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| Titel |
Bryophyte colonization history of the virgin volcanic island Surtsey, Iceland |
| VerfasserIn |
G. V. Ingimundardóttir, H. Weibull, N. Cronberg |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 11, no. 16 ; Nr. 11, no. 16 (2014-08-20), S.4415-4427 |
| Datensatznummer |
250117557
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| Publikation (Nr.) |
 copernicus.org/bg-11-4415-2014.pdf |
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| Zusammenfassung |
| The island Surtsey was formed in a volcanic eruption south of Iceland in 1963–1967 and has since
then been protected and monitored by scientists. The first two moss species were found on Surtsey
as early as 1967 and several new bryophyte species were discovered every year until 1973 when
regular sampling ended. Systematic bryophyte inventories in a grid of 100 m × 100 m quadrats
were made in 1971 and 1972: the number of observed species doubled, with 36
species found in 1971 and 72 species in 1972. Here we report results from an inventory in 2008,
when every other of the grid's quadrats were searched for bryophytes. Despite lower sampling
intensity than in 1972, distributional expansion and contraction of earlier colonists was revealed
as well as the presence of new colonists. A total of 38 species were discovered, 15 of those were not
encountered in 1972 and eight had never been reported from Surtsey before (Bryum
elegans, Ceratodon heterophyllus, Didymodon rigidulus, Eurhynchium
praelongum, Schistidium confertum, S. papillosum, Tortula hoppeana and
T. muralis). Habitat loss due to erosion and reduced thermal activity in combination with
successional vegetation changes are likely to have played a significant role in the decline of
some bryophyte species which were abundant in 1972 (Leptobryum pyriforme,
Schistidium apocarpum coll., Funaria hygrometrica, Philonotis spp.,
Pohlia spp, Schistidium strictum, Sanionia uncinata) while others have
continued to thrive and expand (e.g. Schistidium maritimum, Racomitrium lanuginosum,
R. ericoides, R. fasciculare and Bryum argenteum). Some species (especially
Bryum spp.) benefit from the formation of new habitats, such as grassland within a gull
colony, which was established in 1984. Several newcomers are rarely producing sporophytes on
Iceland and are unlikely to have been dispersed by airborne spores. They are more likely to have been
introduced to Surtsey by seagulls in the form of vegetative fragments or dispersal agents
(Bryum elegans, Didymodon rigidulus, Eurhynchium praelongum, Ceratodon heterophyllus
and Ulota phyllantha). The establishment of the gull colony also means that leakage of
nutrients from the nesting area is, at least locally, downplaying the relative importance of
nitrogen fixation by cyanobacteria growing in bryophyte shoots. |
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