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 land, protected forests falling under the saw of a careless business manager - 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...” A new highway, a new village - let them stand among pine trees, and not among logging residues and burning. 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. Nature retreats not to creative activity, but to purely consumer attitude To her...
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 every hectare of the taiga zone, plants use only about one percent of the incoming solar energy, create approximately 60 centners of plant mass per year; animals transform plant tissue into zoomass, the amount of which is 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
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 zones in order to study and at the same time preserve all the wealth 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 economically effective potential its influx 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.
More than one generation of foresters was brought up on the principle of G.F. Morozova " Rkilling 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 viable regrowth of economically valuable species, capable of adapting to dramatically changed conditions and forming a young forest during one-step felling of the tree stand. Typically these are areas of even-aged low- and medium-density forest stands of coniferous, hard-leaved and soft-leaved species.
Clear cuttings with preliminary artificial reforestation have not found widespread use.
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 forests and other types of forests, where there is great competition for herbaceous vegetation and there is a high probability of resumption of undesirable tree species(soft-leaved) or in the absence of sources of natural forest regeneration.
Due to the significant silvicultural differences between clear cuttings of preliminary and subsequent renewal, at one time the following were distinguished: narrow-medium- and wide-cutting fellings.
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;
Clear-lot (or local) felling when cutting 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 cutting method is established for each specific area (taxation area, cutting area), taking into account, as noted above, forest conditions, composition, structure and current state of the planting, the presence of undergrowth or a second tier, the method of reforestation and the target species of the future planting, as well as the wind resistance of the remaining planting. parts of the forest 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 western and north-western winds, which prevail 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 interstrip and side-by-side abutment. 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 cutting is not included during the abutment: this means that, for example, with a 2-year abutment 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 terms for the adjoining of cutting areas: for soft-leaved stands - 1-2 years, for coniferous and hard-leaved stands - 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 -50 m wide.
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. total area 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 the practice of conducting RGP, both single-operational (chainsaws “Husqvarna”, “Stihl”, “Solo”, skidders such as AMKADOR-2200; MTZ-82; TTR-401; TTR-402 and others) and multi-operational machines are used (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 method of wide apiaries (35-45 m), in the absence of reliable viable undergrowth, trees are felled at an angle of 45-60 degrees to the trail. Since it is difficult to take the entire half-apiary at once in one run, it is conditionally divided into strips 8-10 m wide. 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 the development of belt apiaries
method in the absence of reliable viable youngsters
The diagram shows an apiary 40-45 m wide, 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 5-8 m wide, which are adjacent to 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 make up 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, fire-free 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 economically viable undergrowth in the cutting areas. valuable species. 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 the following measures, the observance of which during logging is mandatory: (organizational and technical elements of clear strip felling):
Width of cutting areas: up to 50 m in coniferous and hard-leaved forests, up to 100 m in soft-leaved forests for group I and 100 m for forests in group II;
The next cutting area is cut down only after the previous one has been fully renewed (the main requirement for the deadline for joining cutting areas);
The choice 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:
Leaving seed trees, the best from a breeding point of view, in the amount of 15-25 trees per hectare 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;
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, on light sandy and sandy loam soils, special tractor rippers, cover strippers and cutters are used (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 a probability of waterlogging, ridges and shafts are created using double-mouldboard forest and swamp-shrub 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-seeding and undergrowth of target tree species includes freeing them from blockage with logging residues, cutting down trees of low-value deciduous species and severely damaged target trees. Damaged hardwood undergrowth is “planted on a stump.”
Projected measures to promote natural forest regeneration are listed in Table 2.
Table 2 – List of measures to promote natural reforestation in cleared areas
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 have not found widespread use.
