure natural regeneration of the forest. At interstriped At the junction, the next cutting area is laid not next to the previous one, but through a strip of forest with a width equal to the width of the cutting area. The disadvantage of this method is the likelihood of massive windfall, and this is most often observed in spruce plantations on poor soils. At backstage at the junction, the remaining strip of forest is two or three times wider than the cut-down areas. Chess The adjoining of cutting areas is rarely used. Figure 2 shows the methods for connecting cutting areas.
The current “Rules...” establishes a direct method of joining cutting areas, although in special cases (in wind-resistant forest stands on fresh and dry soils) natural resumption of felling is ensured by strip and side-by-side joining. The length of the cutting area is determined by the size of the block or the length of the mature forest stand.
Deadline for joining cutting areas. This is the period of time after which felling is carried out at the next cutting site. The period of contiguity is set depending on the conditions for the resumption of felling and is usually equal to the period between two seed years. The year of felling during abutment is not included: this means that, for example, at 2–During the summer period, the cutting areas will be cut down in 2006, 2008. etc.
Subject to satisfactory resumption of the previous cutting area during clear-cutting, the “Rules..” establish the following deadlines for the adjoining of cutting areas: for soft-leaved forest stands - 1-2 years, for conifers and hardwoods – 3-4 years.
Direction of prevailing winds
Cutting direction
Left stripes (backstage)
Figure 2 – Junction of cutting areas:
1 – direct; 2 – interstrip; 3 – rocker; 4 – chess
(a – width of the cutting area; 1….19 – No. of cutting areas, 2001 –2037 – year of felling)
Source of contamination of clearings There may be individual trees, various groups of them, or forest walls that perform the seeding function. Seed trees are well-fruiting, wind-resistant trees with good growth and trunk quality, specially left behind during felling. Seed groups usually less than 0.01 hectares in area are left in the clearing for seeding. Seed clumps are separate stable parts of the tree stand, left in the clearing for its seeding, with an area of 0.01 to 1.0 hectares. Seed strips are left 30 wide -50 m.
All organizational and technical elements of clear-cutting strip felling that are being designed must be shown on the plan (scale 1:10000).
Technology for developing cutting areas includes the technology of felling, skidding, cleaning trunks from branches and loading wood. Logging is the movement of trees, logs (the trunk part of a tree without branches) or assortments (logs cut transversely into pieces of various sizes) from the felling site to a timber loading point or logging road. When drawing up a project for each site of final felling, the text indicates the system and type of felling, methods of skidding and cleaning of felling sites, locations of upper warehouses or loading areas, placement of roads, main and logging roads, as well as measures to preserve undergrowth at the cutting site.
The construction of loading platforms and skids is carried out in places where there is no undergrowth. The total area of skidding roads and loading areas should be no more than 20 percent of the cutting area. The width of skidding roads should not exceed 5 m.
Currently, in practice, RGPs are used as single-operational ones (chainsaws “Husqvarna”, “Stihl”, “Solo”, skidders of the AMKADOR type–2200; MTZ –82; TTR –401; TTR – 402 and others), and multi-operational machines (harvesters and forwarders “Valmet”, “Hiab”, “Sisu”, “Timberjack”) of domestic and foreign production.
When selecting a system of machines and mechanisms and developing the most rational technological schemes for logging operations, it is recommended to use the “Guide to the organization and conduct of logging in the forests of the Republic of Belarus” (5).
Using the example of clear-cutting using the method of wide apiaries in the absence of reliable viable undergrowth, the design of the scheme for developing a cutting area is shown (Figure 3).
Figure 3 – Scheme for the development of cutting areas in the absence of reliable viable undergrowth using a gasoline-powered saw and skidding with tractors: 1 – logging trail, 2 – main drag, 3 – apiary drag, 4 – safety zone, 5 – tree felling, 6 – cutting off branches in the apiary, 7 – laying branches on a drag, 8 – skidding, 9 – growing trees, 10 – stumps from felled trees
The description of the technological process according to this scheme is approximately as follows. The loading point is located on the driest area of the cutting area, taking into account the direction of removal, and the timber hauling point is located along the border of the cutting area. A safety zone with a width of at least 50 m is created around the loading point and along the logging fence. When developing cutting areas using the wide apiary method (35-45 m) in the absence of reliable viable undergrowth, trees are felled at an angle of 45-60 degrees to the portage. Since it is difficult to take the entire half-apiary at once in one run, it is divided conditionally into strips 8 wide-10 m. The strips are developed sequentially: first at the drag, and then, when the whips are shot, the strips farthest from the drag are developed. Clearing trees of branches can begin only after the feller has moved at least 50 meters from the cleaning site. Branches are used to strengthen the drag. Skidding must also be carried out outside the dangerous fifty-meter felling zone. The felling of trees and the skidding of sticks by the tops is carried out from the near end of the apiary. When loading a load, the skidder may come off the drag.
