Co-ordinating Editor: Prof. Meelis Pärtel.
Long-term successional forest dynamics: species and community responses to climatic variability
Article first published online: 26 FEB 2010
© 2010 International Association for Vegetation Science
Journal of Vegetation Science
Volume 21, Issue 4, pages 627–642, August 2010
How to Cite
Kardol, P., Todd, D. E., Hanson, P. J. and Mulholland, P. J. (2010), Long-term successional forest dynamics: species and community responses to climatic variability. Journal of Vegetation Science, 21: 627–642. doi: 10.1111/j.1654-1103.2010.01171.x
- Issue published online: 1 JUL 2010
- Article first published online: 26 FEB 2010
- Received 25 June 2009; Accepted 10 January 2010.
- Climate change;
- Global change;
- Insect outbreaks;
- Palmer Drought Severity Index (PDSI);
- Summer drought;
Question: Are trees sensitive to climatic variability, and do tree species differ in their responses to climatic variability? Does sensitivity of forest communities to climatic variability depend on stand composition?
Location: Mixed young forest at Walker Branch Watershed near Oak Ridge, East Tennessee, USA.
Methods: Using a long-term dataset (1967–2006), we analyzed temporal forest dynamics at the tree and species level, and community dynamics for forest stands that differed in initial species composition (i.e., chestnut oak, oak–hickory, pine, and yellow poplar stands). Using summer drought and growing season temperature as defined climate drivers, we evaluated relationships between forest dynamics and climate across levels of organization.
Results: Over the four-decade study period, forest communities underwent successional change and substantially increased in biomass. Variation in summer drought and growing season temperature contributed to temporal biomass dynamics for some tree species, but not for others. Stand-level responses to climatic variability were related to the responses of component species, except in pine stands. Pinus echinata, the dominant species in pine stands, decreased over time due to periodic outbreaks of pine bark beetle (Dendroctonus frontalis). These outbreaks at Walker Branch could not be directly related to climatic conditions.
Conclusions: The results indicate that sensitivity of developing forests to climatic variability is stand type-dependent, and hence is a function of species composition. However, in the long term, direct effects of climatic variability on forest dynamics may be small relative to autogenic successional processes or climate-related insect outbreaks. Empirical studies testing for interactions between forest succession and climatic variability are needed.