Deforestation


Deforestation in New Zealand.
Satellite image of deforestation in progress in eastern Bolivia. Worldwide, 10% of wilderness areas were lost between 1990 and 2015.[1]
Forest Landscape Integrity Index showing anthropogenic modification of remaining forest.[2]
Annual deforestation
Annual change in forest area

Deforestation or forest clearance is the removal of a forest or stand of trees from land that is then converted to non-forest use.[3] Deforestation can involve conversion of forest land to farms, ranches, or urban use. The most concentrated deforestation occurs in tropical rainforests.[4] About 31% of Earth's land surface is covered by forests at present.[5] This is one-third less than the forest cover before the expansion of agriculture, a half of that loss occurring in the last century.[6] Between 15 million to 18 million hectares of forest, an area the size of Bangladesh, are destroyed every year. On average 2,400 trees are cut down each minute.[7]

The Food and Agriculture Organization of the United Nations defines deforestation as the conversion of forest to other land uses (regardless of whether it is human-induced). "Deforestation" and "forest area net change" are not the same: the latter is the sum of all forest losses (deforestation) and all forest gains (forest expansion) in a given period. Net change, therefore, can be positive or negative, depending on whether gains exceed losses, or vice versa.[8]

The removal of trees without sufficient reforestation has resulted in habitat damage, biodiversity loss, and aridity. Deforestation causes extinction, changes to climatic conditions, desertification, and displacement of populations, as observed by current conditions and in the past through the fossil record.[9] Deforestation also reduces biosequestration of atmospheric carbon dioxide, increasing negative feedback cycles contributing to global warming. Global warming also puts increased pressure on communities who seek food security by clearing forests for agricultural use and reducing arable land more generally. Deforested regions typically incur significant other environmental effects such as adverse soil erosion and degradation into wasteland.

The resilience of human food systems and their capacity to adapt to future change is linked to biodiversity – including dryland-adapted shrub and tree species that help combat desertification, forest-dwelling insects, bats and bird species that pollinate crops, trees with extensive root systems in mountain ecosystems that prevent soil erosion, and mangrove species that provide resilience against flooding in coastal areas.[10] With climate change exacerbating the risks to food systems, the role of forests in capturing and storing carbon and mitigating climate change is important for the agricultural sector.[10]

  1. ^ "Un dizième des terres sauvages ont disparu en deux décennies" (Radio Télévision Suisse) citing Watson, James E.M.; Shanahan, Danielle F.; Di Marco, Moreno; Allan, James; Laurance, William F.; Sanderson, Eric W.; MacKey, Brendan; Venter, Oscar (2016). "Catastrophic Declines in Wilderness Areas Undermine Global Environment Targets". Current Biology. 26 (21): 2929–2934. doi:10.1016/j.cub.2016.08.049. PMID 27618267.
  2. ^ Grantham, H. S.; Duncan, A.; Evans, T. D.; Jones, K. R.; Beyer, H. L.; Schuster, R.; Walston, J.; Ray, J. C.; Robinson, J. G.; Callow, M.; Clements, T.; Costa, H. M.; DeGemmis, A.; Elsen, P. R.; Ervin, J.; Franco, P.; Goldman, E.; Goetz, S.; Hansen, A.; Hofsvang, E.; Jantz, P.; Jupiter, S.; Kang, A.; Langhammer, P.; Laurance, W. F.; Lieberman, S.; Linkie, M.; Malhi, Y.; Maxwell, S.; Mendez, M.; Mittermeier, R.; Murray, N. J.; Possingham, H.; Radachowsky, J.; Saatchi, S.; Samper, C.; Silverman, J.; Shapiro, A.; Strassburg, B.; Stevens, T.; Stokes, E.; Taylor, R.; Tear, T.; Tizard, R.; Venter, O.; Visconti, P.; Wang, S.; Watson, J. E. M. (2020). "Anthropogenic modification of forests means only 40% of remaining forests have high ecosystem integrity". Nature Communications. 11 (1): 5978. Bibcode:2020NatCo..11.5978G. doi:10.1038/s41467-020-19493-3. ISSN 2041-1723. PMC 7723057. PMID 33293507.
  3. ^ SAFnet Dictionary|Definition For [deforestation] Archived 25 July 2011 at the Wayback Machine. Dictionary of forestry.org (29 July 2008). Retrieved 15 May 2011.
  4. ^ Bradford, Alina. (4 March 2015) Deforestation: Facts, Causes & Effects. Livescience.com. Retrieved 13 November 2016.
  5. ^ Deforestation | Threats | WWF. Worldwildlife.org. Retrieved 13 November 2016.
  6. ^ Ritchie, Hannah; Roser, Max (9 February 2021). "Forests and Deforestation". Our World in Data.
  7. ^ "On Water". European Investment Bank. Retrieved 13 October 2020.
  8. ^ "Global Forest Resource Assessment 2020". www.fao.org. Retrieved 20 September 2020.
  9. ^ Sahney, S.; Benton, M.J. & Falcon-Lang, H.J. (2010). "Rainforest collapse triggered Pennsylvanian tetrapod diversification in Euramerica". Geology. 38 (12): 1079–1082. Bibcode:2010Geo....38.1079S. doi:10.1130/G31182.1.
  10. ^ a b The State of the World's Forests 2020. Forests, biodiversity and people – In brief. Rome: FAO & UNEP. 2020. doi:10.4060/ca8985en. ISBN 978-92-5-132707-4. S2CID 241416114.

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