In addition to the scheme for the development of cutting areas, a basic diagram for the development of apiaries is drawn with the application symbols locations of individual logging operations (Figure 4).
Figure 4 – Schematic diagram of apiary development tape
method in the absence of reliable viable teenagers
The diagram shows an apiary with a width of 40-45 m, in the middle of which a 5 m wide drag is laid. In this case, the drags are cut in advance. The cutting of the drag begins from its far end, the first trees are felled into the free spaces between standing trees.
Then the half-apiaries are cut into strips 5 wide-8 m, which adjoin the drag at an angle of 45-60 degrees. The cutting of half-apiaries begins from the far end. The feller fells trees on the apiary belt, starting from the drag. In one go, i.e. on one belt, as many trees should be felled as necessary to collect one pack with a tractor. Skidding is done by trees behind the butt. When developing an apiary using this method, the tractor does not leave the drag. After felling trees on one belt, they must be shot immediately, otherwise trees on the next belt cannot be felled. In order to avoid downtime, the feller moves to the neighboring half-apiary, maintaining safety distances, or a tree choker is included in the team.
The method is used in deep snow in winter and on soft soils– in summer.
Cleaning felling areas. With any type of felling in a cutting area, after skidding and removal of wood, unused cutting residues (tree tops, twigs, branches, etc.) remain, which are scattered throughout the entire area of the cutting area. They are approximately 15-20 percent of the growing stock. This interferes with the growth of undergrowth, natural reforestation, and preparation of soil for forest crops, increases the fire danger in forests by 1.5-3.5 times, and provokes the appearance of pests and diseases. Therefore, simultaneously with the felling of the forest or after its completion, the clearing of the cutting area is carried out.
Logging residues can be used for fuel, production of technological chips, turpentine, vitamin and pine flour and other valuable products.
I. S. Melekhov proposed combining the entire variety of methods for cleaning cutting areas into 3 groups: fire, non-fire and combined (11).
Methods for clearing cutting areas are established differentially, taking into account the types of forest and forest growing conditions, the type of felling, the technology used for cutting operations, etc., and in accordance with the “Rules...”.
“Rules...” recommended placing logging residues on trails when developing cutting areas with narrow apiaries and in waterlogged conditions, felling trees towards the trail so that the main part of the crown is located on it, followed by cutting off the branches and laying them across the trail. Felling residues protect the roots of the remaining growing trees from damage by tractor wheels. This method is most appropriate to use in spruce plantations.
Burning of logging residues used mainly on sandy loam and sandy, as well as on well-drained loamy soils by placing logging residues in heaps up to 1 m high and up to 2 m in diameter, excluding fire damage to growing trees and undergrowth. It is advisable to carry out burning during the snowy period.
Collection of logging residues for rotting It is used mainly in damp and humid growing conditions with their placement in small piles or shafts up to 1 m high and up to 2 m wide between stumps in areas free from undergrowth no closer than 20 m to the forest wall.
Chopping and uniform spreading of logging residues used on dry sandy soils in pine and hardwood plantations. This helps retain moisture and enrich the soil with organic matter, protecting self-seeding from the sun. This method is also used when there is viable undergrowth of economically valuable species in the cutting areas. The crushed logging residues are scattered in areas free from undergrowth. For fire prevention purposes, crushed logging waste should not occupy more than 60 percent of the felling area.
Reforestation activities have the goal of accelerating the reforestation process, creating conditions for the emergence of seedlings or the preservation of undergrowth or young growth of economically valuable species at the stages of the main forest felling and subsequent reforestation.
In clear cuttings for final use, passive and active measures are used to promote the natural regeneration of the forest.
