Nangona kusaziwa ukuba izityalo emini zivelisa ioksijini ngefotosinthesisi kwaye ebusuku zikhupha icarbon dioxide ukuze zenze inkqubo ebizwa ngokuba "kukuphefumla", bambalwa abayaziyo into eyintsingiselo yezityalo. Ngokusisiseko ngumphunga wamanzi abalahlekileyo.
Kodwa kutheni isenzeka? Zeziphi izibonelelo ezifunyanwa zizityalo ngenxa yokulahleka kwamanzi? Yonke le mibuzo nangaphezulu siza kuyiphendula kweli nqaku. Ke ukuba ufuna ukwazi ngakumbi ukubila kwezityalo, funda.
Yintoni ukuphefumla kwezityalo nokubila?
Siza kuqala ngokuchaza iikhonsepthi ezimbini ezahlukeneyo: ukuphefumla kunye nokutshintsha kwezityalo. Zombini zibalulekile, kodwa abafani.
Ukuphefumla kwemifuno kusekwe ekusetyenzisweni kweswekile kunye neoksijini eveliswa kwifotosinthesisi ukuze zivelise amandla ekukhuleni kwazo. Kungatsho ke ukuba ichasene nefotosinthesisi. Ukwenza oku, izityalo zisebenzisa i-CO2 (icarbon dioxide) efumaneka kwindalo ukuvelisa ioksijini kunye neeswekile. Ngelixa i-photosynthesis yenzeka emini, ukuphefumla kwenzeka ebusuku. Ukongeza, iveliswa zizo zonke iiseli eziphilayo zesityalo, kodwa utshintshiselwano ngegesi lwenzeka ikakhulu kwi-stomata, esityebileyo emagqabini.
Malunga nokubila, ilahleko yamanzi ngohlobo lwomphunga yenziwa zizityalo zemithambo yegazi ngokusebenzisa i-stomata. Le nkqubo ibalulekile kwincindi eluhlaza ukuze ikwazi ukusuka emhlabeni (ngeengcambu) iye egqabini nasekulawuleni ubushushu besityalo. Nangona kunjalo, yinxalenye encinci kuphela yamanzi efikelela kumagqabi esetyenziselwa ifotosinthesisi, kuba owona msebenzi uphambili kukuphelisa ngomphunga onke amanzi angasetyenziswanga zizityalo.
Ngokwesiqhelo kunzima kakhulu ukwahlula ngumphunga wamanzi emhlabeni ukusuka ekuphefumlweni kwezityalo. Ke, Yonke le nto ibizwa ngokuba yi "evapotranspiration."
Yintoni ukubaluleka kokutshintshatshintsha kwezityalo?
Kukho imiba eliqela apho ukutshintsha kwezityalo kubaluleke kakhulu kubo.
Ukufunxwa kwamanzi
Okokuqala kukufunxwa kwamanzi. Nangona iingcambu zigcina nje ngaphantsi kwe-5%, la manzi abalulekile kulwakhiwo nokusebenza kwesityalo. Phakathi kwezinto ezibalulekileyo ngamanzi iinkqubo zebhayoloji kunye nokudalwa kweturgor, esivumela isityalo ukuba sime nkqo ngaphandle kwesidingo samathambo.
Ulawulo lobushushu
Emva koko kufuneka sikhankanye ulawulo lobushushu kwimifuno. Ngokusisiseko Umphunga ubangela ukupholisa isityalo. Ngexesha lale nkqubo, xa amanzi engena kwimeko yegesi, kukhutshwa amandla. Yinkqubo eyoyikisayo, kuba isebenzisa amandla ukophula i-hydrogen bond, enoxanduva lokubopha iimolekyuli zamanzi. Yiyo ke le nto iba yirhasi kwaye kunye namandla azo zikhutshelwa emoyeni, zibangela ukuba isityalo sipholile.
