基于双哑变量模型预测透光抚育强度对次生林内红松生长的影响  

Prediction of liberation cutting intensity effect on the growth of Korean pine in secondary forest based on double dummy variable model

作　　者：郝鑫海 牟长城[1] 崔雅如 姬文慧 许文[2] 赵海明[2] HAO Xinhai;MU Changcheng;CUI Yaru;JI Wenhui;XU Wen;ZHAO Haiming(Key Laboratory of Sustainable Forest Ecosystem Management of Ministry of Education,College of Forestry,Northeast Forestry University,Harbin 150040,China;Baihe Forestry Bureau of Jilin Province,Yanbian 133613,Jilin,China)

机构地区：[1]东北林业大学森林生态系统可持续经营教育部重点实验室,哈尔滨150040 [2]吉林省白河林业局,吉林延边133613

出　　处：《应用生态学报》2024年第6期1463-1473,共11页Chinese Journal of Applied Ecology

基　　金：东北林业大学碳中和科学基金项目(HZX220100003);“十四五”国家重点研发计划项目(2022YFF1300502)资助

摘　　要：“栽针保阔”是恢复我国东北阔叶红松林的有效途径,透光抚育能促进冠下红松生长并加快演替进程,但目前有关透光抚育如何影响次生林内红松生长过程仍不清楚。以长白山“栽针保阔”红松林为对象,构建含双哑变量(透光抚育强度和林木分级)的红松胸径和树高生长模型来预测不同透光抚育强度[即对照(未透光)、轻度透光抚育(保留上层郁闭度0.6)、中度透光抚育(0.4)、强度透光抚育(0.2)和全透光(伐除全部上层阔叶树)]林分中红松三级木的生长过程,揭示透光抚育强度对林内红松胸径和树高及高径比的影响规律。结果表明:6个基础模型中,Gompertz为红松胸径(R^(2)=0.46)和树高(R^(2)=0.81)最优基础模型,在基础模型中引入透光抚育强度单哑变量、双哑变量后胸径模型的R^(2)分别提高至0.65和0.89,树高模型的R^(2)分别提高至0.84和0.94;双哑变量模型为预测红松生长的最适模型。被压木胸径生长在整个模拟预测期间(树龄0~80年)均随透光抚育强度增大而递增(增幅为145.8%~933.3%),而平均木和优势木在中期(42年)、中后期(60年)呈此规律。在初期(20年)和中期,全透光与强度透光抚育对红松优势木(64.8%~68.5%)、平均木(100.0%~144.2%)和被压木(138.5%~183.9%)树高生长的影响程度相近,中度透光抚育和轻度透光抚育对其影响相近(24.3%~35.1%、56.0%~92.3%和84.6%~103.2%);在中后期(62年)和后期(80年),红松三级木树高生长均随透光抚育强度增大而递增。各透光抚育强度下红松优势木、平均木和被压木的高径比变化幅度依次增大,分别为0.50~0.95、0.64~1.23和0.73~4.33;仅被压木在树龄0~80年随透光抚育强度增大而递减。因此,透光抚育约40年后,其对红松的胸径生长的促进作用减弱而对树高的促进作用却增强,而且高径比提高,故此时为缓解林木竞争,对轻度透光抚育、中度透光抚育的林分应进行二次透光抚育以�“Planting conifer and reserving broadleaved tree”is an effective way to restore broad-leaved pine forest of temperate zone in Northeast China.Liberation cutting can promote the growth of Korean pine(Pinus koraiensis)under forest crown and accelerate the succession.However,how liberation cutting intensity affects the growth of Korean pine in secondary forest is still unclear.Taking the“Planting conifer and reserving broadleaved tree”Korean pine forest in Changbai Mountain as the object,we constructed a growth model of diameter at breast height(DBH)and tree height of Korean pine with double dummy variables(liberation cutting intensity and tree classification)to predict the growth of Korean pine plantation under different liberation cutting intensities,i.e.control(no liberation cutting),light-intensity liberation cutting(retaining upper canopy closure 0.6),medium-intensity liberation cutting(0.4),heavy-intensity liberation cutting(0.2)and clear cutting(cutting all upper broadleaf trees)stands.We analyzed the effects of liberation cutting intensities on DBH,tree height,and the ratio of tree height to DBH.The results showed that among six theoretical growth equations,the Gompertz model on the DBH(R^(2)=0.46)and tree height(R^(2)=0.81)was optimal basic model.The R^(2) of the DBH model was increased to 0.65 and 0.89,respectively,after the single dummy variable and the double dummy variable were introduced into the basic model,while the R^(2) of the tree height model was increased to 0.84 and 0.94.Therefore,the double dummy variable model was the most suitable for predicting the growth of Korean pine.The growth of DBH of pressed tree increased with the increases of liberation cutting intensity(increase by 145.8%-933.3%)during the whole simulation period(0-80 a).Average and dominant trees showed the same pattern at 42 and 60 a.In the early and middle stages of liberation cutting(20 and 42 a),clear cutting and heavy-intensity liberation cutting had similar effects on the height growth of dominant trees(64.8%-68.5%)

关 键 词：哑变量模型 透光抚育强度 “栽针保阔”红松林 林木分级 生长规律 

分 类 号：S791.247[农业科学—林木遗传育种]