Passive measures include measures, the observance of which during logging is mandatory: (organizationally–technical elements of clear strip felling):
Width of cutting areas: up to 50 m in coniferous and hardwood, up to 100 m– in soft-leaved forests for group I and 100 m– for scaffolding Group II;
- the next cutting area is cut down only after a complete renewal of the previous one (the main requirement for the period of adjoining cutting areas);
- selection of rational technological schemes for the development of cutting areas in the presence of undergrowth (methods of narrow apiaries, for lining trees, etc.), as well as the choice of methods for cleaning cutting areas, etc. Cutting areas with the presence of promising undergrowth are developed mainly in the autumn-winter period.
Among the active measures to promote natural regeneration during clear-cutting, the following are most often used:
ABOUT planting seed trees that are the best from a breeding point of viewin an amount of 15-25 pieces/ha or 4-5 seed groups per 1 hectare, 3-6 trees per group. Seeds high class quality is given by trees of I-II Kraft classes, with a compact, highly raised crown, occupying no more than 1/3 of the trunk height;
M mineralization of the soil surface is carried out in the seed year on fresh cuttings in the presence of sources of contamination or under the forest canopy 3-7 years before cutting. For these purposes, special tractor rippers are used on light sandy and sandy loam soils,skin peelersand cutters(Appendix P).
The cultivated area in clearings should be 30 percent, and under the forest canopy– 15-20 percent. Tillage is carried out from the second half of summer, and in mixed plantings with the participation of deciduous trees in the fall, after the leaves have completely fallen. Under the canopy pine forest tillage is allowed in early spring.
In conditions of damp, excessively moist soils, microelevations are created. On heavy loamy soils with the likelihood of their becoming swamped, ridges and shafts are created using double-dump forest and swamp–bush plows. If there is an admixture of aspen in highly productive pine and spruce plantations, soil preparation is carried out after preliminary ringing of the aspen using chemicals. Banding is carried out 5-6 years before logging;
- caring for self-sowing and undergrowth of target tree species includes clearing them of debris from logging residues, cutting down trees of low-value deciduous species and severely damaged target trees. Damaged hardwood undergrowth« put on a stump» .
Projected measures to promote natural forest regeneration are listed in Table 2.
table 2 – List of measures to promote natural regeneration of forests in cleared areas
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Quarter number, Section No. |
Area, ha |
Characteristic plot *
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Bonitet |
Forest type type of forest conditions |
Events for promoting natural reforestation |
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Note:
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Goal: To promote environmental education, expand students’ knowledge about nature.
Rules of the game: The game has three rounds, the final, a super game, and a game with spectators. In each round, three people play, the task is read to the participants, each has the right to turn the drum and name one letter, if the letter is named correctly, the participant is given one more turn, the one who correctly named the word wins, the winners of three rounds advance to the finals. To play the game, a Power Point presentation is used; if the letter is named correctly, it will appear when you left-click on the corresponding window.
Host: Earth, what is it like?
The earth gives birth to transparent streams. Millions of stems and ears. Carries the oceans and their shadows. Lets birds fly into the sky, swift-footed animals throughout all the forests. Rocks cities on itself. The earth receives all the rain, snow and fog.
Everyone says earth, but everyone means their own:
So what is it, Earth?
The earth has always captivated man with its eternal rebirth, the cycle of springs and winters, and the infinity of its horizons.
Man strove for the Earth, opening it, giving names and names.
But today, progress has raised the problem of human interaction with the earth with all its severity. Powerful human deeds are taking place before our eyes; often people do not notice the consequences of these deeds: territories covered with salt marshes, flooded with swamps, dug up by quarries, unsuitable for habitation and management.
We must not forget that “We only have one Earth...” This beautiful ship has everything necessary for an endlessly long journey on it, but if it breaks down there will be nothing to transfer to. We must take care of what we have.
(The student reads a poem by A. Dudin)
Take care of the Earth!
Take care
Lark at the blue zenith,
Butterfly on dodder leaves,
There are sun glares on the path,
A crab playing on the stones,
There is a shadow from a baobab tree on the grave,
A hawk soaring over a field
Crescent moon over the river calm,
A swallow flickering in life.
Take care of the Earth!
Take care
Miracle of songs
Cities and villages
The darkness of the depths and the will of the heavens,
Old age's last joy,
A woman running to a kindergarten
Helpless singing of tenderness
And love has iron patience.
Take care of young shoots
At the green festival of nature,
Sky in stars, ocean and land
And a soul that believes in immortality, -
All destinies are connected by threads.
Take care of the Earth!
