ChAngEs in rEgionAl ClimAtE Brought ABout By lArgE-sCAlE DEForEstAtion in thE EAstErn lowlAnDs oFCEntrAlAmEriCA ArE AFFECting wEAthEr DownwinD in thE mountAins, impEriling ECosystEms thErE.thE so-CAllED ClouD ForEsts oF montEvErDE liE Along thE CrEst oFCostA riCA’’sCorDillErA DE tilArAn mountAins. thEsE hABitAts rEly on thE Almost pErpEtuAl Fog thAt Forms As moisturE-lADEnCAriBBEAn winDs risE up thE EAstErn slopEs oF thE mountAins AnD pAss through AltituDEs At whiCh ClouDs ConDEnsE, sAys roBErt o. lAwton, An ECologist At thE univErsity oFAlABAmA in huntsvillE. thE humiDity in thosE BrEEzEs is EnhAnCED By moisturE ExpEllED From thE lEAvEs oF lowlAnD ForEsts. By thE EArly 1990s, morE thAn A CEntury oF DEForEstAtion hAD lEFt only 18% oF thECostA riCAn lowlAnD ForEsts EAst oF thE pEAks untouChE
D、thE pAsturEs thAt rEplACED ForEsts Don’’t humiDiFy thE winDs As wEll As ForEsts Do AnD ArE BEttEr At wArming thE AtmosphErE.As A rEsult, thE winDs oFF thEsE pAsturEs must risE FurthEr up thECorDillErA DE tilArAn slopEs BEForE ClouDs ConDEnsE.sAtEllitE photos oF thE lowlAnDs in thE Dry sEAson show thAt ClouDs ArE ABsEnt or spArsE ovEr DEForEstED ArEAs But ArE thiCkEr ovEr thE ForEsts oF nEighBoring niCArAgu
A、ComputEr simulAtions oF DAy-timE ClouD FormAtion in thE ArEA support thEsE oBsErvAtions, lAwton notEs, AnD thEy Also suggEst thAt thE AltituDE oF thE ClouD BAsE woulD risE ABout 200m ABovE toDAy’’s hEight iF thE lowlAnDs wErE ComplEtEly DEForEstE
D、lAwton AnD his CollEAguEs rEport thEir rEsult in sCiEnCE mAgAzinE.thE grADuAl shiFting oF BirD rAngEs upslopE AnD A rECEnt populAtion CrAsh Among Frogs AnD toADs in thE montEvErDE ClouD ForEst suggEst thAt thE vEil oF ClouDs mAy BE liFting. sCiEntists hAD AlrEADy BlAmED thE risE oF thE ClouD BAsE For thE longEr pErioDs oF mistFrEE ConDitions oBsErvED At thE DownwinD EDgE oF thE ForEst. lAwton wArns thAt in thE FuturE, thE ClouDs mAy DisAppEAr From thE montEvErDE slopEs For DAys At A timE During thE Dry sEAson — A DEvElopmEnt thAt CoulD lEAD to CollApsE oF thE ECosystEms thErE. sAtEllitE photos shows thAt thE ClouDs ArE ABsEnt or sCAttErED ovEr DEForEstED ArEAs AnD this CoulD BE supportED By thE Following EviDEnCEsExCEpt For________.
A、thE ClouDs ovEr thE ForEst oF nEighBoring niCArAguA
B、ComputEr simulAtions oF DAy
C．thE grADuAl shiFting oF BirD living upslopE
D、A rECEnt populAtion DECrEAsE oF Frogs AnD toADs