COMPARISON OF ARTHROPOD ABUNDANCE AND DlVERSlTY IN INTERCROPPING AGROFORESTRY AND CORN MONOCULTURE SYSTEMS IN SOUTHERN ONTARIO Heather Dawn Howell A thesis submitted in confomity with the requirements for the degree of Master of Science in Forestry Graduate Faculty of Forestry University of Toronto @Copyright by Heather Dawn Howell, 2001 1*1 National Library Bibliothèque nationale ofCanada du Canada Acquisitions and Acquisitions et Bibliographie Services services bibliographiques The author has granted a non- L'auteur a accordé une licence non exclusive licence aüowing the exclusive permettant à la National Libmy of Canada to Bibliothèque nationale du Canada de reproduce, loan, distribute or seil reproduire, prêter, distribuer ou copies of this thesis in microform, vendre des copies de cette thèse sous paper or electronic formats. la forme de microfiche/fih, de reproduction sur papier ou sur format électronique. The author retains ownership of the L'auteur conserve la propriété du copyright in this thesis. Neither the droit d'auteur qui protège cette thèse. tbesis nor substantial extracts fiom it Ni la thèse ni des extraits substantiels may be printed or otherwise de celle-ci ne doivent être imprimes reproduced without the author' s ou autrement reproduits saas son permission. autorisation. FACULTY OF FORESTRY University of Toronto DEPARTMENTAL ORAL EXAMINATION FOR THE DEGREE OF MASTER OF SCIENCE IN FORESTRY Examination of Ms. Heather HOWELL %&&J/ Examination Chair's Signature: We approve this thesis and affim that it meets the departmental oral examination requirements set dom for the degree of Master of Science in Foresby. Examination Cornmittee: Abstract Cornparison of arthropod abundance and diversity in intercropping agroforestry and corn monoculture systems in southem Ontario. Master of Science in Forestry. 2001. Heather Dawn Howell. Faculty of Forestry, University of Toronto Arthropod communities were compared between a corn (Zea mays L.) monoculture and a corn intercropped agroforestry system in southern Ontario during 1998 and 1999. Pan trap data were used in June 1998 while malaise trap data were examined between June-September 1999. Arthropod abundanœ, representation by functional group, and hymenopteran family richness and diversity were al1 compared between the intercropped and the monoculture sites. Differenœs in arthropod abundance within the intercropped system were also cornPa& between: 1) tree rows with Norway spruce (Picea abies (L.) Karst.) or btack walnut (Juglans nigra L.); and 2) tree rows and crop alleys. Taxa such as Opiliones. Dennaptera and Carabidae, which are associated with organic litter areas that provide shelter during the day, were significantly higher in the agroforestry system than in the monocuiture system. The abundance of Hymenoptera, and several of its families, was also significantly higher in the agroforestry site than in the monoculture site, atthough no differences were observed in temis of overall family richness and diversity. There were significantly higher numbers of parasitoids and detritivores in the intercropped agroforestry system than in the monoculture system, and the intercropped treatment also supported a significantly higher ratio of parasitoids to herbivores. My results suggest that intercropping trees with crops such as corn monoculture can improve pest management by providing habitat to augment natural enemies populations. Dedication During the time when Iw as struggling through this thesis. my little sister Catherine Middleton and my father-in-law Glen Howell undement their own momentous challenges after being diagnosed with cancer. I would like to dedicate my thesis to both of them for having the strength and the courage to overcome their difficult batUe and to thank them for the love and encouragement that they gave me during the course of this work. iii Acknowledgement I wish to thank the many people who have helped me through this adventure. f irst and foremost, I would like to extend my sincere thanks and appreciation to rny supervisor, Dr. Sandy Smith (University of Toronto, Forestry) for providing me with the opportunity to do this study, in addition to her assistance and understanding throughout the development of this thesis. I would also like to extend my gratitude to my cornmittee members for their insightFul guidance and advice: Dr. Andy Kenney (University of Toronto, Forestry) for expanding my knowledge of agroforestry systems and for his guidance in statistics; Dr. Chris Darling (Royal Ontario Museum, Toronto) for sharing his knowledge and enthusiasm for the Hymenoptera; and Dr. Andy Gordon (University of Guelph) for originally inspiring me to do this study many years ago during my undergraduate days. Thanks also to Dr. Isabel Bellocq (University of Toronto, Forestry) for participating in the defence phase and for providing helpful adviœ during the course of the writing. Iw ould like to acknowledge the Faculty of Forestry for their financial support through the Graduate Fellowship in Forestry award. I am also greatly indebted to many people who have contributed a significant amount of their time to help me in the field, the laboratory, with the statistical approach and in other numerous ways. 1 would like to start by giving my deepest thanks to my brother, Doug Middleton, who volunteered a large number of hours helping me out in the field and in the laboratory. Large appreciation also goes out to Ping Zhang, Chantal Lalonde, Robin Thornton, Tanya Campolin and the Kentner family for helping me with aspects of field work. Special thanks to Naresh Thevathasan. Rick Gray (Agoroforestry Research Group) and Peter Milton (University of Guelph Agricultural Research Stations) for