Vegetation mapping of islands in Breiðafjörður, West-Iceland NIBIO RAPPORT | VOL. 4 | NR. 21 | 2018 THOMAS HOLM CARLSEN1, ÁRNI ÁSGEIRSSON2 and JÓN EINAR JÓNSSON2 1NIBIO Tjøtta, 2University of Iceland's Research Centre at Snæfellsnes TITTEL/TITLE Vegetation mapping of islands in Breiðafjörður, West-Iceland FORFATTER(E)/AUTHOR(S) Thomas Holm Carlsen, Árni Ásgeirsson & Jón Einar Jónsson DATO/DATE: RAPPORT NR./ TILGJENGELIGHET/AVAILABILITY: PROSJEKTNR./PROJECT NO.: SAKSNR./ARCHIVE NO.: REPORT NO.: 04.04.2018 4/21/2018 Åpen 630001 18/00307 ISBN: ISSN: ANTALL SIDER/ ANTALL VEDLEGG/ NO. OF PAGES: NO. OF APPENDICES: 978-82-17-02046-2 2464-1162 66 2 OPPDRAGSGIVER/EMPLOYER: KONTAKTPERSON/CONTACT PERSON: Breiðafjarðarnefnd Theódóra Matthíasdóttir STIKKORD/KEYWORDS: FAGOMRÅDE/FIELD OF WORK: Island, Breiðafjörður, vegetasjon, kartlegging, Kulturlandskap og biomangfold plantearter, gjengroing, fugleliv Iceland, Breiðafjörður, vegetation, mapping, Cultural Landscape and Biodiversity plant species, overgrowing, birdlife SAMMENDRAG/SUMMARY: I 2014 ble 22 øyer i Breiðaförður, Vest-Island, vegetasjonskartlagt. Hensikten med kartlegginga var å registrere vegetasjonstyper, artssammensetning og gjengroingsstatus på øyer som har ulik størrelse, topografi, geologisk sammensetning, brukshistorie, samt ulikt fugleliv. De fleste øyer i denne undersøkelsen har ikke blitt kartlagt før, slik at prosjektet har bidratt til ny kunnskap om deler av dette unike øyriket i Breiðafjörður. In 2014, 22 islands in Breiðafjörður, West-Iceland were mapped for vegetation. The purpose to this study was to map vegetation types, distribution of plant species and overgrowing status in islands which differs in size, topography, bedrock composition, land use and birdlife activity. Most of the islands in this study have not been mapped before. This project provides new knowledge to part of the unique archipelago of Breiðafjörður. LAND/COUNTRY: Iceland STED/LOKALITET: 22 islands in Breiðafjörður GODKJENT /APPROVED PROSJEKTLEDER /PROJECT LEADER Knut Anders Hovstad Thomas Holm Carlsen HEAD OF DEPARTMENT RESEARCHER Preface Norwegian Institute for Bioeconomy research, NIBIO in cooperation with the University of Iceland's Research Centre at Snæfellsnes have accomplished vegetation mapping of 22 islands in Breiðafjörður in the west part of Iceland. The project was funded by Breiðafjarðarnefnd (www.breidafjordur.is). The contact person in Breiðafjarðarnefnd was Trausti Baldursson, a former member of the board and Theódóra Matthíasdóttir, the secretary of the board. We want to thank Rannveig Thoroddsen and Guðmundur Guðjónsson at The Icelandic Institute of Natural History for helping out with the vegetation classification. We had good discussions of which legends to use on the different islands regarding to the different plant species found and the distribution of them. We also like to thank Árni’s father Ásgeir Árnasson for boat rental, and Kristján Lár Gunnarsson for driving us to Vaktarhólmi, Stóri Sindingahólmi, Litli Sindingahólmi, Ólafsey and Galtarey in the eastern part of the mapping area. All pictures are taken by © Thomas H. Carlsen, NIBIO Tjøtta, 04.04.18 Thomas Holm Carlsen Project leader NIBIO RAPPORT 4 (21) 3 Innhold 1 Introduction ................................................................................................................................ 5 2 Method ....................................................................................................................................... 6 3 Results....................................................................................................................................... 10 3.1 Kiðey .............................................................................................................................................................. 10 3.2 Sellón ............................................................................................................................................................. 13 3.3 Lyngey ............................................................................................................................................................ 15 3.4 Sellátur ........................................................................................................................................................... 18 3.5 Hjallsey .......................................................................................................................................................... 21 3.6 Stakksey ......................................................................................................................................................... 23 3.7 Landey ........................................................................................................................................................... 25 3.8 Ljótunshólmi .................................................................................................................................................. 29 3.9 Loðinshólmi ................................................................................................................................................... 31 3.10 Vatnsey and Vatnseyjarkálfur ........................................................................................................................ 33 3.11 Lónið .............................................................................................................................................................. 36 3.12 Gimburey ....................................................................................................................................................... 38 3.13 Þorvaldsey ..................................................................................................................................................... 40 3.14 Melrakkaey .................................................................................................................................................... 42 3.15 Elliðaey .......................................................................................................................................................... 44 3.16 Vaðstakksey ................................................................................................................................................... 47 3.17 Arnarey .......................................................................................................................................................... 50 3.18 Vaktarhólmi ................................................................................................................................................... 52 3.19 Ólafsey ........................................................................................................................................................... 55 3.20 Stóri Sindingahólmi ........................................................................................................................................ 58 3.21 Litli Sindingahólmi ......................................................................................................................................... 60 3.22 Galtarey ......................................................................................................................................................... 62 4 Discussion ................................................................................................................................. 64 References ..................................................................................................................................... 66 4 NIBIO RAPPORT 4 (21) 1 Introduction Breiðafjörður is the second largest bay in Iceland, characterized by thousands of islands and shallow waters in between. The islands and tides interact to create tidal currents in several places, particularly near the outlet of the fjord Hvammsfjörður. The tidal amplitude is high and reaches a maximum of five metres, which makes the tidal currents particularly powerful. The geology in Breiðafjörður is relatively uniform: most of the islands consist of basic and intermediate lavas from tertiary, older than 3.1 million years. Some few exceptions are Hrappsey, Purkey, Seley and Klakkeyjar located some few kilometres northeast of Stykkishólmur; these islands have intrusions of basic and intermediate dolerite (Jóhannesson 1994). The islands are vegetated, largely due to fertilizing from abundant birdlife (Ferðafélag Íslands 1989) but also due to historical land use. Historically, island farmers, supported by the abundant natural resources found within the area, inhabited the. Breiðafjörður was commonly called “Iceland‘s treasure chest” due to its rich natural resources. During the mid-20th century, the number of farms in the islands dramatically decreased and subsequent urbanization on the mainland in relation to increased fisheries (Kjartansdóttir 2009). In 1942, 1960 and 1975 there were 26, 8 and 3 islands farms inhabited, respectively (Ferðafélag Íslands 1989) although Brokey remained inhabited year-round until 1982. Island farming was a combination of conventional farming, fisheries and natural resources. Livestock was kept on the “home” islands (is: heimaeyjar) where the people lived or adjacent, smaller islands and islets belonging to each farm. Island farming was labour intensive; for example, haymaking for island farms required visiting every island, cutting, raking, drying and transporting hay from each island with boats. Boats were the main