Forest is one of the important components of the biosphere. Forest area is 4.1 billion hectares in the world, i.e. about half of the total land cover. World reserve of wood is around 360 billion cubic metres, and annual growth – 3 200 million cubic metres.
There are about 30 000 species of timber and shrubs, and thousands of bird and animal species. According to modern understanding, forest is a part of geographic landscape, unity of trees, bushes, grass, animals, birds and micro organisms which are biologically interconnected in the process of their development and affect one another and environment.
A quantitative accumulation of wood species creates new qualitative features in a forest. This ecological complex has significant and versatile impact on the environment. A forest differs from parks and gardens since the trees in a forest create a specific functional interconnections. There are several tiers in a forest that are developed according to the species composition, the biological features of the basic plants, their age and the particular physical geographic conditions.
In complex forests of moderate zone the following tiers are identified: the first one consists of trees that develop first value forest (pine, spruce, fur, beech, oak, etc.); the second one is developed by second value trees (lime, maple, hornbeam, elm, etc.); the third or under wood one is composed by bushes (nut, cornel, hawthorn and so on, etc.); the fourth and fifth ones consist of grass and moss cover. One can meet climbing plants and mosses, mushrooms and algae on the branches in the different tiers of forest. Forests become nonhomogenous on a relatively big territory. Forests differ in species composition (pure – of one species or mixed – composed with several species), form (simple – one tier and complex – multi tier), age (one aged and various aged), origin (seeds and vegetation), frequency, productivity, etc. The species composition and ecological features of forest vegetation change sharply according to the geographic longitudes, i.e. horizontal zones.
Georgia is a highland country, thus almost all forest (97.7%) are located on the mountain slopes. In western Georgia forests begin from sea level and cover lowlands and foothill slopes up to 500 m above sea level. In lowland swampy areas we meet willow, poplar in some places Imeretian oak, ash and beech; Elevated places and foothills are covered by Colchis forests. In under wood rhododendron, bilberry, etc. are growing. There are lots of climbing plants as well.
On lowlands and foothill slopes of dry regions of eastern Georgia (Shiraki, Eldari, Mtskheta, etc.), up to 400 – 600 m above sea level light forests are spread, mostly composed of Georgian maple, pomegranate, pistacia, junipoerus, etc. In lower zone of mountains (from 500 to 900 – 1 000 m) there are oak and chestnut forests. Chestnuts are met in both eastern (Kakheti) and western Georgia. On lime soils of western Georgia and dry districts of eastern Georgia (Kartli, Gare Kakheti) oaks and hornbeams are spread instead of chestnuts. Medlar, hawthorn, cornel, nuts, etc. grow in lower zone of mountains. In middle zone of mountains (900 – 1 000 – 1 500 – 1 600 m) beech is growing in some cases purely and in some cases mixed with hornbeam, field maple, lime, spruce, etc.
In Georgia one cannot meet the beech zone only in Meskhet-Javakheti, here it is replaced by spruce, fir and pine. High zone of mountain is represented by dark coniferous forests. In western Georgia it begins from 1 400 m and often reaches high margin of forest distribution. These forests are composed with the Eastern spruce and Caucasian fir, that form multiaged, highly productive, diverse pure and mixed zones. Beeches, elms, limes as well as pines are also growing here. Great number of pines is also distributed in the mountainous part of Tusheti, Meskheti and Trialeti ridge.
In the districts where there are no spruces and firs (Gare and Shida Kakheti) beeches are spread. Upper zone of mountain (from 1 900 – 2 100 to 2 400 m) is covered by subalpine forests. Crooked forests that are spread in all districts are mainly presented by birches and beeches. Subalpine light is more typical for western Georgia and is composed with highland maple, highland oak. Forest is a global and vital factor for the entire ecological system of the earth. It is one of the live substance accumulators on our planet, as it retains a large amount of chemicals and water in the biosphere. A forest actively interrelates with the troposphere and determines the level of oxygen and carbon balance. Land vegetation and its main component – forest, provide more than 60% of the oxygen in the biosphere. One hectare mixed forest absorbs 13-17 tons of carbon dioxide and generates 10-15 tonnes of oxygen.