Take care
Time takes sharp turns,
The joy of inspiration and work,
Ancient kinship living properties,
Tree of hopes and worries,
Revelation of earth and heaven,
The sweetness of life, milk and bread,
Take care of kindness and pity,
So that she fights for the weak.
Take care of the future for the sake of
This is a word from my notebook.
I give everything!
And I accept everything from you!
Only
Take care
This Earth!
Presenter: The theme of today’s game “Field of Miracles” is “Earth – the cradle of humanity.”
In another way, this place can be called a laboratory in living nature; these laboratories are created in different natural areas In order to study and at the same time preserve all the richness of nature, research here can be carried out for many years.
In this place, all construction, geological exploration and other survey work, deforestation, hunting, picking mushrooms and berries, grazing livestock, and plowing fields are prohibited.
Thanks to these places, it was possible to preserve already endangered species of animals to commercial numbers.)
2-task
Presenter: The rivers of Siberia have long fascinated writers and poets.
A.P. Chekhov wrote: “In my life I have never seen a river more magnificent than the Yenisei, a mighty, frantic hero who does not know what to do with his strength and youth, it seems strange that this strong man has not yet washed away the banks and drilled the bottom.”
And, for example, the rivers of Siberia inspired V. Shishkov with the image of the deserted, wild and capricious Gloomy River.
And now the question:
In the 20th century, they decided to block one of the rivers of Siberia, since the economically effective potential of its inflow is estimated at 20 million kW.
Five hydroelectric power plants are planned on this river. The first to be built was the Bratsk hydroelectric power station.
(Valentin Rasputin, in his story about the last days of Matera, talks about an island that should be flooded when this river is blocked.
The experience of building the Bratsk hydroelectric power station was taken into account during the construction of: Ust-Ilimsk hydroelectric power station, Sayano-Shushenskaya hydroelectric power station, Boguchanskaya hydroelectric power station.
And the poet A.T. Tvardovsky wrote the following lines:
A different beauty will come
To these shores
But, apparently, people are the same
Need a road)
3-task
I love you big time,
But please listen to me:
Don't kill the last taimen,
Let him walk in the dark depths,
Don't destroy the last swamp
Spare the hunted wolf
so that there is something left on the ground,
What makes my chest ache. (S. Kunyaev)
Difficult natural complex– consisting of a wide variety of animals and plants of high economic value.
A natural zone that is located behind the tundra zone and changes to the forest-steppe zone.
(A.P. Chekhov wrote about this place like this: “On both sides of the road there are certainly ordinary forests of pine, larch, birch and spruce. There are no trees five girths wide, no treetops that make you dizzy when you look at them. There is no power here in the giant trees, not in deathly silence, but in the fact that they are alone migratory birds they know where this place ends.”
V. Dahl’s dictionary: “... - vast continuous forests, impenetrable primordial wilderness, where there is no housing ...”)
Playing with spectators
Presenter: Agile and very strong predator for its size. Leads a terrestrial lifestyle. Good at climbing trees. An animal living in the Siberian taiga, by the thirties of the last century this animal was almost completely exterminated within Krasnoyarsk Territory and remained here in almost a small number of non-isolated areas. Later, as a result of conservation measures, the number was restored to its original level in the seventeenth century. At present, a situation has again arisen that threatens this animal.
Host: As you know, the forest is the lungs of the planet. We would simply suffocate if there were no forests on the globe, because plants, carrying out the process of photosynthesis, constantly release oxygen into the surrounding space and absorb carbon dioxide.
And now the task: along the banks of this river a third of all forests on the planet grow, 5 million square meters. km this represents half of the entire territory of Brazil. What is the name of this river?
(By 1975, the Amazon had lost 4% of its trees. If this continues, then by 2005 there will not be a single tree left. The worst thing is that foreign companies are destroying forests, not by cutting them down, but by burning them).
Super game.
Presenter: Ecology is a science that studies the interaction of living organisms with environment, this science explores the relationships between different species, studies the struggle for existence, but the most important task of ecology is to study how humans influence nature, how this influence affects the state of living organisms.
Solving environmental problems is one of the most prominent tasks of humanity. But do you know what the word “Ecos” means?
Our home is in danger. Planet Earth is slowly dying. We are not given another home.
For a long, too long time, we perceived all reports of disasters and losses - poisoned soils and contaminated waters, death of animals and plants - only as unfortunate accidents caused by someone's ignorance and sloppiness. The time has come to realize that the blame for the impending catastrophe lies with each of us.
