Ukuguquka kwesimo sezulu kuthinta imvelo ngokwehlukile. Kungaba khona ezinye ezisengozini enkulu ngenxa yendawo ezikuyo, ezinye ngenxa yamazinga okushisa, imvula, njll. Abaphenyi abavela eNyuvesi yaseGranada (UGR) sebenzisane nethimba lesayensi elivela eCanada futhi bathole ukuthi imvelo yasemanzini yaseSierra Nevada ibe nezinguquko ngenxa yokufudumala kwembulunga yonke kule minyaka engu-150 edlule.
Ngabe ufuna ukwazi yonke idatha yalolu phenyo?
Izinguquko eSierra Nevada
Izinguquko ezitholwe eSierra Nevada zibangelwa yimiphumela ekhiqizwa ukuguquka kwesimo sezulu. Phakathi kwalezi zinguquko, ukunciphisa imvula nokwanda kwamazinga okushisa kungabonakala, ikakhulukazi.
Kulesi simo semvelo, akwenzeki nje kuphela ukuthi imiphumela yokuguquka kwesimo sezulu iyenzeka, kodwa kube khona futhi esinye isici esinqumayo salezi zinguquko eshiwo ngenhla. Lokhu kukhuphuka kokufakwa kothuli lwaseSahara. Abanye bangacabanga, ngabe ukuguquka kwesimo sezulu kuhlobene kanjani nokungena kothuli lwaseSahara ezinhlakeni zemvelo zaseSierra Nevada?
Ukuguquka kwesimo sezulu kwandisa imvamisa kanye namandla esomiso. Indawo lapho imvula ingagcwele kakhulu idala ukuguguleka okukhulu kwenhlabathi ngokungabi nezinhlayiya ezisuselwe kuhlaza. Njengoba imvula incipha ezindaweni zaseSahara naseSahel, inani lothuli lwaseSahara olungena eSpain landa futhi, ngakho-ke, lifakwa endaweni yemvelo yaseSierra Nevada.
Iyini imiphumela yothuli lwaseSahara?
Ucwaningo lukwazile ukunaba ngeminye yemiphumela yothuli lwaseSahara kulesi simiso semvelo. Phakathi kwabo ungabona umphumela wokufaka umquba ekukhiqizeni okuyisisekelo, ngoba lolu thuli olungenayo lunothile nge-phosphorus. Lapho ungena emachibini aseSierra Nevada phakathi namashumi eminyaka adlule, kube nomthelela ekuthuthukisweni okuqhubekayo kwama-cladocerans njengoDaphnia. Lezi zilwane zinezidingo eziphezulu ze-calcium ekudleni kwazo, ezikutholayo nakule mpuphu yaseSahara.
Lawa amachibi atholakala eSierra Nevada, njenge ILaguna de Aguas Verdes noma iLaguna de Río Seco, Banikeze leli qembu locwaningo izinkomba ezicacile zokuthi ukushintsha kwesimo sezulu kubanga imiphumela kuyo yonke imvelo yomhlaba. Okwenzeka ezweni elilodwa kungathinta imvelo yezwe kwelinye izwe, ngoba imvelo ayiqondi imingcele yezepolitiki.
“Ngokuyinhloko, ngenxa yezinguquko ezibonwe emiphakathini yezinto eziphilayo nokukhiqizwa okuyisisekelo okuqale ekuqaleni kwekhulu lama-XNUMX, kodwa okuthe ukuqinisa emashumini eminyaka amuva nje, nokuthi bakhombisa ukusabela ngokwesimo sesimo sezulu kanye nokufakwa kothuli lwaseSahara ", ngokusho kukaLaura Jiménez, umcwaningi e-UGR, obuye abuye athi" lolu cwaningo luqinisekisa ukuthi amachibi aphakeme asezintabeni eSierra Nevada ahle kakhulu izinhlelo zokwakha kabusha izimo zezemvelo zesikhathi esidlule zalezinto eziphilayo zasemanzini ngezinga lamakhulu eminyaka ”.
Iziphetho zokufunda
Ngokuvamile, ukwanda kwamazinga okushisa komoya nokwehla kwemvula kula mashumi eminyaka adlule kudala imiphumela emachwebeni aseSierra Nevada. Kuyadingeka kuphela ukubona ukuthi unyaka nonyaka imvula enesimo seqhwa incane kakhulu. Omunye wemiphumela obonakala kakhulu ngukuthi phambili ekususweni kweqhwa neqhwa, ukwanda kwamazinga okushisa kwamanzi nesikhathi sokuhlala samanzi eside.
Kumele futhi banake ukuthi uthuli lwaseSahara luthinta imiphakathi yama-cladocerae futhi luthanda ukwakheka kwezinhlobo ezithile ezifana ne-Alona quadrangularis, uhlobo olujwayelekile kakhulu kunezinye ezijwayele izimo ezimbi kakhulu noma izindawo ezibandayo njengeChydorus sphaericus.
Ekugcineni, lolu cwaningo lumele obunye ubufakazi bokuthi Ukuguquka kwesimo sezulu kwandisa ukungena kothuli lwaseSahara ePeninsula yase-Iberia, ngoba isomiso eSahara sivame kakhulu. Ngakho-ke, lolu thuli luguqula isimo se-trophic samachibi kanye nesakhiwo semiphakathi yezinto eziphilayo ezihlala kuwo.