马尾松格木幼林混交效果研究

【目的】通过分析不同混交模式下马尾松及格木生长量差异,探讨马尾松与格木混交的适宜模式,为马尾松格木混交林的营建提供理论基础。【方法】以广西凭祥5年生马尾松和格木人工林为研究对象,分析不同混交模式及混交比例马尾松和格木的胸径、树高、冠幅及材积的差异,探寻马尾松格木混交合理的混交模式和混交比例。【结果】1)不同混交模式马尾松胸径、树高、冠幅和材积均差异显著。处理a和CK3林分平均胸径最大,均为5.9 cm,CK3林分平均树高、上下冠幅和左右冠幅最大,分别为4.9、2.4和2.7 m。CK3的单株材积最大为0.0082 m3,处理c林分平均胸径、平均树高和单株材积均最小,分别为5.0 cm、4.1 m和0.0051 m3,同时上下冠幅和左右冠幅最小,分别为2.0 m和2.1 m。2)不同混交模式格木胸径、树高、冠幅和材积均差异显著。CK2林分平均胸径最大为5.1 cm,最小为处理c的4.1 cm。处理a和CK1林分平均树高最高,均为4.8 m,处理c树高最低为4.0 m。处理a、处理b和CK2上下冠幅最大,均为2.4 m,处理c上下冠幅最小为2.0 m,CK1左右冠幅最大为2.8 m,处理c左右冠幅最小为2.1 m。CK2格木单株材积最大为0.0058 m3,处理c单株材积最小为0.0035 m3。3)不同的混交模式和混交比例不影响径级数量的分布规律,各处理及对照中马尾松和格木的径级均呈正态分布。【结论】马尾松与格木幼林4种混交模式在胸径、树高、冠幅和材积均存在显著差异,马尾松与格木(75丛·hm^-2)各项生长指标相对较优,其次为马尾松+格木(4:1)行状混交,生长表现最差为马尾松+格木(210丛·hm^-2)。综合考虑,以培育马尾松大径材为经营目标,早期应选择马尾松与格木(75丛·hm^-2)模式进行混交。

Study on mixed young plantation effect of Pinus massoniana and Erythrophleum fordii

【Objective】Through analyzing the difference of growth amount of Pinus massoniana and Erythrophleum fordii under different mixed models, this study discusses the suitable mixed models, and provides the theoretical basis for the construction of Pinus massoniana and Erythrophleum fordii mixed forest. 【Method】5 years’ plantationsof Pinus massoniana and Erythrophleum fordii in Pingxiang Guangxi were chosen as research objects, Analyze the difference of DBH, height, crown width and volume of Pinus massoniana and Erythrophleum fordii in different mixed models and mixed proportion. explore the reasonable mixed models and mixed proportion of Pinus massoniana and Erythrophleum fordii.【Result】1) There were significant differences in DBH, height,crown width and volume of Pinus massoniana in different mixed models. The average DBH of treated a and CK3 stands was the largest, both of which were 5.9 cm. The average height of trees, the crown width of upper and lower and the crown width of left and right were the largest in CK3 stands, which were 4.9 m, 2.4 m and 2.7 m. The maximum volume plant of CK3 was 0.008 2 m3.The average DBH,average tree height and volume of the treated c stand were the smallest, there were 5.0 cm, 4.1 m and 0.005 1 m3, while the upper and lower crown widths and the left and right crown widths were the smallest, there were 2.0 m and 2.1 m. 2) There were significant differences in DBH, height, crown width and volume of Erythrophleum fordii in different mixed models. The maximum average DBH of CK2 stands was 5.1 cm, and the minimum was 4.1 cm of treated c. The average tree height of treatment a and CK1 stands was the highest(4.8 m), while that of treatment c stands was the lowest(4.0 m). The upper and lower crown widths of treatment a, treatment band CK2 were the largest, both of which were 2.4 m.The upper and lower crown widths of treatment c were the smallest(2.0 m), the left and right crown widths of treatment c were the largest(2.0 m), and the left and right crown widths of treatment c were the smallest, 2.1 m. The maximum volumeof CK2 was 0.005 8 m3, and the minimum volume of treated c was 0.003 5 m3. 3) Different mixed models and proportions didn’t affect the distribution law of the number of diameter classes. The diameter classes of Pinus massoniana and Erythrophleum fordii were normally distributed in each treatment and contrast. Different breeding targets choose different mixing modes.【Conclusion】There were significant differences in DBH, height, crown width and volume in four mixed modes of young forests of Pinus massoniana and Erythrophleum fordii. Growth indexes of Pinus massoniana and Erythrophleum fordii(75 congge·hm^-2) were relatively superior, followed by row mixed of Pinus massoniana and Erythrophleum fordii(4:1), and growth performance of Pinus massoniana and Erythrophleum fordii(210 congge·hm^-2) was the worst. All things considered. Large diameter timber of Pinus massoniana should be selected as the main cultivation target, and the mixture mode of Pinus massoniana and Erythrophleum fordii(75 congge·hm^-2)should be selected.