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 logging areas, a basic diagram of the development of apiaries is drawn with symbols of the 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);
- the choice 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 of high quality are produced 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 of a 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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(clear-cutting), final felling, in which the entire tree stand in the cutting area is cut down in one go. Clear felling of forest stands in separate sections (cuttings) has been carried out since ancient times, with the advent of the so-called. shifting agriculture, in which forest areas were cleared of woody vegetation for the cultivation of agricultural plants. However, the widespread use of clear-cutting is associated with the harvesting of wood for the production of charcoal, which was used in the mining industry. IN late XIX- early 20th century Clear-cutting has become even more widespread due to the development of the pulp and paper industry. The increasing demand for wood in the first half of the 20th century, and then the intensive mechanization of logging operations, led not only to a sharp expansion in the volume of clear-cut timber harvesting, but also to an increase in the size of cutting areas to 200 hectares (concentrated felling), a reduction in the period of contiguity of cutting areas (up to 1- 2 years). It didn't match natural processes dynamics of the forest (in particular, the periodicity of seed years, etc.) and over time led to negative silvicultural and environmental consequences(disruption of reforestation processes, shallowing and disappearance of small rivers, etc.). Based on a generalization of historical experience in clear-cutting in Russia and abroad within the framework of common system For final fellings, a system of “clear cuttings” has been formed. It is divided into 2 subsystems - with preliminary or subsequent reforestation. The main goals of clear cuttings, common to all final fellings - timber harvesting and ensuring the regeneration of economically valuable tree species - have their own specifics: almost simultaneous timber harvesting of the entire forest stand and corresponding complete reforestation. Clear felling has clear advantages compared to other types of felling (primarily selective): comparative simplicity of execution, maximum concentration of harvested wood in accessible areas, minimum costs for the construction of logging roads, timber loading points and timber storage warehouses, etc. The main regulatory regulation of clear-cutting is carried out by type, identified taking into account the characteristics of the regeneration of forest-forming species (see Type of final felling, Intensity of final felling).
Fellings with preliminary renewal are divided into 2 types - with natural renewal and artificial restoration. Clear cuttings with preliminary natural regeneration are carried out in areas with tree stands, under the canopy of which there is valuable viable undergrowth that can adapt to dramatically changed conditions and form a young forest stand. These are usually areas of even-aged, predominantly low- and medium-density forest stands coniferous species and hardwood species with a density of 0.5 and below, soft-leaved species - 0.6-0.7 and below. The vitality and prospects of a teenager decrease as his age increases. For the zone of coniferous-deciduous forests of the European part of the Russian Federation age limit spruce undergrowth, which remains viable and promising under the canopy, usually does not exceed 40-50 years. However, as you move north, the viability of the undergrowth remains even with sufficient high age(ate - up to 80 years or more in the northern taiga subzone). Clear cuttings with preliminary artificial reforestation are not widespread. They can be carried out, if necessary, more smoothly than with subsequent renewal, changing generations of the forest. This is possible in areas where there is no natural regeneration of target species under the canopy of a mature tree stand and it is difficult or impossible to ensure it with measures to promote natural regeneration. Clear-cutting followed by natural regeneration (typical clear-cutting) is carried out in groups of forest types, where, in the absence of preliminary regeneration under the canopy, felling of the tree stand with additional measures assistance (partial removal of litter, mineralization of the soil surface or its loosening, etc.) ensures the natural regeneration of the target species. Such fellings are usually effective in groups of forest types with poor, sandy, dry soils (lichen pine forests, lingonberry forests and similar types in different regions countries), as well as on waterlogged soils when their surface is mineralized and microelevations are created. Clear-cutting followed by artificial regeneration (typical clear-cutting) corresponds to the nature of even-aged stands of such groups of forest types, where there is no preliminary regeneration of the target species and it is very difficult to achieve it by measures to promote natural regeneration. These are indigenous complex pine and