Above Ground Biomass References for Urban Trees from Terrestrial Laser Scanning Data
- 1Swiss Federal Institute for Forest, Snow and Landscape Research WSL , Land Change Science, Remote Sensing, Switzerland (daniel.kuekenbrink@wsl.ch)
- 2Remote Sensing Laboratories, University of Zurich, Winterthurerstrasse 190, CH-8045 Zurich, Switzerland
- 3School of Agricultural, Forest and Food Sciences HAFL, Länggasse 85, CH-3052 Zollikofen, Switzerland
- 4Federal Office for the Environment FOEN, CH-3003 Bern, Switzerland
- 5Nategra LLC, Nydeggstalden 30, CH-3011 Bern, Switzerland
Trees supply a multitude of ecosystem services (e.g. carbon storage, suppression of air pollution, oxygen, shade, recreation etc.) not only in forested areas but also in urban landscapes. Many of these services are positively correlated with tree size and structure. The assessment of carbon storage potential via the quantification of above ground biomass (AGB) is of special importance. However, quantification of AGB is difficult and applied allometries are often based on forest trees, which are subject to very different growing conditions, competition and form compared to urban trees. In this contribution, we highlight the potential of terrestrial laser scanning (TLS) techniques to extract high detailed information on tree structure and AGB with a focus on urban trees.
A total of 55 urban trees distributed over eight cities in Switzerland were measured using TLS and traditional forest inventory techniques before they were felled and weighted. Tree structure, volumes and AGB from the TLS point clouds were extracted using Quantitative Structure Modelling (QSM). TLS derived AGB estimates were compared to allometric estimates dependent on diameter at breast height only. The allometric models were established within the Swiss National Forest Inventory and are therefore optimised for forest trees.
TLS derived AGB estimates showed good performance when compared to destructively harvested references with an R2 of 0.954 (RMSE = 556 kg), compared to an R2 of 0.837 (RMSE = 1159 kg) for allometrically derived AGB estimates. A correlation analysis showed that different TLS derived wood volume estimates as well as trunk diameters and tree crown metrics show high correlation in describing total wood AGB.
The presented results show that TLS based wood volume estimates show high potential to estimate tree AGB independent of tree species, size and form. This allows us to retrieve highly accurate, non-destructive AGB estimates that could be used to establish new allometric equations without the need of extensive destructive harvest.
How to cite: Kükenbrink, D., Gardi, O., Morsdorf, F., Thürig, E., Schellenberger, A., and Mathys, L.: Above Ground Biomass References for Urban Trees from Terrestrial Laser Scanning Data, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-5399, https://doi.org/10.5194/egusphere-egu21-5399, 2021.
