Analysis of 3D-structures of single trees using terrestrial laser scanning

The consequences of a loss of biodiversity on the functionality and productivity of forest ecosystems are not yet fully understood. Especially mixed forests are highly diverse due to larger numbers of different tree species. Many ecologists are interested in in the competition and interaction between individual trees as this provides valuable information on the current and future conditions of a forest stand. To capture trees as a whole, terrestrial laser scanning (TLS) can be applied. TLS is a modern, non-destructive surveying techniques that delivers a full three-dimensional picture of a tree including the branches (3-D point clouds). The achievable accuracies are in the millimeter level. Converting the point clouds of individuals tree into quantitative structure models (QSMs) is of high relevance for research in ecology and forestry. Using such QSMs, for instance, allows to measure wood volumes, the number of branches, or crown structures amongst many other relevant inventory variables. Using multi-temporal TLS allows to study forest dynamics and growth on a new level of detail compared to conventional inventory methods.

At the Professorship of Biodiversity and Nature Protection high-resolution, multi-temporal TLS datasets from two large forest biodiversity experiments, BEF-China (www.bef-china.de) and BIOTREE Germany (http://www.treedivnet.ugent.be/ExpBIOTREE.html), are analysed. The main research focus is the analysis of tree growth, tree-tree-interactions as well as crown plasticity with regards to changes diversity gradients (species diversity and functional diversity).

Contact person:  Dr. Matthias Kunz