their technical support with the research fields. Thank you to Alexi Baev for al1 of his hard work in the laboratory with arthropod sorting and identification. I would also like to give a note of appreciation to Deborah Yurman, Bill McMartin and Christine Vance who gave me advice on my statistical analysis. My sincere gratitude goes to Dr. Fuhua Liu (Faculty of Forestry), who spent many hours with me, analysing my data together while patiently helping me to improve my knowledge of statistics. Thank you also to Robert Moloney (Agriculture Co-op, Barrie), for his expert knowledge on aspects of agronomy. I would also like to express my gratitude to Wendy Lake, Alison Howell, Rita Howell and Glen Howell for their careful editing assistance. Additionally, 1 would like to thank my friends and colleagues in my laboratory and within the Faculty of Forestry for their warm friendship, advice and support over the years I have been a student at the university. Most importantly I would like to thank my family and friends, especially my mom and my grandfather, for their love and encouragement throughout my thesis work. 1 have reserved my last note of heartfelt love and gratitude for my husband, Morley Howell, who has given me the tremendous technical, financial and ernotional support that made it possible to achieve my dream of completing a masters thesis. Table of Contents ................................................................................................................................. . Abstract II ... ......................................................................................................................... Dedication III .............................................................................................................. Acknowledgement iv .............................................................................................................. Table of Contents vi ... ................................................................................................................... List of Tables VIII ..................................................................................................................... List of Figures x ......................................................................................................................... Introduction 1 RATIONALE.. ........................................................................................................................ 1 .................................................................................................... Literature Review ARTHROPODINS AGROECOSYSTE.M..S... .................................................................... Ecological Funetions of Arthropods in the Agroecosystem .................................. Importance of Hymenoptera in Agroecosystems ................................................. VEGETATIONADL IVERSITAYN D AGROECOSYSTESMTA BILITY.. ............... Habitats with Adjacent Vegetation ................................. ................ lntercropping Systems .................................................. ................. AGROFQRESTR~YN, TERCROPP~ANGGR OFORESTRAYN D ART'H ROPODS .. Agroforestry in North America .................................... ................. Intercropping Agroforestry in North America ........................................................... 7 8 Arthropods in Agroforestry Systems ........................................................................ 20 ...................................................................................................... Materials and Methods 27 SITE SELECTIONF OR SAMPLING.. ....................................................................................... -28 DATAA NALYS IS .................................................................................................................. 34 Environmental Data ................................................................................................. 34 Arthropod Abundance ............................................................................................. 34 Arthropod Funetional Group Cornparison (19 99 Malaise Traps) ............................. 35 Hymenoptera Richness and Diversity (19 99 Malaise Traps). .................................. 36 ............................................................................................................................... Results 37 GENERAALR THROPOADB UNDANC..E.. ................................................................................ -41 1998 Pan Traps. ...................................................................................................... 47 1999 Malaise Traps. ................................................................................................ 47 CONIPARISONO F NORWASYP RUCE-INTERCROPPAINGGR OFORESTARNYD ............................................................................ CONVENTIONAML ONOCULTURSEY STEMS 42 ...................................................................................................... 1998 Pan Tmps 4 2 ................................................................................................. 1999 Malaise Traps 42 Functional Arthmpoâ Groups and Selected FamiliedOrders from 1999 Malaise ...................................................................................................................... Tmps 48 ............... Hymenopteran Family Richness and Divetsity from 1999 Malaise Traps 61 COMPARISONO F NORWASYP RUCEAN D BLACKW ALNUTIN THE ~NTERCROPPING .................................................................................................. AGROFORESTRSYYS TEM -62 ....................................................................................................... 