Examining the effects of distance from mature forest and successional stage on beetle community recolonisation and assembly Nicholas Fountain-Jones BA, BSc (Hons) Submitted in fulfilment of the requirements for the Degree of Doctor of Philosophy University of Tasmania September 2014 Declaration This thesis contains no material which has been accepted for the award of any other degree or diploma in any tertiary institution, and to the best of my knowledge and belief, contains no material previously published or written by another person, except where due reference is made in the text of the thesis. The publishers of the papers comprising Chapters 2 and 3 hold the copyright for that content, and access to the material should be sought from the respective journals. The content from these Chapters may be downloaded, reused, reprinted, modified, distributed, and/or copied, without requiring permission from the authors or the publishers, as long as the original authors and source are cited. The remaining non- published content of the thesis may be made available for loan and limited copying and communication in accordance with the Copyright Act 1968. Signed Nicholas M. Fountain-Jones B.A /B.Sc (Hons) Date: 16th September 2014 i Statement of co-authorship The following people contributed to the publication of work undertaken as part of this thesis: Nicholas M. Fountain-Jones, School of Biological Science, University of Tasmania, Hobart, Australia = Candidate Susan C. Baker, School of Biological Science, University of Tasmania, Hobart, Australia = Author 2 Gregory J. Jordan, School of Biological Science, University of Tasmania, Hobart, Australia = Author 3 Christopher Burrdige, School of Biological Science University of Tasmania, Hobart, Australia = Author 4 Tim Wardlaw, Forestry Tasmania, Hobart, Australia = Author 5 Lynne Forster, School of Land and Food, University of Tasmania = Author 6 Jayne Balmer, School of Land and Food, University of Tasmania, Hobart, Australia = Author 7 Thomas P. Baker, School of Biological Science, University of Tasmania, Hobart, Australia = Author 8 Morgana Petersfeld, School of Biological Science, University of Tasmania, Hobart, Australia = Author 9 The details of which papers the co-authors contributed to, the contributions they made, and where the papers can be found are listed below and at the start of the relevant chapters in the thesis: Chapter 2 is in press: Fountain-Jones, N.M., Baker, S.C. and Jordan, G. (in press). ‘Moving beyond the guild concept: developing a consistent functional trait framework for terrestrial beetles‘ Ecological Entomology. ii The candidate was the primary author. The Candidate as well as authors 2 and 3 contributed to developing the idea. Chapter 3 is in press: Fountain-Jones, N.M., Jordan, G., Baker, T.P., Balmer, J., Warlaw, T. and Baker, S.B. (in press). ‗Living near the edge: Being close to mature forest increases the rate of succession in beetle communities.’ Ecological Applications. The candidate was the primary author, undertook most of the field and laboratory work and conducted the data analysis. Authors 2, 3 and 5 assisted with data analysis and authors 7 and 8 assisted with field work, obtaining, and preparing data. The candidate as well as authors 2 and 3 contributed to developing the main idea, and approach. Authors 2, 3, 7 and 8 assisted with refining the text. Chapter 4 is in preparation: Fountain-Jones, N.M., Jordan, G., Baker, T.P., Burridge, C., Petersfeld, M., Wardlaw, T., Forster, L. and Baker, S.B. ‗Beetle trophic groups show differential effects of phylogeny and environment along a successional gradient.‘ The candidate was the primary author and was involved in all field and laboratory work. Measurments of beetle functional traits was done in collaboration with author 9. The candidate conducted all of the data analysis. The candidate as well as authors 2, 3 and 4 developed the main ideas, and approach. Authors 2, 3, 4, 5 and 7 assisted with refining the text. Chapter 5 is submitted: Fountain-Jones, N.M., Jordan, G., Baker, T.P., Burridge, C., and Baker, S.C. (in review). ‗Environmental filtering, biotic interactions or both? Understanding iii beetle responses to habitat manipulation using a combined functional and phylogenetic approach. Animal Ecology. Candidate was the primary author and conducted most of the field and laboratory work with assistance from author 8. The candidate conducted all of the data analysis. The candidate as well as authors 2 and 3 developed the main ideas and approach. Authors 2, 3, 4 and 8 assisted with refining the text. We the undersigned agree with the above stated ―proportion of work undertaken‖ for each of the above published (or submitted) peer-reviewed manuscripts contributing to this thesis: Signed: __________________ Signed: __________________ Gregory Jordan Anthony Koutoulis Supervisor Head of School School of Biological Sciences School of Biological Sciences University of Tasmania University of Tasmania Date:_____________________ Date:_____________________ iv Abstract How mature forest impacts adjacent disturbed forest, or "forest influence", is a poorly understood ecological concept that is important for sustainable forest management worldwide. Specifically, this thesis investigated whether beetles can recolonise disturbed areas from adjacent mature forests, and how this changed with forest succession. Furthermore, I applied a combined functional trait and phylogenetic approach to better understand what processes were important for succession and recolonisation. This involved a review and three studies based on two large-scale experiments. Functional trait approaches for beetles lack consistent methodology and conceptual basis. Chapter 2 reviews previous beetle functional trait studies and outlines a broadly applicable trait framework, including a potentially useful list of traits, analysis approaches and future challenges for this discipline. This manuscript is accepted for publication in Ecological Entomology. Chapter 3 illustrates that forest influence operates for beetle communities, and that these effects changed greatly over time. This was based on analysing beetle community composition from pitfall traps at fifteen sites, using replicated transects across mature forest boundaries into adjacent harvested stands, over a chronosequence of three secondary forest stages (~7, ~27 and ~45 years old). Environmental characteristics were measured at each plot and used to model how beetle communities were responding across the forest boundaries, and to assess if successional beetle communities were responding to the same environmental forces. Within 200 m from mature forest, the beetle community in ~45 year old secondary forest had largely recovered. The important environmental factors differed in each forest age, yet leaf litter variables and microclimate were consistently correlated with species distribution. This manuscript is accepted in Ecological Applications. Chapter 4 uses functional trait and phylogenetic approaches on data collected from the experiment described in Chapter 3 to gain deeper insights into community assembly processes underlying beetle succession. I also test whether different beetle v trophic groups (decomposers/primary consumers versus predators) assembled the same way. A molecular phylogeny constructed from two DNA barcoding regions and 14 functional traits were calculated for 133 common species. Successional patterns in the phylogenetic and trait datasets were modelled using 16 environmental variables. Environmental filtering was the dominant process shaping beetle community succession for both trophic groups, yet the traits driving this pattern, and evolutionary forces underpinning them, were strongly divergent. Microclimate and leaf litter were key trait filters, particularly for decomposers/primary consumers. This manuscript is in pre–review with Axios. Microclimate and leaf litter inputs were manipulated in an experimental trial (Chapter 5) to understand the role of dispersal limitation and habitat on beetle recolonisation. The trial was established within a recently harvested site with a mature forest boundary nearby, and beetle communities were sampled using pitfall traps under sterilized leaf litter, artificial shade plots and control (no litter or shade) in a randomized block design. Litter addition and shading significantly altered beetle abundance and community composition and allowed some species adapted to older forest to successfully recolonise. Species functional traits and phylogenetic relationships were also used to explore how environment affects community assembly. Environmental filtering was also the dominant process overall, yet biotic interactions were important for community assembly in open control plots. This manuscript is submitted to Animal Ecology. My results demonstrate that forest influence is important for beetles in production forests and that forest influence may alter the successional trajectory of beetle communities. Microclimate and leaf litter were both important in facilitating recolonisation, yet dispersal limitation still plays a role. Furthermore, this thesis has helped elucidate what forces shape beetle community assembly over succession, and demonstrates that litter addition and shade not only alters species composition it also changes how beetle communities assemble. vi Acknowledgments First and foremost, I am enormously thankful for my three supervisors Greg Jordan, Sue Baker and Chris Burridge, for without them this thesis would not be possible.