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Itacen da aka bugu

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Itacen da aka bugu
Wani daji da aka bugu a Siberiya wanda ya haifar da narkewar permafrost (hoton NASA).

Bishiyoyin buguwa, bishiyar da aka karkata, ko dajin da aka sha buguwa, tsayin bishiyoyi ne da ke jujjuyawa daga daidaitawarsu ta yau da kullun. [1]

Wannan yawanci yana faruwa ne a cikin dazuzzukan taiga na arewacin subarctic na baƙar fata spruce ( Picea mariana ) wanda a ƙarƙashinsa ya katse permafrost ko kankara, [2] yana sa bishiyoyi su karkata a kusurwoyi daban-daban. [3]

Hakanan ana iya haifar da bishiyar da aka karkata ta hanyar hawan sanyi, da haɓakar palsa na gaba, [4] hummocks, [5] kwararar ƙasa, [6] gandun daji masu dusar ƙanƙara, zabtarewar ƙasa, ko girgizar ƙasa . [7] A cikin tsayin bishiyoyin spruce na daidaitattun shekarun da suka tsiro a cikin Layer mai aiki na permafrost bayan wuta, karkatarwa yana farawa lokacin da bishiyoyi ke da shekaru 50 zuwa 100, yana nuna cewa hawan saman daga sabon haɓakar permafrost na iya haifar da gandun daji na bugu. [2]

Permafrost

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Permafrost, wanda shine ƙasa (ko dutse) wanda ya rage ƙasa 0 °C na aƙalla shekaru biyu a jere, [8] ya samar da ƙaƙƙarfan matrix a cikin ƙasa wanda zai iya wuce zurfin ɗaruruwan mita. The permafrost yana hana bishiyoyi daga haɓaka tsarin tushe mai zurfi; alal misali, baƙar fata spruce wanda ya dace da ƙasa na permafrost ba shi da wani taproot mai mahimmanci. A cikin wuraren da zafin jiki na permafrost yana kusa da wurin narkewa na ruwa, sauye-sauyen yanayi, ko asarar ciyayi daga wuta, ambaliya, gine-gine, ko sarewar daji, na iya narke saman saman permafrost, haifar da thermokarst, [9] sunan kimiyya don raguwar ƙasa da ke haifar da narkewar permafrost. [7] Thermokarst yana lalata tushen tushen bishiyoyin nan mara zurfi, yana sa su karkata ko faɗi. Tafkunan Thermokarst suna kewaye da zoben bishiyoyi masu shaye-shaye suna karkata zuwa tafkin, wanda ke sa ana iya gane waɗannan siffofi cikin sauƙi.

Bishiyoyin buguwa na iya mutuwa a ƙarshe saboda ƙauransu, [10] kuma a cikin permafrost mai arzikin ƙanƙara, ana iya lalata duk yanayin dajin da aka bugu ta hanyar narkewa. [11] Bishiyoyin da ba su karkata ba na iya murmurewa ta hanyar amfani da gravitropism don dawo da girma a tsaye, ta yadda za su ɗauki siffa mai lankwasa. [12] Za'a iya yin nazarin itacen amsawa ta hanyar wannan tsari ta amfani da dendrochronology ta amfani da zoben girma na shekara-shekara don sanin lokacin da bishiyar ta kasance ta karkata. [11] [13]

Dangantaka da sauyin yanayi

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Bishiyoyin buguwa ba sabon abu bane gaba ɗaya - shaidar dendrochronological na iya kwanan wata thermokarst karkata zuwa aƙalla karni na 19. [14] Yankin kudu na permafrost na subarctic ya kai kololuwa a lokacin Ƙananan Ice Age na ƙarni na 16th da 17th, [15] kuma yana raguwa tun lokacin. [16] [17]

Permafrost yawanci yana cikin rashin daidaituwa tare da sauyin yanayi, kuma yawancin permafrost ɗin da ya rage yana cikin yanayin da ya dace . [10] [18] Duk da haka, yawan narke yana karuwa, [19] [20] kuma ana sa ran yawancin ragowar permafrost zai narke a cikin karni na 21st. [21] [22]

Al Gore ya ba da misalin bishiyoyin buguwa sakamakon narkewar permafrost a Alaska a matsayin shaida na ɗumamar yanayi, a matsayin wani ɓangare na gabatar da shi a cikin fim ɗin 2006 na gaskiya mai ban sha'awa . Irin wannan ɗumamar da ke haifar da narkewar permafrost a cikin Siberiya maƙwabta an danganta shi da haɗuwa da canjin yanayi na anthropogenic, yanayin yanayi na yanayi wanda aka sani da Arctic oscillation, da albedo tabbatacce feedbacks lalacewa ta hanyar biyu lokacin da narkewar kankara fallasa danda ƙasa da teku wanda sha, maimakon tunani, hasken rana radiation . [23]

