Submitted to: Ecology Society of America Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: January 1, 1998
Publication Date: January 1, 1999
Citation: Frohne, P.S. Havorson, J., Ibekwe, A.M., and Kennedy, A.C. Characterization of microbial communities in Mount St. Helens pyroclastic substrate using FAME analyses. Ecol. Soc. Amer. Abstracts. Spokane, WA. p. 251. 1999. Technical Abstract: A unique opportunity to study microbial communities in a developing soil ecosystem containing little C or N occurred with the 1980 eruption of Mt. St. Helens. Soil samples collected 1981-1986, 1988, and 1990 were extracted for fatty acid methyl esters (FAME). Resulting fingerprints were compared using principal component analysis (PCA). We sampled soil (0-5, 5-10, and 10-15 cm) near Spirit Lake in 1997, including bare soil with no plant development (BARE) and soil under living (LIVE) and dead (DEAD) lupine (Lupinus lepidus). Fatty acid methyl esters were extracted from these samples, and these fingerprints were compared to fingerprints from archived soil using PCA. Archived BARE fingerprints were less variable than fresh BARE (1997) samples, indicating that the appearance of cryptogamic crusts, or storage since 1988, has influenced lipid profiles. Fatty acid methyl ester fingerprints were influenced by the presence of lupine, depending on the distance of the plant from the sample. LIVE and DEAD lipid profiles were distinct from and more variable than those from BARE. Our data indicate whole soil lipid profiles in early successional ecosystems are directly impacted by living and dead plant material.