Lidar methods for measurement of trees in urban forests

Abstract

This study compares the estimations of biophysical parameters of Platanus hispanica urban trees, namely total height, crown height, crown volume, and the amount of residual biomass from pruning, obtained by terrestrial laser scanner (TLS), airborne laser scanner (ALS) of low density (0.7 points · m − 2), and measured by standard field methods. Regression models were calculated to obtain the relationships among parameters retrieved by all techniques, testing all possible combinations (manual-TLS, manual-ALS, TLS-ALS, and vice versa). The most accurate fits were found for vegetation attributes (stem and crown diameter) estimated by TLS and ALS data with R2 between 0.84 and 0.96, respectively. The least accurate models were found when crown height and pruning biomass were estimated from ALS data (R2 = 0.68 and R2 = 0.59, respectively). The methods reported in this research might be of interest for the management of urban forests to study residual biomass calculation, sink CO2, the influence of humidity and of shadow areas whatever the information capture system used, whether it is derived from ALS, TLS, or classical dendrometry measurements.