Nature needs help.
Take care of these lands, these waters,
I love even a small epic.
Take care of all the animals of nature.
Kill only the beasts within yourself.
Literature:
- Igor Akimushkin “ Invisible threads nature”, \Moscow publishing house “Mysl” 1985\ pp. 270-274.
- A.N. Zakhlebny “Book for reading on nature conservation”, \Moscow education” 1986\ pp. 75-132.
Clear cutting of forest plantations
Clear cuttings arose later than selective cuttings.
IN ancient times clear cuttings were not used for timber harvesting, but mainly for clearing land for fields, which modern classification more consistent with other fellings.
It was not until the 19th century that clear-cutting developed as a forestry system. Clear cuttings were a more rational and complete form of forest management than the unregulated or weakly regulated forced selective and mine cuttings that were widespread in Russia at that time.
The use of clear cuttings made it possible to obtain a larger amount of wood per unit area and stably satisfy the growing needs of industry, Agriculture and the population in the business and firewood industries. After clear-cutting, not always, but more often than after forced-selective felling, favorable conditions are created for obtaining reliable natural regeneration. But, most importantly, they made it possible to remove false and other genetically unreliable trees.
Over the course of the 19th and 20th centuries, clear cuttings gradually became widespread in our country and became the main method of cutting mature plantations (according to the classification in force at that time - final felling). However, at first, along with clear cuttings themselves, the so-called conditional clear-cutting (CCF).
During these fellings in the cutting area intended for clear cutting, not the entire tree stand was cut down, and the least operationally valuable part of the trunks, which did not reach the established diameter, remained standing. The implementation of SRM was justified from a silvicultural point of view by the fact that during standing felling, young, promising trees that had not reached operational size were left for growing. This is more or less true in plantings of absolutely different ages. But SRM was also carried out in even-aged stands, where their consequences were similar to the consequences of forced selective logging. The part of the trees left standing consisted mostly of stunted trees of dew classes 4 and 5 (according to Kraft).
Modern Rules USR timber harvesting is not provided. Some positive experiences from these fellings were transformed into long-term gradual fellings that have completely different rules of purpose. They will be discussed in detail in the next topic.
During the period of industrial growth of the USSR economy, in conditions of an ever-increasing need for wood, clear cuttings began to be carried out more and more widely. However poor development the transport network in the forests hindered this process. Then they appeared solid concentrated cuttings TO timber resource base- a section of the forest fund in which mature and overmature plantings are compactly concentrated - a logging road was laid, often a narrow-gauge one Railway(UZD). Clear-cutting areas were concentrated along it. Logging sites could have big sizes– up to a kilometer or more. They joined one another and turned into one huge clearing. The road was built further, and logging continued.
Clear cuttings in general and concentrated cuttings in particular, in which its main component, the tree stand, is completely or almost completely removed from the plantation, have a significant impact Negative influence to the forest in which they are held. The climate of a vast clearcut approaches that of a vast open space. All forest conditions in the complex change.
Wind speed increases in clearing areas. Snow in winter is blown to the edges of the clearing and does not form a thick cover. The soil freezes deeper, and the snow melts quickly in the spring. As a result, phenomena known to you from the forestry course occur that have a detrimental effect on seedlings and young growth. This:
1. freezing of parts of plants uncovered by snow and useful forest entomofauna overwintering in the forest litter, under extreme conditions low temperatures air;
2. “squeezing” seedlings on damp, heavy soils;
3. damage by late spring frosts to plants that began to grow early on soil that was prematurely cleared of snow;
4. death of plants due to “physiological dryness” caused by the fact that the buds begin to grow, and when the root system is frozen, the tissues are not supplied with water, and the young growth dries out.
In clearings, the air temperature is higher than under the forest canopy in hot weather, and in cold weather- below. In clearings, especially small ones, the probability of late spring and early autumn frosts is much higher than under the forest canopy. Under the influence of heat, the process of mineralization of the forest floor intensifies, and under the influence of precipitation and wind, some compaction of the soil occurs.
The hydrological regime of the soil in cleared areas also undergoes significant changes. A cut down tree stand stops the transpiration of water, and in damp soils, in the absence of surface runoff, it accumulates, causing waterlogging of the soil. Swampy clearings are overgrown with marsh grasses and moisture-loving shrubs - willows, alders, transpiration resumes, the soil gradually becomes swampy, but it takes long time. On dry soils at low levels groundwater The soil becomes even more dry because the roots of the trees stop absorbing moisture and lifting it from the lower horizons to the higher ones.
