Clearcutting , clearfelling or logging is a forestry/logging practice where most or all trees in an area are logged uniformly. Along with logging of trees and seeds, the tree is used by foresters to create certain species of forest ecosystems and to promote certain species that require abundance of sunlight or grow in large and evenly distributed stands. Logging companies and forest unions in some countries support practices for scientific, safety and economic reasons, while critics consider them to be deforestation that destroys natural habitats and contributes to climate change.
Clearcutting is the most common and economically profitable logging method. However, it also creates adverse side effects, such as loss of humus, a charge heavily disputed by economic, environmental and other interests. In addition to the purpose of harvesting timber, clearcuts are used to make farmland. "Unsatisfied human demand for timber and fertile land" through logging out and other activities has resulted in the loss of more than half of the world's rain forests.
While tropical and tropical rainforest clearance, both tropical and tropical through clear-cuts, has received considerable media attention in recent years, other major forests in the world, such as taiga, also known as boreal forests, are also under rapid development threat. In Russia, North America and Scandinavia, creating protected areas and providing long-term leases to care for and regenerating trees - thereby maximizing future crops - is one way that is used to limit the harmful effects of clear-cutting. Long-term logged-over forest studies, such as the study of Pasoh Rainforest in Malaysia, are also important in providing insight into the preservation of forest resources worldwide.
Video Clearcutting
Jenis
Many variations are clear; the most common professional practices are:
- Clear (uniform) standards - removal of each bar (whether commercially viable), so no canopy remains.
- Sort out - removal of all bars in a predefined (patch) area.
- Clearcut strips - removal of all rods in strips, usually placed perpendicular to prevailing winds to minimize the possibility of windthrow.
- Clear-out-with-backup - removal of the majority of standing rods keeps some reserves for other purposes (eg as barriers to wildlife habitats), (often confused with seed tree methods).
- Slash-and-burn - permanent conversion of tropical and subtropical forests for agricultural purposes. This is most prevalent in tropical and subtropical forests in densely populated areas in developing and underdeveloped countries. Slash-and-burn involves deleting all the stems in a certain area. This can be a form of deforestation, when the soil is converted to other uses. However, some indigenous forest communities, such as the nineteenth century Forest Finn spin on the ground and return to the forest and this will be sustainable. Slash and burn techniques are commonly used by civilians to look for land for livelihoods and agriculture. The first forest was cut clearly, and the remaining material was burned. One of the driving forces behind this process is the result of overpopulation and further sprawl. This method also occurs as a result of commercial agriculture. Timber is sold for profit, and the land, cleared of all the rest of the brush and suitable for agricultural development, is sold to farmers.
- Cutting selection - which can be done for logging or for ecological reasons. when done so often called ecoforestry.
Minimizes contrast with selective cuts, such as high grading, where only commercial valuable trees are harvested, leaving the other. This practice can reduce the genetic viability of the forest over time, resulting in a poorer or less powerful offspring in the stands. Clearcutting also differs from the slavery system, by allowing revegetation by seeds. In addition, destructive forms of forest management are commonly referred to as 'clear-cut'.
It has been argued, however, that in New Zealand the clearance is more eco-friendly because it uses less resources for logging and less land for timber production that allows other lands to be stored as old growth forests.
Maps Clearcutting
Reduce regeneration, harvesting or system
Clearcutting can be divided into
- Clear cuts - clean cuts with complete exploitation and removal of all trees in one operation... harvest method
- Clearcutting Method - methods for regeneration even community by removing all adult trees
- Clearing system - silvicultural system which combines the clearcut method to remove (clean) the adult community in a large area at one time
Confusion between the different uses of this term is common. Furthermore, as indicated above many variations mean technically correct use may not be descriptive enough to know what is meant on that particular occasion.
Effects on environment
Environmental groups criticize clear-cuts for damaging water, soil, wildlife, and atmosphere, and recommend the use of sustainable alternatives. Clear-cutting has a huge impact on the water cycle. Trees hold water and topsoil. Deforestation clearly removes trees that should have altered large volumes of water and also physically damages the grass, moss, mosses, and ferns that fill the lower plants. All of these bi-mass usually retain water during rain. Abolition or biota damage reduces local capacity to retain water, which can worsen flooding and lead to increased nutrient leaching from the soil. Maximum nutritional losses occur around the second year, and return to pre-clearance levels in the fourth year.
Clear cuts also prevented trees from the shady river banks, which increased the temperature of rivers and streams, contributing to the extinction of several species of fish and amphibians. As the trees no longer hold the ground, the riverbanks further erode the sediment into the water, creating excess nutrients that aggravate changes in rivers and create miles of distress, at sea. All the extra sediments and nutrients that flow into the river cause increased river acidity, which can kill marine life if the increase is large enough. The nutrient content of the soil is rediscovered to a five per cent pre-clearance rate after 64 years, which shows how clear-cuts affect the environment for years.
