Abstract:

Using ground real data as a control,this study applied terrestrial laser scanning (TLS) to scan eucalyptus plantations at different stand ages(2,5,10 a)in Guangxi State-owned Gaofeng Forest Farm,assessed the ability of TLS in individual tree identification and extraction of tree parameters and further explored its feasibility for extracting forest parameters. The results showed that:1) TLS had a strong ability to identify individual tree in eucalyptus plantations,with an overall recognition rate of 93.45%. Its extracted tree parameters of various types were significantly different among different stand ages (P<0.05),which was consistent with the measured trend. 2) In the 2a eucalyptus plantation,there was no difference between the measured values and the estimated values of DBH,basal area,tree volume by TLS. At the same time,it was found that the method of reconstructing tree models based on TLS combined with AdQSM was feasible,and it had a very significant linear correlation with the results calculated by the standing tree volume model (P<0.01,R²=0.96,MAE=0.05 m³). 3) At the stand level,the estimation accuracy of TLS were 94.69%,93.75%,89.66%,and 84.22% for the average diameter at breast height,average tree height,stand basal area,and standing volume,respectively,with superior estimation ability. The study showed that the application of TLS can rapidly estimate the forest parameters of eucalyptus plantations at the sample plot scale.

Key words: eucalyptus, terrestrial laser scanning, tree parameters, forest parameters, quantitative structure model