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Environmental problems of Northern Eurasia

Deforestation and Degradation of Forests

<<< Commercial Exploitation of Forests | Environmental Problems Index | Insect Invasions and Fires >>>

Logging Practices and Impacts in the Areas of Commercial Exploitation

With respect to timber harvesting, there are two major practices: selective logging (the highest value wood is cut) and clear-felling. Although selective logging does not cause deforestation, the removal of tall trees and valuable species degrades forest structure and composition in comparison with the untouched mature forests. For example, in the Arkhangelsk oblast and the Komi Republic valuable softwood has been consistently over-cut while hardwood remains underused. As a result, primary forests occur mainly in the remote eastern part of Komi while in more accessible southern and western areas tall pine stands have been widely replaced by small-leaved deciduous stands. In the south of the Arkhangelsk oblast, primary spruce stands have been replaced by birch and aspen forests and only in the north do productive coniferous forests exist. Similarly, in the Novgorod, Pskov, and Kaliningrad oblasts secondary birch, aspen, and alder forests dominate. Around St. Petersburg, coniferous forests now exist only on the Karelian Isthmus and in the east of the Leningrad oblast (Sostoyanie, 1995).

Clear-felling, which causes the most drastic modification of vegetation and is a primary cause of deforestation, is a predominant practice in the timber-rich regions. The Russian way of clear-felling implies that all mature commercial trees are felled and, although young trees and undergrowth are not harvested, they are mostly destroyed by heavy machinery which is used to skid tree trunks taking the shortest possible route. Slash (branches, bark, conifer needles, and debris) is not utilized but left on site, and stumps and roots remain in the ground. This practice prompts yet another negative aspect of logging, the breeding of vermin insects. About 35 million m3 of wood is wasted during felling and timber rafting (transport by rivers) annually. Total losses account for 30 per cent of the cut wood. The wood-processing industry in the FSU is notorious for its inefficiency. Thus in 1988, the Soviet wood-processing industry produced 6.1 tonnes of plywood, 18.9 tonnes of chipwood blocks, and 28 tonnes of cardboard out of 1000 m3 of timber, whereas Finland produced 13.5, 13.5, and 190 tonnes, respectively (Khrushchev, 1997).

The scale of forest clearance can be enormous. It is not unusual for the vast forest massifs, which occupy hundreds of thousands of hectares, to be cut, reducing vegetation cover virtually to zero. In regions of excessive moisture supply, such as Western Siberia, cleared areas are prone to the formation of swamps in the course of a few years. Vast open areas create favourable conditions for the development of windfalls. Even more significant from a long-term perspective is that natural regeneration is impeded because young trees are killed or severely damaged when commercial trees are felled. Regeneration of forests through seeding is almost impossible because mature forests are located too far away.

Apart from destroying vegetation, logging practices destroy wildlife habitats and contribute to the degradation of soils. Soil cover is damaged by heavy machinery which destroys the upper strata and bring to the surface deeper loamy and gleyey substrates. Overcompaction of soils on clearings is a typical problem. In sandy soils at a depth of 20 cm, the compaction ratio increases by 27 per cent and in loamy soils by 44 per cent, leading to the reduction in porosity of soils and hampering their aeration regime (Serebryanny and Zamotaev, 1997b). Soil erosion problems are most obviously associated with forest clearance in the mountains. Extremely high erosion rates were observed in the Carpathian mountains where soil layers up to 1-1.5 m thick were washed off the swathes of cleared forest (Gensiruk, 1979). In the Baikal region, where forests develop at a limit of their natural distribution and therefore grow slowly, deforestation of slopes resulted in a rapid development of gully erosion which on many occasions made transportation of timber from logging sites impossible. Local communities were affected because routes to the montane pastures were disrupted. Mudflows are now a problem and increased sediment yields now cause silting of dams and reservoirs.

There is now an ongoing debate about the methods adopted by the timber industry with respect to both environmental and social aspects. The practice of a 'migrating logging site' has come under particularly strong criticism. This practice refers to the intensive development of a designated area which involves the construction of a settlement and roads leading to logging sites and subsequent clear-felling. Once timber has been logged, the site is abandoned and a new one is selected at a greater distance from the settlement, thus migrating further and further away. Each time, large investments are required for road construction and greater pressure is imposed on the workforce. Frequently, forests are cleared completely over large areas around such a settlement in a short period of time. It is not unusual after a few years of exploitation to abandon settlements, forcing dwellers to leave or face severe economic and social problems. Already in the 1960s, a different scheme was proposed which involved a radial network of roads servicing logging areas and at later stages aiding reforestation measures and limiting annual cutting to the annual regrowth (Armand, 1966). Such a system would be more economical, sustainable, and create better living conditions. However, in the present economic situation, it is unlikely that these recommendations will be implemented.

To overcome the problem of the poor transport infrastructure in the areas of commercial timber exploitation, timber rafting was widely used in Russia, especially in Siberia and the European north. The major impacts of rafting are the accumulation of large volumes of timber in rivers and on river beds and decomposition of wood. A gigantic timber jam, up to 15 km in length, forms close to the mouth of the river Pinega, which drains the timber-producing Arkhangelsk oblast each year preventing the migration of salmon and other species to the Northern Dvina. A large amount of timber is carried to the Arctic Ocean. Timber can drift over substantial distances and it is not unusual for it to be discovered on the coasts of Novaya Zemlya and Spitsbergen. Decomposition of wood which remains in rivers leads to water pollution with toxic substances, primarily phenol. In recognition of the severe environmental damage inflicted by rafting, this practice was recently prohibited. This measure could help to improve environmental quality across many northern and Siberian rivers and promote more efficient use of wood. Unfortunately, however, this enforcement is proving difficult.

<<< Commercial Exploitation of Forests | Environmental Problems Index | Insect Invasions and Fires >>>

 

 


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