Ectomycorrhizal Communities Associated with a Pinus Radiata Plantation in the North Island, New Zealand

ECTOMYCORRHIZAL COMMUNITIES ASSOCIATED WITH A PINUS RADIATA PLANTATION IN THE NORTH ISLAND, NEW ZEALAND A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University by Katrin Walbert Bioprotection and Ecology Division Lincoln University, Canterbury New Zealand 2008 Abstract of a thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy ECTOMYCORRHIZAL COMMUNITIES ASSOCIATED WITH A PINUS RADIATA PLANTATION IN THE NORTH ISLAND, NEW ZEALAND by Katrin Walbert Aboveground and belowground ectomycorrhizal (ECM) communities associated with different age classes of the exotic plantation species Pinus radiata were investigated over the course of two years in the North Island of New Zealand. ECM species were identified with a combined approach of morphological and molecular (restriction fragment length polymorphism (RFLP) and DNA sequencing) analysis. ECM species richness and diversity of a nursery in Rotorua, and stands of different ages (1, 2, 8, 15 and 26 yrs of age at time of final assessment) in Kaingaroa Forest, were assessed above- and belowground; furthermore, the correlation between the above- and belowground ECM communities was assessed. It was found that the overall and stand specific species richness and diversity of ECM fungi associated with the exotic host tree in New Zealand were low compared to similar forests in the Northern Hemisphere but similar to other exotic plantations in the Southern Hemisphere. Over the course of this study, 18 ECM species were observed aboveground and 19 ECM species belowground. With the aid of molecular analysis the identities of Laccaria proxima and Inocybe sindonia were clarified. In the aboveground study, five species were found associated with P. radiata that were previously not reported with this host in New Zealand (Inocybe sindonia, Lactarius rufus, Lycoperdon gunii, Rhizopogon pseudoroseolus and Wilcoxina mikolae). Belowground, the species Psudotomentella sp., P. tristis, R. luteorubescens, Tomentella sp., Wilcoxina mikolae were found as new associates of P. radiata in New Zealand, additionally nine ECM types were found that could not be identified with molecular analysis. There was little correlation between the species fruiting and the species colonising root tips. Only seven species were found in common between the above- and belowground communities, furthermore the dominant species aboveground were not observed in the belowground ECM communities. The influence of host age on the above- and belowground ECM communities of different age classes of P. radiata plantations was investigated. The aboveground species richness increased from the nursery to the oldest age group investigated (26 yrs), while diversity increased to the 15 yr old age group and decreased slightly to the oldest stand. A clear ii sequence of ECM species changes was observed to be related to stand age with a growing complexity over the chronosequence. The belowground ECM communities showed a different picture and richness and diversity initially decreased from the nursery to the outplanting but increased thereafter. Belowground no change in ECM composition that was directly related to the age of the host was observed, but two distinct groups of ECM species were found – a ‘young’ and a ‘plantation forest’ group, with the respective discriminating species being Rhizopogon rubescens and Type unknown Basidiomycete/Amanita muscaria. Another aspect of the study was the fate of the nursery ECM species in the outplanting and the arrival of non-nursery species. The ECM communities of seedlings in the nursery were investigated in 2006 and these seedlings were followed up over eight assessments in the field for one year, furthermore data from the 1-, 2 and 8 yr old plantation stands was analysed. It was found that the nursery species do survive the first year of outplanting and are dominant in the first year. The first non-nursery species occurred six months after outplanting but was only in minor abundance. Nursery ECM were dominant for two years after the seedlings were planted, and were completely replaced after seven years. Rhizopogon rubescens was found to be the most persistent and dominant species in the outplanting, facilitating the successful establishment of the seedlings in the plantation forest. Key words: ectomycorrhiza, Pinus radiata, New Zealand, exotic plantation, nursery, diversity, succession, above- and belowground, ITS-RFLP, direct sequencing, outplanting, species displacement. iii ACKNOWLEDGMENTS “excuse me but I just have to explode explode this body off me wake‐up tomorrow brand new a little tired but brand new” björk – pluto First and foremost I want to thank Sue McCurdy for placing me with this PhD and the Forest Biosecurity and Protection Group at Scion. Without you I would not be here and write these acknowledgments! This research was funded by the Foundation for Research & Technology C04X0302 who also supported me with a scholarship over the course of the study. I would like to acknowledge and thank my foursome team of supervisors - Dr. Eirian Jones and Dr. Hayley Ridgway from Lincoln University and Dr. Tod Ramsfield (please notice the Times New Roman!!!) and Margaret Dick from Ensis, Rotorua. Thank you all for your help, guidance, advice and for getting and especially keeping me on track. Dr. Geoff Ridley, thanks for taking me on initially and your help with species identifications and valuable comments for this thesis. iv I would like to acknowledge Kaingaroa Timberlands for the use of their nursery and plantation sites for this research and thank especially Nigel Heron for all his help and 4WD driving with me! Thanks to Alison Lister and James Ross for statistical advice and analysis. I want to say a big thank you to the whole Forest Biosecurity and Protection Group at Scion Rotorua who made me feel welcome and managed to accept all my quirky habits, and no, I still don’t get the idea of morning and afternoon tea! I am especially thankful to Lindsay Bulman and Brian Richardson for the support and the opportunity to continue to work in this great team. Matt ‘Robin’ Power – cheers big time for all your help in the Batcave, you never got tired of my stupid questions! And thanks to MichL for never bidding on anything on TradeMe which I really wanted!!! The whanau - ‘cher bro’ goes out to my crew here in Rotovegas. You never got sick of asking me where the magic mushrooms grow…but I’m not telling! Thanks for spending all these hours of PhD distraction in form of running, biking, swimming and having fun together, and especially for not mentioning the “T”-word at the end! Thanks to my friends spread all over the world…especially Caro and Louise, my transatlantic PhD buddies who shared so much of the pain, kept me going and endured my whinging! And finally, thanks to my family for being with me and there for me so far away. Last but not least I would like to thank Scion/Ensis and Lincoln University for the financial support in my sporting adventures, which allowed me to represent New Zealand in the XTERRA World championships in 2005 and fulfil my sado-masochistic dream of Ironman. 3 ½ years later and I do feel like Björk’s Pluto – just exploded, a little tired but brand new and ready for all the challenges that lie ahead of me. Kat March 2008 v CONTENTS Declaration......................................................................................................................... i Abstract ............................................................................................................................. ii Acknowledgments ............................................................................................................... iv Contents ............................................................................................................................ vi Abbreviations...................................................................................................................... x Figures............................................................................................................................... xi Tables................................................................................................................................ xiv 1 Introduction.............................................................................................................. 1 1.1 Mycorrhiza..............................................................................................................1 1.1.1 Ectomycorrhizae (ECM)................................................................................2 1.2 ECM Succession ......................................................................................................7 1.2.1 Theory .......................................................................................................7 1.2.2 The discrepancy between above- and belowground communities.....................9 1.2.3 Approaches to study succession....................................................................9 1.3 Forestry................................................................................................................11 1.3.1 The Forestry sector in New Zealand ............................................................11 1.3.2 Dominance of Pinus radiata in New Zealand Forestry....................................12 1.3.3 The Host: Pinus radiata D. Don 1836 ..........................................................12 1.3.4 Origin

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