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Durham E-Theses The landscape ecology of butteries in traditionally managed Norwegian farmland Fjellstad, Wendy Jane How to cite: Fjellstad, Wendy Jane (1998) The landscape ecology of butteries in traditionally managed Norwegian farmland, Durham theses, Durham University. Available at Durham E-Theses Online: http://etheses.dur.ac.uk/4657/ Use policy The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that: • a full bibliographic reference is made to the original source • a link is made to the metadata record in Durham E-Theses • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders. Please consult the full Durham E-Theses policy for further details. Academic Support Oce, Durham University, University Oce, Old Elvet, Durham DH1 3HP e-mail: [email protected] Tel: +44 0191 334 6107 http://etheses.dur.ac.uk 2 THE LANDSCAPE ECOLOGY OF BUTTERFLIES IN TRADITIONALLY MANAGED NORWEGIAN FARMLAND A Ph.D. thesis submitted to University of Durham Department of Biological Sciences by Wendy Jane Fjeilstad 1998 The copyright of this thesis rests APR 1999 with the author. No quotation from it should be published without the written consent of die author and information derived from it should be acknowledged. "There is a theory which states that if ever anyone discovers exactly what the Universe is for and why it is here, it will instantly disappear and be replaced by something even more bizarre and inexplicable." (Douglas Adams; The Hitch Hiker's Guide To The Galaxy) THE LANDSCAPE ECOLOGY OF BUTTERFLIES IN TRADITIONALLY MANAGED NORWEGIAN FARMLAND Ph.D. thesis submitted by Wendy Fjellstad, Autumn term 1998. ABSTRACT The modernisation of agriculture has lead to changes in Norwegian farming landscapes that have consequences for butterfly distribution and abundance. Particularly important is the abandonment of traditionally managed grasslands and the consequent increase in potential barriers of scrub and trees in the landscape. In this thesis I use a landscape ecological perspective to explore the effects of abandonment on butterfly dispersal. I demonstrate that landscape elements influence butterfly movement behaviour: tall structures were significant barriers for a range of species and even low features, such as roads, elicited significant behavioural responses which shaped the movement patterns of butterflies. Behavioural differences between species were related to ecological and physiological characteristics. Movement patterns of Scarce Coppers (Lyceana virgaureae) were recorded by mark-release- recapture (MRR) techniques. Of 1711 recorded displacements, over 90 % were under 150 m. Exchange rates between meadows were dependent upon distance and the structure of intervening vegetation. A simple spatial model, parameterised with data from the behavioural experiments, was validated using MRR observations. This confirmed that the behaviour of individuals responding to single landscape elements has consequences at the level of populations and entire landscapes. The life history and movement behaviour of the endangered Apollo {Parnassius apollo), were examined using MRR. The butterfly is well adapted to a mosaic landscape structure; however, inter-meadow movement declined exponentially with increasing distance between meadows. Abandonment of hay meadows on steep slopes, with consequent forest succession, will adversely affect the Apollo by increasing the distances between open habitat. Genetic analyses support the findings of MMR studies and add a wider spatial and temporal perspective. As a conservation management priority, I recommend population mapping to identify key sites in regional networks of populations. Finally, I consider the links between empirical studies, modelling and the practical application of theory, and discuss the implications of landscape change for the butterflies of Norwegian farmland. in NORWEGIAN ABSTRACT SOMMERFUGLER I TRADISJONELLE NORSKE JORDBRUKSOMRADER: ET LANDSKAPS0KOLOGISK PERSPEKTIV Ph.D. avhandling av Wendy Jane Fjellstad REFERAT Modernisering av driftsmetoder i jordbruket bar f0rt til forandringer i norsk jordbrukslandskap som bar konsekvenser for utbredelsen eg mangfoldet av sommerfugler. Saerlig viktig er nedleggingen av tradisjonelt skj0ttede slatteenger og den paf0lgende 0kningen av mulige barrierer i landskapet i form av busker og traer. I denne avhandlingen unders0ker jeg ut fra et landskaps0kologisk perspektiv hvordan opph0r av drift pavirker spredning av sommerfugler. Jeg paviser at landskapselementer virker inn pa sommerfuglenes bevegelser: H0ye strukturer var signifikante bevegelsesbarrierer for en rekke arter, og selv lave