I-tundra ibhekwa njengento ebalulekile umgodi we-carbon, osebenza njengosinki ogcina inani elikhulu lekhabhoni emhlabathini wawo oyiqhwa. Nokho, imiphumela ye ukushintsha kwesimo sezulu Bawushintsha kakhulu lo msebenzi. Ukwanda okuqhubekayo kwamazinga okushisa kubangela ukukhululwa kwale carbon ngesimo se i-dióxido de carbono (CO2) y i-methane emkhathini, okwandisa ukufudumala kwembulunga yonke.
I-Tundra ecosystems, etholakala ezindaweni zase-arctic njengeGreenland, iSiberia ne-Alaska, izwela kakhulu ekushintsheni kwesimo sezulu. Sekuyiminyaka engaphezu kweshumi, abacwaningi esiteshini saseZackenberg enyakatho yeGreenland beqaphe isabelomali sekhabhoni i-northern hemisphere tundra, edalula ukuthi izinto eziphilayo ezihlala kulezi zifunda ziyishintsha kanjani indima yazo ukusuka ekugcinweni kwekhabhoni ukuya ekukhipheni inetha.
Ocwaningweni lwakamuva, olushicilelwe ku Journal of Research Geophysical, kuyacaca ukuthi ukukhishwa kwe-carbon dioxide ngezinto eziphilayo liyakhula njengoba amazinga okushisa enyuka. Ngokufanayo, inqubo ye i-photosynthesis, ukhiye wokuthwebula i-CO2, nawo uthinteke kabi. Kunamazinga okushisa abucayi, afana no-7ºC, ake adlula, ukugcinwa kwekhabhoni kulezi zindawo zemvelo kuyaphela.
Umthelela wokushintsha kwesimo sezulu kumjikelezo we-tundra carbon
Umjikelezo wekhabhoni ku-tundra uthonywa ngokuqondile amazinga okushisa. Njengoba isimo sezulu sifudumala, ungqimba olungaphezulu lwe-permafrost luyancibilika, oluvumela ama-microorganisms ukuba abole. izinto eziphilayo iqandisiwe ngaphambilini. Le nqubo iphumela ekukhululweni kwenani elikhulu le-CO2 kanye i-methane, amagesi abamba ukushisa akhulisa umthelela wokushintsha kwesimo sezulu.
Izifundo ezahlukahlukene, njengalezo eziqondiswe yi- NASA e-Arctic, bonisa ukuthi i-tundra iguqukela ekuziphatheni okufana kakhulu nalokho amahlathi e-boreal, ama-ecosystem atholakala ezindaweni eziphansi. Lesi simo sihlanganisa ukufuduka kwezinhlobo zezitshalo ezifana nezihlahla nezihlahla ezincane zibheke enyakatho, okuphinde kuthinte umjikelezo wekhabhoni.
Ukubhekwa kwesathelayithi, kusetshenziswa ubuchwepheshe obuthuthukisiwe obufana ICESat-2 y I-Landsat, baye benza kwaba nokwenzeka ukubhala lezi zinguquko emjikelezweni wekhabhoni kanye nokuhamba kohlaza kuya e-Arctic. Ngobuningi bezitshalo zezihlahlana, i-tundra ingamunca i-CO2, kodwa ukuncibilika kwe-permafrost kusalokhu kuwusongo olubalulekile, njengoba ukukhishwa kwekhabhoni endala kuzoqeda noma yikuphi ukumuncwa okwengeziwe kwezimila.
Ukuqothulwa kwangaphambi kwesikhathi kanye nemiphumela yako
Enye yezinselelo ezinkulu ezibhekene ne-tundra defrosting ekuqaleni okuhambisana nokushintsha kwesimo sezulu. Iqembu labacwaningi liye labonisa ukuthi ukuqhubekela phambili kwentwasahlobo, okwenzeka ngenxa yobusika obubandayo, kushintsha umjikelezo wokuphila kwezitshalo e-tundra. Lolu shintsho lunganciphisa ikhono le-tundra lokwenza njenge- usinki we-carbon.
