Louisiana State University LSU Digital Commons LSU Doctoral Dissertations Graduate School July 2020 Habitat Fragmentation and Range Margin Effects on Dispersal and Interactions between Competitors Rachel Roxann Harman Louisiana State University and Agricultural and Mechanical College Follow this and additional works at: https://digitalcommons.lsu.edu/gradschool_dissertations Part of the Ecology and Evolutionary Biology Commons Recommended Citation Harman, Rachel Roxann, "Habitat Fragmentation and Range Margin Effects on Dispersal and Interactions between Competitors" (2020). LSU Doctoral Dissertations. 5338. https://digitalcommons.lsu.edu/gradschool_dissertations/5338 This Dissertation is brought to you for free and open access by the Graduate School at LSU Digital Commons. It has been accepted for inclusion in LSU Doctoral Dissertations by an authorized graduate school editor of LSU Digital Commons. For more information, please [email protected]. HABITAT FRAGMENTATION AND RANGE MARGIN EFFECTS ON DISPERSAL AND INTERACTIONS BETWEEN COMPETITORS A Dissertation Submitted to the Graduate Faculty of the Louisiana State University and Agricultural and Mechanical College in partial fulfillment of the requirements for the degree of Doctor of Philosophy in The Department of Biological Sciences by Rachel Roxann Harman B.S., Indiana University – Purdue University Fort Wayne, 2012 M.S., Indiana University – Purdue University Fort Wayne, 2014 August 2020 ACKNOWLEDGEMENTS First and foremost, I would like to thank my husband, Dan, who has been so supportive of my doctoral journey. We signed the marriage certificate just 5 days before moving 1,000 miles to Baton Rouge, LA, which was our “honeymoon” trip. Throughout this crazy journey, he has pushed me to be a better researcher, teacher, and person. I have received tremendous support from my family and Dan’s family as well. I would like to thank my parents, who taught me how to be a dedicated worker and the importance of a good education. I would like to thank my three siblings, with whom I have always been close, as they were always there for me if I needed to rant or chat as the case may be. During my six years in Louisiana, I was blessed with six nephews, whose laughs and shenanigans often made me smile and push harder to finish my dissertation objectives to be able to visit them on the holidays. I have greatly enjoyed my time in Baton Rouge. The lifelong friendships, the way too tasty food, and the support of the wonderful faculty and staff made each day special. In particular, I would like to thank my adviser, Jim Cronin, who inspired me to become a better scientist and to think for myself. He supported me through sand and flour, success and failure, providing me with guidance when I needed it and letting me dive into the (literal) research marsh when I did not. I would also like to thank the other members of my committee, Kyle Harms and Bret Elderd, who were always available for discussions, laughs, and advice. I would also like to thank Barry Aronhime, who let me use my pedagogical training and express my passion for teaching as I developed curriculum for the ecology lab course. Additionally, I would like to thank my collaborators, Jerome Goddard II and Ratnasingham Shivaji from Auburn University Montgomery and the University of North Carolina Greensboro, respectively, as it has been a pleasure working with them as we combined ii detailed models with ecology. I would also like to thank Christopher Carlton for his invaluable assistance with identifying my insects and taking his time to show us how to sex Tribolium spp. My coworkers and friends have always been supportive of me and there are so many of them that I would like to thank here, but I will keep the list to direct assistance of my research and not the scores of names of people that provided me with moral support, though I thank you all too. In particular, I would like to thank: Katherine Hovanes, Lorelei Patrick, Luis Santiago- Rosario, Lorissa Radunzel-Davis, Herie Lee, Joseph Johnston, Nathan Harms, Warwick Allen, Ganesh Bhattarai, Carrie Barker, Andrew Flick, Matthew Faldyn, Jordan Croy, Scott Grimmell, Jason Janeaux, and Michael Garvey for helping me count beetles, double check manuscripts, or talk through my research. You all have helped push me through this crazy experience. During my years at LSU, I have also had the great fortune of mentoring so many undergraduates who assisted me with my research. I would like to thank Celine Rochon, Matthew Berry, Charles “Marshall” Stephenson, Madeline Guidry, Madelyn Smith, Raven Daigle, Daniel Ruppert, Taylor Boyd, Alex Hollander, Amanda Monceaux, Marshall Kellerman, Benjamin Gaither, Connor Doyl, Nicholas Uzee, Elaine Arendt, Florencia Scaglia Drusini, Mitchell Guedry, Kaylyn Riley, and Rhae Sevin for all of their