spruce forests, oak forests and other groups of forest types of various forest growth zones, where there is great competition for herbaceous vegetation and a high probability of regeneration of non-target, usually soft-leaved species, and also in the absence of sources of natural regeneration. According to the parameters of cutting areas, 3 types of felling are conventionally distinguished: narrow-cutting, medium-cutting, and wide-cutting. Because the Negative consequences clear cuttings generally increase with an increase in the area of cutting areas; their maximum value should decrease with the deterioration of environmental and forest conditions. In the most optimal conditions for forests in the southern and middle taiga subzones of the European part of Russia, taking into account the characteristics of forest types, logging can be carried out with different normative and permissible parameters for cutting areas. With the increase in extreme ecological conditions for forests in the southern and northern directions, wide- and medium-forest clear-cutting is limited or excluded. Appropriate restrictions are necessary when environmental conditions become more complex within one forestry district or natural area, primarily for forest types with unstable, poor, shallow soils (lichen, etc.). Similar restrictions are necessary in mountain forests - in the direction from bottom to top, with increasing slope steepness, taking into account their exposure - from northern (north-eastern, northern, north-western) to southern (south-eastern, southern, south-western, western ). Significant differences consequences of clear cuttings are associated with the parameters and features of almost all organizational and technical elements of cutting areas. The width of cutting areas is of primary importance for typical clear cuttings with subsequent regeneration (especially natural) of coniferous and hardwood species. Due to the small radius of scattering of seeds (50-100 m) of these species, narrow cuttings followed by natural reforestation are most acceptable and effective in areas where forest walls are used as sources of seeding. In forest-forming coniferous species (pine, spruce, larch, etc.), forest walls can provide seed regeneration in cutting areas up to 100-150 m wide. In hardwood species with heavy seeds (oak, beech), only a small strip (slightly larger than the radius) is seeded from the walls crowns), which corresponds to the minimum width of the cutting area established for seed oak - 50 m. The width of the cutting area for Siberian pine pine can be set similarly. In addition, in a narrow cutting area, the forest walls provide quite favorable environmental conditions compared to treeless space. The weakening of the seeding function of forest walls with an increase in the width of the cutting area is to a certain extent compensated by leaving sources of seeding in the form of individual stable seed trees, seed groups, seed clumps and seed strips. Individual trees or small groups of 3-5 trees are left in lichen pine forests (10-15 trees per 1 ha) and lingonberry pine forests (15-20 trees per 1 ha); in pine forests of the blueberry group of forest types, groups of trees of 5-6 pieces are left. in the amount of 15-25 groups per 1 hectare. The distance between groups should not exceed 100 m, and to simplify the implementation of other measures to promote renewal and subsequent harvesting (after performing the seeding functions), it is advisable to arrange them in rows or in another convenient pattern. Forest walls or intra-cutting sources of contamination can perform the function of seeding if cutting coincides with the harvest year. Since harvest years for many target species are repeated, as a rule, after several years, the period of contiguity of cutting areas should be no less than the repetition period is sufficient good harvests renewable breeds. It is taken into account that the recurrence periods of productive years fluctuate significantly and differ significantly across regions and forest zones. Minimum standard adjacency periods are established taking into account the specified factors. If for the southern and middle subzones of the European taiga the adjacency period for pine and larch is set at 5 years, and for spruce and fir - 4 years, then in the northern taiga subzone it is 8 years. Along with the width of cutting areas and timing of abutment important factor, which determines the total period of felling of forest stands, is the number of fellings - cutting areas in one year. The maximum permissible number of cuts is established per 1 km of the territory in the direction of felling. The number of cuts is established in such a way that between them there are strips that are multiples of the width of the cutting area, in exceptional cases equal to it, but not less than 150-200 m, taking into account the stability of the strips left. Depending on the width of the cutting area, the number of cuts should be: with a cutting area width of 50 m - 5; 51-100 - 4; 101-150 - 3; 151-250 - 2; 251-500 m - 1. Operational capabilities clear cuttings
may be regulated in lowland forests in the territory drainage basins or other territorial entities.
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