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1、第40卷第5期林業(yè)科學(xué)Vol.40,No.52004年9月SCIENTIASILVAESINICAESep.,2004長白落葉松人工林樹冠形狀的模擬李鳳日(東北林業(yè)大學(xué)林學(xué)院哈爾濱150040)摘要:以長白山地區(qū)26a生長白落葉松人工林為研究對象,采用枝解析的方法,測定了25株林木(直徑10.5~24.9cm)的樹冠變量,并建立了預(yù)測樹冠外側(cè)形狀的冠形模型?;谥l著枝深度(DINC)和林木變量所建立的樹冠形狀模型包括:基徑、枝長、著枝角度和弦長等預(yù)估模型。對于大小相同樹木的主要枝條來講,這些樹冠變量是隨著DINC的增加而增大;而林木
2、的胸徑(DBH)和樹高(HT)變量很好地反映了不同大小樹木的冠形變化。冠形預(yù)測模型預(yù)測效果良好,充分體現(xiàn)了樹冠結(jié)構(gòu)的變化趨勢:樹冠形狀在樹冠的中上部呈拋物線體,而在樹冠的下部則為近圓柱體。文中所建模型,可以合理地描述長白落葉松人工林的樹冠形狀及其變化規(guī)律。關(guān)鍵詞:長白落葉松,基徑,枝長,著枝角度,樹冠形狀,枝解析中圖分類號:S758.1文獻標識碼:A文章編號: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