Abstract
Ryan Lake, a 1.6-hectare basin lake near the periphery of the tree blowdown area in the blast zone 19 km north of Mount St. Helens, was studied from August to October 1980 to determine the microbial and chemical response of the lake to the eruption. Nutrient enrichment through the addition of fresh volcanic material and the organic debris from the surrounding conifer forest stimulated intense microbial activity. Concentrations of such nutrients as phosphorus, sulfur, manganese, iron, and dissolved organic carbon were markedly elevated. Nitrogen cycle activity was especially important to the lake ecosystem in regulating biogeochemical cycling owing to the limiting abundance of nitrogen compounds. Nitrogen fixation, both aerobic and anaerobic, was active from aerobic benthic and planktonic cyanobacteria with rates up to 210 nmol of N2 cm−1 h−1 and 667 nmol of N2 liter−1 h−1, respectively, and from anaerobic bacteria with rates reaching 220 nmol of N2 liter−1 h−1. Nitrification was limited to the aerobic epilimnion and littoral zones where rates were 43 and 261 nmol of NO2 liter−1 day−1, respectively. Potential denitrification rates were as high as 30 μmol of N2O liter−1 day−1 in the anaerobic hypolimnion. Total bacterial numbers ranged from 1 × 106 to 3 × 108 ml−1 with the number of viable sulfur-metal-oxidizing bacteria reaching 2 × 106 ml−1 in the hypolimnion. A general scenario for the microbial cycling of nitrogen, carbon, sulfur, and metals is presented for volcanically impacted lakes. The important role of nitrogen as these lakes recover from the cataclysmic eruption and proceed back towards their prior status as oligotrophic alpine lakes is emphasized.
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- Belser L. W., Mays E. L. Specific inhibition of nitrite oxidation by chlorate and its use in assessing nitrification in soils and sediments. Appl Environ Microbiol. 1980 Mar;39(3):505–510. doi: 10.1128/aem.39.3.505-510.1980. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Belser L. W. Population ecology of nitrifying bacteria. Annu Rev Microbiol. 1979;33:309–333. doi: 10.1146/annurev.mi.33.100179.001521. [DOI] [PubMed] [Google Scholar]
- Brezonik P. L., Harper C. L. Nitrogen fixation in some anoxic lacustrine environments. Science. 1969 Jun 13;164(3885):1277–1279. doi: 10.1126/science.164.3885.1277. [DOI] [PubMed] [Google Scholar]
- Collins M. D., Jones D. The distribution of isoprenoid quinones in streptococci of serological groups D and N. J Gen Microbiol. 1979 Sep;114(1):27–33. doi: 10.1099/00221287-114-1-27. [DOI] [PubMed] [Google Scholar]
- Cook R. J., Barron J. C., Papendick R. I., Williams G. J., 3rd Impact on agriculture of the mount st. Helens eruptions. Science. 1981 Jan 2;211(4477):16–22. doi: 10.1126/science.211.4477.16. [DOI] [PubMed] [Google Scholar]
- Fruchter J. S., Robertson D. E., Evans J. C., Olsen K. B., Lepel E. A., Laul J. C., Abel K. H., Sanders R. W., Jackson P. O., Wogman N. S., Perkins R. W., VAN Tuyl H. H., Beauchamp R. H., Shade J. W., Daniel J. L., Erikson R. L., Sehmel G. A., Lee R. N., Robinson A. V., Moss O. R., Briant J. K., Cannon W. C. Mount st. Helens ash from the 18 may 1980 eruption: chemical, physical, mineralogical, and biological properties. Science. 1980 Sep 5;209(4461):1116–1125. doi: 10.1126/science.209.4461.1116. [DOI] [PubMed] [Google Scholar]
- Hardy R. W., Holsten R. D., Jackson E. K., Burns R. C. The acetylene-ethylene assay for n(2) fixation: laboratory and field evaluation. Plant Physiol. 1968 Aug;43(8):1185–1207. doi: 10.1104/pp.43.8.1185. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hobbie J. E., Daley R. J., Jasper S. Use of nuclepore filters for counting bacteria by fluorescence microscopy. Appl Environ Microbiol. 1977 May;33(5):1225–1228. doi: 10.1128/aem.33.5.1225-1228.1977. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Knowles R. Denitrification, acetylene reduction, and methane metabolism in lake sediment exposed to acetylene. Appl Environ Microbiol. 1979 Sep;38(3):486–493. doi: 10.1128/aem.38.3.486-493.1979. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Oren A., Blackburn T. H. Estimation of sediment denitrification rates at in situ nitrate concentrations. Appl Environ Microbiol. 1979 Jan;37(1):174–176. doi: 10.1128/aem.37.1.174-176.1979. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Park P. K., Gordon L. I., Hager S. W., Cissell M. C. Carbon dioxide partial pressure in the columbia river. Science. 1969 Nov 14;166(3907):867–868. doi: 10.1126/science.166.3907.867. [DOI] [PubMed] [Google Scholar]
- Staley J. T., Lehmicke L. G., Palmer F. E., Peet R. W., Wissmar R. C. Impact of mount st. Helens eruption on bacteriology of lakes in the blast zone. Appl Environ Microbiol. 1982 Mar;43(3):664–670. doi: 10.1128/aem.43.3.664-670.1982. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Stewart W. D., Fitzgerald G. P., Burris R. H. In situ studies on N2 fixation using the acetylene reduction technique. Proc Natl Acad Sci U S A. 1967 Nov;58(5):2071–2078. doi: 10.1073/pnas.58.5.2071. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Vincent W. F., Downes M. T. Nitrate accumulation in aerobic hypolimnia: relative importance of benthic and planktonic nitrifiers in an oligotrophic lake. Appl Environ Microbiol. 1981 Oct;42(4):565–573. doi: 10.1128/aem.42.4.565-573.1981. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wissmar R. C., Devol A. H., Nevissi A. E., Sedell J. R. Chemical changes of lakes within the mount st. Helens blast zone. Science. 1982 Apr 9;216(4542):175–178. doi: 10.1126/science.216.4542.175. [DOI] [PubMed] [Google Scholar]
- Wissmar R. C., Devol A. H., Staley J. T., Sedell J. R. Biological responses of lakes in the mount st. Helens blast zone. Science. 1982 Apr 9;216(4542):178–181. doi: 10.1126/science.216.4542.178. [DOI] [PubMed] [Google Scholar]