hard work throughout the years. The second chapter of my dissertation was published in the American Naturalist journal. I would like to thank them for the use of the paper for dissertation publication. Lastly, I would like to extend my thanks to the National Science Foundation (DMS-1516833, DMS-1516560, and DMS-1516519), Louisiana Environmental Education Commission, and Biograds LSU organization for their financial support of my research. iii TABLE OF CONTENTS ACKNOWLEDGEMENTS........................................................................................................ ii LIST OF TABLES .................................................................................................................... vi LIST OF FIGURES ................................................................................................................. vii ABSTRACT ............................................................................................................................. ix CHAPTER 1. INTRODUCTION ...............................................................................................1 CHAPTER 2. FREQUENCY OF OCCURENCE AND POPULATION-DYNAMIC CONSEQUENCES OF DIFFERENT FORMS OF DENSITY-DEPENDENT EMIGRATION ...7 INTRODUCTION ...................................................................................................................7 OBJECTIVE 1: FORMS OF DENSITY-DEPENDENT EMIGRATION .................................9 OBJECTIVE 2: PRESENCE OF DDE FORMS IN THE LITERATURE .............................. 11 OBJECTIVE 3: POPULATION DYNAMICS OF DDE ........................................................ 18 DISCUSSION ....................................................................................................................... 24 CONCLUSIONS ................................................................................................................... 30 CHAPTER 3. MOVEMENT BEHAVIOR OF ISCHNODEMUS CONICUS (VAN DUZEE) IN FRAGMENTED SALT-MARSH HABITATS .......................................................................... 32 INTRODUCTION ................................................................................................................. 32 MATERIALS AND METHODS ........................................................................................... 35 RESULTS ............................................................................................................................. 47 DISCUSSION ....................................................................................................................... 59 CONCLUSIONS ................................................................................................................... 66 CHAPTER 4. REDUCTION IN DISPERSAL IS CAUSED BY CONCURRENT SELECTION OF COMPETITIVE ABILITY IN RANGE EXPANDING POPULATIONS ............................ 68 INTRODUCTION ................................................................................................................. 68 MATERIALS AND METHODS ........................................................................................... 72 RESULTS ............................................................................................................................. 83 DISCUSSION ....................................................................................................................... 92 CONCLUSIONS ................................................................................................................. 100 CHAPTER 5. CONCLUSIONS .............................................................................................. 103 APPENDIX A. SUPPLEMENTARY MATERIAL FOR CHAPTER 2. .................................. 110 APPENDIX B. SUPPLEMENTARY MATERIAL FOR CHAPTER 3. .................................. 118 APPENDIX C. SUPPLEMENTARY MATERIAL FOR CHAPTER 3. .................................. 122 APPENDIX D. COPYRIGHT INFORMATION. .................................................................... 124 iv REFERENCES ....................................................................................................................... 129 VITA ...................................................................................................................................... 152 v LIST OF TABLES Table 3.1. Ischnodemus conicus density-emigration model selection results using Akaike’s information criterion corrected for small sample size (AICc). ........................................ 49 Table 3.2. Effect of habitat type on Ischnodemus conicus movement behavior.. ........................ 50 Table 3.3. Effect of sex and age class on Ischnodemus conicus movement behavior within the patch arenas ..................................................................................................................