Contribution of Disturbance to Increasing Seasonal Amplitude of Atmospheric CO2
S. A. Zimov,
1
S. P. Davidov,
1
G.
M. Zimova,
1
A. I. Davidova,
1
F. S. Chapin
,
III,
2*
M. C. Chapin,
2
J. F. Reynolds
3
Recent increases in the seasonal amplitude of atmospheric carbon
dioxide (CO2) at high latitudes suggest a widespread
biospheric response to high-latitude warming. The seasonal amplitude of
net ecosystem carbon exchange by northern Siberian ecosystems is shown to be greater in disturbed than undisturbed sites, due to increased summer influx and increased winter efflux. Increased disturbance could
therefore contribute significantly to the amplified seasonal cycle of
atmospheric carbon dioxide at high latitudes. Warm temperatures reduced
summer carbon influx, suggesting that high-latitude warming, if it
occurred, would be unlikely to increase seasonal amplitude of carbon
exchange.
1 North-East Scientific Station, Pacific
Institute for Geography, Far-East Branch, Russian Academy of Sciences,
Republic of Sakha, Yakutia, 678830 Cherskii, Russia.
2 Institute of Arctic Biology, University of Alaska,
Fairbanks, AK 99775-7000, USA.
3 Department of
Botany, Duke University, Durham, NC 27708-0340, USA.
*
To whom correspondence should be addressed. E-mail:
fschapin{at}lter.uaf.edu
