HR: 0800h
AN: A51B-0034    [Abstracts]
TI: Methyl Halide Production by Fungi
AU: * Dailey, G D
EM: gail.dailey@unh.edu
AF: Climate Change Research Center, Institute for the Study of Earth, Oceans and Space University of New Hampshire, Durham, NH 03824 United States
AU: Varner, R K
EM: ruth.varner@unh.edu
AF: Climate Change Research Center, Institute for the Study of Earth, Oceans and Space University of New Hampshire, Durham, NH 03824 United States
AU: Blanchard, R O
A51B-0034 AF: Department of Plant Biology, University of New Hampshire, Durham, NH 03824 United States
AU: Sive, B C
EM: bcsive@gust.sr.unh.edu
AF: Climate Change Research Center, Institute for the Study of Earth, Oceans and Space University of New Hampshire, Durham, NH 03824 United States
AU: Crill, P M
EM: patrick.crill@geo.su.se
AF: Institutionen f”r Geologi och Geokemi, Stockholm University, Stockholm, 106 91 Sweden
AB: Methyl chloride (CH₃Cl), methyl bromide (CH₃Br) and methyl iodide (CH₃I) are methyl halide gases that contribute significant amounts of halogen radicals to the atmosphere. In an effort to better understand the global budget of methyl halides and their impact on the atmosphere, we need to identify the natural sources in addition to the known anthropogenic sources of these compounds. We are investigating the role of fungi in the production of methyl halides in the soils and wetlands in southern New Hampshire, USA. Previous research has shown that wood decay fungi and ectomycorrhizal fungi, which are within a group of fungi called basidiomycetes, emit methyl halides. In our study, measurements of headspace gas extracted from flasks containing fungi grown in culture demonstrate that a variety of fungi, including basidiomycetes and non-basidiomycetes, emit methyl halides. Our research sites include four ecosystems: an agricultural field, a temperate forest, a fresh water wetland, and coastal salt marshes. We have collected and isolated fungi at each site by culturing tissue samples of fruiting bodies and plant material, by using wood baits, and from the direct culture of soil. We compared the rates of methyl halide emissions from the fungi in the four ecosystems. In addition, we measured emissions from previously assayed fungal isolates after reintroducing them to sterilized soils that were collected from their original environments. Fungal biomass was determined by substrate-induced respiration (SIR). The emission rate by the fungus was determined by a linear regression of the concentration of methyl halide in the sample headspace over time divided by the fungal biomass.
DE: 0315 Biosphere/atmosphere interactions (0426, 1610)
DE: 0322 Constituent sources and sinks
DE: 0414 Biogeochemical cycles, processes, and modeling (0412, 0793, 1615, 4805, 4912)
DE: 0486 Soils/pedology (1865)
DE: 0490 Trace gases
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005