The living ground cover in the conditions of most types of clearings is quickly replaced by light-loving species with a developed high aboveground part, the projective cover increases, and the sodding of the soil increases.
All these changes create problems for the natural regeneration of logging. Moreover, the more extensive the deforestation, the greater the problem, as a rule. .
In several better conditions there are soft-leaved species that bear fruit abundantly every year and have significant opportunities vegetative resumption. It is they who quickly occupy clearings in most forest conditions, and a classic change of species occurs. However, in forest types on dry sandy soils, pine and larch in cleared areas regenerate quite well without changing species. In forest types of the sphagnum group, pine also does not give way to other species in clearing areas. Just in these conditions herbaceous plants and soft-leaved trees generally grow poorly.
Cleared areas are better suited than many other categories of land for artificial reforestation—the creation of forest crops. The development of clear cuttings certainly stimulated the development of silviculture. However, it is important to create crops immediately after cutting is completed, until the above-mentioned changes in forest conditions have fully occurred. IN production forests This was often not possible, especially in concentrated felling areas. In addition, crops created in cleared areas require numerous first agrotechnical and then silvicultural care. Carrying out care requires huge costs for the operation of equipment and manual labor. In case of untimely or lack of care, crops are drowned out; deprived of light, they grow poorly. In autumn, the grass growing along the edges of the furrows falls onto the furrows, and the crops, pressed by the grass to the ground, damp out and rot along with the grass. Even if all care is carried out on time, it is not a fact that the crops will be successful. There are frequent cases of them getting wet, “squeezed out” and dying from exposure to other unfavorable environmental conditions.
As a result of many years of practice of widespread use of clear concentrated cuttings in the forests of Russia, today we have huge areas of soft-leaved young stands and middle-aged plantations, even in indigenous forest types coniferous species. A considerable area of clearings has turned into wastelands, swamps and plantations formed by shrub species.
Therefore, clear cutting should be carried out with restrictions. First of all, the size of cutting areas needs to be limited.
Clear cuttings with limited widths of cutting areas – solidnarrow-cutting (SLR)– have also been carried out for a long time, and are an alternative to clear concentrated cuttings. Adverse changes natural environment in their clearings they are not so pronounced; natural regeneration is more successful. Today these fellings are the most common.
However, to minimize the adverse consequences of clear cuttings and improve the conditions for their natural regeneration, restrictions on the size of cutting areas alone are not enough. There are several more rules regulating the location of cutting areas, their location in the block and the procedure for joining each other. They are generally called organizational and technical elements cutting area
· Direction of cutting area – the location of the long side of the cutting area in relation to the cardinal points. Logging areas CPR on flat terrain and on slopes no more than 10 degrees. have the long side perpendicular to the direction of the prevailing winds, and cutting areas on slopes of greater steepness are located along the horizontal lines of the slope, perpendicular to the direction of the slope.
· Cutting direction – the direction in which each subsequent cutting area is located relative to the previous one. The direction of felling establishes the sequence of allotment of cutting areas SLR in areas whose dimensions exceed the permissible sizes of cutting areas. The direction of felling cutting areas is CPR on flat terrain and on slopes up to 10 degrees. is installed against the prevailing winds, and on slopes of greater steepness - from the foot of the slope to
top.
Rice. 36 The direction of felling and the direction of cutting areas in an area located on flat ground. A – direction of the prevailing winds (western); B – direction of cutting areas (from south to north or from north to south); B – cutting direction (from east to west); 1, 2, 3, 4, 5, 6, 7 – the sequence of withdrawal of cutting areas and their entry into felling.
The direction of cutting on flat terrain is designed to reduce wind speed in clearing areas, and on slopes to reduce the risk of soil erosion.
The direction of felling is established in the interests of natural regeneration of fellings. Seeds from the forest wall that has not yet been touched by felling will fly with the wind (or downhill), ending up primarily in felling
- The deadline for joining cutting areas is the time interval after which felling is carried out in a cutting area bordering on a previously cleared one.
The timing of the contiguity of cutting areas is also established in the interests of renewing logging, and takes into account the average period of recurrence of seed years for various tree species of Siberia.
The period for contiguity of cutting areas is established on both the long and short sides of the cutting area, regardless of the method of reforestation of the felled area - natural or artificial. In order for logging to resume, a contiguity period of 2–5 years is established.