1998 Par! Traps 62 ................................................................................................. 1999 Malaise Traps 62 COMPARISOONF TREER OWSAN D CROPA LLEYSI N THE ~NTERCROPPING AGROFORESTRSYYS TEM... ................................... .. ...........................................................- 68 ....................................................................................................... 1998 Pan Traps 68 ................................................................................................. 1999 Malaise Traps 68 COMPARISOONF ~NTERCROPPING AGROFORESTRAYND CONVENTIONAL MONOCULTURSYES TEM.S.. .................................................................................................7 7 COMPARISONO F NORWASYP RUCEAN D BLACKW ALNUTT REER OWS IN THE 1N TERCROPPING AGROFORESTRSYY STEM.. ........................................................................- 89 COMPARISONO F TREER OM AND CROPA LLEYSIN THE INTERcROPPING ................................................................................................... AGROFORESTRSYYS TEM -90 ....................................................................................................................... Conclusions 93 Literature Sited ........................................................................................................ ..........97 Appendices ............................................................q....................O.............................1....7.. . APPENDIXI NUMBERO F ARTHROPODS IN EACH ORDER/CLASS USlNG PAN TRAPS DURING JUNE1 998 FROM NORWASYP RUCE AND BLACK WALNUT SITES WiTHIN THE INTERCROPED AGROFORESTRY AND CORN MONOCULTURE SITES. AT THE GUELPH AGRICULTURARL ESEARCHS TATION( ~=60..). ................................................................... 1 7 APPENOIX2 .N UMBERO F ARTHROPODS IN EACH ORDER USlNG MALAISET RAPS DURING JUNE-SEPTEMBE4R9 99. FROM NORWASYP RUCE AND BLACK WALNUT SITES WlTHlN THE INTERCROPPING AGROFORESTRY AND CORN MONOCULTURE ........................... STUDY SITES. AT THE GUELPHAG RICULTURARLE SEARCHS TATIO(N~ 4 8 ) 118 APPENDIX3 .N UMBERO F ARTHROPODS IN 61 SELECTED FAMILIES AND 2 SELECTED ORDERS THAT ARE REPRESENTING THE PARASITOID. PREDATOR. POCLINATOR. OETRITIVORE AND HERBlVORE FUNCTIONAL GUlLDSf CAUGHT IN JUNE-SEPTEMB1E9R9 9 IN THE INTERCROPPING AGROFORESTRY NORWAY SPRUCE AND THE CORN MONOCULTURE STUDY SITE. AT THE GUELPH AGRICULTURARLE SEARCHS TATION( ~=32...).. ......................................... vii List of Tables Table 1. Summary of analysis methods and number of samples for each treatment cornparison and sampling season. ................................................ 31 Table 2. Selected arthropod families and their associated functional groups' ............. 33 Table 3. Environmental data collected from a weather station at the Guelph Agricultural Research Station during the summer of 1999. Data based on 3-day mean for each month in which malaise traps were placed in a given treatment. .......................................................................... 38 Table 4. Mean abundance of arthropod orders collected in pan traps over a 3- day period from a corn intercropped agroforestry site and a monoculture site at the Guelph Agricultural Research Station. 5-8 June 1998 (N=40). ......................................................................................... 43 Table 5. Mean abundance of arthropod orders collected in malaise traps over a 3-day period from a corn intercropped agroforestry site and a monoculture site at the Guelph Agricultural Research Station, June- September 1999 (N=32). ............................................................................... 44 Table 6 Mean abundance of arthropod orders collected in malaise traps over a 3-day period from a corn intercropped agroforestry site or a monoculture site at the Guelph Agricultural Research Station, June- September 1999 (N=32). ............................................................................... 46 Table 7 Arthropod abundance by functional groups from malaise traps operating for 3-day periods in a corn monoculture and an intercropped corn site at the Guelph Agriculture Research Station, Ontario, June-September 1999 (N=32). ........................................................ 49 Table 8 Abundance of arthropods by functional groups from malaise traps placed three days each month in a corn intercropped agroforestry site and a corn monoculture site at the Guelph Agricultural Research Station. June-September 1999 (N=32)... ....................................................... 50 Table 9 Mean ratio between the number of predators or parasitoids and herbivores collected over three days using malaise traps in a corn monoculture site and a intercropped agroforestry site at the Guelph Agriculture Research Station, Ontario, June-September 1999 (N=32). ......................................................................................................... -51 Table 10. Mean abundance of arthropod familiesforders in malaise traps over a 3-day period from a corn intercropped agroforestry site and a corn monoculture site at the Guelph Agricultural Research Station, June- September 1999 (N=32). ............................................................................... 53 Table II.M ean monthly abundance of selected arthropod familiesforders collected in malaise traps over a 3-day period frorn a corn intercropped agroforestry site and a corn monoculture site at the Guelph Agricultural Research Station. June-September 1999 (N=32). .......................................................................................................... 55