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Clearcutting, clearfelling or clearcut logging is a forestry/logging practice in which most or all trees in an area are uniformly cut down. Along with shelterwood and Seed tree, it is used by to create certain types of forest ecosystems and to promote select species that require an abundance of sunlight or grow in large, even-age stands. Clearcutting is a forestry practice that mimics the stand initiation stage of forest succession after a natural disturbance such as Wildfire or Windthrow, and is successful for regeneration of fast growing, Douglas fir and wildlife species that readily regenerate in post-stand replacing sites. Logging companies and forest-worker unions in some countries support the practice for scientific, safety and economic reasons, while detractors consider it a form of deforestation that destroys natural habitatsU.S. Environmental Protection Agency, Washington, DC (1992). "Clear cut." Terms of Environment: Glossary, Abbreviations and Acronyms. p. 6. Document no. EPA-175-B-92-001. Accessed 2011-10-12. and contributes to climate change.Center for Biological Diversity, Tucson, AZ. "Clearcutting and Climate Change." Accessed 2011-10-12. Environmentalists, traditional owners, local residents and others have regularly campaigned against clearcutting, including through the use of blockades and nonviolent direct action.
Clearcutting is the most economically efficient method of logging. It also may create detrimental side effects, such as the loss of topsoil, the costs of which are intensely debated by economic, environmental and other interests. In addition to the purpose of harvesting wood, clearcutting is used to create land for farming. Ultimately, the effects of clearcutting on the land will depend on how well or poorly the forest is managed,Rodney J. Keenan, & J.P. (Hamish) Kimmins (1993). "The ecological effects of clear-cutting" Environmental Reviews, 1(2), 121–144. Retrieved September 16, 2020. and whether it is converted to non-forest land uses after clearcuts.FAO (2016). "State of the World's Forests 2016"
While deforestation of both temperate forest and through clearcutting has received considerable media attention in recent years, the other large forests of the world, such as the taiga, also known as boreal forests, are also under threat of rapid development. In Russia, North America and Scandinavia, creating Nature reserve and granting long-term leases to tend and regenerate trees—thus maximizing future harvests—are among the means used to limit the harmful effects of clearcutting.Kunganavolok (June 25, 1998). "Taiga! taiga! burning bright." The Economist. Retrieved: 2013-08-06. Long-term studies of clearcut forests, such as studies of the Pasoh Rainforest in Malaysia, are also important in providing insights into the conservation of forest resources worldwide.Khan, Madeline (February 9, 2004). "Clear cut forests in Malaysia offer lessons for logging worldwide." The Varsity, University of Toronto. Retrieved: 2013-08-06.
Clearcutting contrasts with selective cutting, such as high grading, in which only commercially valuable trees are harvested, leaving all others. This practice can reduce the genetics viability of the forest over time, resulting in poorer or less vigorous offspring in the stand. Clearcutting also differs from a coppicing system, by allowing revegetation by . Additionally, destructive forms of forest management are commonly referred to as 'clearcutting'.
Confusion between these different uses of the term is common. Furthermore, as indicated above many variations mean technically correct usage may not be descriptive enough to know what is meant on that particular occasion.
A clearcut is distinguished from selective logging where typically only a few trees per hectare are harvested in proportions dictated by management objectives. Clearcut logging is also distinct from wildland fire use, and from forest thinning. In these latter two it is common practice to leave trees that are considered undesirable, such as those that are too diseased, stunted or small to be marketable. Selective logging is usually practiced in areas with access to infrastructure.
Removing trees surrounding stream banks prevents shading of the water body, which raises the temperature of riverbanks and rivers. Because the trees no longer hold down the soil, riverbanks increasingly erosion as sediment into the water, creating excess nutrients which exacerbate the changes in the river and create problems miles away, in the sea. Clear cutting on a large scale in a watershed can cause sediment and nutrients that leach into the streams cause the acidity of the stream to increase. The nutrient content of the soil was found to return to five percent of pre-clearcutting levels after 64 years.Covington, W. W. (1981). Changes in forest floor organic matter and nutrient content following clear cutting in northern hardwoods. Ecology, 41-48.
In Temperateness and Taiga climates, clearcutting can have an effect on the depth of snow, which is usually greater in a clearcut area than in the forest, due to a lack of interception and evapotranspiration. This results in less Frost line, which in combination with higher levels of direct sunlight results in snowmelt occurring earlier in the spring and earlier peak runoff.
The world's rain forests could completely vanish in a hundred years at the current rate of deforestation. Between June 2000 and June 2008, more than of rainforest were cleared in the Brazilian Amazon. Huge areas of forest have already been lost. For example, only eight to fourteen percent of the Atlantic Forest in South America now remains. While deforestation rates have slowed since 2004, forest loss is expected to continue for the foreseeable future. Future threats to the Amazon rainforest Farmers slash and burn large parcels of forest every year to create grazing and croplands, but the forest's nutrient-poor soil often renders the land ill-suited for agriculture, and within a year or two, the farmers move on. National Geographic:rain forest threats
Clearcutting can be used by as a method of mimicking a natural disturbance and increasing primary successional species, such as Populus (aspen), willow and Prunus serotina in North America. Clearcutting has also proved to be effective in creating animal habitat and browsing areas, which otherwise would not exist without natural stand-replacing disturbances such as , large scale windthrow, or .
Clearcuts are used to help regenerate species that cannot compete in mature forests. A number of them are aspen, jack pine, and, in areas with poor soils, oaks—are important species for both game and nongame wildlife species. Clearcutting can also lead to increased vascular-plant diversity in the area. This is most pronounced after a couple years of clearcutting and in herb-rich forests where scarification took place.
No significant changes in water temperature were observed when patch clearcutting was done away from a river. This suggests that patch clearcutting is a possible solution to concerns about changes in water temperature due to clearcutting. The effects of clearcutting on soil nutrient content were not examined in this study.Brown, G. W., & Krygier, J. T. (1970). Effects of clear-cutting on stream temperature. Water resources research, 6(4), 1133–1139.
More recently, forest managers have found that clearcutting oak stands helps regenerate oak forests in areas of poor soil. The tree canopies in oak forests often shade out the ground, making it impossible for newly sprouted oaks to grow. When the mature trees are removed, the saplings stand a chance of recruiting into the forest.
In Canada, the black-tailed deer population is at further risk after clearcutting. The deer are a food source for wolves and cougars, as well as First Nations and other hunters. While deer may not be at risk in cities and rural countryside, where they can be seen running through neighbourhoods and feeding on farms, in higher altitude areas they require forest shelter.
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