机构地区:[1]广西大学计算机与电子信息学院,广西南宁530004 [2]广西大学林学院,广西南宁530004 [3]广西林业勘测设计院,广西南宁530011
出 处:《西部林业科学》2018年第1期110-116,共7页Journal of West China Forestry Science
基 金:广西壮族自治区林业勘测设计院科研业务费专项(GXLKYKJ201601)
摘 要:在杉木、松树、桉树、一般阔叶树人工林中分别设置25-31块共110块30m×30m样地(分为9个10m×10m样方)进行每木调查,每块样地分别组合为100m^2、200m^2、300m^2、400m^2、600m^2和900m^26个不同面积的样地,分析了不同样地面积的林分平均直径()、平均高()、优势高(DH)、每公顷断面积(G)、每公顷株数(N)、每公顷蓄积量(M)的变化情况。结果表明,各个优势树种中,不同面积大小样地的、、G、N、M总平均值均十分接近,最大值和最小值的相对相差均在8%以内(松树、桉树和一般阔叶树绝大部分在5%以内);随着样地面积的增大,DH呈增大的趋势,样地间各个林分参数的变动系数均呈逐渐减小的趋势;不同面积大小样地林分参数值与900m^2样地相应参数值的平均相对偏差,随着样地面积的增大呈逐渐减小的趋势,当样地面积达到600m^2时,所有树种组的、、DH、G及桉树的N、M平均相对偏差均小于5%,杉木、松树和一般阔叶树的N、M偏差略大,但均小于8%;当样地面积逐渐增大时,其林分参数与900m^2样地相应参数偏差大的样地数量逐渐减少;不同面积大小样地的林木直径变动系数的总平均值十分接近,但随着样地面积增大,样地间的变化系数呈减小的趋势。根据以上结果,在采用抽样方法进行森林资源调查时,样地面积以300-600m^2为宜,在进行林分参数建模样地设置时,600m^2的样地即可足够。To analyze the change of stand parameter with different sizes of the sample plot,110 plots of 30 m×30 m in size( divided into 9 quadrates with the size of 10 m×10 m) were surveyed in plantation,the forest was grouped into four classes according to the dominant tree species( Cunninghamia lanceolata,Pinus,Eucalyptus and broadleaf),each class had 25 to 31 plots. Each species sampling plot was composed of 6 plots with the area of 100 m^2,200 m^2,300 m^2,400 m^2,600 m^2 and 900 m^2,the changes of mean diameter breast high( ) and height( ),basal area( G) and dominant height( DH),number of stem( N) and stand volume( M) per hectare were analyzed in this paper. The result indicated that: for all plots and classes,the mean of ,,G,N and M of different sizes of plot were very close,while their relative phase difference of maximum value and minimum value were less than 8 percent,and most of them( Pinus,Eucalyptus and broadleaf) were less than 5 percent; as the plot size increased,DH increased and the variation coefficient of all parameters decreased; when the plot area increased from 100 m^2 to 200 m^2,300 m^2,400 m^2 and 600 m^2,the mean relative deviation of all parameters to those of 900 m^2 plot decreased gradually,when the sample plot area reached 600 m^2,the mean relative deviation of ,,DH,G of all species groups and G and M of Eucalyptus were less than 5 percent,while the deviation of N,M of Cunninghamia lanceolata,Pinus and broadleaf were slightly larger,less than 8 percent; as the area of sample plot increased gradually,the number of plot that had large deviation of their stand parameter to those of plot with 900 m^2 decreased; the mean variation coefficient of diameter breast high of different size plots were very close,but as the area increased,the variation coefficient between plots decreased. Based on the above results,it is suggested that,plot with the area of 300-600 m^2 is suitable for forest resources inventory,and plot of 600 m^2 meets with requirement for modeling forest parameter.
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