Linking Physiology, Temperature, and Recruitment: a Classic Competitive Story Rewritten by Climate Maeve Kerrigan Snyder University of South Carolina
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University of South Carolina Scholar Commons Theses and Dissertations 2018 Linking Physiology, Temperature, And Recruitment: A Classic Competitive Story Rewritten By Climate Maeve Kerrigan Snyder University of South Carolina Follow this and additional works at: https://scholarcommons.sc.edu/etd Part of the Biology Commons Recommended Citation Snyder, M. K.(2018). Linking Physiology, Temperature, And Recruitment: A Classic Competitive Story Rewritten By Climate. (Master's thesis). Retrieved from https://scholarcommons.sc.edu/etd/4691 This Open Access Thesis is brought to you by Scholar Commons. It has been accepted for inclusion in Theses and Dissertations by an authorized administrator of Scholar Commons. For more information, please contact [email protected]. LINKING PHYSIOLOGY, TEMPERATURE, AND RECRUITMENT: A CLASSIC COMPETITIVE STORY REWRITTEN BY CLIMATE by Maeve Kerrigan Snyder Bachelor of Science Coastal Carolina University, 2014 Submitted in Partial Fulfillment of the Requirements For the Degree of Master of Science in Biological Sciences College of Arts and Sciences University of South Carolina 2018 Accepted by: Thomas J. Hilbish, Director of Thesis David S. Wethey, Reader Jesus Pineda, Reader Cheryl L. Addy, Vice Provost and Dean of the Graduate School © Copyright by Maeve Kerrigan Snyder, 2018 All Rights Reserved ii ii ACKNOWLEDGEMENTS I would like to extend my sincere and deep gratitude first and foremost to Dr. Jerry Hilbish, without whose encouragement, patience, and mentorship, this work would not have been possible. Through opportunities and confidence in my ability, Dr. Hilbish has enabled me to grow and improve as a researcher and an individual. I am also appreciative to Dr. David Wethey and Dr. Jesus Pineda for their guidance, input, and inspiration. Amy Zyck, Jesse Turner, Sophia Sudak, and Cameron Good contributed enormously to this work as research and field assistants. I am additionally grateful to Rachel Steward, Mike Bramson, Rhiannon Rognstad, and Sam Crickenberger for their contributions and advice. Special thanks to my friends and family for their loving support. This work was funded by NASA (NNX11AP77G) and NSF (OCE 1129401) grants to DSW and TJH and a Magellan Voyager Grant from the University of South Carolina Office of Undergraduate Research to JMT. iii iii ABSTRACT Climatic changes have the potential to alter population and community dynamics, ultimately influencing the biogeographic distributions of species. For many organisms, reproduction is physiologically tied to temperature. We tested the hypothesis that a physiological mechanism for reproductive failure in the acorn barnacle, Semibalanus balanoides, would result in predictable patterns of larval recruitment over broad geographic scales. Recruitment density was predicted to be dependent on the duration of permissive temperatures (< 10oC). for successful reproduction in adult populations of S. balanoides. We found that temperature was a reliable predictive variable for recruitment densities throughout our study region. Post-recruitment processes were also considered, specifically the competition between Semibalanus balanoides and Chthamalus montagui, described in Joseph Connell’s 1961 experiment. The competitive hierarchy outlined in this experiment is not consistently observed throughout the range overlap of the two species. Growth and mortality were found to differ dependent on species and latitude, indicating that climate mediates this classic ecological system. Our results provide useful knowledge for refining models of biogeographic shifts. A consistent failure of larval supply and a breakdown of competitive advantage could accelerate the pace of predicted range contraction for S. balanoides. Further investigation of how environmental variables interact with physiology and ecological processes is necessary for accurate predictions of climate change effects. iv iv TABLE OF CONTENTS ACKNOWLEDGEMENTS ................................................................................................... iii ABSTRACT ............................................................................................................................ iv LIST OF TABLES.................................................................................................................. vi LIST OF FIGURES ............................................................................................................... vii LIST OF ABBREVIATIONS .............................................................................................. viii CHAPTER 1: PREDICTING RECRUITMENT SUCCESS FROM A TEMPERATURE – BASED PHYSIOLOGICAL MECHANISM ACROSS A BROAD LATITUDINAL RANGE .....................................................................................................................................1 1.1 INTRODUCTION .................................................................................................2 1.2 METHODS.............................................................................................................9 1.3 RESULTS ............................................................................................................ 15 1.4 DISCUSSION ..................................................................................................... 19 CHAPTER 2: REVISITNG CONNELL: A CLASSIC COMPETITIVE SYSTEM LINKED TO CLIMATE ....................................................................................................... 38 2.1 INTRODUCTION .............................................................................................. 39 2.2 METHODS.......................................................................................................... 44 2.3 RESULTS ............................................................................................................ 49 2.4 DISCUSSION ..................................................................................................... 51 LITERATURE CITED ......................................................................................................... 66 v v LIST OF TABLES Table 1.1 Sampling period by region for 2015 and 2016. .................................................. 27 Table 1.2 Summary statistics of salinity time series for all sites ........................................ 28 Table 2.1 Subquadrats and corresponding experimental treatments .................................. 60 vi vi LIST OF FIGURES Figure 1.1 Study region and sites (in blue) on the west coast of the United Kingdom ..... 29 Figure 1.2 Time series of hourly air temperature, daily sea surface temperature, and composite air and SST for both study years ........................................................................ 30 Figure 1.3 Relationship between low tide CFSR air temperature and iButton temperature at Whitsand Bay ..................................................................................................................... 31 Figure 1.4 Figure 4. Relationship between combined SST and adjusted - air temperature and iButton temperature at Whitsand Bay ........................................................................... 32 Figure 1.5 Cumulative days below 10oC using composite air and sea surface temperature across the latitudinal gradient of the study sites for both sample years ............................. 33 Figure 1.6 Number of days below 10oC using composite air and sea surface temperature during the embryonic brooding period using composite temperature vs. recruitment density of S. balanoides at all sites ....................................................................................... 34 Figure 1.7 Early juvenile mortality of Semibalanus balanoides. Recruitment density sampled in May 2016 vs. recruitment density in June 2016 ............................................... 35 Figure 1.8 Log – transformed chlorophyll a concentration vs. recruitment density ......... 36 Figure 1.9 Averaged daily salinity data vs. recruitment density at each site ..................... 37 Figure 2.1 Experimental groupings for measurements of mortality and growth rate ....... 61 Figure 2.2 Average proportional cover of SB and CM across sites. Sites 1 – 18 are southwest England. Sites 18 – 23 are Wales. Sites 23 – 28 are Scotland .......................... 62 Figure 2.3 Percent cover analysis of simulated SB recruitment failure ............................. 63 Figure 2.4 Mortality (mean ± standard error) of SB and CM across latitude in isolation and interspecific groupings ................................................................................................... 64 Figure 2.5 Growth rate (mean ± standard error) of SB and CM across latitude in isolation and interspecific groupings ................................................................................................... 65 vii vii LIST OF ABBREVIATIONS CM .......................................................................................................... Chthamalus montagui SB ....................................................................................................... Semibalanus balanoides SST ....................................................................................................Sea Surface Temperature UK ...................................................................................................................United Kingdom viii viii CHAPTER 1 PREDICTING RECRUITMENT SUCCESS FROM A TEMPERATURE – BASED PHYSIOLOGICAL MECHANISM ACROSS A BROAD LATITUDINAL RANGE1 1 Maeve