GRADUATE AND POSTDOCTORAL STUDIES FINAL ORAL EXAMINATION

Transcription

1 GRADUATE AND POSTDOCTORAL STUDIES MCGILL UNIVERSITY FINAL ORAL EXAMINATION FOR THE DEGREE OF DOCTOR OF PHILOSOPHY OF DOROTHY Y MAGUIRE NATURAL RESOURCE SCIENCES THE EFFECT OF LANDSCAPE STRUCTURE ON INSECT HERBIVORY AND BIODIVERSITY: IMPLICATIONS FOR FOREST ECOSYSTEM SERVICES IN THE MONTÉRÉGIE, QUÉBEC Friday February 27th 1:15 PM Macdonald Stewart Building, Room MS McGill University, Macdonald Campus COMMITTEE: Dr. Gregory Mikkelson, (Pro-Dean) (Philosophy) Dr. J Whalen (Chair) (Natural Resource Sciences) Dr. C Buddle (Co-Supervisor) (Natural Resource Sciences) Dr. E Bennett (Co-Supervisor) (Natural Resource Sciences) Dr. B Coté (Internal Examiner) (Natural Resource Sciences) Dr. Y Mauffette (External Member) (UQAM) Dr. Martin Kreiswirth, Dean of Graduate and Postdoctoral Studies Members of the Faculty and Graduate Students are invited to attend

2 ABSTRACT Anthropogenic disturbances are fragmenting forested areas around the world, fundamentally changing the structure of landscapes in a manner that has poorly understood consequences for biodiversity, ecological processes, and ecosystem services. This lack of understanding makes it difficult for land managers to make optimal decisions that balance environmental benefits and costs of land use change. In this thesis, I address this gap in our understanding by using a combination of theoretical and empirical approaches to quantify how and when fragmentation affects ecosystem processes that have distinct impacts on forest ecosystem services. Specifically, I test the role that insect herbivory plays in mediating the effects of landscape structure on ecosystem services in forest ecosystems in the Montégerie in southwest Quebec. Insect herbivory is a good model system to test these effects because it is sensitive to landscape structure, can have strong effects on ecosystem services, and can be either beneficial or harmful depending on the herbivore species and the ecosystem context. In this thesis, I quantify the effects of landscape structure on insect herbivory and biodiversity, and assesses the implications of these effects for forest ecosystem services in four steps: 1) In the first chapter, I examine the known relationships between landscape structure, herbivory and ecosystem services through a semi-quantitative literature review and show that herbivory plays an important role mediating effects of connectivity on ecosystem services. The results of this review show assessing the mechanisms that regulate the response of insect herbivores to landscape structure would allow for better predictions regarding this process. 2) In the second chapter, I quantify the relationship between landscape structure and herbivory, and test potential mechanisms (i.e. predation pressure) driving the response, using a manipulative field experiment in the Montérégie. I find that landscape structure alone does not explain levels of herbivory, even though there was strong vertebrate predation pressure on herbivores that varied with landscape structure. Because these results show structure at the landscape scale does not explain patterns of herbivory, my next step was to determine whether insect herbivory is spatially heterogeneous at a finer scale. 3) In the third chapter, I measure the spatial heterogeneity of insect herbivory in remnant forest patches at both the landscape and patch level, quantifying herbivore damage on sugar maple trees at the edge, interior, and canopy of remnant forest patches that differ in size and connectivity. I find that patterns of herbivory are affected by the interaction of landscape and patch level sources of spatial heterogeneity. 4) Finally, to better understand the mechanisms by which these finer scale patterns occur, I measure the effects of landscape structure and location within a forest patch (i.e., edge, interior, canopy) on arthropod functional and taxonomic biodiversity. I find that canopies of fragmented forest patches are important reservoirs of arthropod biodiversity, even in fragmented forest ecosystems.

3 Human activities, such as fragmentation or restoration, continue to affect the structure of forest ecosystems, with unknown consequences for the ecosystem services provided by forests. My thesis advances our understanding of the effects of landscape structure on ecosystem services by using herbivory as a model system to provide a conceptual framework with which to balance the social and environmental costs and benefits associated with altering landscape structure.

