2006 Annual Meeting and Arctic Forum | Abstracts

Trends in Circumpolar Photosynthetic Activity from 1982-2003

Scott Goetz¹, Andrew Bunn^2
1Woods Hole Research Center, 149 Woods Hole Road, Falmouth, MA, 02540, USA, Phone 508-540-9904, Fax 508-540-9700, sgoetz@whrc.org
²Woods Hole Research Center, 149 Woods Hole Road, Falmouth, MA, 02540, USA, Phone 508-540-9904, Fax 508-540-9700, abunn@whrc.org

Temperature increases in the northern high latitudes over the past few decades have led to a wide variety of ecosystem changes, including modification of the productivity of plants as measured by ground cover (growth) and associated changes in global CO₂ exchange. Well-known studies of "greening" trends between 1982 and 1991 in high latitude vegetation indicate an earlier onset of growing season and more active photosynthesis in the mid-summer months. Our recent work indicates that these trends do not continue uniformly in time or space but instead vary between vegetation types and different periods of the growing season. These results provide some of the first evidence that high latitude forests may be in decline following an initial growth spurt associated with CO₂ and warming. The satellite observations are supported by a range of field observations, and indicate that natural ecosystems may be responding to climate change in unexpected ways that will have significant further effects on the biosphere.