Estudio de la estructura y del valor adaptativo de poblaciones portuguesas de "Juniperus navicularis"

Mário Rui Castro, Anabela Ferreira Belo, Anabela Afonso, M. Amely Zavattieri
2016 Lazaroa  
Juniperus navicularis Gand. isadioeciousendemicconiferthatconstitutestheunderstoryofseasidepine forestsinPortugal,areascurrentlythreatenedbyincreasingurbanexpansion.Theaimofthisstudyistoassesstheconservationstatusofpreviouslyknownpopulationsofthisspecieslocatedonitscoreareaofdistribution.Thestudywas performedinsouth-westcoastofPortugal.Threepopulationsvaryinginsizeandpinedensitywereanalyzed.Number
more » ... ted.Female cone,seedcharacteristicsandseedviabilitywerealsoevaluated.ResultssuggestthatJ. navicularis populationsare vulnerablebecauseseminalrecruitmentisscarce,whatmayleadtoareductionofgeneticvariabilityduesolelyto vegetativepropagation.Thisvulnerabilityseemstobestronglydeterminedbyclimaticconstraintstowardincreasing aridity.Ratiobetweenmaleandfemaleshrubsdidnotdifferfrom1:1inanypopulation.Deviationsfrom1:1between matureandnon-matureplantswerefoundinallpopulations,denotingpopulationageing.Verylowseedviabilitywas observed.AmajorpartofdescribedJuniperus navicularis populationshavedisappearedthroughdirecthabitatlossto urbandevelopment,lossoffitnessindrierandwarmerlocationsandlowseedviability.Thisstudyisthefirsttoaddress J. navicularis conservation,andrepresentsavaluablefirststeptowardthisspeciespreservation.
doi:10.5209/lazaroa.47929 fatcat:cjpmn3kxzrgfhpbbsuqqgybavy