The Long-Term and Large-Scale Effects of the Establishment of an Exotic Plantation on Species of Native Forest Beetles and Butterflies
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The long-term and large-scale effects of the establishment of an exotic plantation on species of native forest beetles and butterflies Maldwyn John Evans Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy of The Australian National University February 2016 Cover images: Top row left and middle, middle row left and right are property of Chris Margules. All other images are property of Jeff McClenahan. Dedication I dedicate this thesis to my parents Jayne Evans and John Macken. i Declaration This thesis is my own work, except where otherwise acknowledged. Maldwyn John Evans February 2016 ii Preface This thesis is presented as a series of connected papers that either have been submitted for publication in peer reviewed scientific journals, have been re-submitted following reviews or are in preparation for submission. Each paper is intended as a stand-alone piece of work. Repetition between papers has therefore been unavoidable. Each paper is preceded by a short paragraph of text that introduces the paper. In accordance with The Australian National University’s College of Medicine, Biology and Environment guidelines for submitting a ‘Thesis by Compilation’, this thesis also contains an Extended Context Statement. This statement is not intended as a comprehensive review of the literature relevant to this thesis; rather, its purpose is to demonstrate the relationship between all aspects of the research presented. It includes a brief introduction, outlines of experimental design, short summaries of each paper, and finally, a synthesis of the work of the entire thesis. The context statement is included at the start of the thesis as a stand-alone body of text. As a result, the thesis does not include a separate conclusion chapter after the main body of work; instead, all conclusions are presented in the context statement at the start of the thesis. Because of the data-rich nature of the research in the papers, it was necessary to include supplementary materials including extra tables and figures for papers I, II and III. These materials are included at the back of the thesis. The majority of the work included in this thesis is my own. I received considerable guidance throughout from my supervisors Don Driscoll, Sam Banks and Kendi Davies and also gained assistance from a number of collaborators. My supervisors and collaborators form the co- authors on my papers and their contributions are fully acknowledged in the paper list below. All co-authors have agreed in writing with the author contribution statements provided. I iii supply details of any other assistance in the acknowledgements section in this thesis, and in the acknowledgements for each individual paper. Paper I. Evans, M. J., Banks, S.C., Davies, K.F., McClenahan, J., Melbourne, B.A., Driscoll, D.A. The use of traits to interpret responses to large scale edge effects – a study of epigaeic beetle assemblages across a Eucalyptus forest and pine plantation edge. Landscape Ecology. Re-submitted following revisions. Author contributions: ME led the conceptualisation with advice from SB, KD, BM and DD; ME and JM collected the data; ME led the analysis with advice from SB, KD, BM and DD; ME led the writing; and SB, KD and DD made substantial contributions to manuscript revision. Paper II. Evans, M. J., Banks, S.C., Davies, K.F., King, A.J., Sweaney, N., Driscoll, D.A. When the matrix isn’t a matrix. A pine plantation provides new habitat for butterflies in a long term fragmentation experiment. In prep. Author contributions: ME led the conceptualisation with advice from SB, KD, NS and DD; ME and AK collected the data; ME led the analysis with advice from SB, KD and DD; ME led the writing; and SB, KD, AK, NS and DD made contributions to manuscript revision. Paper III. Evans, M. J., Banks, S.C., Driscoll, D.A., Melbourne, B.A., Davies, K.F. Short-term effects do not predict long-term impacts of fragmentation in a long-term fragmentation experiment. Ecology. Revisions currently underway. iv Author contributions: ME led the conceptualisation with advice from SB, DD, BM and KD; ME, BM and KD collected the data; ME led the analysis with advice from SB, DD, BM and KD; ME led the writing; and SB, DD, BM and KD made substantial contributions to manuscript revision. Paper IV. Evans, M. J., Banks, S.C., Barton, P.S., Davies, K.F., Driscoll, D.A. A long-term habitat fragmentation experiment leads to morphological change in two carabid species. In prep. Author contributions: ME led the conceptualisation with advice from SB, PB, KD and DD; ME and KD collected the data; ME led the analysis with advice from SB, PB, KD and DD; ME led the writing; and SB, PB, KD and DD made contributions to manuscript revision. v Acknowledgements I would like to thank my supervisors, Don