Katarina Hedlund
Professor
Corridor or drift fence? The role of medial moraines for fly dispersal over glacier
Author
Summary, in English
Corridors are often considered to promote dispersal between habitat patches. In this paper, we study whether or not corridors induce colonisation of nunataks (ice-free areas in glacier surroundings) by promoting dispersal from lowland to the nunataks. On outlet glaciers, debris originating from nunataks forms the so-called medial moraines that stretch from the nunataks down-glacier to the lowland, forming corridors of debris on the glacier. Aerial dispersal was determined with yellow sticky traps on the moraines, bare glacier and glacier foreland. Dipterans were sampled in pitfall traps on the nunataks. Flying insects that were present on the vegetated glacier foreland belonged to five orders, that is, Diptera, Hemiptera, Hymenoptera, Lepidoptera and Trichoptera. On the glacier and medial moraines, however, mainly dipterans were present, with the majority of individuals found on the moraines. Hoverflies (Syrphidae) were abundant on the moraines and on the edges of nunataks close to the moraines, but were not present on the vegetated foreland. The origin of the hoverflies is thus not the nunataks and not the lowland. Rather, they are brought in by air currents towards the glacier, where they aggregate on a land type where they have a chance of survival, although it is not habitable. Thus, we conclude that the medial moraines do not function as regular corridors but as drift fences that direct the dispersal towards the adjacent land types, that is, the nunataks and the glacier foreland.
Department/s
- Biodiversity
- Evolutionary ecology
- BECC: Biodiversity and Ecosystem services in a Changing Climate
- Soil Ecology
- Theoretical Population Ecology and Evolution Group
Publishing year
2013
Language
English
Pages
925-932
Publication/Series
Polar Biology
Volume
36
Issue
7
Document type
Journal article
Publisher
Springer
Topic
- Ecology
- Biological Sciences
Keywords
- Subarctic
- Long-distance dispersal
- Colonisation
- Iceland
Status
Published
Research group
- Soil Ecology
- Theoretical Population Ecology and Evolution Group
ISBN/ISSN/Other
- ISSN: 1432-2056