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).
简介:Basedoninvestigationof53gapsand25quadrats(15m×15meach)ofnon-gapclosedstandinanold-growthtropicalmontanerainforestofHainanIsland,China,canopydisturbanceregimesandgapregenerationwerestudied.Gapswereellipticalinhorizontalform,theratiooflongaxis/shortaxiswasabout1.4.Percentageofexpandedgaps(EG)andcanopygaps(CG)areainthelandscapewere53.5%and25.2%respectively.EGrangedfrom31.4m2to488.2m2andCG/rom14.9m2to354.2m2,theiraveragesizes...
简介:木质的种类的差异和新生在二生态的壁龛viz被调查。在旧生长的季节联盟者的差距和未经触动的植被弄干Shorea柔韧一(Gaertn。f.)在尼泊尔的森林。我们也联系了差异措施和新生属性的变化到差距特征。树和灌木部件的茎密度比在未经触动的植被在差距是更高的。S的幼苗密度。柔韧andTerminaliaalata(B。Heyne前Roth)比在未经触动的植被在差距是更高的,当矛盾的结果为T被观察时。bellirica(Gaertn。前Roxb)并且Syzigium枯茗i(L。Skeels)以幼苗密度。在幼苗层的Simpson索引,平均索引,和种类个人比率的补充比未经触动的植被在差距是更低的。差距尺寸能解释种类丰富和种类建立率。在不同的年里到多重树下降创造的差距有S的更高的幼苗密度。柔韧a比单个或多重的树创造的差距掉在一样的年里。在结论,差距由增加柳安森林的幼苗密度,和帮助新生维持种类差异。除了差距尺寸,另外的差距属性也影响种类差异和新生。