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1、第40卷第5期林业科学Vol.40,No.52004年9月SCIENTIASILVAESINICAESep.,2004长白落叶松人工林树冠形状的模拟李凤日(东北林业大学林学院哈尔滨150040)摘要:以长白山地区26a生长白落叶松人工林为研究对象,采用枝解析的方法,测定了25株林木(直径10.5~24.9cm)的树冠变量,并建立了预测树冠外侧形状的冠形模型。基于枝条着枝深度(DINC)和林木变量所建立的树冠形状模型包括:基径、枝长、着枝角度和弦长等预估模型。对于大小相同树木的主要枝条来讲,这些树冠变量是随着DINC的增加而增大;而林木
2、的胸径(DBH)和树高(HT)变量很好地反映了不同大小树木的冠形变化。冠形预测模型预测效果良好,充分体现了树冠结构的变化趋势:树冠形状在树冠的中上部呈抛物线体,而在树冠的下部则为近圆柱体。文中所建模型,可以合理地描述长白落叶松人工林的树冠形状及其变化规律。关键词:长白落叶松,基径,枝长,着枝角度,树冠形状,枝解析中图分类号:S758.1文献标识码:A文章编号:1001-7488(2004)05-0016-09ModelingCrownProfileofLarixolgensisTreesLiFengri(ForestryCollege
3、,NortheastForestryUniversityHarbin150040)Abstract:Modelsforestimatingcrownprofileofprimarybrancheswithinlivecrownweredevelopedina26_year_oldLarixol-gensisplantationinChangbaiMountain.Dataofcrownattributeswerecollectedfrom25sampletreesrangingindiameteratbreastheight(DBH)
4、from10.5cmto24.9cmusingthemethodofbranchanalysis.Crownprofilemodels,includingbranchdiameter,branchlength,angleoforigin,andbranchchordlength,weredevelopedfrombranchattributesandtreevariables.Thesecrownattributesofprimarybranchesforaspecifiedtreeincreasewiththedepthintocr
5、own(DINC)increasing.DBHandtotalheight(HT)wereadequatevariablesoftreeforsummarizingtheeffectsofexternalconditionsoncrownprofile.Thepredictingmodelsofcrownprofilewerelogicalandperformwelltorepresentthetrendsincrownstructure.Allcrownshapesareparabolicintheupperandmiddlepar
6、tofcrown,andfollowapproximatelycylinderatlowerpartofcrown.Overall,themodelsweresuitableindescribingthetrendsandinherentvariabilityofcrownprofileforLarixolgensisplantation.Keywords:Larixolgensis,Branchdiameter,Branchlength,Branchangle,Crownprofile,Branchanalysis1Introduc
7、tionPhotosynthesis,respiration,andtranspirationofatreemainlytakeplaceinthecrown.Crowndimensionsofatreedetermineitsfoliagedistributionandconsequentlyaffectitsphotosyntheticcapacity.Therelationsbetweencrowndimen-sionsandfoliagebiomassmaybealsoofconsiderableinteresttobette
8、runderstandtreegrowthvariationsandrelatethemtotreestatusandenvironmentalconditions.Thusanaccuratedescriptionof