Inordertobetterunderstandthereasonswhyeucalyptveneercheckseasilyandseverely,woodsamplesofthreeeucalyptspecieswereselected,andtheiranatomicalandphysicalpropertieswereexaminedaccordingtoconventionalmethodsandthenationalstandards.Theeffectsofvariancesincellwallthicknessofwoodfibreandvessel,anddiameterofthecelllumenaswellasthetissueratioonthequalityofplywoodveneerwereanalysed.Theresultsshowthat:1)ThereisagreatdifferenceinfibrecellwallthicknessanddiameterofthecelllumenbetweenearlywoodandlatewoodofEucalyptusdelegatensis.2)E.obliquahasahighwoodfibretissueratioandthethickestfibrecellwall,butthedifferenceinthefibrecellwallthicknessbetweenearlywoodandlatewoodisthesmallest.3)ThewoodfibretissueratioofE.regnansissmallerthanthatofE.obliqua,anditswoodfibrecellwallisthethinnestandthereisonlyaverysmalldifferenceinfibrecellwallthicknessbetweenearlywoodandlatewood.Thedifferenceinthediameterofwoodfibrecelllumenamongearlywood,transitionareaandlatewoodisalsosmall.4)E.delegatensishasthehighesttangentialshrinkagerateandradial-tangentialshrinkagerate,andE.obliquahasthelowest.Itisthevariabilityofwoodanatomicalpropertiesofthesespeciesthatcausethedifferenceintheveneershrinkage,andthenaffectsplywoodveneerquality.
