Biological Dinitrogen Fixation (Acetylene Reduction) Exhibited by Blue-Green Algae (Cyanobacteria) In Association with Mosses Gathered on Surtsey, Iceland

Abstract

The island of Surtsey, formed in volcanic eruptions from 1963 to 1967, is a national protected area giving scientists the ability to study the biological succession without interference from man. At present considerable areas of Surtsey are covered with mosses. Blue-green algae (cyanobacteria) in association with genera of the mosses Bryum, Ceratodon, and Rhacomitrium gathered on Surtsey were shown to have the ability to fix dinitrogen (acetylene reduction) in laboratory experiments. The nitrogenase activity recorded was found to be derived from the leaf region of the mosses. Nostoc calcicola was mainly responsible for the acetylene reduction observed. In a Rhacomitrium canescens sample an unidentified dinitrogen-fixing Nostoc species was found growing endophytically.