福州市国有林场杉木林林分材种出材率研究

发布时间：2018-10-12 11:57

【摘要】：根据林分平均胸径、平均树高、林龄、林分密度、立地质量及分布区域等林分因子的不同,从福州市国有林场近15年来的伐区中选取具有代表性的杉木林分,以伐区调查数据为依据,按照"三倍标准差原理"对林分平均胸径、平均树高进行筛选,共采集501片伐区木材生产相关数据。采用SPSS19.0数据统计软件分析林分各材种出材率与各林分因子之间的相关系数,分析表明,平均胸径、平均树高与林分规格材、经济材、废材及商品材的出材率之间呈高度相关,林分密度与薪材出材率之间呈高度正相关,杉木林分不同分布区域和立地质量对各材种出材率的影响均为极显著。影响林分材种出材率大小的因子依次为林分平均胸径、平均树高及林分密度,总体上,随着林分平均胸径、平均树高的增大,规格材、经济材和商品材的出材率逐渐上升,非规格材、薪材和废材的出材率则逐渐降低;随着林分密度的增加,规格材和经济材的出材率逐渐降低,薪材和废材的出材率逐渐增加,非规格材和商品材的出材率基本上保持平缓状态。文中通过分析林分各材种出材率与各林分因子之间的变化规律,建立基于林分平均胸径的林分一元材种出材率模型、基于林分平均胸径和平均树高的林分二元材种出材率模型、基于诸多林分因子的林分多元材种出材率模型,以残差平方和RSS和调整系数R2来判断回归模型的拟合精度,对满足拟合精度要求的回归模型再进一步根据平均相对误差E、总相对误差RS、平均相对误差绝对值RMA以及预估精度P和F检验等适用性检验指标的大小,从中选择最优的材种出材率模型。最优出材率模型通过适用性检验后,为确保一片林分内所计算的各材种出材率之和等于理论值100%,对根据所选用的一元、二元、多元材种出材率方程计算的各材种出材率进行修正,使其满足理论要求,其中多元材种出材率回归方程计算的规格材、经济材、薪材及商品材的出材率可不必修正,可直接编制成表。
[Abstract]:According to the difference of stand factors such as average DBH, average tree height, stand age, stand density, site quality and distribution area, the representative Chinese fir stands were selected from the cutting areas of the state-owned forest farm in Fuzhou in the past 15 years. Based on the survey data of cutting area, according to the principle of "three times standard deviation", the average DBH and average tree height of stand were screened, and 501 pieces of wood production data were collected. The correlation coefficient between stand timber yield and stand factors was analyzed by SPSS19.0 data statistic software. The results showed that the average DBH and average tree height were highly correlated with stand specifications, economic wood, scrap and commercial timber. There was a high positive correlation between stand density and wood yield of fuelwood. The effects of different distribution areas and site quality of Chinese fir stand on the yield of different timber species were very significant. The factors influencing the yield of timber were the average diameter of stand, the average height and density of stand. As a whole, with the increase of average diameter of stand, the average height of tree, the yield of standard wood, economic wood and commercial wood increased gradually. The yield of non-standard wood, fuelwood and waste wood decreased gradually, and with the increase of stand density, the yield of standard wood and economic wood decreased gradually, and that of fuelwood and waste wood increased gradually. The output rate of non-standard materials and commercial materials is basically in a smooth state. Based on the analysis of the variation of stand yield and stand factors, a stand yield model based on stand average DBH, and a stand yield model based on stand average DBH and average tree height were established in this paper. On the basis of many stand factors, the fitting accuracy of the regression model was judged by the sum of residual square and RSS and adjustment coefficient R2. For the regression model which meets the requirement of fitting precision, according to the magnitude of average relative error (E), total relative error (RS,) average relative error absolute value (RMA) and prediction accuracy (P and F test), etc. The optimal model of timber outage rate was selected. In order to ensure that the sum of each timber output rate calculated in a stand is equal to the theoretical value of 100, according to the selection of one element, the optimum yield model passes the applicability test, in order to ensure that the sum of each timber output rate is equal to the theoretical value of 100. In order to meet the theoretical requirements, the extraction rate of each material calculated by the equation of extraction rate of multicomponent materials can be modified to meet the theoretical requirements. The extraction rate of specifications, economic wood, fuelwood and commercial materials can be calculated by regression equation of multiple species of timber without modification. Can be compiled directly into a table.
【学位授予单位】：福建农林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S758

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