应用生态学报2024，Vol.35Issue(6)：1463-1473,11.DOI:10.13287/j.1001-9332.202406.004
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
摘要
Abstract
"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 cut-ting(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(R2=0.46)and tree height(R2=0.81)was optimal basic model.The R2 of the DBH model was increased to 0.65 and 0.89,respec-tively,after the single dummy variable and the double dummy variable were introduced into the basic model,while the R2 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 in-creases 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％),average trees(100.0％-144.2％),and pressed trees(138.5％-183.9％).The effects of medium-intensity liberation cutting and light-intensity liberation cutting on the height growth were similar(24.3％-35.1％,56.0％-92.3％,84.6％-103.2％).While in the middle and late period(42 and 80 a),height growth of three grade trees increased with the increases of liberation cutting intensity.Under each liberation cutting intensity,the ratio of height to DBH of the dominant,average,and pressed trees increased successively,ranging from 0.50-0.95,0.64-1.23,and 0.73-4.33,respectively.Only the pressed tree decreased with the in-creases of liberation cutting intensity at 0-80 a.Therefore,about 40 years after the implementation of liberation cut-ting,the promoting effect of different liberation cutting intensities on DBH growth was significantly weakened,the promoting effect on tree height growth was significantly enhanced,and the ratio of tree height to diameter began to increase.In order to alleviate forest competition,second liberation cutting should be carried out for light-intensity liberation cutting and medium-intensity liberation cutting stands to further release the growth potential of Korean pine,and thinning management should be carried out in clear cutting and heavy-intensity liberation cutting stands.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Key words
dummy variable model/liberation cutting intensity/Korean pine forest by planting conifer and reser-ving broadleaved tree/tree classification/growth law引用本文复制引用
郝鑫海,牟长城,崔雅如,姬文慧,许文,赵海明..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[J].应用生态学报,2024,35(6):1463-1473,11.基金项目
本文由东北林业大学碳中和科学基金项目(HZX220100003)和"十四五"国家重点研发计划项目(2022YFF1300502)资助. （HZX220100003）
