Session Information
| Session | Poster Session | | Date | Monday (2008-04-07) | | Time | 5:00 PM - 7:00 PM | | Room | Grand Terrace |
Presentation Information
| Presenter | Melanie Harsch | | Title | Treeline dynamics: Pattern and process at multiple spatial scales | | Affiliation | Lincoln University | | Authors | Melanie Harsch | | Keywords | Climate change, Treeline | | Presentation Type | Poster | Abstract:
Identifying a single global process controlling treeline pattern or response to climatic change has been elusive. Although many processes have been proposed, no universally accepted process, acting at multiple spatial scales, has yet been identified. Alternatively, identifying patterns resulting from controlling processes may help to identify the critical factors and their interactions that shape and control treeline dynamics. Treeline formation is postulated to result from temperature induced growth limitations and pattern is postulated to result from interactions between one process, facilitation, and one factor, abiotic stress. Global treeline patterns were compared using meta-analysis. Meta-analytical results were directly tested by paired planting of two tree species (slow growing Nothofagus solandri var. cliffortioides and fast growing Pinus contorta) along elevation transects above the treeline. Analysis of 247 studies indicates that treeline response to climate change is related to treeline form and environmental severity. The hypotheses were then tested at a regional scale by comparing the demography (treeline form, recruitment patterns, growth rates) and general response to climate change (vertical release, recruitment rates, advance rates) of two divergent natural treelines (abrupt and diffuse) within New Zealand. Finally, the relationships between critical processes (temperature, facilitation/competition) and factors (a/biotic stress, interannual variability) will be used to explain regional and global treeline patterns and response to climate change. |
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