【作者】 卢军；

【导师】 李凤日；

【作者基本信息】 东北林业大学 ， 森林经理学， 2005， 硕士

【摘要】 本研究以长白山地区白河林业局天然混交林作为研究对象,采用1990年～2000年10年间复测的712块固定样地数据,通过分析各主要树种单木直径生长量与其自身大小、竞争和立地条件的关系,找出影响林木生长量的主要因子,并采用逐步回归技术建立了形式简洁、预估良好并便于生产应用的天然混交林15个树种与距离无关的单木生长模型。 各树种单木模型的研究结果表明,影响天然混交林各树种单木直径生长量的最主要因了是林木直径大小(D),其次是竞争指标,而立地条件对其影响不大。在全部15个树种的直径生长量预估模型中,均包含了InD和D~2二个变量。各树种的直径越大,其直径生长量也越大。单木模型反映林木竞争状态的指标中,相对直径(RD)、林分郁闭度(P)和对象木直径与林分中最大林木直径之比(DDM)对直径生长量有一定影响,而其他林分密度指标,如林分断面积(G)、林分密度指数(SDI)、大于对象木的断面积(BAL)等,对所有树种的平方直径生长影响都不显著。各树种的相对直径(RD和DDM)越大,竞争能力越强,其直径生长量也越大。林分郁闭度越大树木的生长量越小。地位级指数(SCI)、坡度(SL)和坡向(ASP)等立地因子对各个树种直径生长影响非常小,可以忽略不计。采用独立样本数据对模型的检验结果表明,天然混交林各树种单木直径生长量预估模型的预估精度均大于94%,说明本研究所建立的单木模型适用性较强,可以很好的描述各树种林木的生长。另外,文中采用Logistic模型建立了天然混交林各主要树种的单木枯损模型,结果表明林木的直径是影响林木枯损的最重要因子,直径越小,枯损概率越大。 本研究所构造的单木生长模型,客观地反映了白河林业局天然混交林各树种的生长动态,可较好地模拟树木和林分的生长过程,为该地区天然混交林的集约经营和生产决策提供了详细的林木生长信息,具有一定的理论和实践价值。更多还原

【Abstract】 The data used to develop individual model for natural mixed forests were collected from 712 remeasured permanent sample plots of 10-year periodic from 1990 to 2000 in Baihe Forest Bureau of Changbai mountains, northeat Chian. Based on analyzing relationship between diameter increment of individual trees with tree size, competitive status, and site condition and finding out the major independent variables, the growth models for individual trees of 15 species in the natural mixed forests, that have simple form, good predicting precision, and easily applicable, were developed using stepwise regression method.The research results for individual trees growth model of each species showed that main variable to influence on diameter increment of individual trees for natural mixed forests were tree size (D) and then competition index. The site condition was not related with diameter increment. The natural logarithm of DBH (lnD) and square diameter (D~2) were included in the predicting models of diameter increment for all 15 species. The diameter increment was directly proportional to tree diameter for each species. For the competitive indexes in growth model, the relative diameter (RD), canopy closure (P), and the ratio of diameter of subject tree with maximum diameter (DDM) were related to diameter increment and the stand density measures, e.g. stand basal area (G), stand density index (SDI), and the basal area of larger trees than the subject tree (BAL). were not significantly influenced on diameter increment. As the relative diameter (RD and DDM) increase, tree’s competitive capacity and diameter increment increase. As canopy closure (P) increase, tree increment decreases. The site conditions, such as site class index (SCI), slope, and aspect, were performance less of factors in increment predictions and were deleted from model. Using independent data set, validation measures were evaluated for predicting models of diameter increment developed in this study. The result indicated that the estimated precision values of diameter were all greater than 94% and the models were more applicable and suitable to describe diameter increment. In addition, mortality model for each species was developed based on logistic equation. Tree’s diameter was significantly related to mortality. As diameter decrease, the mortality probability increases.The individual growth model developed in this study can actually reflect the tree increment of 15 species and be generally well suited for simulating tree and stand growth for natural mixed forests in the Baihe forest Bureau. Furthermore, it will provide detail information of tree increment to intensive forest management and decision-making for natural mixed forest. Therefore, this research has the theoretic foundation and practical value.更多还原