Growth at the microscale:long term thinning effects on patterns and timing of intra-annual stem increment in radiata pine

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    摘要 Background:Stemradialgrowthinforestsisnotuniform.Rather,itischaracterizedbyperiodsofrelativelyfastorslowgrowth,orsometimesnogrowthatall.Thesefluctuationsaregenerallyafunctionofvaryingenvironmentalconditions(e.g.wateravailability)and,importantly,willalsobeassociatedwithadjustmentsinpropertiesinthewoodformed.Standlevelconditionsandforestmanagement,particularlythinningandstanddensitywill,however,alsohaveamajorinfluenceonpatternsofgrowthvariation.Weexplorehowdifferentthinninghistoriesand/orstanddensitiesinfluencethesedynamicsoftreegrowthintheimportantcommercialplantationspeciesPinusradiotaD.Don.Methods:DailystemsizechangewasmeasuredusingelectronicpointdendrometersovertwogrowingseasonsonP.rodiatatreesattwosites,subjectedtodifferentthinningregimes.Timing,ratesandperiodicityofannualgrowthwerecalculatedfromthesedata.Results:Greateroverallcross-seaionalgrowthinthinnedplotswasdrivenmainlybytwodynamics.First,thecessationofseasonalgrowthoccurredatleast3weekslaterinthestandsinwhichthinninghadtakenplace.Therewasnodifferencebetweenthinned/unthinnedstands,however,inthetimingofgrowthonset.Second,withinthelongerseason,treesinthinnedplotshadmoregrowthdays(asmuchas20%more)thanunthinnedplots.Theratesofgrowthondayswhengrowthoccurredwerenotdifferent,however.Inthiscontext,itisnotablethatintreesintheunthinnedplotsexperiencingthemostseverecompetitiontherewerestrongMpulsesMofgrowthfollowingdrought-breakingrainfallevents.Unthinnedplotsathighstanddensitiesalsomaintainedasmaller(butconsistent)zoneofdividingcellsthroughouttheseasonthanthinnedplots.Conclusions:InPinusradiatogrowingunderconditionsasinourstudy,conditionslateinsummer,particularlydrought,haveanimportanteffectonthetimingofcessationofgrowth.Earlyseasontemperatureappearstohavenoeffectin
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    出版日期 2018年04月14日(中国Betway体育网页登陆平台首次上网日期,不代表论文的发表时间)
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