Links between agricultural management and wader populations in sub-arctic landscapes Lilja Jóhannesdóttir Faculty of Life and Environmental Sciences School of Engineering and Natural Sciences University of Iceland 2017 Links between agricultural management and wader populations in sub-arctic landscapes Lilja Jóhannesdóttir Dissertation submitted in partial fulfilment of a Philosophiae Doctor degree in biology Advisor Dr. Tómas Grétar Gunnarsson PhD Committee Professor Jennifer A. Gill Dr. José A. Alves Opponents Dr. Hlynur Óskarsson Dr. James Pearce-Higgins Faculty of Life and Environmental Sciences School of Engineering and Natural Sciences University of Iceland Reykjavik, June 2017 Links between agricultural management and wader populations in sub-arctic landscapes Agriculture and wader populations in Iceland Dissertation submitted in partial fulfilment of a Philosophiae Doctor degree in Biology Copyright © 2017 Lilja Jóhannesdóttir All rights reserved Faculty of Life and Environmental Sciences School of Engineering and Natural Sciences University of Iceland Sæmundargata 2 101 Reykjavík Iceland Telephone: 525 4000 Bibliographic information: Lilja Jóhannesdóttir, 2017, Links between agricultural management and wader populations in sub-arctic landscapes, PhD dissertation, Faculty of Life and Environmental Sciences, University of Iceland, 129 pp. ISBN 978-9935-9344-5-1 Printing: Háskólaprent Reykjavik, Iceland, June 2017 Abstract The development and expansion of agriculture throughout the world has been a major driver of biodiversity loss in recent decades. Icelandic agriculture is currently not as intense and widespread as in many other western countries, and the effects of agriculture on biodiversity in Iceland and similar farming systems are largely unknown. Iceland supports big populations of several wader species of international importance and the aim of this thesis is to explore the links between agriculture and breeding wader populations. This was done by surveying waders in agricultural landscapes across Iceland and by carrying out a questionnaire survey among farmers. Surveys of wader density in areas of varying agricultural management intensity throughout lowland Iceland revealed high densities of breeding waders in all three management categories. However densities are generally lower on more intensely managed land, suggesting possible negative effects of future expansion of agriculture, given that the majority of farmers questioned for the study reported they were likely to expand cultivated land in the coming years. The volcanic nature of Iceland and varying temperatures have a strong influence on bird distribution and abundance, and interact with the effects of cultivated land on birds. In areas further from volcanic activity, wader density increases when there is more cultivated land around but the reverse occurs in areas with high levels of historic volcanic ash fall. This suggests that the location of cultivated land expansion can partly determine future effects on birdlife. Currently there are few efforts towards protecting these species in Iceland and, when questioned about their views towards birdlife, farmers reported that they do not currently take bird conservation into consideration in their land use management, although they do consider it important to have rich birdlife on their land and were positive towards participating in proposed conservation management. Cooperation with farmers, who own most of the lowlands, will therefore be crucial in maintaining these widespread and internationally important wader breeding populations. Útdráttur Hnignun líffræðilegrar fjölbreytni í heiminum á síðustu áratugum má að stórum hluta rekja til aukinnar útbreiðslu og ákefðar í landbúnaði. Íslenskur landbúnaður hefur enn ekki náð sömu ákefð og útbreiðslu og víða í vestrænum ríkjum og áhrif landbúnaðar á líffræðilega fjölbreytni eru að mestu óþekkt hérlendis, sem og í öðrum sambærilegum landbúnaðarkerfum. Ísland er mikilvægt varpsvæði margra ábyrgðartegunda og hér finnast stórir stofnar vaðfugla. Markmið doktorsverkefnisins er að skýra tengsl landbúnaðar og vaðfuglastofna á norrænum slóðum með mælingum á Íslandi. Þetta var gert bæði með að meta þéttleika vaðfugla á landbúnaðarsvæðum sem og að spyrja bændur um fyrirætlanir þeirra í landnýtingu og viðhorf þeirra til fuglalífs á landi þeirra. Mat á þéttleika vaðfugla á svæðum undir mismiklum áhrifum landbúnaðar sýnir að almennt er hár þéttleiki á öllum svæðunum en þéttleikinn er lægri á svæðum undir meiri landbúnaðaráhrifum. Þetta bendir til að ef flatarmál ræktað lands eykst muni það hafa neikvæð áhrif á þéttleika vaðfugla en meirihluti þeirra bænda sem rætt var við fyrir verkefnið sögðust stefna á að auka ræktað land á komandi árum. Eldvirkni og hitastig hafa