Biodiversity-Ecosystem-Functioning (BEF) research in forests has become a vibrant field of research in the last decade. The main objective of the international research training group TreeDì - 林地 (lín dì, forest land) is to understand how tree-tree interactions at the local neighbourhood level of varying diversity translate into the observed positive tree species richness effects on key ecosystem functions at the community scale. Tree-tree interactions involve important ecosystem processes such as resource use complementarity, above- and belowground competition and facilitation. A core hypothesis to be tested is that net biodiversity effects at the community scale emerge from a dominance of positive over negative relationships at the local heighbourhood scale. In-depth knowledge of each interaction type and interdisciplinary teamwork are essential to understand the underlying processes. All research projects are carried out on the BEF-China platform in subtropical China - the largest forest BEF experiment worldwide.
The subproject of University of Lüneburg (Institute of Ecology) and the University of Dresden (Institute of general Ecology and Environmental Protection) analyses the spatio-temporal dynamics of canopy space filling by neighbouring trees in relation tree species richness. We hypothesize that species richness fosters net biodiversity effects via processes such as enhanced canopy space filling or canopy packing. The project makes use of terrestrial laser scanning (TLS), which is a light detection and ranging (LiDAR) system that overcomes limitations of previous destructive approaches. TLS is capable to acquire rapidly 3D structural information with a very high resolution, and repeated measurements in time allow for a precise quantification of crown dynamics and shifts in biomass allocation patterns in relation to the abiotic and biotic environment. We expect outcomes of the subproject to be essential for a better understanding of tree species richness effects on important ecosystem functions and services such as biomass production. More information on the TreeDi research training group is available under „https://www.idiv.de/de/treedi.html“.