Monday, August 4, 2008 - 4:40 PM

COS 3-10: Carbon balance of coastal forested wetlands

Asko Noormets1, Michael Gavazzi2, Ge Sun2, Jiquan Chen3, and Steve G. McNulty2. (1) North Carolina State University, (2) USDA Forest Service, (3) University of Toledo

Background/Question/Methods
Coastal ecosystems comprise a small portion of total land area, but the soils of these ecosystems are rich in carbon and may therefore play a disproportionately large role in ecosystem-climate feedbacks. The role of these ecosystems in continental carbon exchange is largely unclear because they have been underrepresented in flux monitoring networks.

Results/Conclusions
We monitored ecosystem carbon fluxes and pools for three years in two coastal forests in different stages of succession – a 16-year-old loblolly pine plantation (LP), and a new plantation (clearcut, CC), converted from native mixed hardwood stand. The decrease in ecosystem respiration (from 2160 to 1620 g C m-2 yr-1) and soil respiration (from 1970 to 1280 g C m-2 yr-1) at CC follows the decrease in post-harvest residue (from 2000 to 730 g C m-2). In LP, on the other hand, both ER and SR have been relatively stable at 2075-2120 g C m-2 yr-1 (ER) and 824-845 g C m-2 yr-1 (SR). The interannual differences in temperature and precipitation affected primarily productivity, but have had limited effects on respiration.