Qualitative development of beech canopies after early canopy loss depending on stand area and stage of development

The aim of the project is to investigate the effect of early canopy loss on the quality of beech canopies. In addition to the canopy cover, the number of plants is also decisive for the qualitative development of the canopy (LEDER and WEIHS 2000; LEONHARDT and WAGNER 2006; RUMPF and PETERSEN 2008). The first working hypothesis to be investigated is therefore:
The qualitative development of the beech canopy after canopy loss is dependent on the number of plants, or stand space per beech. It is to be expected that canopy loss will have less negative effects on the quality of densely planted pre-cultivations (small stand space per beech) than on widely planted ones (large stand space per beech).
Furthermore, the time of canopy loss over the beech trees also plays a role in their further development. Above all, the degree of stand closure achieved is significant for the qualitative differentiation (e.g. natural branch cleaning) of the beech trees (RUMPF and PETERSEN 2008). The second hypothesis to be investigated is derived from this assumption:
The qualitative formation of the beech forebranches depends on the development phase of these at the time of canopy loss. It is assumed that the quality of the front growth that had not yet reached the thickening stage at the time of canopy loss is lower than that of those where stand closure had already occurred.

Figure 1 shows a possible progression of quality with the duration of the pre-cultivation, whereby the desired development (without canopy loss) at different plant densities is indicated by the olive-green straight lines. The red curves show conceivable quality development trends with canopy loss before thickening as a function of the plant density per ha. Similarly, the blue curve shows the development of canopy loss after thickening. Differentiated according to the influencing factors shown, the study aims to clarify the question of how beech trees with shade habitus react to a sudden release and how this is reflected in the quality. The results will be used to derive implementation-oriented, differentiated decision-making aids and treatment recommendations on how to deal with beech plantations of different development stages and plant densities on calamity areas. The study should also help to derive plant densities for future pre-cultivations that take into account an increased storm risk of the canopies in order to apply the precautionary principle.