Wild Pollinator Communities of Commercial Almond Plantations And

Wild pollinator communities of native woodlands and commercial almond plantations in a semi-arid Australian landscape: Implications for conservation of insects and ecosystem services Manu E Saunders B Arts; B Env Sc (Ecology) Hons, University of Queensland July 2014 This thesis is submitted in fulfilment of the degree of Doctor of Philosophy Charles Sturt University Faculty of Science School of Environmental Sciences Supervisors: Professor Gary W Luck Professor Geoff M Gurr Dr Margaret M Mayfield (UQ) ii iii iv Table of Contents Page Preface viii Acknowledgements ix Abstract xi List of Figures xiii List of Tables xiv PART I: GENERAL BACKGROUND 1 Chapter 1: Introduction and Scope 3 1.1 Agroecosystem function 3 1.2 Insects as purveyors of ecosystem functions 4 1.3 Aims and Scope 6 1.4 Justification of terms used in this work 8 Chapter 2: Study system and sampling protocol 11 2.1 Study area 11 2.2 Mallee woodlands and shrublands 12 2.3 Almond cultivation in the Mallee 15 2.4 Sampling protocol 16 PART II: ANALYSIS 19 Chapter 3: Almond orchards with living ground cover host more wild 23 pollinators 3.1 Introduction 24 3.2 Methods 27 3.3 Results 37 3.4 Discussion 44 Chapter 4: Wild pollinators in flowering almond orchards and 49 proximity to unmanaged vegetation 4.1 Introduction 50 4.2 Methods 52 4.3 Results 59 4.4 Discussion 65 Chapter 5: The influence of a semi-arid woodland —almond 71 plantation edge on wild pollinator communities 5.1 Introduction 72 v 5.2 Methods 75 5.3 Results 81 5.4 Discussion 88 Chapter 6: Food and habitat resources available to wild pollinators in 95 a late winter flowering crop 6.1 Introduction 96 6.2 Methods 99 6.3 Results 104 6.4 Discussion 114 PART III: SYNTHESIS 121 Chapter 7: Synthesis and Conclusions 123 7.1 Synthesis and general discussion 123 7.2 Conclusions 126 PART IV: REFERENCE MATERIAL 129 Literature Cited 130 Appendix 1: Pan trap catches of pollinator insects vary with habitat 163 (published manuscript) Appendix 2: Taxonomic lists of flower visitor observations and trap 183 samples Appendix 3: Full set of models for analyses of ground cover vegetation — 197 pollinator relationships (Chapter 3) Appendix 4: Location attributes and pollinator occurrence along ecotone 202 gradients (Chapter 5) Appendix 5: Physical attributes and full candidate sets of models for 211 analysis of habitat structure relationships (Chapter 6) vi Certificate of Authorship I hereby declare that this submission is my own work and to the best of my knowledge and belief, understand that it contains no material previously published or written by another person, nor material which to a substantial extent has been accepted for the award of any other degree or diploma at Charles Sturt University or any other educational institution, except where due acknowledgement is made in the thesis. Any contribution made to the research by colleagues with whom I have worked at Charles Sturt University or elsewhere during my candidature is fully acknowledged. I agree that this thesis be accessible for the purpose of study and research in accordance with normal conditions established by the Executive Director, Library Services, Charles Sturt University or nominee, for the care, loan and reproduction of thesis, subject to confidentiality provisions as approved by the University. Name: Signature: Date: vii Preface This thesis includes five individual manuscripts that have been published in academic journals. Consequently, there will be some repetition across chapters, especially within discussions of background material and methodological details. Chapter 2 provides a brief summary of the study area and an overview of the general sampling approach but specific methodological and analytical procedures for each individual study are detailed in each chapter. A single reference list is provided at the end of the thesis to avoid unnecessary duplication. I am personally responsible for conceptualising the project, all data collection and analysis, and the majority of written text. Gary Luck, Margie Mayfield and Geoff Gurr contributed to the planning and sampling design stages and to the papers they have co-authored with me. Peer-reviewed publications from this work: Chapter 3: Almond orchards with living ground cover host more wild insect pollinators. (Saunders ME, Luck GW, Mayfield MM ( 2013 ) Journal of Insect Conservation 17:1011-1025). Chapter 5: Spatial and temporal variation in pollinator community structure relative to a woodland —almond plantation boundary. (Saunders ME, Luck GW ( 2014 ) Agricultural and Forest Entomology , doi:10.1111/afe.12067). Chapter 6: Keystone resources available to wild pollinators in a winter- flowering tree crop plantation. (Saunders ME, Luck GW, Gurr GG ( in press ) Agricultural and Forest Entomology ). Appendix 1: Pan trap catches of pollinator insects vary with habitat. (Saunders ME, Luck GW ( 2013 ) Australian Journal of Entomology 52:106-113). Conference presentations from this work: Saunders ME, Luck GW, Mayfield MM (2012) Living ground cover influences native pollinator abundance in commercial almond orchards. 