Effects of forest management and experimental dead wood removal on macrofungal communities in boreal, mixedwood forests of Ontario by Melanie Croydon-Sugarman A thesis submitted in conformity with the requirements for the degree of Master of Science in Forestry Faculty of Forestry University of Toronto Ó Copyright by Melanie Croydon-Sugarman 2019 Effects of forest management and experimental dead wood removal on macrofungal communities in boreal, mixedwood forests of Ontario Melanie Croydon-Sugarman Master of Science in Forestry Faculty of Forestry University of Toronto 2019 Croydon-Sugarman, Melanie. 2019. Effects of forest management and experimental dead wood removal on macrofungal communities in boreal, mixedwood forests of Ontario. Master of Science in Forestry, Faculty of Forestry, University of Toronto. Abstract Boreal macrofungi are an ecologically diverse group of organisms that are threatened by forest management, including harvest-associated reductions in coarse woody debris (CWD) supplies. In this thesis, I compared richness and composition of macrofungal communities in old-growth and post-logged mixedwood stands in boreal northeastern Ontario, including post-logged stands in which downed CWD availability had been experimentally manipulated. Canonical Correspondence Analysis showed a strong distinction between macrofungal communities of unlogged and logged plots, correlated with harvest-related reductions in large-diameter CWD supplies. Rarefaction revealed that macrofungal richness, particularly of saprotrophs, was higher in unlogged compared to logged plots, especially those with experimentally-reduced CWD supplies. These results demonstrate the negative effects of post-harvest decreases in CWD on macrofungal richness and suggest that forest management in Canada may, over time, lead to the harvest-related biodiversity losses of boreal Europe. Management practices that better emulate habitat conditions in old-growth stands, including availability of large-diameter CWD, are discussed. ii Acknowledgements I would sincerely like to thank my supervisors, Dr. Jay Malcolm and Dr. Jean-Marc Moncalvo, for the opportunity to pursue this project; for Dr. Malcolm’s continuous support and insight throughout its duration; and for Dr. Moncalvo’s guidance regarding the molecular identification of the fungi collected. I would also like to thank my committee member Dr. Sandy Smith for her valuable insights provided during this thesis. For invaluable assistance during the DNA sequencing portion of this project, I extend a huge thank-you to Simona Margaritescu at the Royal Ontario Museum. I could not have completed this huge body of work without her. Thanks also to the Kapuskasing field crew, especially Paul Piascik, for assistance during the collecting periods and tremendous amount of help processing my samples. Finally, thank you to everyone in the Wildlife Ecology Lab and the Graduate Department of Forestry for fostering a wonderfully supportive environment and close-knit community. Funding for this project is provided by the Sustainable Forest Management Network, Natural Science and Engineering Research Council of Canada, Ivey Foundation, Tembec, Canadian Forest Service, Ontario Ministry of Natural Resources, and the Faculty of Forestry. iii Table of Contents Abstract ........................................................................................................................................ ii Acknowledgements ..................................................................................................................... iii List of Tables ............................................................................................................................... vi List of Figures ............................................................................................................................ vii List of Appendices .................................................................................................................... viii Chapter 1. General Introduction ............................................................................................... 1 Fungi in boreal forests ....................................................................................................... 4 Forest management effects on fungi in Fennoscandia .................................................... 10 Forest management effects on fungi in Canada .............................................................. 16 Chapter 2. Effects of forest management and experimental dead wood removal on macrofungal communities in boreal, mixedwood forests of northeastern Ontario ............. 21 Introduction ...................................................................................................................... 21 Methods ............................................................................................................................ 29 Study sites ............................................................................................................. 29 Coarse downed woody debris manipulation experiment...................................... 30 Downed woody debris sampling........................................................................... 31 Additional habitat variables ................................................................................ 32 Fruiting body sampling ........................................................................................ 33 DNA extraction and ITS sequencing .................................................................... 35 BLAST sequence alignment and phylogenetic analysis ....................................... 37 Statistical analyses ............................................................................................... 39 Results .............................................................................................................................. 41 Molecular identification ....................................................................................... 41 Fruiting body sampling ........................................................................................ 42 Macrofungal community variation ...................................................................... 44 Rarefaction ........................................................................................................... 45 Richness of ecological guilds ............................................................................... 46 Discussion ........................................................................................................................ 48 Fruiting body sampling ........................................................................................ 48 Molecular identification ....................................................................................... 53 iv Community composition ....................................................................................... 55 Ecological guilds ................................................................................................. 60 Chapter 3. General Conclusions ............................................................................................... 64 Literature Cited ......................................................................................................................... 65 Tables ...........................................................................................................................................96 Figures ..........................................................................................................................................99 Appendices ................................................................................................................................ 103 v List of Tables Table 1. Characteristics of the boreal mixedwood plots sampled for fungi in the vicinity of Kapuskasing, Ontario in 2011, including location, treatment, year of origin, stand replacing disturbance type, basal areas of common tree species, percent deciduous cover, position on shrub-derived ecological gradients, and shrub density. See text for details. Table 2. Significance levels from permutation tests for canonical correspondence analyses of fungal communities of boreal mixedwood stands sampled in three sampling periods constrained by various habitat variables (n.s. = not significant [p > 0.05]). Coarse woody debris (CWD) variables were measured by wood volume; environmental gradients corresponding to light exposure/conifer composition (DCA1) and soil moisture gradient (DCA2) were from detrended correspondence analyses on shrub community variation (see text for details). Table 3. Mean (± SE) species richness in each of four ecological guilds and the total number of morphospecies across treatment plots (FR = full-removal, HR = half-removal, CO = control, UL = unlogged) during three sampling periods in mixedwood forests of boreal northeastern Ontario. Letters in common indicate no significant difference between treatment means (Tukey’s HSD, α=0.05). ECM = ectomycorrhizal morphospecies; WS = wood saprotrophs; LS = litter saprotrophs; PARA = parasites; Total = total richness. vi List of Figures Figure 1. Canonical correspondence analyses conducted on macrofungal species assemblages in unlogged and logged plots in mixedwood forests of northeastern Ontario from sampling periods 1 (upper), 2 (mid) and 3 (lower). Asterisks denote environmental variables with significant effects in constraining community composition