This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by McKinley, V. L. Articles by Vestal, J. R. Search for Related Content PubMed PubMed Citation Articles by McKinley, V. L. Articles by Vestal, J. R. Agricola Articles by McKinley, V. L. Articles by Vestal, J. R.

 Previous Article  |  Next Article 

Appl Environ Microbiol. 1982 May; 43(5): 1188-1195

Effects of Acid on Plant Litter Decomposition in an Arctic Lake

¹ Department of Biological Sciences, University of Cincinnati, Cincinnati, Ohio 45221

ABSTRACT

The effects of acid on the microbial decomposition of the dominant aquatic macrophyte (Carex sp.) in Toolik Lake, Alaska were studied in microcosms during the ice-free season of 1980. Toolik Lake is slightly buffered, deep, and very oligotrophic. Microbial activities, as determined by ¹⁴C-acetate incorporation into extractable lipids, associated with Carex litter were significantly (P < 0.01) reduced within 2 days at pHs of 3.0 and 4.0, but not 5.0, 5.5, or 6.0, as compared with ambient controls (pH 7.4). ATP levels were significantly reduced at pH 3.0, but not at the other pHs tested. After 18 days, microbial activity significantly correlated with weight loss (P < 0.05), nitrogen content (P < 0.01), and C/N ratios (P < 0.01) of the litter, but did not correlate with ATP levels. Scanning electron microscopy of the litter surface revealed that the fungi present at ambient pH did not become dominant at pHs below 5.5, diatoms were absent below pH 4.0, and bacterial numbers and extracellular slime were greatly reduced at pH 4.0 and below. Mineralization of Carex¹⁴C-lignin-labeled or ¹⁴C-cellulose-labeled lignocellulose was reduced at pH 2.0, but not at pH 4.0, 5.0, or 6.0, compared with controls (pH 7). We concluded that if the pH of the water from this slightly buffered lake was sufficiently reduced, rates of litter decomposition would be significantly reduced.

This article has been cited by other articles:

• Rudd, J. W. M., Kelly, C. A., Schindler, D. W., Turner, M. A. (1988). Disruption of the Nitrogen Cycle in Acidified Lakes. Science 240: 1515-1517 [Abstract]