Sacha Jellinek
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The value of revegetated linear strips and patches of habitat for faunal conservation: Reconciling ecological and landholder perspectives Sacha Jellinek A thesis submitted in total fulfilment of the requirements of the degree of Doctor of Philosophy February 2012 School of Botany The University of Melbourne ii Abstract A large-scale loss of biodiversity is currently occurring around the world, and it has been argued that extensive restoration of the landscape is necessary to reduce species extinctions. I assessed the effectiveness of revegetation for maintaining reptile (Reptilia) and beetle (Coleoptera) communities in two fragmented, agricultural landscapes of south-eastern Australia, and investigated how the management actions of landholders influenced the composition and structural attributes of revegetated and remnant areas. Reptiles and beetles were surveyed using pitfall traps from January to March in 2008 and 2009. I established the variation in reptile and beetle species richness and abundance in remnant, revegetated and cleared linear strips, in remnant patches of vegetation and in revegetated areas adjacent to the remnant patches. Habitat variables such as rock cover and the proportion of native plants were also recorded. In order to determine landholders‟ past and planned revegetation activities, the composition of plantings, and their attitudes towards and intentions to manage revegetated and remnant areas, I quantitatively surveyed 400 landholders using postal questionnaires. I then used Bayesian Networks to integrate the ecological and social data I collected and demonstrate the conceptual link between management actions and biodiversity outcomes. Overall I found that reptile and beetle species richness, abundance and community composition did not substantially differ between revegetated, remnant, and cleared linear strips; revegetated and remnant patches; or between revegetated linear strips and revegetated patches. However, I found some reptile and beetle species showed a trend towards higher abundance in remnant linear strips than in revegetated and cleared linear strips. Interestingly, species richness and abundance of rare reptiles, overall reptile abundance, and abundance of Carlia tetradactyla increased in remnant linear strips but decreased in revegetated and cleared linear strips as distance from remnant patches increased. Reptile species richness and abundance were positively influenced by rock cover, and reptile and beetle community composition was substantially influenced by environmental variables such as rock, litter and herb iii cover. Three-quarters of survey respondents had previously undertaken revegetation on their land, the majority of them having replanted with native trees and shrubs along linear strips. Respondents that had revegetated or planned to revegetate were usually Landcare members with an off-farm income. Landholder attitudes towards revegetated and remnant areas influenced their intention to manage these areas, with landholders who considered replanted and remnant areas to be detrimental to their property most likely to undertake management actions such as pest control. Using Bayesian Networks, I determined that the management actions of landholders were more likely to increase reptile and beetle species richness in cleared linear strips than in other linear strips and patches. The most cost- effective management actions for increasing reptile and beetle species richness were weed control, planting trees and shrubs and adding leaf litter and fallen timber/coarse woody debris. The agricultural landscapes I studied are highly degraded, and the remaining reptile and beetle species are mostly a robust subset of previously present species, with species requiring good quality ground layers persisting along remnant linear strips. Bayesian Networks are an effective tool for integrating ecological and social data to inform management decisions, and increase the value of revegetation for wildlife. iv Declaration This is to certify that: The thesis comprises only my original work towards the PhD except where indicated in the Preface, Due acknowledgement has been made in the text to all other material used, The thesis is fewer than 100,000 words in length, exclusive of tables, maps, bibliographies and appendices. ------------------------------ ------------------------------ (Signature) (Date) v Acknowledgements This project was largely based in the field and would not have been possible without the assistance of numerous volunteers who helped me to set up, survey, and take down my field sites. Special thanks to my brother Nick, for his hard work and sceptical criticism of my project: it was a good laugh to be out digging holes with you. Anthony was also amazingly hard-working and put up with my bouts of disorganisation very well. Other volunteers include but are not limited to Rakhee, Lee, Laura, Chris, Achim, Abby and Squattie and friends. Thank you to all the landholders who allowed me onto their properties and were interested in my project and results. Thank you also to Greening Australia, The Little Desert Lodge, the Regent Honeyeater Project and Trust for Nature for providing me with all of the information and contacts I needed to start this project. Thank you to Kate Daniels and Bruce Burnell for providing accommodation while I was out in the field. Thank you to my supervisors, Dr Don Driscoll, Dr Kirsten Parris and Dr Brendan Wintle, for being so supportive throughout this project. Don, you were amazing to work with again and your constant guidance and critical reviewing, although sometimes painful, were fantastic. Kirsten, I really appreciated your guidance and advice, and your detailed editing – thank you for your support and advice and being around to bounce ideas off. Thank you Brendan for helping me get my head around Bayes nets in particular. Thanks also to the School of Botany and the AEDA/CEED lab at the University of Melbourne for supporting my project and providing me with guidance. I am also grateful to Libby Rumpff for reviewing a number of drafts of my Bayesian chapter and Mick McCarthy for helping me with my WinBUGS code. Thanks to Peter Dwyer and Monica Minnegal for their guidance, reviewing, and advice on the landholder questionnaires and the social chapter. Thanks also to Liz Gosling for helping me with my landholder questionnaire and finding landholders. vi The CSIRO Entomology lab in Canberra assisted me with my beetle identification. I thank Tom Weir especially, who took the time to look at my collection. Thanks also to the CESAR lab at the University of Melbourne and Michael Nash for helping with beetle identification and giving me lab space. Thanks also to Fabian Douglas for helping with the initial identification of my beetles and Clive Crouch for his passion for all the critters in the Wimmera. My scholarship was provided by the Albert Shimmins Postgraduate award. Funding for this project was provided by the Norman Wettenhall Foundation, Greening Australia, the Wimmera Catchment Management Authority, Vic Roads and AEDA and the School of Botany at the University of Melbourne. Travel grants to attend conferences were provided by the School of Botany, the Ecological Society of Australia and the David Ashton travel grant, supplementing funding from AEDA/CEED. Finally, a huge hug and many thanks to my friends and family for putting up with me and keeping me somewhat sane. Much love to Anna for keeping life going as normal and for supporting me, you kept me going. Anna and my mum Judy played an instrumental role in editing my thesis so an extra big thanks for that. Prof. Geoff Cumming also assisted in editing and with statistics advice. Thanks also to Kel, Yoshi and the rest of the house and also to the Whallery gang, Kerryn and Bryn for your constant distractions and reality checks. Cheers to Briony, Sarah, Yacov, Marissa and many others from the various labs I was involved with for coffees and conversation. vii Table of Contents Abstract ................................................................................................... iii Declaration .................................................................................................... v Acknowledgements ......................................................................................... vi Table of Contents .......................................................................................... viii List of Tables .................................................................................................. xii List of Figures ................................................................................................ xvi List of Appendices ........................................................................................ xix Chapter 1. Introduction ............................................................................... 1 Background ..................................................................................................... 2 Ecological processes................................................................................... 2 Social processes ......................................................................................... 5 Chapter outline ............................................................................................... 6 Chapter 2. Biodiversity benefits of restoring vegetation: A review ......... 9 Introduction ................................................................................................... 10 Methods .......................................................................................................