Umjikelezo ovamile we-tundra uqinisekisa ukuthi izitshalo, njengoba zibola, zikhulula kancane kancane ikhabhoni ebusika obude, okuvumela inhlabathi ukuyigcina. Kodwa-ke, ukuncibilika kwangaphambi kwesikhathi kudala ukungalingani kulo mjikelezo, okwenza kube lula ukuphuma kwe-CO2 ngaphambi kokuba izitshalo zimunce amanani abalulekile nge-photosynthesis. Umphumela uba negalelo elikhulu ekwandeni kwamagesi abamba ukushisa.
Ukufudumala kwe-Arctic nokuhlehla kwe-tundra
Phakathi kwemiphumela emangalisa kakhulu yokufudumala kwe-Arctic yi- ukuhlehla kwe-tundra. Ngokusho kocwaningo lwakamuva, uma izinyathelo zokushintsha kwesimo sezulu zingasetshenziswa ngokuqinile, kulinganiselwa ukuthi phakathi nale nkulungwane yeminyaka, kuphela i-6% ye-tundra yamanje ezohlala enyakatho-mpumalanga yeRussia. Le nqubo ibangelwa ukwanda kwezinhlobo zezihlahla ezifana i-larch yaseSiberia, eqhubekela enyakatho ngesilinganiso samakhilomitha angu-30 ngeshumi leminyaka, isusa izitshalo eziyisici ze-tundra.
Lokhu kuguqulwa akugcini nje ngokuba nemiphumela emilanjeni nasezilwaneni zase-Arctic, kodwa futhi kuthinta amandla asevele abuthakathaka e-tundra okugcina ikhabhoni, okusheshisa ukuguquka kwesimo sezulu emhlabeni wonke. Amazinga okushisa afudumele avumela ukubola okukhulu kwezinto eziphilayo, okubuye kukhiphe ikhabhoni eningi ku-permafrost.
I-tundra njengosinki we-carbon usengozini
Ngokomlando, i-tundra ibithathwa njenge-a usinki we-carbon esebenza kahle ngenxa yamazinga okushisa aphansi akhawulela ukubola kwezinto eziphilayo. Nokho, imiphumela yokufudumala kwembulunga yonke ibangela ukuba le ndima yokucwila ibe sengozini. Njengoba i permafrost iyancibilika, inani elikhulu lekhabhoni eligcinwe amakhulu eminyaka liqala ukukhishwa, elingase liguqule i-tundra ibe umthombo onetha wekhabhoni kunokuba usinki.
Ucwaningo lwesayensi lusaqhubeka nokuphikisana ngokuthi lezi zindawo ze-Arctic zizokwazi yini ukuqhubeka nokufeza indima yazo njengoba i-carbon icwila ngaphansi kwezimo zezulu zamanje, kodwa okusobala ukuthi ukwanda lokushisa futhi inhlabathi encibilikayo ayiphathi kahle umthamo wokugcinwa kwekhabhoni we-tundra. Lesi simo siholele ekutheni umphakathi wezesayensi wenze izicelo eziphuthumayo zokuvikelwa kwalezi zinhlelo zemvelo, usebenzise izinyathelo ezinqala zokunciphisa ukuguquguquka kwesimo sezulu.
Ucwaningo lwakamuva luyaqhubeka lubonisa ukuthi i-tundra, i-ecosystem entekenteke, isemgudwini wenguquko engashintsha umsebenzi wayo oyinhloko njengosinki wekhabhoni. Ngaphandle kwezinyathelo ezanele, ukuncibilika ngokushesha kwe-permafrost kuzoqhubeka nokukhipha amagesi amaningi abamba ukushisa, okuqhubeka kube nomthelela ekufudumaleni komhlaba.