Manazarta

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  1. ↑ Empty citation (help)
  2. ↑ 2.0 2.1 (Sarah M. ed.). Missing or empty |title= (help)
  3. ↑ Ranson, Jon (2007-08-01). "Science Blog - Expedition to Siberia". Siberia Blog. NASA Earth Observatory. Archived from the original on 2007-08-08. Retrieved 2007-12-19. Permafrost that has not melted provides a solid foundation that holds trees upright. When permafrost melts, as it has here, the layer of loose soil deepens and trees lose their foundations, tipping over at odd angles.
  4. ↑ Scott, Peter A.; Hansell, Roger I.C.; Erickson, William R. (1993). "Influences of wind and snow on northern tree-line environments at Churchill, Manitoba, Canada" (PDF). Arctic. 46 (4): 316–323. doi:10.14430/arctic1359. Archived from the original (PDF) on 2011-05-24. Retrieved 2007-12-19. Such trees develop in association with frost heaving and subsequent palsa development, resulting in “drunken forests”
  5. ↑ Zoltai, S.C. (1975). "Tree Ring Record of Soil Movements on Permafrost". Arctic and Alpine Research. 7 (4): 331–340. doi:10.2307/1550177. JSTOR 1550177. Trees growing on hummocky permafrost terrain are subject to periodic tilting, and this tilting is recorded as compression wood.
  6. ↑ ""Drunken Forest" in Colorado". Incorporated Research Institutions for Seismology. Archived from the original on 2008-07-23. Retrieved 2007-12-16. Photo showing tilted trees in the "drunken forest". The trees grow atop the Slumgullion earthflow, which is four miles long and 2000 feet wide, near Lake City, CO.
  7. ↑ 7.0 7.1 Rozell, Ned (1995-09-21). "Formerly Frosty Footing Causes Drunken Forests, Alaska Science Forum". Geophysical Institute, University of Alaska Fairbanks. Archived from the original on 2007-12-27. Retrieved 2007-12-16. Melting permafrost is the most common cause of the drunken forest.… Landslides and earthquakes also can create drunken forests,…
  8. ↑ "Permafrost Landscapes" (PDF). Denali National Park and Preserve. National Park Service. Archived from the original (PDF) on 2007-01-12. Retrieved 2007-12-16. Permafrost is soil or rock that remains below 0°C for at least two consecutive years.… Spruce trees leaning in different directions (known as “drunken forest”) can be a clue to frost heaving or melting of permafrost beneath.
  9. ↑ (Sarah J. ed.). Missing or empty |title= (help)
  10. ↑ 10.0 10.1 Vitt, H.D.; Halsey, L.A.; Zoltai, S.C. (2000). "The changing landscape of Canada's western boreal forest: the current dynamics of permafrost". Can. J. For. Res. 30 (2): 283–287. doi:10.1139/cjfr-30-2-283. Archived from the original (PDF) on 2004-08-14. Retrieved 2007-12-17. As permafrost is in disequilibrium with climate, much of the permafrost that remains is in a relict state.… As the permafrost surface subsides, trees die and are tilted resulting in the development of “drunken forests” and the formation of compression wood…
  11. ↑ 11.0 11.1 Osterkamp, T.E.; Viereck, L.; Shur, Y.; Jorgenson, M.T.; Racine, C.; Doyle, A.; Boone, R.D. (2000). "Observations of Thermokarst and Its Impact on Boreal Forests in Alaska, USA". Arctic, Antarctic, and Alpine Research. 32 (3): 303–315. doi:10.2307/1552529. JSTOR 1552529. At sites generally underlain by ice-rich permafrost, forest ecosystems can be completely destroyed.… Tipped trees at the edge of thermokarst can be used to age the time of thawing of the underlying permafrost…
  12. ↑ Alman, Josh. "Drunken Trees - OISE-UTS - ENCORE". Canadian biodiversity concerns. University of Toronto Schools. Archived from the original (wiki) on 2007-12-25. Retrieved 2007-12-16. Some drunken trees recover by using gravitropism to re-orient themselves upwards; others simply topple sideways and die.
  13. ↑ "Dendrochronology - the study of tree rings". Activities. GLOBE Canada. Archived from the original on 2007-12-26. Retrieved 2007-12-18. Trees on the edge of a patch of degrading permafrost … will all exhibit reaction wood starting as soon as the event happens or in the following spring, if the tilting happened in the winter.
