Effects of nutrient transfer by great skuas (Stercorarius skua) and arctic skuas (Stercorarius parasiticus) on vegetation and soil at Breiðamerkurjökull, SE-Iceland

Abstract

Seabirds can play a vital role in primary succession by transferring nutrients from sea to land. Here, we examine the effects of sparse seabird colonies on primary succession at the Breiðamerkurjökull glacial fore-field in SE-Iceland. The area is generally characterized by low vegetation cover, where mosses are dominant, with scattered, grassy vegetation “islands” (bird hummocks) formed through point-centered influence of seabirds. The aim of this study was to assess the influence of bird presence on vegetation and soil properties. This was done by examining how vegetation and soil properties changed with the distance from bird hummocks and the influence of time on that relationship. Total vegetation cover and grass and forb cover were found to be significantly affected by the birds’ presence, as well as the concentration of soil organic matter and pHH2O . These results demonstrate the importance of seabirds as natural fertilizers in primary succession and early soil formation processes.