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Alpine forest-tundra ecotone response to temperature change,Sayan Mountains, SiberiaModels of climate change predict shifts of vegetation zones. Tree response to climate trends is most likely observable in the forest-tundra ecotone, where temperature mainly limits tree growth. There is evidence of vegetation change on the northern treeline However, observations on alpine tree line response are controversial. In this NEESPI related study we show that during the past three decades in the forest-tundra ecotone of the Sayan Mountains, Siberia, there was an increase in forest stand crown closure, regeneration propagation into the alpine tundra, and transformation of prostrate Siberian pine and fir into arboreal forms. We found that these changes occurred since the mid 1980s, and strongly correlates with positive temperature (and to a lesser extent, precipitation) trends. Improving climate for forest growth( i.e., warmer temperatures and increased precipitation) provides competitive advantages to Siberian pine in the alpine forest-tundra ecotone, as well as in areas typically dominated by larch, where it has been found to be forming a secondary canopy layer. Substitution of deciduous conifer, larch, for evergreen conifers, decreases albedo and provides positive feedback for temperature increase.
Document ID
20080030109
Document Type
Conference Paper
Authors
Ranson, K Jon (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Kharuk, Vyetcheslav I. (Sukachev Inst. of Forest Academgorodok Russia)
Date Acquired
August 24, 2013
Publication Date
December 10, 2007
Subject Category
Geosciences (General)
Meeting Information
American Geophysical Union (AGU) 2007 Fall Meeting(San Francisco, CA)
Distribution Limits
Public
Copyright
Other