Responses of ground beetles (Coleoptera: Carabidae) to variation in woody debris supply in boreal northeastern Ontario by Paul Wojciech Piascik A thesis submitted in conformity with the requirements for the degree of Master of Science in Forestry Faculty of Forestry University of Toronto © Copyright by Paul Piascik 2013 Responses of ground beetles (Coleoptera: Carabidae) to variation in woody debris supply in boreal northeastern Ontario Paul Piascik Master of Science in Forestry Faculty of Forestry University of Toronto 2013 Piascik, Paul. 2013. Responses of ground beetles (Coleoptera: Carabidae) to variation in woody debris supply in boreal northeastern Ontario. Master of Science in Forestry, Faculty of Forestry, University of Toronto. Abstract The maintenance of downed woody debris supplies is increasingly being recognized as an integral part of forest management. In order to better manage this resource, it is important to assess its role in supporting biodiversity. In this thesis, I investigate the responses of carabid communities to variation in woody debris availability in an experimental manipulation of woody debris volume in closed-canopy forests and following a biomass harvest in a clearcut. Within closed-canopy forests, total carabid abundance and the abundances of eight species increased significantly with increasing volumes of various types of woody debris, particularly large-diameter, late-decay conifer wood. Similarly, a strong affinity with woody debris was observed in the clearcut. These findings suggest that reductions in woody debris will have negative consequences for carabids and indicate the need to ensure a diverse and abundant supply of woody debris during stand development. ii Acknowledgements I would like to thank my advisors, Dr. Jay Malcolm and Dr. Sandy Smith, for the opportunity to take on this study and for their continuous support throughout its duration. I thank my committee member Dr. Chris Darling for his guidance and valuable inputs. For invaluable help in the initial stages of learning carabid identification, I would like to thank Kathleen Ryan and Nurul Islam. I thank Henri Goulet at the Canadian National Collection for his hospitality and for helping to enhance my identification skills. Thanks to Brad Hubley at the Royal Ontario Museum for providing me access to study the carabid collection. Thanks to the Kapuskasing field crews for their efforts, enthusiasm, and for making each season very enjoyable and memorable. I am very grateful to all those who spent long hours in the lab tediously processing my samples. I would like to thank everyone in the Wildlife Ecology and Forest Entomology labs for their support, encouragement, and insightful discussions. I would also like to thank my friends and colleagues in the faculty for a great atmosphere and continued inspiration that was an integral part of my experience. Funding for this project has been 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. A special thanks to Ian Thompson and Dave Morris for logistic support. iii Table of Contents Abstract .......................................................................................................................................... ii Acknowledgements ...................................................................................................................... iii List of Tables ................................................................................................................................. v List of Figures ............................................................................................................................... vi List of Appendices ....................................................................................................................... vii General Introduction .................................................................................................................... 1 Chapter 1: The response of ground beetles (Coleoptera: Carabidae) to a large-scale downed woody debris manipulation in boreal northeastern Ontario ...................................... 7 Introduction ................................................................................................................................. 7 Methods ....................................................................................................................................... 9 Study Sites ................................................................................................................................ 9 Experimental Design ............................................................................................................. 10 Carabid Sampling .................................................................................................................. 11 Downed Woody Debris Sampling .......................................................................................... 13 Statistical Analyses ................................................................................................................ 15 Results ....................................................................................................................................... 17 Discussion ................................................................................................................................. 26 Chapter 2: The importance of slash for ground beetles (Coleoptera: Carabidae) in a biomass clearcut .......................................................................................................................... 35 Introduction ............................................................................................................................... 35 Methods ..................................................................................................................................... 38 Study Site ............................................................................................................................... 38 Experimental Design ............................................................................................................. 41 Carabid Sampling .................................................................................................................. 41 Statistical Analyses ................................................................................................................ 42 Results ....................................................................................................................................... 43 Discussion ................................................................................................................................. 50 General Conclusions ................................................................................................................... 58 Literature Cited .......................................................................................................................... 65 Appendices ................................................................................................................................... 77 iv List of Tables Table 1.1. P values of downed woody debris (DWD) volume effects from mixed-model ANCOVAs on total carabid abundance, species richness, and the abundances of the 20 most abundant carabid species as a function of variation in nine DWD variables. Carabids were collected between 2010 and 2011 on a DWD manipulation experiment in northeastern Ontario (see text for details) (vtot represents total volume of DWD, in all other cases the first letter of the acronym represents size [s = small-diameter, l = large-diameter], the second letter the taxon [c = conifer, d = deciduous], and the last two numbers the decay class [12=early, 35=late]). Table 2.1. Mean abundance (standardized to 100 bucket-nights), total abundance, and species richness of carabids collected in 2010 and 2011 in a biomass clearcut in northeastern Ontario near (<5 m away) and far (>83 m away) from slash piles at three distances from forest edge (Near = 34-40 m, Medium = 66-84 m, Far = 181-268 m). Each mean represents abundances from two pitfall arrays; means are over three collection periods (August of 2010 and June and August of 2011). v List of Figures Figure 1.1. Most significant positive relationships between abundances of carabids and volume of various downed woody debris types in a downed woody debris manipulation experiment in mature mixedwood forests of northeastern Ontario. Figure 1.2. Most significant negative relationships between abundances of carabids and volume of various downed woody debris types in a downed woody debris manipulation experiment in mature mixedwood forests of northeastern Ontario. Figure 1.3. Individual-based rarefaction on total carabid captures in 2010 and 2011 from study plots divided into three classes of downed woody debris volumes (low = white, medium = grey, and high = black) for each of nine downed woody debris variables measured in a woody-debris manipulation experiment in northeastern Ontario. Shown are 95% confidence intervals. Figure 2.1. Map of the biomass clearcut in northeastern Ontario sampled for carabid beetles in 2010 and 2011. Pitfall trap arrays were close to slash piles (<5 m; circles) or far from slash piles (> 83 m; squares). White = forest; grey with black border = clearcut; solid black