Driscoll, Sam Banks and Kendi Davies, for their support during my PhD. Don’s guidance throughout, especially during the drafting stage, has been instrumental to my progress. He has kept me on my toes right the way through and has pushed me to achieve a standard that I couldn’t have otherwise achieved. Sam’s feedback and patience have helped keep me motivated, as has his impressive brain for ecological ideas. Kendi’s encouragement, support and feedback, despite the fact that she resides over 13,000 km from Canberra, has been constant and invaluable. The majority of the work in my thesis would not have been possible without her immense effort to keep research going at the Wog Wog site. I would like to thank Brett Melbourne for his advice throughout, in particular when it came to matters of statistical significance. I also thank the helpful folk at the Australian National Insect Collection, especially Cate Lemann, Beth Mantle, Tom Weir, Nicole Fisher and Robyn Meier. I have spent a large chunk of my time in the collection and without their help and advice, I could not have completed this PhD. Thanks to Mauro Davanzo and Pier Bairstow for their field support and blokey conversations. Thank you to Saul Cunningham for allowing the extensive use of his lab facilities and for his extremely helpful advice. I thank the many people that have been involved in establishing and maintaining the Wog Wog Habitat Fragmentation Experiment, including Chris Margules, Mike Austin and A. O. (Nick) Nicholls. I am also grateful to all of the people who have helped with fieldwork over the history of the experiment, particularly George Milkovits. Thanks to the Forestry Corporation of New South Wales for their cooperation and assistance in the day-to-day running of the experiment. I would also like to acknowledge the incredible work of John vi Lawrence and Andy Hicks in identifying and mounting the beetles caught in the fragmentation experiment. There are many friends that have helped me in many different aspects of my PhD. These include Philip Barton, Marwan El Hassan, Nic Engerer, Brad Farmilo, Claire Foster, Brett Howland, Karen Ikin, Andrew King, Mandy King, Pia Lentini, Jeff McClenahan, Laura Rayner, Chloe Sato, Ben Scheele, Ingrid Stirnemann, Dejan Stojanovic, Nici Sweaney, Kika Tuff and Martin Westgate. A special thanks goes to Brett Howland for his help in the field, including his demonstration of superb manskills involving a winch (!) and a 4WD. Thanks also to my volunteer Dave Portway – such good quality help has never come so cheap. Thank you to my good friend Philip Barton, whose advice, encouragement and clarity have been a constant source of motivation. A big thank you goes out to all of my family and friends. This includes my amazing parents Jayne Evans and John Macken. A special thanks also goes to Jane and Simon McMillan who have provided unwavering support throughout. My two gorgeous boys Maldwyn and Aneirin Evans have been a source of delight, humour, fatigue and motivation. Finally, and most especially, I thank my partner, Joanne McMillan – without her help, love and support I would simply not have been able to do this. vii Abstract Abstract The influence of the land type between patches of remnant vegetation on species' survival is now widely acknowledged. From the species’ perspective, this land could be hostile (defined as a matrix) or amenable (defined as new habitat). In this thesis, I was interested in whether species were favoured or hindered by fragmentation of their natural Eucalyptus forest habitat into remnants surrounded by a pine plantation and the mechanisms behind their responses. I took advantage of the Wog Wog Habitat Fragmentation Experiment, in Australia, to investigate the response of beetles and butterflies to this landscape change. In a large scale edge effects study, I demonstrated that the effect of a Eucalyptus forest-pine plantation edge was widespread for the beetle community and that phytophagous beetles respond predictably to vegetation change along the edge gradient. Furthermore, I highlighted that many species responded to edge effects up to and beyond the scale tested (1000 metres). In a study of butterflies at the Wog Wog Habitat Fragmentation Experiment, I demonstrated that butterfly species were richer in the pine plantation than the remnants and continuous forest. This suggested that the pine plantation offers new and possibly preferable habitat for butterflies than the corresponding native Eucalyptus forest. Furthermore, there was evidence for a mass effect within the remnants, with the pine plantation potentially boosting species richness and abundance of common species in the remnants when compared with the controls. Revisiting carabid beetle species studied originally between 1985 and 1992, I found that responses in the long term (more than 25 years post-fragmentation) contrasted with those in the short term (five years post-fragmentation).