THE DIURNAL PATTERN OF DINITROGEN FIXATION BY CYANOBACTERIA IN SITU

Abstract

The diurnal patterns of cyanobacterial acetylene reduction (nitrogen fixation) and seasonal variations in these patterns were investigated in situ on a salt marsh and in a limestone cave. In the field, the non‐heterocystous species fixed N2 mainly at night, while heterocystous species fixed N2 mainly during the day. These basic patterns could be influenced by environmental conditions such as O2 availability and temperature. No acetylene reduction was observed in December, January or February. Copyright © 1987, Wiley Blackwell. All rights reserved