Empirical study on mortality within tree regeneration
This project aims to improve our understanding of mortality processes within the tree regeneration layer by combining different data (field, tree rings, and inventory) at different stages of the tree regeneration (seedlings, saplings, trees with dbh < 10 cm) and with different foci (temporal, spatial, and growth-related).
In the first part of the project, we estimate seedling mortality rates based on field data and perform survival analyses to elucidate the temporal variability of mortality. We use data of microsite and seedling characteristics to model the survival time of seedlings. In addition, we will investigate the existence of a trade-off between germination date and the risks of frost or desiccation.
In the second part of the project, we conduct a tree-ring analysis to investigate growth-mortality relationships of saplings by computing radial and height growth rates and growth trends of living and dead trees of different species in nine mountain forests across the Swiss Alps based on regional curve standardization and state-space models. Using data on light availability derived from hemispherical photos, we perform a sensitivity analysis to provide insights into the species-specific shade tolerance across the study sites.
In the third part of the project, we employ growth rates and spatial coordinates from inventory data of the Swiss Forest Reserve Network plots to infer mortality probabilities related to stand structure. The inventory data are further utilised in spatial point pattern analysis to investigate the distribution of living and dead juvenile trees.
Funding
The project is part of the SNF Project Advanced Tree MOrtality MOdeling (ATMO2). For more details see the project webpage of the external pageSNSF.
Status of the project
The project runs from April 2016 to March 2019.
Contact
Please contact Eva Bianchi for more information. Christof Bigler and Harald Bugmann supervise the project.
