Insights into tree morphology and canopy space occupation under the influence of local neighbourhood interactions in mature temperate forests using laser scanning technology

Mounting evidence suggests that tree species richness promotes ecosystem functioning in forests. However, the mechanisms driving positive biodiversity ecosystem functioning relationships remain largely unclear. This also holds for the previously proposed key mechanisms of resource partitioning in canopy space. Until recently, surveying and hence the study of crown space was very time-consuming and the images low resolution. The application of high-resolution laser scanning, however, now enables a fast and precise recording of entire forests. This thesis presents how the abandonment of management strongly alters the individual tree structure from the wood distribution along the trunk to the crown, a tree species-rich neighbourhood can increase the wood volume and crown dimension of individual trees as well as the productivity of large-sized trees, mobile laser scanning in forests is suitable for the acquisition of high-quality point clouds and determination of relevant management parameters, and the direction and strength of the relationship between tree species richness and canopy occupation depends on the definition of both canopy and species richness. These results reinforce the influence of species richness on ecosystem functions in oldgrowth forests and underline the importance of laser scanning for forest ecology research. The findings of the comparative analyses further highlight the importance of underlying definitions for the results obtained