Florida State University Libraries Electronic Theses, Treatises and Dissertations The Graduate School 2012 The Effects of Landscape Structure on Biodiversity, Network Architecture, and Ecosystem Function Brian J. Spiesman Follow this and additional works at the FSU Digital Library. For more information, please contact [email protected] THE FLORIDA STATE UNIVERSITY COLLEGE OF ARTS AND SCIENCES THE EFFECTS OF LANDSCAPE STRUCTURE ON BIODIVERSITY, NETWORK ARCHITECTURE, AND ECOSYSTEM FUNCTION By BRIAN J. SPIESMAN A Dissertation submitted to the Department of Biological Science in partial fulfillment of the requirements for the degree of Doctor of Philosophy Degree Awarded: Fall Semester, 2012 Brian Spiesman defended this dissertation on October 19, 2012. The members of the supervisory committee were: Brian D. Inouye Professor Directing Dissertation Mike Mesterton-Gibbons University Representative Austin R. Mast Committee Member Thomas E. Miller Committee Member Nora Underwood Committee Member The Graduate School has verified and approved the above-named committee members, and certifies that the dissertation has been approved in accordance with university requirements. ii ACKNOWLEDGEMENTS I am grateful for the guidance, advice, and support of my advisor, Brian Inouye. I thank Nora Underwood and the rest of the Inouye-Underwood lab group. I thank the rest of my committee, Tom Miller, Austin Mast, and Mike Mesterton-Gibbons for their help in developing my research. I thank Sophie Hyson for her help in the field and Andrés Plata Stapper for his essential help in the lab. Funding for this dissertation was provided by the National Science Foundation (DEB- 1110738), the COFRS program at FSU, the Robert K. Godfrey Endowment, the FSU Dept. of Biological Science, and the FSU Graduate School. I am grateful to my family for their support. Lastly, but most importantly, I thank Tania Kim. This dissertation would not have been possible without her. iii TABLE OF CONTENTS List of Tables ................................................................................................................................. vi List of Figures ............................................................................................................................... vii Abstract .......................................................................................................................................... ix 1. INTRODUCTION ...................................................................................................................1 2. HABITAT LOSS ALTERS THE ARCHITECTURE OF PLANT-POLLINATOR INTERACTION NETWORKS .......................................................................................................5 2.1 Introduction ....................................................................................................................7 2.2 Methods..........................................................................................................................9 2.2.1 Study area and sampling ....................................................................................9 2.2.2 Deriving explanatory variables ........................................................................11 2.3 Results ..........................................................................................................................13 2.3.1 SEM analysis ...................................................................................................14 2.4 Discussion ....................................................................................................................15 2.4.1 Conclusions and future directions ....................................................................18 2.5 Tables ...........................................................................................................................20 2.6 Figures..........................................................................................................................28 3. MATRIX HABITAT QUALITY MEDIATES THE EFFECTS OF PATCH SIZE AND ARRANGEMENT ON METACOMMUNITY STRUCTURE AND ECOSYSTEM FUNCTION ...................................................................................................................................36 3.1 Introduction ..................................................................................................................36 3.1.1 Matrix effects on local communities ................................................................37 3.1.2 Incorporating ecosystem level processes .........................................................38 3.2 Methods........................................................................................................................39 3.2.1 Experimental design.........................................................................................39 3.2.2 Leaf litter decomposition .................................................................................40 3.2.3 A molecular characterization of leaf litter microbial communities .................40 3.2.4 Statistical analysis ............................................................................................41 3.3 Results ..........................................................................................................................42 3.4 Discussion ....................................................................................................................43 3.4.1 Future directions ..............................................................................................45 3.5 Figures..........................................................................................................................46 4. THE CONSEQUENCES OF MULTIPLE INDIRECT PATHWAYS OF INTERACTION FOR SPECIES COEXISTENCE ...................................................................................................52 4.1 Introduction ..................................................................................................................52 iv 4.2 The Model ....................................................................................................................54 4.2.1 Model analysis .................................................................................................55 4.3 Results and Discussion ................................................................................................57 4.3.1 Community-level effects of mutualism ...........................................................59 4.3.2 Conclusions ......................................................................................................60 4.4 Figures..........................................................................................................................61 5. CONCLUSION .....................................................................................................................67 APPENDICES ...............................................................................................................................69 A. LANDSCAPE STRUCTURE EFFECTS ON OAK COMMUNITY STRUCTURE ...........69 B. LANDSCAPE AND COMMUNITY STRUCTURE EFFECTS ON ECOSYSTEM FUNCTION ...................................................................................................................................70 C. MATRIX QUALITY MEDIATES THE EFFECTS OF PATCH SIZE AND ARRANGEMENT ON OAK LITTER COMMUNITY STRUCTURE .......................................71 REFERENCES ..............................................................................................................................73 BIOGRAPHICAL SKETCH .........................................................................................................82 v LIST OF TABLES 2.1 List of plant species ...........................................................................................................20 2.2 List of pollinator morphospecies .......................................................................................22 2.3 Unstandardized/standardized path coefficients and covariance/correlations ....................26 2.4 Matrices of standardized total (A) and indirect (B) effects ...............................................27 A1 Type III summary of linear mixed effects model testing the effect of oak patch size, arrangement, and matrix quality on species composition in oak patches ..................69 A2 Type III summary of linear mixed effects model testing the effect of oak patch size, arrangement, and matrix quality on species richness in oak patches ........................69 B1 Type III summary of linear mixed effects model testing the effect of patch size, arrangement, and matrix quality on the rate of oak leaf litter decomposition ...................70 B2 Type III summary of linear mixed effects model testing the effect of oak species richness and composition on the rate of oak leaf litter decomposition ..............................70 C1 Type III summary of linear mixed effects model testing the effect of a bare ground matrix on species richness in oak patches .............................................................71 C2 Type III summary of linear mixed effects model testing the effect of bare ground matrix on species composition in oak patches ...................................................................71 C3 Type III summary of linear mixed effects model testing the effect of a pine litter matrix and pine species composition on species composition in oak patches ...................71 C4 Type III summary of linear