elementer, slik som veier, forarsaket atferd som formet sommerfuglenes bevegelser. Atferdsforskjeller mellom arter forklares i henhold til 0kologiske og fysiologiske karakterer. Den 0stlandske gullvingens {Lyceana virgaureae) bevegelsesm0nstre ble registrert ved bruk av merke-gjenfangstsmetoder (MRR). Over 90 % av 1711 registrerte forflytninger var pa mindre enn 150 m. Utvekslingsraten mellom enger var avhengig av avstanden og vegetasjonsstrukturen mellom engene. En enkel romlig model, med parametre hentet fra atferdstudiene, ble pr0vd ut ved hjelp av observasjonene fra merke-gjenfangstfors0ket. Denne bekreftet at enkeltindividers reaksjon pa de enkelte landskapselementene bar konsekvenser pa populasjons- og landskapsniva. Merke-gjenfangst ble ogsa benyttet for a unders0ke livshistorien og bevegelsesatferden til en truet art, apoUosommerfuglen (Parnassius apollo). Sommerfuglen er godt tilpasset et landskap med mosaikkstruktur; men likevel gikk antall bevegelser mellom enger eksponensielt ned med 0kende avstand. Nedlegging av slatteenger i bratte bakker, med paf0lgende gjengroing, vil gjennom den 0kte avstanden mellom apent habitat komme til a ha en negativ virkning pa apollosommerfuglenen. Genetiske analyser st0tter resultatene fra merke-gjenfangstfors0kene og bidrar til et bredere geografisk og historisk perspektiv. Ut fra denne innsikten vil jeg foresla at naturforvaltningen prioriterer identifikasjon av n0kkellokaliteter innenfor et nettverk av sommerfuglbestander. Til slutt vurderer jeg sammenhengene mellom empiriske studier, modellering og praktisk anvendelse av teori, og diskuterer de f0lgene landskapsendringer kan fa for sommerfugler med tilhold i norsk jordbrukslandskap. iv ACKNOWLEDGEMENTS Firstly, I gratefully acknowledge the Norwegian Institute for Nature Research (NINA) for financing this thesis and providing an office and computer facilities; and the British Council for a Cultural Exchange Scholarship which financed my first year in Norway. I am indebted to my supervisor at Durham University, Tom Sherratt, for advice, comments and statistical help, and for convincing me that there was light at the end of the tunnel. And a big thank-you to Gary Fry at NINA for introducing me to landscape ecology and to Norway, for your friendship, and for providing endless opportunities. I can safely say that my life would not have been the same without you! Special thanks for comments on the manuscript (particularly for removing all those nasty weasel-words!). Kaare Aagaard gave great encouragement throughout the writing of this thesis by sharing his knowledge of butterflies with me and discussing study approaches and methods of analysis. I am also grateful for having been allowed to join in the mnemosyne project, which has given annual doses of motivation. Wenche Dramstad has been a source of inspiration, pardcularly regarding the study of landscape change. More importandy, Wenche has been a source of coffee and biscuits and her contagious optimism has been invaluable! Thanks to Erik Framstad, and colleagues at NINA for help and kind support; to Svein-Erik Sloreid for digitising the map used in Plate 12; and especially to Gerd Aarsand who has given continual encouragement and moral support, in addition to sorting out all manner of practicalities. Massive thanks to my teams of ace field workers: Jakob Haugen, Norwegian expert in the construction of artificial hedges; Hazel Knight and Marie Schaffer who spent so many hours watching green tarpaulins; Rob McCall and Kate Trumper for walking back and forth along field boundaries, and slogging up the hill at Bandak; Mike and Robert Williams, Simon Barker, Linda Bamett and Craig Emms for watching and enthusiasdc catching of Apollos at Hjartdal; Torgrim Fjellstad, Konrad Piitz, Liv Kjersti Finholt, Benoit Baudry and Astrid Eblenkamp for marking all those fiddly litde Scarce Coppers. I thank the farmers and land-owners of my study sites in Telemark, in particular Jon Gr0stad, for giving access to their land. Jan Heggenes greatly eased logistics by allowing us to use his summer house in Telemark. Ann Norderhaug introduced me to the Hjartdal cultural landscape and was a big help during the early stages of the field work. Ame Ivar Sletnes and colleagues at the Norwegian Institute of Land Inventory (NIJOS) provided access to equipment and gave valuable practical help and advice on the analysis of aerial photographs. Geir-Harald Strand contributed helpful discussion on methodology for Chapter 2. Special thanks to Kjetil Hindar for making the genetics chapter possible, both through technical expertise and for giving me access to hard-won data on ApoUos from Oppland and Buskerud. Thank you