简介：Effectsofthreegapswhicharelarge(118m2),medium(86m2)andsmall(20m2),respectively,andundercanopyofTsugalongibracteataforestontheseedlingestablishmentofT.longibracteatawerestudiedthroughseedburialexperimentsfromDecember2003toJanuary2005inTianbaoyanNationalNatureReserveofFujian,China.TheresultsshowedthattheareaofgaphadanevidenteffectontheseedlingestablishmentofT.longibracteata.TheseedlingemergenceratesofT.longibracteatainplotsoflargegap,mediumgap,smallgapandundercanopywere10%,10%,4%and6%,representinganincreasingtrendalongwiththegapsizeincreasingwithoutasignificantdifference.Rainerodingandinsectsfeedingweretwomainfactorsleadingtoseedlingdeath.Thelargerthegapsizewas,themoreseedlingswerekilledbyrainerosionandthefewerseedlingswerekilledbyinsectsfeeding.Theemergencetimeofseedlingswasalmostsameinallplotswhiletheirdeathtimewasdifferentrespectively.Thegapsizehadasignificantimpactonseedlingsurvivalrate.Theseedlingsurvivalratewashighestinthemediumgapplot(27.0%)andnexttothehighestinlargegapplot(7.3%),andseedlinginsmallgapplotandundercanopyplotdiedoutafteronegrowingseason.Increasedlightsupplyingapswasfavorablefortheseedlingsgrowthandsurvival.IncreasedlightsupplyinthelargegapcouldenhancethegrowthofseedlingleafandrootofT.longibracteata,andtheseedlinginturnallocatedmoredrymasstorootandleaf,butithaslittleimpactonthegrowthofstem.ThisresearchindicatesthatT.longibracteataisapioneerspeciesanditsseedlingestablishmentneedamediumorlargegap(>50m2).