4 CURRICULUM VITAE Education present, Post Doctoral Fellow, USDA-ARS (Montpellier, France) present PhD Candidate, McGill University Masters in Forest Conservation, Faculty of Forestry, University of Toronto B.Sc. Hon s, Cell and Systems Biology, Min Art History, Trinity College, University of Toronto Publications Maguire DY., Nicole T., Bennett EM., Buddle CM. (2014). Effect of fragmentation on predation pressure of insect herbivores in a north temperate deciduous forest ecosystem. Ecological Entomology, (in Press). Maguire DY., Robert K., Brochu K., Larrivee M., Buddle CM., Wheeler TA. (2014). Vertical Stratification of Beetles (Coleoptera) and Flies (Diptera) in Temperate Forest Canopies. Environmental Entomology, 43(1): 9-17 Liss KN., Mitchell MGE., MacDonald, GK., Mahajan SL., Methot J., Jacob AL., Maguire DY., Metson GS., Ziter C., Dancose K., Martins K., Terrado M., Bennett EM. (2013). Variability in ecosystem service measurement: a pollination service case study. Frontiers in Ecology and the Environment, 11(8): Maguire DY., Sforza R., Smith SM. (2010). Impact of herbivory on performance of Vincetoxicum spp., invasive weeds in North America. Biological Invasions, 13(5): Selected Presentations Maguire DY*, Bennet EM, Buddle CM, James PMA. (2014). Landscape Connectivity And Insect Herbivory: A Framework For Understanding Tradeoffs Among Ecosystem Services. May International Association for Landscape Ecologists (US-IALE) Annual Symposium, Anchorage, AK, USA. Oral Presentation (International). Maguire DY*., Sim KA., Bennett EM., Buddle CM., James PMA. (2013). Patterns of Gene Flow of the Gypsy Moth (Lymantris dispar) in a Fragmented Forest Landscape. Dec Quebec Centre for Biodiversity Science Symposium, Montreal, QC, Canada. Poster Presentation (Provincial). Maguire, DY*., Buddle CM., Bennett EM. (2013). Patterns of Insect Herbivory Across a Fragmented Forest Landscape. Oct 20-23, Joint Annual Meeting of the Entomological Society of Canada, Guelph, ON, Canada. Oral Presentation (National). Maguire, DY*., Nicole T., Buddle CM., Bennett EM. (2012). Landscape Structure and the Regulation of Herbivory by Predators. Nov 4-7, Joint Annual Meeting of the Entomological Society of Canada, Edmonton, AB, Canada. Oral Presentation (National). Sforza R*., Maguire DY., Towmey C., Riquier A., Augé M., Smith SM (2011). Ecological data key to building successful biocontrol programmes: A case study

5 using Chrysochus asclepiadeus (Col., Chrysomelidae) against Vincetoxicum spp. (Apocynaceae). Sep 11-16, International Symposium on the Biological Control of Weeds, Waikoloa, Hawaii, USA. Oral Presentation (International). Awards 2014 NASA-MSU Professional Enhancement Award ($700) 2014 Quebec Centre for Biodiversity Science (QCBS) Excellence Award ($700) 2014 GREAT Travel Award, McGill ($500) 2013 President s Prize for Oral Presentation (2 nd place), Entomological Society of Canada 2011/ 2012/ 2013 Tomlinson Millennium Fellowship, McGill ($12,000/yr) 2012 Quebec Centre for Biodiversity Science (QCBS) Seed Grant ($5000) 2011 President s Prize for Oral Presentation (2 nd place), Entomological Society of Canada 2011 GREAT Travel Award, McGill ($500) 2010 Provost s Graduate Fellowship, McGill ($6000) 2009 Fred G Jackson prize, U of T ($1000) 2008 Graduate Fellowship, U of T ($2000) 2004 Trinity College Scholarship, U of T Professional Associations International Association of Landscape Ecology (IALE) Quebec Centre for Biodiversity Science (QCBS) Entomological Society of Canada (ESC) Community Involvement Writer and Editor for Montreal s Ecosystems at Your Service ( present Student Representative for McGill University, Quebec Centre for Biodiversity Science (QCBS) Athlete, McGill Olympic Cross Country/ Track and Field Team Athlete, McGill Varsity Cross Country/Track and Field Team Student Representative, Forestry Graduate Student Association