桂东南地区柳杉人工林生长规律研究

[目的]分析桂东南地区31 a柳杉人工林的生长规律,为该树种的科学营林提供依据.[方法]采用树干解析法研究柳杉人工林的树高(H)、胸径(D)、材积(V)3个测树因子与树龄(T)间的关系,并拟合其生长回归模型.[结果]柳杉人工林的树高、胸径的连年生长曲线和平均生长曲线多次相交,变动幅度较大.树高连年生长量曲线在生长初期和调查期均出现了生长高峰期;胸径连年生长曲线在第10年达到了最高值,之后均处于下降趋势;而材积的连年生长曲线变动幅度相对较小,单株材积的平均生长量与连年生长量的曲线没有交点.所拟合的生长预测模型相关指数R2均在0998以上,其中树高、胸径和材积的最优生长模型均是二次函数方程.[结论]柳杉的树高、胸径生长量在31a的过程中保持较快的生长速度,连年生长量随着树龄的增加大致呈现出先上升后下降的趋势,材积生长未达到数量上的成熟.柳杉生长初期旺盛,在31 a后仍有生长趋势,拟合的模型可适用于实际生产中.

Growth regularity of Cryptomeria fortunei plantation in southeast Guangxi

【Objective】Growth regularity of Cryptomeria fortunei plantation in southeast Guangxi was analyzed to provide references for scientifically managing Cryptomeria fortunei plantation. 【Method】The relationship among tree height， DBH， stem volume and age in artifical plantation was studied by stem analytical method. Regression model of growth in was constructed with 3 tree factors. 【Result】Successive annual growth curves of tree height and DBH intersected with the average growth curve for many times and changed drastically. Successive annual growth curve for tree height showed two growth peaks at initial growth stage and survey stage， DBH successive annual growth curve reached the maximum in the 10th year， then decreased in the coming years. However， the successive annual growth curve for stem volume showed relatively less variation than that for tree height and DBH，and there was no intersection point between average growth curve and successive annual growth curve for stem volume of single plant. Correlation index R2 of each fitted growth forecast model was over 0.998， and Quadratic Curve equation proved to be the best growth model for tree height， DBH and stem volume. 【Conclusion】Tree height， DBH and stem volume grew relatively fast before 31 a， successive annual increment showed the tendency of increasing first and then descending with tree age. Cryptomeria fortunei grew vigorously during initial growth period and maintained growing after 31a. The fitted growth model could be applied in practical production.