Details

Autor(en) / Beteiligte

• Kaplan, Louis A.
• Bott, Thomas L.

Titel

Diel Fluctuations in Bacterial Activity on Streambed Substrata During Vernal Algal Blooms: Effects of Temperature, Water Chemistry, and Habitat

Ist Teil von

• Limnology and oceanography, 1989-06, Vol.34 (4), p.718-733

Ort / Verlag

Waco, TX: American Society of Limnology and Oceanography

Erscheinungsjahr

1989

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• Diel fluctuations in stream water temperature and chemistry, microbial biomass, and bacterial activity were measured in White Clay Creek, Pennsylvania, during vernal algal blooms in three different years. DOC concentrations increased 24-37% over early morning minima and temperature increased nearly $10^\circ C$ over a 7-10-h period. Total carbohydrates and monosaccharides exhibited irregular fluctuations with total carbohydrates showing concentration peaks in the morning and affternoon. Acetate concentrations were highest in midafternoon, while the concentration pattern for primary amines differed from the DOC pattern with highest values at midnight. No distinct diel patterns were found for streambed ATP, GTP : ATP, Chl a, and total or active bacteria, although significant year-to-year and between-habitat differences were observed. Bacterial activity, measured by phopholipid biosynthesis, total lipid biosynthesis, respiration, and incorporation of $[^3H]$thymidine into DNA increased 1.4-fold to 3.0-fold from morning to afternoon. Microcosm experiments indicated that the activity of bacterial attached to sediments was more sensitive to increases in water temperature than to changes in water chemistry, whereas bacteria attached to porcelains disks responded to the influences of both tempereature and water chemistry.