Study On The Method Of Estimating Aboveground Biomass Of Phyllostachys Eudlis Based On Terrestrial LiDAR

Phyllostachys edulis is a very special forest resource.It has excellent carbon sequestration potential and economic value as well as ecological value.And it plays an important role in promoting country economic development and coping with climate change.Terrestrial three-dimensional laser scanning has some unique characters,such as non-contact,speediness,initiative and abundant information,because of which,terrestrial three-dimensional laser scanning has been wider used to investigate forest resource,study stand structure and build three-dimensional model of single tree.In this study,we analyze impacts of different factors on accuracy of point cloud from terrestrial three-dimensional laser scanning in order to ensure the high quality of point cloud.Then we analyze the information of laser scanning intensity of moso bamboo with different ages so as to distinguish the bamboo age rapidly.At last,we build biomass models of trunks,branches and leaves,which provides a new way to estimate biomass of single bamboo accurately.The results were as follows.?1?Impacts of the distance and color of target object on accuracy of the point cloud.Distance is inversely proportional to the number of point cloud.Color has a significant impact on the reflection intensity of point cloud.The reflection intensity of point cloud from strongest to weakest is white,green,blue,red,black.Distance is inversely proportional to the n accuracy of the point cloud.There is a power function relation as=(6⁽-?7? between the stand deviation and reflection intensity of point cloud.?2?Mathematical model between laser scanning intensity and trunk age.There is a significant difference in laser intensity of bamboos with different ages and in different trunks?P<0.01?,while the difference is not significant in laser intensity of bamboos in the same trunk?P>0.05?.The intensity of1-year,3-year and 4-year old trunks has a decreasing trend,but the trend of 2-year old trunk increases first and then decreases.We analyze the information of laser scanning,model the relationship between trunk No.and laser scanning intensity,and the R² were 0.997,0.928,0.973 and 0.990.?3?Biomass models of trunks.Acquire trunk point cloud data by using terrestrial three-dimensional laser scanning,from which we can get DBH?diameter at breast height?and height.Then we model the relationship between DBH,height and biomass in different age trunks,and the R²were 0.923,0.940,0.912 and 0.933.Acquire branches and leaves point cloud data by using terrestrial three-dimensional laser scanning,and calculate the density of point cloud.Then we model the relationship between density of point cloud and biomass in different age branches and leaves,and the R² were 0.990,0.967,0.931 and 0.981.Combine above-mentioned three models,we obtain a complete biomass model of single bamboo,which estimate biomass of single bamboo accurately and rapidly.