Clearcutting can damage the ecological integrity of a region in various ways, including: destruction of buffer zones that reduce the severity of the flood by absorbing and retaining water; the immediate felling of the forest canopy, destroying the habitat for many rain-dependent insects and bacteria; removal of forest carbon sinks, leading to global warming by increasing the formation of human-induced and natural carbon dioxide in the atmosphere; elimination of fish and wildlife species due to soil erosion and habitat loss; removal of underground worms, fungi and bacteria that condition the soil and protect the plants that grow in it from the disease; loss of small-scale economic opportunities, such as fruit picking, sap extraction, and rubber tapping; and destruction of aesthetic values ​​and recreational opportunities.
Negative impact
Logging can have a major negative impact, both for humans and on local flora and fauna. A study from the University of Oregon found that in certain zones, the cropped areas clearly had nearly three times the amount of erosion due to slides. When the road required by logging has been taken into account, the increase in slide activity appears to be about 5 times greater than forested areas nearby. Roads built to cut off normal surface drainage are disturbing because roads are not permeable like normal ground cover. The streets also alter the movement of subsurface water due to the redistribution of soil and rock. Clear cuts can lead to increased river flow during storms, habitat loss and species diversity, opportunities for invasive and underweight species, and negative impact on landscapes, as well as property degradation; recreation, hunting and fishing opportunities are reduced. Clear cuts reduce the occurrence of natural disturbances such as forest fires and natural extractions. Over time, this can spend a local seed bank. An example of what clearcutting in Ontario before 1900 can be found in Edmund Zavitz.
In temperate and boreal areas, clearcutting can have an impact on the depth of snow, which is usually larger in cleared areas than in forests, due to lack of interception and evapotranspiration. This results in less ice of the soil, which in combination with higher levels of direct sunlight in the snow melt that occurred earlier in the spring and the start of peak runoff.
The world's rainforests can disappear completely within a hundred years at the current rate of deforestation. Between June 2000 and June 2008, more than 150,000 square kilometers of rainforest was cleared in the Brazilian Amazon. Large forest area has been lost. For example, only eight to fourteen percent of the Atlantic Forest in South America is now left. While deforestation rates have slowed since 2004, forest loss is expected to continue in the future. Farmers cut and burned many forest clumps each year to create grazing land and crops, but nutrient-poor soils in forests often make land unsuitable for agriculture, and within a year or two, farmers move.
Positive perspective
Clearcutting can be done to encourage the growth and proliferation of tree species that require high light intensity. In general, a wider harvest area of ​​twice the height of adjacent trees will no longer be subject to the moderating effects of forest on microclimate. The area of ​​the harvest area can determine which species will dominate. Those with high tolerance for extreme temperatures, soil moisture, and resistance to exploration can be established, especially secondary successional pioneer species.
Clearcutting can be used by foresters as a method to mimic natural disturbance and increase primary successional species, such as poplar (aspen), willow and black cherries in North America. Clearcutting has also been shown to be effective in creating animal habitats and exploration areas, which would otherwise exist without long-lasting replacement disruptions such as forest fires, large-scale windthrows, or avalanche.
Clearcuts are used to help regenerate species that can not compete in adult forests. A number of them are aspen, pine jack and, in areas with poor soil, oak trees - are an important species for wildlife species game and nongame. Clearcutting can also lead to an increase in the vascular diversity of plants in the area. This is most obvious after several years of clear-cutting and in the rich forests where scarification is occurring.
No significant changes in water temperature were observed when a clear-cut patch was performed 100 meters from the river. This suggests that a clearcut patch is a possible solution to concerns about changes in water temperature due to clear cuts. The effects of logging on soil nutrient content were not examined in this study.
Recently, forest managers have found that oak logging helps to regenerate oak forests in bad soil areas. The tree canopy in the oak forest often shrinks the ground, so it is unlikely that the new oak tree grows. When the mature tree is removed, the saplings have a chance to recruit into the forest.
Effects on wildlife
The main damage Clearcutting is to habitat, where its habitat becomes more vulnerable in the future to damage by insects, diseases, acid rain, and wind. The removal of all trees from an area will destroy the physical habitat of many species in the wild. Also clearcuts may contribute to problems for forest-dependent ecosystems, such as rivers and streams running through it.
In Canada, the black-tailed deer population is at higher risk after clear-cutting. Deer is a source of food for wolves and cougars, as well as the First Nation and other hunters. While deer may not be risky in towns and villages, where they can be seen running through the neighborhood and feeding on farms, in higher altitudes they need forest protection.
See also
- Clearcutting in British Columbia
- Land clearing in Australia
- Even aged wood management
- List of tree species with shade tolerance - intolerant shade and some intermediate species mainly regenerated with clearcuts
- Seed production and genetic diversity
- Deforestation
- the Amazon rainforest
- Deforestation and climate change
References
External links
- Canadian Broadcasting Corporation (CBC) Digital Archive - Cutting and Logging: The War of the Woods
- Congressional Research Service (CRS) Report on Clearcutting, accessed December 14, 2009
- Forest Policy Research page: California residents to stop Sierra Pacific plan to clear one million hectares of Sierra forest, accessed December 14, 2009
- Ancient Forest News - Clearcutting threatens the black-tailed deer
- Nova Scotia Public Coalition: Removing Cutting
- "Free Grassy» Boreal Forest ". Archived from the original on 2010-04-05 . Retrieved 2014-06-29 .
Source of the article : Wikipedia
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