Availability of plant nutrients and pollutans in the young soils of Surtsey compared to the older Heimaey and Elliðaey volcanic islands.
Sigurdsson, B. D. and N. I. Leblans. 2020.
Abstract
Surtsey and the older islands in the Vestmannaeyjar archipelago offer a unique possibility to study how
sub-Arctic ecosystems develop from unvegetated mineral substrate that lacks soil cover to grasslands with
thick Brown Andosol soils. The present study was carried out on Surtsey, Heimaey and Elliðaey in 2013
and involved an incubation of resin membranes in the 0-10 cm topsoil layer in different ecosystems, which
were either inside or outside seabird colonies. We compared the effects of seabird presence on soil nutrient
availability as well as the importance of time for soil development (at least ca.1600 years vs. 50 years).
Further we looked for build-up of Cd and Pb within the seabird colonies. Seabird presence enhanced the
availability of most nutrients (N, P, K, Mg, Ca, S, Fe, Mn and Zn) except B and Cu, irrespective of the
age of the islands. Soil age was also a significant factor for nutrient availability for all macro- and micronutrients except B. Nutrient ratios indicated that N was the most limiting nutrient in all ecosystems, except
in the thicker tephra soils on Surtsey where low P availability may lead to co-limitation. The role of P in
ecosystem function on Surtesy warrants a futher study. No accumulation of Cd and Pb was found within
the seabird colonies.