1st Apimondia ApiEcoFlora Symposium , San Marino, Republic of San Marino, 4-6 October 2012, poster presentation. (Chapter 3) Saunders ME, Luck GW (2013) Pan trap catches of pollinator insects vary with habitat context. VII Southern Connection Congress , Dunedin, New Zealand, 21-25 January 2013, poster presentation. (Appendix 1) viii Acknowledgements Submission of this thesis is a beginning for me, not an end. I am especially grateful to my principal supervisor, Gary Luck, who provided the precise relative proportions of humour, guidance, encouragement and patience that I needed. He gave me freedom to learn to be the ecologist I am, and direction when tangents knocked at my door. I could not have asked for a better supervisor. My co- supervisor, Margie Mayfield, has been an equally inspirational force, before I even knew I was going to undertake a PhD. I cannot thank her enough for giving me the opportunity as an undergraduate student to develop my interest in pollination ecology and for being part of this project. I also sincerely thank Geoff Gurr, for project advice and intellectual contributions; the Institute for Land Water and Society and the School of Environmental Sciences, for financial, administrative and logistic support; Simon McDonald, Deanna Duffy and Gail Fuller, for technical support, patience with all my ignorant questions about GIS and GPS and swiftness in delivering top-quality conference posters; the indispensable lab staff, particularly Lauren Sheather, who helped with equipment, field work preparation, and assistance during the long days I spent staring down a microscope; Ken Walker for voluntary identification of my (very poorly- mounted) native bee specimens; Select Harvests and Manna Farms, for kindly providing access to their almond trees; and the Department of Sustainability and Environment, Victoria, for research access to mallee national parks. Many other people have contributed, either directly or indirectly, to me reaching this point (in no particular order): Alison Matthews, Lisa Smallbone, Paul Humphries, Nicole McCasker, Ian Lunt, Gill Earl, Janet Cohn, Katrina Lumb, Tobias Smith, Peter Spooner, Wayne Robinson, Antonio Castro, Simon Watson, Saul Cunningham, Alan Yen, Michael Batley, Peter Lillywhite, Gimme Walter and Barbara Gemmill-Herren. James, you and Sarge have kept me afloat over the last 3.5 years, and there would have been more tears than smiles without you and the music. Most importantly, I thank my mother for teaching me to believe in what truly matters. ix x Abstract Understanding how monocultures of introduced crop species interact with native ecosystems and wildlife in the surrounding landscape is vital for the ecological management of agroecosystems, and can have far-reaching benefits for biodiversity conservation and crop yields. Insects make essential contributions to ecosystem functions in all types of ecosystems and many functions are synergistically linked, like pollination and biological pest control. Thus, the conservation of invertebrate communities in agricultural landscapes is paramount. Although many studies have investigated pollinator communities using field crops (e.g. canola), more information is needed on how plantations of deciduous tree crops influence local insect communities, as these agroecosystems can create permanent spatial and temporal homogeneity across agricultural landscapes. I sampled potential wild pollinators in commercial almond plantations and native mallee vegetation in northwest Victoria, Australia, over two almond flowering seasons in late winter of 2010 and 2011. The aim of the study was to provide information on the abundance, richness and composition of insect pollinator communities at this time, which is the critical life stage for both almond trees (reproduction) and insects (emergence and reproduction). In particular, I focused on comparing patterns of insect community distribution relative to environmental attributes of mallee vegetation and almond plantations, with the goal of identifying how plantations might influence the conservation of wild insect communities, and thus enhance ecosystem service provision in commercial plantations. Overall, I found that potential wild pollinators were using almond plantations in the Victorian mallee during the almond flowering season. However, their movement into plantation interiors was limited by homogeneous vegetation structure and a lack of essential resources,

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