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Effects of experimental water table and temperature manipulations on ecosystem CO2 fluxes in an Alaskan rich fen

Ecosystems

By:
, , , , and
DOI: 10.1007/s10021-009-9292-y

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Abstract

Peatlands store 30% of the world's terrestrial soil carbon (C) and those located at northern latitudes are expected to experience rapid climate warming. We monitored growing season carbon dioxide (CO2) fluxes across a factorial design of in situ water table (control, drought, and flooded plots) and soil warming (control vs. warming via open top chambers) treatments for 2 years in a rich fen located just outside the Bonanza Creek Experimental Forest in interior Alaska. The drought (lowered water table position) treatment was a weak sink or small source of atmospheric CO2 compared to the moderate atmospheric CO2 sink at our control. This change in net ecosystem exchange was due to lower gross primary production and light-saturated photosynthesis rather than increased ecosystem respiration. The flooded (raised water table position) treatment was a greater CO2 sink in 2006 due largely to increased early season gross primary production and higher light-saturated photosynthesis. Although flooding did not have substantial effects on rates of ecosystem respiration, this water table treatment had lower maximum respiration rates and a higher temperature sensitivity of ecosystem respiration than the control plot. Surface soil warming increased both ecosystem respiration and gross primary production by approximately 16% compared to control (ambient temperature) plots, with no net effect on net ecosystem exchange. Results from this rich fen manipulation suggest that fast responses to drought will include reduced ecosystem C storage driven by plant stress, whereas inundation will increase ecosystem C storage by stimulating plant growth. ?? 2009 Springer Science+Business Media, LLC.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Effects of experimental water table and temperature manipulations on ecosystem CO2 fluxes in an Alaskan rich fen
Series title:
Ecosystems
DOI:
10.1007/s10021-009-9292-y
Volume
12
Issue:
8
Year Published:
2009
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Ecosystems
First page:
1329
Last page:
1342
Number of Pages:
14