HR: 1340h
AN: B33E-1677    [Abstracts]
TI: The effects of high ozone episodes on photosynthetic activity of temperate wetland plants
AU: * Goodrich, J P
EM: jpd2@unh.edu
AF: Institute for the Study of Earth, Oceans, and Space, Climate Change Research Center, University of New Hampshire, Morse Hall, Durham, NH 03824, United States
AU: Phillips, S
EM: steve.phillips@unh.edu
AF: Institute for the Study of Earth, Oceans, and Space, Climate Change Research Center, University of New Hampshire, Morse Hall, Durham, NH 03824, United States
AU: Bubier, J
EM: jbubier@mtholyoke.edu
AF: Environmental Studies Program, Mount Holyoke College, South Hadley, MA 01075, United States
AU: Crill, P
EM: patrick.crill@geo.su.se
AF: Department of Geology and Geochemistry, Stockholm University, Stockholm, 11691, Sweden
AU: Crill, P
EM: patrick.crill@geo.su.se
AF: Institute for the Study of Earth, Oceans, and Space, Complex Systems Research Center, University of New Hampshire, Morse Hall, Durham, NH 03824, United States
AU: Varner, R K
EM: rkv@gust.sr.unh.edu
AF: Institute for the Study of Earth, Oceans, and Space, Climate Change Research Center, University of New Hampshire, Morse Hall, Durham, NH 03824, United States
AB: Photosynthetic activity in certain wetland plant species is reduced when ozone (O₃) exposure increases. Few studies have examined the response of whole ecosystems during episodic events. We investigated net ecosystem exchange (NEE) response in a temperate wetland to periods of high ozone levels. The autochamber system at Sallie's Fen, Barrington, New Hampshire provides long-term measurements of NEE of carbon dioxide (CO₂). These data were paired with ozone data from the AIRMAP site at Thompson Farm, Durham, NH (10 km to the south) for analysis of trends. Two chambers with the highest percentage cover of Carex rostrata were chosen for preliminary analysis. Residual analysis was conducted from non-linear regression in which a rectangular hyperbola was used to fit photosynthetically active radiation (PAR), which is known to affect NEE. This indicated a trend in the residuals for PAR in the two autochambers during the month of September toward a reduction in productivity with increased ozone mixing ratios for the period of 2001-2005. Leaf level photosynthesis measurements were also conducted at this fen during the summer of 2007 for Carex rostrata, Chamaedaphne calyculata and Alnus incana ssp.rugosa using a Li-6400 portable photosynthesis system. Initial findings showed a decrease in the photosynthetic activity of C. rostrata when O₃ levels increased. C. rostrata was expected to be the most sensitive of the three species due to high stomatal density and thus higher uptake levels.
DE: 0400 BIOGEOSCIENCES
DE: 0497 Wetlands (1890)
DE: 3322 Land/atmosphere interactions (1218, 1631, 1843)
SC: Biogeosciences [B]
MN: 2007 Fall Meeting