摘要
为合理经营黄土高原区刺槐人工林,利用LAI-2200植物冠层分析仪,研究了不同密度刺槐人工林冠层结构特征及月变化。结果表明:密度对LAI(叶面积指数)有影响,随着密度的增加,林分叶面积指数趋于一致;在生长月份上,LAI为先增后降趋势,最大值出现在6月底。密度与冠层开度呈显著负相关,随着密度的增加,刺槐林DIFN明显降低,925～1 125株/hm2与其他3个密度林分有显著性差异;DIFN(无截取散射)随月份的变化均呈"V"字型变化,在6月底至8月初DIFN最低。密度与MTA(平均叶倾角)呈显著正相关,密度在925～1 125株/hm2范围的刺槐林分,叶片几乎处于水平状态,其他3种密度林分MTA均在40°～50°之间有最大分布频率,而月份对MTA影响不显著。对叶面积指数与冠层开度进行回归分析,发现两者之间呈指数回归关系(R2=0.998)。
In order to develop the reasonable managements in the black locust plantations in the Loess Plateau, the charac- teristics of canopy structure （ Leaf area index, LAI ; Diffuse non-interceptance, DIFN ; Mean tilt angle, MTA ） of black lo- cust plantations with different densities and monthly dynamics were studied by using a LA1-2200 plant canopy analyzer. The results showed that the densities had affection on LAI, and LAI converged with the increases of density of black locust stands. With the increase of density, LAI increased firstly and then decreased in the growing stages, and the peak value oc- curred in late June. An extremely negative correlation was observed between the stand density of black locust and DIFN, DIFN decreased sharply with the increase of density. And there was a significant difference of DIFN between the densities of 925-1 125 plants per hm2 and other three densities of black locust plantations. The DIFN presented roughly a V-shaped trend in the growing months, and the minimum value appeared in late June and early August. The densities of black locust stands were significantly positive correlated to MTA. The leaves with the densities of 925-1 125 plants per hm2 were almost in a horizontal status, however, the MTA with other densities had high distribution frequency from 40 to 50 degree. The MTA was no significant changes with the growing months. The regression analysis indicated that the LAT was exponentially correlated with the DIFN （R2 = 0. 998）.
出处
《林业科技开发》
2011年第5期16-20,共5页
China Forestry Science and Technology
基金
国家"十一五"科技支撑计划项目(编号:2006BAD03A1207)
关键词
刺槐人工林
林分密度
冠层结构
叶面积指数
月动态
black locust plantations
stand density
canopy structure
leaf area index
monthly dynamics
