Many ways to die – partitioning tree mortality dynamics in a near-natural mixed deciduous forest
Article first published online: 16 NOV 2012
© 2012 The Authors. Journal of Ecology © 2012 British Ecological Society
Journal of Ecology
Volume 101, Issue 1, pages 220–230, January 2013
How to Cite
Holzwarth, F., Kahl, A., Bauhus, J., Wirth, C. (2013), Many ways to die – partitioning tree mortality dynamics in a near-natural mixed deciduous forest. Journal of Ecology, 101: 220–230. doi: 10.1111/1365-2745.12015
- Issue published online: 21 DEC 2012
- Article first published online: 16 NOV 2012
- Manuscript Accepted: 9 OCT 2012
- Manuscript Received: 23 MAY 2012
- DFG Priority Program 1374
- Infrastructure-Biodiversity-Exploratories. Grant Number: 2045/7-1
- demographic trait;
- growth estimation;
- growth-related mortality;
- mortality mode;
- mortality model;
- plant population and community dynamics;
- size-related mortality
- Partitioning of tree mortality into different modes of death allows the tracing and mechanistic modelling of individual key processes of forest dynamics each varying depending on site, species and individual risk factors. This, in turn, may improve long-term predictions of the development of old-growth forests.
- Six different individual tree mortality modes (uprooted and snapped (both with or without rot as a predisposing factor), standing dead and crushed by other trees) were analysed, and statistical models were derived for three tree species (European beech Fagus sylvatica, hornbeam Carpinus betulus and common ash Fraxinus excelsior) based on a repeated inventory of more than 13 000 trees in a 28 ha near-natural deciduous forest in Central Germany.
- The frequently described U-shaped curve of size-dependent mortality was observed in beech and hornbeam (but not ash) and could be explained by the joint operation of processes related to the six distinct mortality modes. The results for beech, the most abundant species, suggest that each mortality mode is prevalent in different life-history stages: small trees died mostly standing or being crushed, medium-sized trees had the highest chance of survival, and very large trees experienced increased rates of mortality, mainly by uprooting or snapping. Reduced growth as a predictor also played a role but only for standing dead, all other mortality modes showed no relationship to tree growth.
- Synthesis. Tree mortality can be partitioned into distinct processes, and species tend to differ in their susceptibility to one or more of them. This forms a fundamental basis for the understanding of forest dynamics in natural forests, and any mechanistic modelling of mortality in vegetation models could be improved by correctly addressing and formulating the various mortality processes.