Study On The Influence Of Site Conditions On The Growth And Wood Properties Of Cunninghamia Lanceolata

Cunninghamia lanceolata is one of the important fast-growing timber species in southern China.Due to the differences in site factors,it will inevitably have an impact on the Cunninghamia lanceolata growing in different site conditions.In order to study the growth law,nutrient utilization characteristics,and the change law of Cunninghamia lanceolata wood properties under different site conditions,this paper takes 3 30-year-old Cunninghamia lanceolata plantations with different site conditions at Huangfengqiao Forest Farm in Youxian County,Zhuzhou City,Hunan Province as the research object.Analytical method and harvest method to study its growth law and stand biomass and its structural characteristics;through the determination of C,N,P,K,Ca in different organs(roots,branches,stems,leaves)of standard Cunninghamia lanceolata in three plots,Mg content to explore the spatial and temporal distribution characteristics of forest stand nutrient elements;through the determination of 3 sample plots of Cunninghamia lanceolata plantation wood fiber shape and density,hardness,compressive strength along the grain,flexural strength,flexural elastic modulus,impact toughness and other physics The mechanical properties study the influence of the growth status of Cunninghamia lanceolata in different sites on the wood properties of Cunninghamia lanceolata.The results of the study are as follows:(1)The average diameter at breast height,tree height,and volume per plant of Cunninghamia lanceolata plantations in 3 different sites increased with the increase of tree age.Plotl increased the fastest,Plot 2 followed,and Plot 3 was the slowest.The relationship among the average diameter at breast height,tree height,and volume per plant of the three plots of Cunninghamia lanceolata plantations was:Plot 1>Plot 2>Plot 3.Plot 1 is located at the foot of the mountain and has better soil conditions and higher nutrient element content,which together promote the faster growth of forest trees;Plot 2 has the same soil conditions as Plot 3,but Plot 2 The relatively low altitude is conducive to the growth of Cunninghamia lanceolata.(2)The biomass per plant of Cunninghamia lanceolata plantations in 3 different sites were:483.65kg on Plot 1>388.33kg on Plot 2>246.00kg on Plot 3;the aboveground and underground biomass of Cunninghamia lanceolata on Plot 1 were 393.50kg and 90.15kg,respectively.,Accounting for 81.36%and 18.64%of the biomass of a single plant;the aboveground and underground biomass of Cunninghamia lanceolata in Plot 2 were 317.45kg and 70.88kg respectively,accounting for 81.75%and 18.25%of the biomass of a single plant;The underground biomass is 199.76kg and 46.24kg respectively,accounting for 81.20%and 18.80%of the biomass of a single plant.The order of biomass size of each organ of Cunninghamia lanceolata in plots Plot 1,Plot 2,and Plot 3 is:trunk>root>branches>leaves.The relationship between the biomass of roots,branches,trunks,and leaves of Cunninghamia lanceolata in the three sites was Plot 1>Plot 2>Plot 3.(3)The order of total nutrient content of the roots of Cunninghamia lanceolata in 3 different sites is Plot 1>Plot 3>Plot 2;the order of total nutrient content of branches is Plot 2>Plot 1>Plot 3;the total nutrient content of stems and leaves The order of size is 1>2>3.The contents of C,N,P,K,Ca,and Mg in the organs of the three site Cunninghamia lanceolata exhibited different performances in different seasons.In the vigorous season of Cunninghamia lanceolata growth,the N and P elements in the roots and leaves of Plot 1 Cunninghamia lanceolata were significantly higher than those of Plot 2.(4)The relationship between the mechanical indexes of the Cunninghamia lanceolata grown on the woodland of 3 different site conditions is as follows:air-dry density,total dry density,basic density,string surface hardness,grain compression strength,and flexural elastic modulus are all Plot 3.>Plot 2>Plot 1;End surface hardness,radial surface hardness,bending strength,and impact toughness are Plot 2>Plot 3>Plot 1.(5)The growth rate of Cunninghamia lanceolata in Plot 1 and Plot 2 plots slowed down with the rise of slope position.The fiber length,width and aspect ratio of Cunninghamia lanceolata in different slope positions were significantly different.Except for impact toughness,the physical and mechanical properties of wood were one of the differences.The physical and mechanical properties of Cunninghamia lanceolata wood in Plot 2 were significantly better than those in Plot 1.The growth rate of Cunninghamia lanceolata in Plots 2 and 3 slowed down with the increase in altitude.The fiber length and width of Cunninghamia lanceolata at different altitudes There are significant differences,there is no significant difference between the aspect ratios,and the physical and mechanical properties of wood are not significantly different.However,the physical and mechanical properties of the Cunninghamia lanceolata wood of the Plot 2 are better than those of the plot 3.The comprehensive ranking of wood properties for the three site conditions is Plot 2>Plot 3>Plot 1.