  14. ↑ Rozell, Ned (1995-09-21). "Formerly Frosty Footing Causes Drunken Forests, Alaska Science Forum". Geophysical Institute, University of Alaska Fairbanks. Archived from the original on 2007-12-27. Retrieved 2007-12-16. Melting permafrost is the most common cause of the drunken forest.… Landslides and earthquakes also can create drunken forests,…
  15. ↑ Perkins, Sid (2007-03-10). "Not-So-Perma Frost". Science News. Archived from the original on 2007-10-16. Retrieved 2007-12-16. When the centuries-long cold spell called the Little Ice Age ended about 150 years ago, glaciers and permafrost reached their maximum extent of the past few millennia.
  16. ↑ Halsey, L.A.; Vitt, D.H.; Zoltai, S.C. (1995). "Disequilibrium response of permafrost in boreal continental western Canada to climate change". Climatic Change. 30 (1): 57–73. Bibcode:1995ClCh...30...57H. doi:10.1007/BF01093225. S2CID 154162870. In the midboreal zone, internal lawns are present in bogs and in fens. These internal lawns do not presently contain permafrost but did in the recent past, representing degradation of permafrost since the Little Ice Age.
  17. ↑ Jorgenson, M.T.; Racine, C.H.; Walters, J.C.; Osterkamp, T.E. (2001). "Permafrost Degradation and Ecological Changes Associated with a Warming Climate in Central Alaska". Climatic Change. 48 (4): 551–579. doi:10.1023/A:1005667424292. S2CID 18135860. Evidence indicates this permafrost degradation began in the mid-1700s and is associated with periods of relatively warm climate during the mid-late 1700s and 1900s.
  18. ↑ "Permafrost - Permafrost and Climate Change". Geological Survey of Canada. Natural Resources Canada. 2006-06-15. Archived from the original on 2007-12-25. Retrieved 2007-12-18. …permafrost … is in disequilibrium with the present climate and has been slowly disappearing in response to climate warming since the Little Ice Age.… Much of the area of discontinuous permafrost is already in disequilibrium with the current climate and is still responding to changes of the last century.
  19. ↑ "Climate Change And Permafrost Thaw Alter Greenhouse Gas Emissions In Northern Wetlands". TerraDaily. 2007-08-12. Retrieved 2007-12-19. But rising atmospheric temperatures are accelerating rates of permafrost thaw in northern regions, says MSU researcher Merritt Turetsky
  20. ↑ Payette, S.; Delwaide, A.; Caccianiga, M.; Beauchemin, M. (2004). "Accelerated thawing of subarctic peatland permafrost over the last 50 years". Geophysical Research Letters. 31 (18): L18208. Bibcode:2004GeoRL..3118208P. doi:10.1029/2004GL020358. Rapid permafrost melting over the last 50 years caused the concurrent formation of thermokarst ponds and fen-bog vegetation with rapid peat accumulation through natural successional processes of terrestrialization.
  21. ↑ Camill, P. (2005). "Permafrost Thaw Accelerates in Boreal Peatlands During Late-20th Century Climate Warming". Climatic Change. 68 (1): 135–152. Bibcode:2005ClCh...68..135C. doi:10.1007/s10584-005-4785-y. S2CID 129006634. Permafrost thaw in central Canadian peatlands has accelerated significantly since 1950,… This magnitude of warming will begin to eliminate most of the present range of sporadic and discontinuous permafrost in central Canada by 2100.
  22. ↑ Lawrence, D.M.; Slater, A.G. (2005). "A projection of severe near-surface permafrost degradation during the 21st century" (PDF). Geophys. Res. Lett. 32 (24): L244010. Bibcode:2005GeoRL..3224401L. doi:10.1029/2005GL025080. Archived from the original (PDF) on 2007-04-16. Retrieved 2007-12-21. CCSM3 projections show dramatic permafrost degradation by 2100 under both high and low greenhouse gas emission scenarios.
  23. ↑ Pearce, Fred (2005-08-11). "Climate warning as Siberia melts". New Scientist. Retrieved 2007-12-19. Western Siberia has warmed faster than almost anywhere else on the planet, with an increase in average temperatures of some 3°C in the last 40 years.… Similar warming has also been taking place in Alaska:…
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