这是因为影像点云对林分上层结构特征体现较好，对单木及林分的中下层结构特

This is because the image of the point cloud superstructure better reflect the characteristics of the stand, can not very well reflected in the underlying structural characteristics of individual tree and stand, and Metasequoia single wooden structure than regular Poplar, Poplar branches than the crown more, so the face crown poplar relatively complex structures, when single-precision division lower than the fir tree [31]

This is because the image point cloud on the forest superstructure characteristics reflect better, the characteristics of the middle and lower structure of the single wood and forest division can not be very good embodiment, and the water fir single-wood structure than the poplar tree regulation, poplar tree canopy branch more, so in the face of the relatively complex tree canopy structure, the accuracy of single wood division is lower than the water fir .

This is because the image point cloud can better reflect the upper structure characteristics of the stand, and can not well reflect the single wood and the middle and lower structure characteristics of the stand, while the single wood structure of Metasequoia is more regular than that of poplar, and the crown branches of poplar are more, so in the face of the relatively complex crown structure of poplar, the accuracy of single wood segmentation is lower than that of Metasequoia [31]<br>