摘要
叶倾角分布(LAD)直接决定着植被冠层对辐射的截获量,同时对入射太阳辐射的大小与走向也起着决定性作用,是定量遥感中的关键参数.本研究基于Campbell椭球分布函数和迭代方法拟合大兴安岭林区主要树种的LAD,定量分析冠层叶片分层与不分层时模型的拟合情况及不同龄组对LAD的影响.结果表明:大兴安岭地区6种主要树种的LAD均属于横椭球分布,针叶树的平均叶倾角小于阔叶树;无论对叶片分层处理与否,模型拟合叶倾角的结果与实测结果基本一致;白桦和落叶松的拟合结果与实测结果线性回归的相关系数分别是0.8268、0.8192,均方根误差分别是3.7%、4.3%,说明Campbell模型应用于森林冠层是可靠的;考虑龄组的影响时,虽然分层处理时叶倾角的分布趋势与龄组无关,但幼龄落叶松的平均叶倾角小于成熟落叶松,表明龄组对叶倾角分布取值有正向影响,而对消光系数取值有负向影响.
Leaf inclination angle distribution directly decides the amount of radiation interception by vegetation canopy, and also, decides the size and direction of the incident radiation, being the key parameter in quantitative remote sensing. This paper simulated the leaf inclination angle distribution of the main tree species in Daxing＇ an Mountains forest region based on the Campbell ellipsoid dis- tribution model and iterative method, and quantitatively analyzed the fitting resuks of canopy with and without leaf stratification as well as the effects of tree age group on the leaf inclination angle dis- tribution. For the test 6 main tree species, the leaf inclination angle distribution was in planophile shape, and the mean leaf inclination angle was smaller for coniferous tree than for broadleaved tree. Whether with or without stratify, the fitting result and the measured result were basically identical. For Betula platyphylla and Larix gmelinii, the correlation coefficient between the simulated and measured values was O. 8268 and O. 8192, and the root mean square error was 3.7% and 4.3% re- spectively, indicating that the Campbell model was reliable applied for forest canopy. Considering the effects of tree age group, though the leaf inclination angle distribution trend with leaf stratifica- tion had no correlation with age group, the mean leaf inclination angle of young L. gmelinii was rel- atively smaller than that mature one, suggesting that age group had positive effects on the numerical design of leaf inclination angle distribution and negative effects on the numerical design of extinction coefficient.
出处
《应用生态学报》
CAS
CSCD
北大核心
2013年第11期3199-3206,共8页
Chinese Journal of Applied Ecology
基金
"十二五"国家科技支撑计划项目(2011BAD37B01)资助
关键词
叶倾角分布
椭球分布
大兴安岭
定量遥感
leaf inclination angle distribution
ellipsoid distribution
Daxing＇ an Mountains
quan-titative remote sensing.