umtalsverð áhrif á fuglalíf á Íslandi, en að auki geta áhrif ræktaðs lands á þéttleika vaðfugla ráðist af þessum tveimur þáttum. Á sumum svæðum minnkar þéttleiki með aukinni útbreiðslu ræktað lands en á öðrum svæðum eykst þéttleikinn. Áhrif aukningar ræktaðs lands á vaðfuglastofna ráðast því að hluta til af staðsetningu. Það eru litlar áherslur lagðar á vernd þessara tegunda á Íslandi og þegar bændur voru spurðir út í viðhorf þeirra til fuglalífs á landi þeirra sögðust þeir almennt ekki taka mikið tillit þess við landnýtingu þrátt fyrir að telja mikilvægt að hafa ríkulegt fuglalíf. Aftur á móti voru bændur jákvæðir gagnvart þeim verndraðgerðum sem lagðar voru til en vitað er að samvinna við landeigendur er lykilatriði ef á að viðhalda þeim þáttum líffræðilegrar fjölbreytni sem hafa víðtæka útbreiðslu. List of publications This thesis is based on the following papers. Within the thesis, references to these papers will be by their Roman numerals. Paper I: Jóhannesdóttir, L., Gill, J. A., Alves, J. A., & Gunnarsson, T. G. (201X). Icelandic meadow breeding waders: status, threats and conservation challenges. International Wader Study - Submitted. Paper II: Jóhannesdóttir, L., Alves, J. A., Gill, J. A., & Gunnarsson, T. G. (201X). Use of agricultural land by breeding waders in low-intensity farming landscapes. In review. Paper III: Gunnarsson, T. G., Jóhannesdóttir, L., Alves, J. A., Þórisson, B., & Gill, J. A. (2016). Effects of spring temperature and volcanic eruptions on wader productivity. Ibis, doi: 10.1111/ibi.12449 Paper IV: Jóhannesdóttir, L., Gill, J. A., Alves, J. A., & Gunnarsson, T. G. (201X). Interacting effects of agriculture and landscape structure on breeding wader populations in Iceland. Manuscript. Paper V: Jóhannesdóttir, L., Alves, J. A., Gill, J. A., & Gunnarsson, T. G. (2017). Reconciling biodiversity conservation and agricultural expansion in the sub-arctic environment of Iceland. Ecology and Society, doi: 10.5751/es-08956-220116 Papers I and III, V are reproduced with kind permission from the publishers. In addition, some unpublished data are presented. Other publications included as an appendix in the doctoral thesis (with permission from the publisher): Jóhannesdóttir, L., Arnalds, Ó., Brink, S., & Gunnarsson, T. G. (2014). Identifying important bird habitats in a sub-arctic area undergoing rapid land-use change. Bird Study, 61(4), 544-552. doi: 10.1080/00063657.2014.962481 Author’s contribution Paper I. Lilja Jóhannesdóttir collated the data for this paper, was the leading author in collaboration with co-authors and is the corresponding author. Paper II. Lilja Jóhannesdóttir, in collaboration with co-authors, designed the methods and was responsible for all data collection. Lilja Jóhannesdóttir analysed and interpreted the results, wrote the paper together with co-authors and is the corresponding author. Paper III. Lilja Jóhannesdóttir helped with design of the methods, data analysis, writing, and is the second author on this paper. Paper IV. Lilja Jóhannesdóttir designed the methods, together with co-authors, and collected all the bird data. Sigmundur H. Brink extracted land cover information. Lilja Jóhannesdóttir analysed and interpreted results, wrote the paper together with co-authors and will be the corresponding author. Paper V. Lilja Jóhannesdóttir designed the questionnaire, in collaboration with co-authors, and carried out all of the interviews with farmers. She analysed and interpreted the results, wrote the paper together with co-authors and is the corresponding author. Table of Contents List of Figures ................................................................................................................... xiii List of Tables ..................................................................................................................... xiv Acknowledgements ............................................................................................................ xv 1 Introduction ..................................................................................................................... 1 1.1 Agriculture............................................................................................................... 1 1.1.1 Intensification of agriculture .......................................................................... 1 1.1.2 Consequences of agricultural intensification ................................................. 2 1.1.3 Birds and agriculture ...................................................................................... 3 1.2 Icelandic agriculture ................................................................................................ 4 1.2.1 Location, landscape and climatic conditions ................................................