title: Growth and senescence in plant communities exposed to elevated CO2concentrations on an estuarine marsh.
abstract: Three high marsh communities on the Chesapeake Bay were exposed to a doubling in ambient CO2concentration for one growing season. Open-top chambers were used to raise CO2concentrations ca. 340 ppm above ambient over monospecific communities of Scirpus olneyi (C3) and Spartina patens (C4), and a mixed community of S. olneyi, S. patens, and Distichlis spicata (C4). Plant growth and senescence were monitored by serial, nondestructive censuses. Elevated CO2resulted in increased shoot densities and delayed sensecence in the C3species. This resulted in an increase in primary productivity in S. olneyi growing in both the pure and mixed communities. There was no effect of CO2on growth in the C4species. These results demonstrate that elevated atmospheric CO2can cause increased aboveground production in a mature, unmanaged ecosystem.
authors.affiliation: Smithsonian Environmental Research Center, Box 28, 21037, Edgewater, MD, USA.
authors.forename: P S
authors.initials: PS
authors.lastname: Curtis
authors.affiliation: Smithsonian Environmental Research Center, Box 28, 21037, Edgewater, MD, USA.
authors.forename: B G
authors.initials: BG
authors.lastname: Drake
authors.affiliation: Smithsonian Environmental Research Center, Box 28, 21037, Edgewater, MD, USA.
authors.forename: P W
authors.initials: PW
authors.lastname: Leadley
authors.affiliation: Smithsonian Environmental Research Center, Box 28, 21037, Edgewater, MD, USA.
authors.forename: W J
authors.initials: WJ
authors.lastname: Arp
authors.affiliation: Smithsonian Environmental Research Center, Box 28, 21037, Edgewater, MD, USA.
authors.forename: D F
authors.initials: DF
authors.lastname: Whigham
keywords: Elevated CO2; Productivity; Salt marsh; Scirpus olneyi; Spartina patens