Seasonal differences in the CO2 exchange of a short-hydroperiod Florida Everglades marsh

Authors

Jessica L. Schedlbauer, Department of Biological Sciences, Florida International UniversityFollow
Steven F. Oberbauer, Department of Biological Sciences, Florida International University and Fairchild Tropical Botanic GardenFollow
Gregory Starr, Department of Biological Sciences, University of AlabamaFollow
Kristine L. Jimenez, Department of Biological Sciences, University of Alabama

Abstract

Although wetlands are among the world's most productive ecosystems, little is known of long-term CO₂ exchange in tropical and subtropical wetlands. The Everglades is a highly managed wetlands complex occupying >6000 km² in south Florida. This ecosystem is oligotrophic, but extremely high rates of productivity have been previously reported. To evaluate CO₂ exchange and its response to seasonality (dry vs. wet season) in the Everglades, an eddy covariance tower was established in a short-hydroperiod marl marsh. Rates of net ecosystem exchange and ecosystem respiration were small year-round and declined in the wet season relative to the dry season. Inundation reduced macrophyte CO₂ uptake, substantially limiting gross ecosystem production. While light and air temperature exerted the primary controls on net ecosystem exchange and ecosystem respiration in the dry season, inundation weakened these relationships. The ecosystem shifted from a CO₂ sink in the dry season to a CO₂ source in the wet season; however, the marsh was a small carbon sink on an annual basis. Net ecosystem production, ecosystem respiration, and gross ecosystem production were −49.9, 446.1 and 496.0 g C m⁻² year⁻¹, respectively. Unexpectedly low CO₂ flux rates and annual production distinguish the Everglades from many other wetlands. Nonetheless, impending changes in water management are likely to alter the CO₂ balance of this wetland and may increase the source strength of these extensive short-hydroperiod wetlands.

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Copyright © 2010 Elsevier.

The definitive publisher-authenticated version is available online at http://dx.doi.org/10.1016/j.agrformet.2010.03.005

This material is based upon work supported by the National Science Foundation through the Florida Coastal Everglades Long-Term Ecological Research program under Cooperative Agreements #DBI-0620409 and #DEB-9910514. Any opinions, findings, conclusions, or recommendations expressed in the material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

Recommended Citation

Publisher Version: Schedlbauer, J., S. Oberbauer, G. Starr, K.L. Jimenez. 2010. Seasonal differences in the CO2 exchange of a short-hydroperiod Florida Everglades marsh. Agricultural and Forest Meteorology 150(7-8): 994-1006.