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| Titel |
Effects of seagulls on ecosystem respiration, soil nitrogen and vegetation cover on a pristine volcanic island, Surtsey, Iceland |
| VerfasserIn |
B. D. Sigurdsson, B. Magnusson |
| 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 ; 7, no. 3 ; Nr. 7, no. 3 (2010-03-05), S.883-891 |
| Datensatznummer |
250004582
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| Publikation (Nr.) |
 copernicus.org/bg-7-883-2010.pdf |
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| Zusammenfassung |
| When Surtsey rose from the North Atlantic Ocean south of Iceland in 1963, it
became a unique natural laboratory on how organisms colonize volcanic
islands and form ecosystems with contrasting structures and functions. In
July, 2004, ecosystem respiration rate (Re), soil properties and surface
cover of vascular plants were measured in 21 permanent research plots
distributed among the juvenile communities of the island. The plots were
divided into two main groups, inside and outside a seagull (Larus spp.) colony
established on the island. Vegetation cover of the plots was strongly
related to the density of gull nests. Occurrence of nests and increased
vegetation cover also coincided with significant increases in Re, soil
carbon, nitrogen and C:N ratio, and with significant reductions in soil pH
and soil temperatures. Temperature sensitivity (Q10 value) of Re was
determined as 5.3. When compared at constant temperature the Re was
found to be 59 times higher within the seagull colony, similar to the
highest fluxes measured in drained wetlands or agricultural fields in
Iceland. The amount of soil nitrogen, mainly brought onto the island by the
seagulls, was the critical factor that most influenced ecosystem fluxes and
vegetation development on Surtsey. The present study shows how ecosystem
activity can be enhanced by colonization of animals that transfer resources
from a nearby ecosystem. |
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