Study On Key Technical Parameters Of Multi-functional Forest Management In Chinese Fir Plantation

Through the typical plots of Cunninghamia lanceolata plantation in 42 different developmental stages,the trunk analysis of dominant trees of large-diameter forests and the multi-functional management experiment of Chinese fir plantation were carried out to establish the DBH and tree of Chinese fir plantation.The relationship between height and crown width,combined with the growth of DBH,tree height and volume of dominant wood of large-diameter Chinese fir plantation,the multi-functional management parameters in the unit area of different stages of Chinese fir plantation were proposed.Multi-functional management provides a theoretical basis.The main research contents are as follows:(1)A survey of 42 typical plots of Chinese fir plantations at different developmental stages indicated that the arbor layer of Chinese fir plantation mainly consisted of Chinese fir,pseudo-alder,wild paulownia,bitter buckwheat,rice bran,Cyclobalanopsis,Dendrobium,Angelica,sweet sorghum,Bitter,Pinus massoniana,Paulownia,Yingchun Sakura,Elm,Mika,Hawthorn,Prickly Pear,Du Ying and other tree species;shrub layer from eucalyptus prickly ash,Daqing,medicinal herbs,red nan,rectangular leaf thorn,bitter buckwheat,lacquer tree,hawthorn,black mullet,Yingchun cherry,pseudo-alder,mountain pepper,eucalyptus,deep mountain smile,eucalyptus,sarcophagus,black rice,Yichang viburnum,abacus,etc.;snake berry,white,fern,sable,raspberry,cold plum,medlar,saxifrage,collateral,bamboo grass,buckwheat and so on.The tree species appearing at each development stage are basically similar.In addition to Chinese fir,the paulownia layer has the highest frequency of paulownia,spring cherry,hawthorn,masson pine,mouse stalk,sarcophagus and bitter buckwheat.It appears in all stages of development,and it is planned to be alder and Cyclobalanopsis.Bitterness only occurs in the stage of competitive growth and quality selection.Rice bran,sweet glutinous rice,eucalyptus,wild paulownia,and white peony only appear in the competitive growth stage;shrub layer except for the eucalyptus leaves,other tree species only It occurs in one or two stages;the herb layer has more types in the competitive growth stage and the target tree growth stage,and there are fewer types in the quality selection stage.In the diameter-level structure of Chinese fir plantation forests at different developmental stages,the diameter of the competition growth stage is mainly concentrated between 10 and 20 cm,accounting for 72.55%of the total sample plots.The 20～25a diameter grade is mainly concentrated between 20 and 30cm,accounting for 62.23%of the total sumple plot.The diameter of the target tree growth stage is mainly concentrated between 30 and 40 cm,accounting for 65.52%of the total sample plot(2)According to the trunk analysis results of dominant wood of 50a artificial Chinese fir plantation,the best regression equation for the relationship between DBH and tree height of dominant wood of Chinese fir is:Y=0.3618X+4.4979,the fitting degree of the model is R2=0.7965,among which X=DBH;Y=tree height;the best regression equation for the correlation between DBH and crown width is:Y=0.1379X+0.8589,the fit of the model is R2=0.8816,where X=DBH;Y=crown.According to the study of species composition and diameter structure of Chinese fir plantations of different ages,Chinese fir plantation can be divided into five stages according to the development stage,among which:the dominant wood height is less than 5m in the forest establishment stage and the dominant wood height is 5～in the competitive growth stage.10m,the reasonable density of stands is about 2000 plants·hm-2;the dominant wood height is 10-15m in the quality selection stage,the reasonable density of forest stands is about 1500 plants·hm-2,and the target tree number is about 240 plants·hm-2.Suitable;the dominant tree height in the target tree growth stage is 15-22 m,the reasonable density of the stand is less than 1375 plants·hm-2,and the target tree number is about 90 hm-1;the growth of the large diameter forest stand growth stage The wood is higher than 22m,the reasonable density of the forest is less than 800 plants-hm-2,and the target tree number is about 60 plants·hm-2(3)The results of multi-functional management experiment of Chinese fir plantation showed that the difference of DBH growth between different management methods was obvious.The average DBH growth rate of the 3a stands was multi-kinetic energy management(32.17%)>traditional tending thinning(22.65%)>unmanaged forest stand(3.10%);the distribution of the diameter distribution of Chinese fir plantations in different management methods was also significantly different.The function-oriented forest stands are significantly more than the traditional tending and management operations.The growth rate of the breast diameter of the target tree and the non-target tree of the multi-functional management plot is higher than that of the traditional management plot and the control business plot;The mixed degree and uniformity of the stand can be greatly improved,and the vegetation type is more than the traditional management and tending control operation,and the community structure is relatively complete.