The possibility to follow up the succession of microbial life in a virgin soil quite free
from organic substances has been fascination. In 1972, five years after the eruptions
ended on Surtsey, soil samples could still be gathered which did not show any
evidence of microbial life.

It was not unexpected that free-living blue-green algae with the ability to use sun energy and
the molecular nitrogen of the air for growth and development, were among the primary
immigrants of Surtsey. The algae, which nowadays (1982) frequently occur on the island,
are also found to live in associations with mosses.

Moisture is a necessary condition for nitrogen fixation.
© c/o www.vulkaner.no

The first evidence of biological nitrogen fixation on Surtsey was recorded in 1970, when it was found in laboratory experiments that
microorgnisms in Surtsey soils showed the activity of nitrogenase, the enzyme which is necessary for all biological nitrogen fixation.
The organismsms involved were found to be light-depended. By cultivation it was found
that the nitrogenase activity was derived from the blue-green algae Anabaena variabilis.

It may be surprising that algal nitrogen fixation at a high level can be recorded in soils where
blue-green are not visitble to the naked eye. Therefore, it must be incorrect when earlier
research stated that blue-green algae are unimportant as primary colonisers of Surtsey,
since one could not detect them...

A necessary condition for nitrogen fixation (nitrogenase activity) is moisture. Vast areas of
Surtsey are therefore often unsuitable for nitrogen fixation and growth of nitrogen-fixing microorganisms. Samples from this area were analysed for occurence of living
microorganisms in Uppsala, August 1972.
© c/o www.vulkaner.no

In fact, the nitrogen-fixing activities on Surtsey are well established and are of major
importance for the nitrogen input and nitrogen economy during the primary ecological
stage of development.

During the last decade the plants of Honkenya peploides have increased greatly in number
on Surtsey. Many plants have been buried under sand drifts and new ones have arrived.
These circumstances must result in accumulation of organic matter into the soil. Old roots
are decomposed, and from living roots organic substances are exudated into the
root environment.

The text above is Based upon a report by Lars Eric Henriksson and Elisabet Henriksson
Institute of Physiological Botany, University of Uppsala, Uppsala, Sweden
Surtsey Research Progress Report IX.

Here you can find more information about:

	Plants
	Birds
	Bird migration
	Insects
	Sealife
	Fossils on Surtsey
	Picture-review
	The eruption

February 18th, 2003

See the last report from Surtsey Research - 2009. Click here

Any questions, or a feeling of knowing more, just get in touch!

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