Ukufumana izondlo
Enye into ekufuneka uyiqwalasele ngale ndlela kukufumana izondlo emhlabeni. Xa isityalo sifumana amanzi ngeengcambu, sikwafumana izakha mzimba ezibalulekileyo ukuze sikhule kakuhle. Iingcali zikholelwa ukuba ukubila kwezityalo kukonyusa ukufunxeka kwezondlo.
Igalelo le-CO2
Kwakhona igalelo lekhabhon dayoksayidi enkosi kukubila kubaluleke kakhulu. Ngexesha lale nkqubo, i-stomata sivulekile ukuvumela ukutshintshiselana ngegesi phakathi kweatmosfera kunye negqabi. Ngale ndlela, ngexesha lokuvulwa kwe-stomata amanzi ayaphuma, kodwa kwangaxeshanye i-CO2 ingena kwisityalo. Ikharbhon diokside ibalulekile ukuze ifotosinthesisi ibekho. Nangona kunjalo, amanzi amaninzi ahlala eshiya kunenani le-CO2 engenayo.
Zeziphi iintlobo zokubila kwizityalo?
Iindidi zokubila zemifuno ziyahluka ngokwendawo esenzeka kuyo inkqubo. Ke ngoko sinako ukwahlula ngale ndlela:
- Ukubila kwangaphambi kokubeleka: Ukubila kwenziwa nge-stomata. Yindlela elawulwa zizityalo kwaye imele malunga neepesenti ezingama-90 zamanzi apheleleyo alahlekileyo.
- Ukubila kwelenticel: Inkqubo yenzeka ngokusebenzisa iilensi. Isityalo asiyilawuli le ndlela kwaye ngokwenani limele ubuninzi be-10% eseleyo. Ukongeza, xa i-stomata ivaliwe, ngenxa yokunqongophala kwamanzi, olu hlobo lokubila lubaluleke ngakumbi.
- Ukubila okukhethekileyo: Kulo mzekelo, umbilo wenziwa cuticle. Njengakwimeko ye-lenticellar, isityalo asinakulawula kule ndlela kwaye kwinqanaba lobungakanani asibonisi ngaphezulu kwe-10%. Ikwayindlela ekubaluleke kakhulu ukuba inyuke xa i-stomata ivaliwe. Kwiindawo ezomileyo, izityalo ze-xerophytic zinamagqabi anezicuku ezityebileyo kakhulu ngamanye amaxesha ezigutyungelwa nge-wax. Umbilo osikayo kwezi meko awudluli kwi-1% lamanzi alahlekileyo nge-stomata.
Zeziphi izinto ezinefuthe kutshintsho lwezityalo?
Ukutshintsha kwezityalo kuxhomekeke ikakhulu kwizinto ezimbini: Iimpawu zamanzi kunye ne-anatomy yangaphakathi yesityalo. Xa ukuhamba kwamanzi nge-xylem kukhulu, inkqubo yokubila inamandla ngakumbi. Njengoko oku kusenzeka, uxinzelelo lwe-xylem luyancipha. Ngenxa yoko, umahluko phakathi koxinzelelo lwe-xylem kunye noxinzelelo lweatmosferi luyanda, yiyo loo nto kuthanda ukutshintsha kwezityalo.
Ngokusebenzisa ithiyori yomanyano-yokuphefumla, ukuhamba kwamanzi kwizityalo kungachazwa. Oku kusekwe kwiipropathi ezininzi zamanzi:
- Umahluko kwi-electronegativity phakathi kwe-hydrogen kunye neoksijini.
- I-engile yebhondi yenziwe ngamabhondi amabini adibeneyo kunye nobude bawo.
- Ubungakanani bemolekyuli, inoxanduva lokudala ukunamathela kunye nokudibana kunye noxinzelelo lomphunga.
- Ukusekwa kweebhondi ze-hydrogen.
Ndiyathemba ukuba eli nqaku likuncedile ukuba ucacise onke amathandabuzo akho malunga nokuphefumla kwezityalo kwaye wazi indlela yokwahlula kwi-photosynthesis okanye ukuphefumla. Zonke ezi nkqubo zibalulekile kwizityalo nakuthi.