In logging areas with preliminary renewal, the period for contiguity of logging areas with CPR is set at 2 years.
· The year of felling is not included in the period of contiguity of cutting areas! Method of joining cutting areas - method of placing cutting areas different years relative to each other.
There are 4 ways to connect cutting areas:
1. Direct adjoining of cutting areas.
The next cutting area is joined to the previous one after the established period of contiguity according to long side(Fig. 37).
Rice. 37 Direct connection of cutting areas with a connection period of 2 years.
The direct adjoining of cutting areas creates optimal conditions for their natural regeneration, but this method has one significant drawback. With a small permissible width of the cutting area, the felling of a large plot of area may take a fairly long time (in the proposed example, the plot will be completely cleared in only 16 years; if the adjoining period were large, for example, 5 years, then the cutting would drag on until 2037! ) Over such a period, a ripe tree stand may well lose its commercial qualities.
It is possible to reduce the period of cutting down large areas with a small permissible width of cutting areas
2. Screw junction of cutting areas.
The next cutting area is joined to the previous one the following year through a wide strip (cutting edge) equal in width to double or triple the permissible width of the cutting area. Within the boundaries of the cutting area, the cutting area enters the cutting area with direct adjacency (Fig. 38).
Rice. 38 Rocker connection of cutting areas with a connection period of 2 years.
As shown in the figure, the period for complete clearing of the plot is significantly reduced. In plantations that require even more urgent cutting down, it is used
3. Interstriated junction of cutting areas.
The next cutting area is joined to the previous one the following year through a strip equal to the maximum permissible width of the cutting area. The missing strips are cut down after the established deadlines for joining the cutting areas (Fig. 39).
The use of inter-strip junctions of cutting areas is not allowed unless necessary, since wind speed increases significantly, and tree stands that are not sufficiently resistant to windfall and windfall can be severely damaged by the wind. Dark coniferous plantations are especially susceptible to wind damage. Plantings of other species growing on shallow, swampy and other unstable soils are also at risk. Therefore, inter-strip joining of cutting areas is rarely used, mainly in plantations whose stands quickly lose marketability.
From the point of view of providing conditions for the natural resumption of fellings, inter-strip abutment is inferior to direct and en-route abutment.
Rice. 39 Interstriated junction of cutting areas with a junction period of 2 years.
4. Checkerboard junction of cutting areas.
The cutting areas, cut in the form of chessboard cells, are joined to each other by corners annually, the rest are joined after the adjoining period
The staggered juxtaposition of cutting areas makes it possible to somewhat reduce the harmful effects of wind on uncut cutting areas. More suitable for areas whose dimensions exceed the permissible dimensions of cutting areas not only in width, but also in length.
Adjacent plots designated for clear cutting, belonging to the same type of farm, having the same method of renewal and the same position, can be combined into enlarged sections.
Clear-cutting areas in enlarged areas are located as in one area, without taking into account the boundaries of the areas that make up the enlarged area (Fig. 40).
Rice. 40 Placement of clear-cutting areas in an enlarged division, consisting of divisions 16, 17 and 22.
· Number of cuts in a quarter.
Shows how many clearcut cutting areas, not bordering each other, subject to felling in one year, can be allocated in a forest quarter.
Clause 45 of the Wood Harvesting Rules establishes that with a cutting area width of up to 50 m, 4 cuts per year are allowed, with a cutting area width of 51 - 150 m, 3 cuts per year are allowed, with a cutting area width of 151 - 250 m, 2 cuts per year are allowed, with greater width logging is allowed 1 cut per year.
When allocating clear-cutting areas, all parameters of the organizational and technical elements of the cutting areas must be observed simultaneously.
During CPR, all trees in the cutting area are subject to felling. The exceptions are:
1. Trees of relict and endemic species. The list of species prohibited for logging throughout Russia is given in paragraph 15 of the Rules for the release of standing timber in the forests of the Russian Federation, 1998 (read it in detail). In addition, on the basis of the same paragraph, trees of other valuable and rare species, according to lists approved by the authorities, are not subject to felling state power subjects Russian Federation, including those listed in the Red Book of the Russian Federation and the red books of the constituent entities of the Russian Federation. On the territory of the Toguchin Forestry Technical School, for example, Siberian larch is classified as such species.
Literature and regulatory and technical documentation:
