Creation of an explicit spatio-temporal model to illustrate the regeneration process from diaspore dispersal to establishment using the example of the silver birch (Betula pendula ROTH.)

The regeneration process – controlled by natural or anthopogenic factors – has important influences on stand dynamics as a whole. The vitality of the regeneration largely depends on the quality of environmental factors during several phases of the life cycle. Therefore, the spatial dispersion of developmental growth stages is essential for regeneration survival in a heterogeneous environment. While interactions between the environmental factors and phases of the life cycle are well-known, there is a lack of detailed studies about regeneration phases and their implementation in silvicultural and ecological systems. This project includes the specific analysis and modeling of regeneration processes exemplified by Betula pendula ROTH. An explicit spatial model will be developed based on empirical data concerning seed disperal, seed storage, germination and establishment as part of  the regeneration process. The data is collected both under controlled and natural conditions and used to parameterize and validate the regeneration model.
Study sites are located in the Forest of Tharandt  and represent the very common mature single-layered spruce stands (between 90 and 120 years old) featuring a small proportion of deciduous pioneer tree species. A site-specific grid of seed traps is established at each site allowing for a spatial and temporal description of seed dispersal. Subsequent to the dispersal measurements, morphology, mass and germination capacity of diaspores will be investigated. Furthermore, collected seeds are used for some germination experiments with different ground covers (mineral soil, grass, needle litter). It is thus possible to describe regeneration establishment and development by quantitative and qualitative parameters as additional input for the model.