Arctic tree-line reproduction in Canada and Siberia: Possible greenhouse effect?
- Univ. of Colorado, Boulder, CO (United States)
The arctic tree-line is sensitive to climatic changes as indicated by paleo-ecological studies, and it is predicted to respond strongly to global warming. Northern Canadian studies of tree-line reproduction spanning two decades demonstrate a widespread switch from infertility due to cold summers (early 1970`s) to pollen and cone production (1990s), in line with greenhouse warming predictions. Ecotonal cone formation is usually sporadic and localized, but this largescale reproductive shift, along a 1500 km transect, suggests widespread climatic warming since the 1970s. These Siberian studies (at 27 sites) represented only a modest fraction of the Eurasian tree-line, but the widespread fertility at so many locations, plus the extensive Canadian evidence, suggests that the predicted polar warming may be responsible. Whether this is due to natural or anthropogenic climatic change, and whether it will be short or long-term, is unclear, and merits further study.
- OSTI ID:
- 577347
- Report Number(s):
- CONF-970522--
- Country of Publication:
- United States
- Language:
- English
Similar Records
Potential effects of global climate change on ecosystems of the Pacific Northwest
Interspecific differences in the effects of sulfur dioxide on angiosperm sexual reproduction