Stability of the boreal forest-tundra ecotone: A test for the greenhouse effect
- Univ. of Colorado, Boulder, CO (United States). Dept. of EPO Biology
The Greenhouse Warming hypothesis predicts that high northern latitudes will experience greater temperature increases than lower latitudes over the next century. Arctic meteorological data indicates some recent surface warmings, while tropospheric level cooling has occurred over the last 40 years, over the North American arctic. These equivocal signals indicate the need to examine the reproductive status of the arctic tree-line, which integrates the climatic trends of the circumpolar regions. The boundary between the boreal forest and the arctic tundra is sensitive to climate change according to climatic theory, and it is expected to respond to global atmospheric warming, as demonstrated by paleo-ecological studies of the forest limit during the last several thousand years. Much of the forest edge and the dwarf spruce true islands'' in the arctic tundra are currently infertile and reproduce by vegetative layering, due to insufficient summer warmth, but are expected to produce ripened seed and pollen when sufficient warming occurs. Since weather observatories are few and far between in the arctic, these tree islands act as quasi-meteorological stations to give us early warning of climatic change. These clonal trees will act as beacons'' throughout the circumpolar areas to indicate climatic warming, and will need to be monitored by ground survey using pollen and seed collections. Then sensitivity of northern ecosystems and human cultures to climatic change require the collaboration of several arctic nations in field and remote-sensing studies to assess these dichotomous possibilities.
- OSTI ID:
- 6980648
- Report Number(s):
- CONF-930415--
- Journal Information:
- World Resource Review; (United States), Journal Name: World Resource Review; (United States) Vol. 5:3; ISSN WRRVE5; ISSN 1042-8011
- Country of Publication:
- United States
- Language:
- English
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