不同地形条件下闽楠幼林生长情况研究

Growth of Phoebe bournei Young Plantation Under Different Terrain Conditions

为探索影响闽楠生长的关键因子,提高闽楠造林成效,对不同地形条件下闽楠的生长情况进行了系统调查和研究。结果表明:在坡位方面,闽楠在冠幅、枝下高、最大分枝基径、树高、胸径、平均树高年生长量和平均胸径年生长量指标上均表现为下坡位>中坡位>上坡位。其中,树高、胸径、平均树高年生长量和平均胸径年生长量在不同坡位上的差异达到极显著水平。在坡向方面,林龄4.5年的闽楠,在平均胸径指标上,东北坡向为4.78cm,东南坡向为4.77cm,均极显著高于西北坡向的3.55cm;在平均树高指标上,西北坡6.23m,东北坡6.19m,均显著低于东南坡向的6.70m;冠幅生长的情况与胸径较为相似,东北坡向的闽楠在冠幅生长上略高于东南坡向,明显大于西北坡向的1.51m;枝下高则是西北坡向(1.79m)大于东南坡向(1.69m)和东北坡向(1.28m)。在地形方面,在平均树高指标上,山谷极显著高于山脊;其他指标在两种地形上差异不显著。

In order to explore the key factors that affects the growth of Phoebe bournei and improve the afforestation efficiency, growth of Phoebe bournei in different terrain conditions were studied. Result shows that： for slope posi-tions, the growth indices （crown width,clear bole height, largest base diameter of branch,tree height,DBH, annual growth of average tree height annual growth of average DBH） of Phoebe bournei all show the bottom slope posi-tion〉 middle slope position〉top slope position. For slope direction, average DBH of 4. 5-year-old Phoebe bournei is 4. 78 cm in northeast, 4. 77 cm in southeast, both very significantly higher than that of the northwest （3. 55 cm） ;for average tree height, northwest slope is 6. 23 m〉 with the northeast 6. 19 m〉both significantly lower than that of the southeast （6. 70 m）. Growth of crown width is similar to average DBH, the northeast slope is slightly higher than that of the southeast,and are both significantly higher than the northwest （1. 51 m） . The clear bole height of Phoebe bournei in northwest,southeast and northeast is 1. 79 m, l . 69 m 1. 28 m respectively. Between the valley and ridge,average tree height of Phoebe bournei is very significantly higher in the former than the latter,with the other indices have small difference between the two.