Nondestructive and accurate measurement of volume and stem carbon storage for urban greening tree species based on terrestrial laser scanning point cloud

Abstract

Nondestructive and accurate measurement of stem volume and carbon storage for urban green tree species play an important role in forest carbon stock. To explore terrestrial laser scanning (TLS) potential, to determine the effect of different section lengths on measurement precision, and to evaluate the accuracy of the existing models, 30 point cloud samples of Sapindus mukorossi were collected by TLS, and the stem drill cores were also sampled according to the diameter grade by CO250 to obtain stem volume and carbon storage data using different section lengths. Afterward these were compared with data derived from existing models. Results showed that. (1) The diameter at breast height (DBH) and tree height could be measured with high accuracy based on TLS with a mean relative error for DBH of 1.97% and for height of 4.85%. (2) Based on TLS, when the section length was less than 0.50 m, stem volume could be measured accurately. (3) The existing models (including one-way volume model and standard volume model and stem carbon storage model) are not suitable for the stem volume and carbon storage of urban greening tree species, as the result of one-way ANOVA are significant (P < 0.05). Therefore, TLS is reliable in the field of nondestructive and accurate measurement of stem volume and carbon storage for urban greening tree species.