Gandun daji
Gandun daji, yankewa, yankewa ko sharewa shine kawar da gandun daji ko tsayayyen bishiyoyi daga ƙasa wanda daga baya aka koma amfani da shi.[2] Gandun daji na iya haɗa da sauya ƙasar daji zuwa gonaki, wuraren kiwo, ko amfani da birane. Mafi yawan gandun daji yana faruwa ne a dazukan daji na wurare masu zafi.[3] Kimanin kashi 31% na doron ƙasa ya sami gandun daji.[4] Tsakanin hekta miliyan 15 - 18 na gandun daji, wani yanki mai girman Belgium ya lalace kowace shekara, aƙalla ana sare bishiyoyi 2,400 kowane minti.[5]
 Gandun daji | |
|---|---|
process (en)  da resource depletion (en) | |
 | |
| Bayanai | |
| Ƙaramin ɓangare na | human impact on the environment (en) |
| Ta biyo baya | tillage (en) |
| Karatun ta | Kimiyyar muhalli |
| Hannun riga da | reforestation (en) |
.jpg)
Hukumar Abinci da Aikin Noma ta Majalisar Ɗinkin Duniya ta bayyana sare bishiyoyi a matsayin sauya dazuzzuka zuwa wasu amfani da kasa (ba tare da la’akari da cewa mutum ne ya jawo hakan ba). "Gandun daji" da "canjin yanki na net" ba iri daya bane: na karshen shine adadin duk asarar dazuzzuka (sare bishiyoyi) da duk wata gandun daji da aka samu (fadada gandun daji) a cikin wani lokaci. Canjin net, sabili da haka kuma, na iya zama mai kyau ko mara kyau, gwargwadon ribar da aka samu ta wuce asara, ko akasin haka.[6]
Babban jigon sare gandun daji shine fadada harkar noma. Ana sare bishiyoyi don amfani da su azaman kayan gini, katako ko sayar da shi azaman mai (wani lokacin a matsayin gawayi ko katako), yayin da ake amfani da filayen da aka share a matsayin makiyayar dabbobi da amfanin gona. Mafi yawan ayyukan noma da ke haifar da gandun daji ana samun tallafi ne daga kudaden harajin gwamnati.[7] Rashin kulawa da kimar da aka zaba, kula da gandun daji, da karancin dokokin muhalli wasu dalilai ne da ke haifar da gandun daji babba. Gandun daji a cikin ƙasashe da yawa-na faruwa a ɗabi'a[8] da na ɗan adam-lamari ne mai ci gaba.[9] Tsakanin shekarar 2000 da 2012, an sare kilomita murabba'in miliyan 2.3 (890,000 sq mi) na dazuzzuka a duniya aka sare.[10]
Cire bishiyoyi ba tare da wadataccen dashen daji ba ya haifar da lalacewar mahalli, asarar halittu, da ƙanƙantar ruwa. Gandun daji yana haifar da ƙarewa, canje-canje ga yanayin yanayi, kwararowar hamada, da kuma yin ƙaura daga yawan jama'a, kamar yadda yanayin yau da kullun ya lura kuma a da ta hanyar bayanan burbushin halittu.[11] Haka kuma gandun daji yana da illa ga illolin da ke cikin iskar carbon dioxide, yana ƙaruwa da ra'ayoyi marasa kyau da ke taimakawa canjin yanayi. Har ila yau, canjin yanayi na ƙara matsin lamba ga al'ummomin da ke neman wadatar abinci ta hanyar share dazuzzuka don amfanin noma da rage filayen noma gaba ɗaya. Yankunan da aka sare itace yawanci suna haifar da wasu mahimmancin tasirin muhalli kamar lalata ƙarancin ƙasa da lalacewa zuwa cikin kurarren daji. Dangane da binciken da aka buga a Rahoton Kimiyyar Yanayi idan gandun daji ya ci gaba a halin yanzu a cikin shekaru 20 - 40 masu zuwa, zai iya haifar da cikakken ko kusan ƙarewar ɗan adam. Don kaucewa hakan ya kamata ɗan adam ya wuce daga wayewar da tattalin arziki ya mamaye zuwa "al'adun al'adu" cewa "yana da fifikon fa'idodin yanayin ƙasa sama da sha'awar mutum ɗaya na abubuwan da aka haɗa, amma ƙarshe bisa dacewa da fa'idar gama gari".[12]
Gandun daji ya fi tsauri a cikin dazuzzuka masu zafi da ƙauyuka a cikin ƙasashe masu tasowa. Fiye da rabin dukkan nau'in dabbobi da tsire-tsire a duniya suna rayuwa a cikin dazuzzuka masu zafi.[13] Sakamakon sare dazuzzuka, murabba'in kilomita miliyan 6.2 (mil mil miliyan 2.4) ne kawai suka rage na ainihin murabba'in kilomita miliyan 16 (mil mil miliyan 6) na gandun dazuzzukan wurare masu zafi waɗanda suka mamaye Duniya a da.[14] Ana share yanki mai girman filin kwallon kafa daga dajin Amazon kowane minti, tare da fadin kadada miliyan 136 (hekta miliyan 55) na dazuzzuka don noman dabbobi gaba daya.[15] Fiye da hekta miliyan 3.6 na gandun daji mai zafi na budurwa a cikin 2018.[16] Amfani da samar da naman shanu shi ne babban direba na sare dazuzzuka a cikin Amazon, inda kusan kashi 80% na dukkan filayen da aka canza ana amfani da su wajen kiwon shanu.[17][18] Kashi 91% na yankin Amazon da aka yi dazuzzuka tun shekara ta 1970 an canza shi zuwa kiwon shanu.[19][20] Asarar shekara-shekara na asarar bishiyoyi ya kai kimanin biliyan 10.[21][22] A cewar binciken albarkatun gandun daji na duniya na duniya (Global Forest Resources Assessment) 2020, matsakaiciyar kasa da aka sare shekara-shekara a shekara ta 2015 zuwa 20-demi-goma ya kai hekta miliyan 10 kuma matsakaicin asarar da yankin ke samu a duk shekara a cikin shekaru 2000 - 2010 ya kai hekta miliyan 4.7.[23] Duniya ta yi hasarar ha miliyan 178 na gandun daji tun 1990, wanda yanki ne kamar girman Libya.[24]