Forest is the most productive formation of our planet and is characterised by the highest intensity of the biological circle. A biomass accumulated in the forest considerably exceeds the biomass of grass and other vegetations. Annual growth of one hectare forest phitomass is 10-30 tonnes on average, of vegetation – 9 tonnes and of tundra – 2 tonnes.
Forest has various functions: forest is a strong accumulator of the solar energy. It has a significant influence on climate formation, on water turnover in nature, and air circulation in the atmosphere; thus, forest ensures the conditions necessary for human life.
The starting point of this circle is the process of photosynthesis that generates oxygen. While in 30-50s forest was generating just 30% of planet’s oxygen, now forest provides 60% of biologically active oxygen, the rest is supplied by marine and oceanic plankton, and field and garden plants. Oxygen generated by a forest is qualitatively different from marine and ocean oxygen, since it is full of negative ions. This significantly increases biological features of forest, since a positive influence of negative ions on the human organism is proved by scientists. Ionization of forest oxygen is 2-3 times more than marine one and 5-10 times more than ionization of urban atmosphere. Forest cleans the air form dust.
One hectare forest filters 50-70 tonnes of dust annually, and consequently forests of Georgia filter about 135-190 million tonnes of dust. Forest regulates intensity of snow melting, significantly reduces speed of air circulation and protects useful fauna and microorganisms. A lot of forest plants restrain disease-causing organisms and make the environment healthier. Forest is a powerful sanitary factor that ensures human life and health. Water protecting function of forest is very important. It facilitates normal and equal supply of water to the rivers and other water resources (lakes, springs, etc.), prevents floods, improves water quality and protects it from pollution. The role of forest is also important for increasing the soil fertility and protecting it from water and wind erosion.
A majority of the arable lands are located in unstable and insufficient humidity zones. A protective forest planting belongs to the activities directed against draught and erosion. Forest is distributed on all continents, except Antarctica. In the past times forest was spread over a larger area, part of which was later occupied by agricultural lands, cities and industrial complexes. Forest is a source of many resources: timber, bark, branches, leaves, fruit, seeds, mushrooms, etc. It is widely used in industry and other sectors. Forest is one of the biological resources that have regeneration ability.
It has biochemical function, participates in formation of diverse landscapes, has a great water preserving, soil protecting, climate regulating and sanitary hygienic importance; thus, protection of forest and its rational use has a great economic and vital importance.
In Georgia forest fund is registered in every ten years. For the first time this was done in 1959 in Borjomi, Akhaltsikhe and Abastumani forests. Statistical survey of the Borjomi forests was a first attempt of organizing processing forestry information on mountain forests in the Caucasus. Organizing forest parks is one of the forms of arranging forests in Georgia. The main goal of the forestry is meeting the demand for forest products of national economy and population, without exhausting the forest resources. This problem should be solved without reducing the forest area, preserving forest productivity, and protecting its environmental, sanitaryhygienic and other useful characteristics. Forestry, as a production sector, has a peculiarity – a significantly long period of forest growth.
One turnover of forestry takes as much time as necessary for 80 – 150 turnovers of agriculture. Changes in the forestry are basically unnoticeable for one generation. Forest is a renewable natural resource – in case of a rational use, it retains and improves its natural features and ensures a proper change of generations. A miscellaneous importance, the length of growth, and the need for a rational use of forest determine specificity of relations between human and forest. Timber logging should be done carefully in order to encourage development of highly productive forests. Lack of adequate road infrastructure hinders proper logging in Georgia. Road construction in mountainous regions is very expensive, thus agencies interested in a complex utilization of highland areas should cooperate. Protecting forests from fire has a great ecological importance – fire destroys young trees and burns vegetation; this of course worsens physical – chemical, water preserving, and soil protecting features of soil.
Danger of wind and water erosion also increases. In the past wildfire was quite frequent in Georgia and was spread on large areas. For example, there was a strong forest fire in 1884, named “Gujareti”. It covered 30 thousand hectares of forest from Tsagvery-Bakuriani to ravine of the River Tana. The wildfire was active for several months, population of Kartli and the military divisions were mobilized for its localization. Implementation of forestry activities is very important for fighting against forest fires. Fire brigades should be organized and properly equipped, public awareness should be improved concerning these issues.