Louisiana State University LSU Digital Commons LSU Historical Dissertations and Theses Graduate School 1985 Production and Nitrogen Dynamics of a Vallisneria Americana Grass Bed in Lake Pontchartrain, Louisiana (Nitrogen Cycle, Modeling, Seagrasses, Decomposition Phenology, Vallisneria-Celery Grass-Eelgrass, Environmental Factors). Diana Lee Steller Louisiana State University and Agricultural & Mechanical College Follow this and additional works at: https://digitalcommons.lsu.edu/gradschool_disstheses Recommended Citation Steller, Diana Lee, "Production and Nitrogen Dynamics of a Vallisneria Americana Grass Bed in Lake Pontchartrain, Louisiana (Nitrogen Cycle, Modeling, Seagrasses, Decomposition Phenology, Vallisneria-Celery Grass-Eelgrass, Environmental Factors)." (1985). LSU Historical Dissertations and Theses. 4165. https://digitalcommons.lsu.edu/gradschool_disstheses/4165 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 Historical Dissertations and Theses by an authorized administrator of LSU Digital Commons. For more information, please contact [email protected]. INFORMATION TO USERS This reproduction was made from a copy of a manuscript sent to us for publication and microfilming. While the most advanced technology has been used to pho­ tograph and reproduce this manuscript, the quality of the reproduction is heavily dependent upon the quality of the material submitted. Pages in any manuscript may have indistinct print. In all cases the best available copy has been filmed. The following explanation of techniques is provided to help clarify notations which may appear on this reproduction. 1. Manuscripts may not always be complete. When it is not possible to obtain missing pages, a note appears to indicate this. 2. When copyrighted materials are removed from the manuscript, a note ap­ pears to indicate this. 3. 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ColPh.D. 1985 University Microfilms International 300 N. Zeeb Road, Ann Arbor, Ml 48106 PLEASE NOTE: In all cases this material has been filmed in the best possible way from the available copy. Problems encountered with this document have been identified here with a check mark V . 1. Glossy photographs or pages ______ 2. Colored illustrations, paper or print ______ 3. Photographs with dark background _____ 4. Illustrations are poor copy ______ 5. Pages with black marks, not original copy ______ 6. Print shows through as there is text on both sides of page _______ 7. Indistinct, broken or small print on several pages V 8. Print exceeds margin requirements ______ 9. Tightly bound copy with print lost in spine_______ 10. Computer printout pages with indistinct print ______ 11. Page(s) ____________ lacking when material received, and not available from school or author. 12. Page(s) ____________ seem to be missing in numbering only as text follows. 13. Two pages numbered . Text follows. 14. Curling and wrinkled pages ______ 15. Dissertation contains pages with print at a slant, filmed as received • 16. Other________________________________________________________________________ University Microfilms International PRODUCTION AND NITROGEN DYNAMICS OF A VALLISNERIA americana GRASS BED IN LAKE PONTCHARTRAIN, LOUISIANA 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 Marine Sciences by Diana Lee Steller B.A., Cornell University, 1972 M.S., University of Florida, 1976 December 1985 ACKNOWLEDGEMENTS I"would like to thank each member of my committee for their time and cooperation. This work would not have been possible without their support. Funding for the field work came from the U. S. Army Corps of Engineers* New Orleans# Louisiana. Dr. James Stone was instrumental in arranging funding# student worker help* and equipment. 1 would like to thank the American Association of University Women for their fellowship which funded one year of this work. Financial support was also given by the Mathematics Department* L.S.U. and the Mathematics Departments of Southern University and Southeastern Louisiana University. Thanks go to the many tireless workers who helped in the fieldwork (B. Johnson, G. Happ# J. Day* L. Bahr* N. Walker* G. Rainey* T. Gayle* M. Casselman* G. Root* M. Fannally# R. Allen# D. Smith* K. Hoffman* A. Witzig* and A. Matherne) and particular thanks to Albert J. Meier whose presence was a constant joy and inspiration. Drs. J. Gosselink and W. Wiseman showed patience and persistence in reading and correcting this manuscript. TABLE OF CONTENTS I. CHAPTER 1 1 INTRODUCTION 1 1.0 ORIGIN OF LAKE PONTCHARTRAIN GRASSBEDS 4 1.1 GRASSBED DEVELOPMENT RELATED TO SAND BEACH TRENDS 6 1.2 GRASSBED DECLINE 7 1.3 REFERENCES CITED 9 II. CHAPTER 2 24 LITERATURE REVIEW 2.0 INTRODUCTION 24 2.1 PRODUCTIVITY AND DISTRIBUTION RELATED TO ENVIRONMENTAL FACTORS 25 2.1.1 Light 26 2.1.2 Temperature 29 2.1.3 Salinity 31 2.1.4 Currents and Wave Action 31 2.1.5 Sediment 32 2.2 LIMITING NUTRIENTS 32 2.2.1 Carbon 32 2.2.2 Nitrogen 33 2.2.3 Phosphorus 37 2.2.4 Techniques 37 2.3 DECOMPOSITION 39 2.4 COMMUNITY 41 2.5 HUMAN INFLUENCE 42 2.6 LITERATURE CITED 44 III. CHAPTER 3 55 PRODUCTION OF A SUBMERGED GRASS BED IN LAKE PONTCHARTRAIN, LOUISIANA, INCLUDING LITTERFALL AND DECOMPOSITION USING A HARVEST TECHNIQUE 55 ABSTRACT 55 3.0 INTRODUCTION 56 3.1 THE STUDY AREA 58 3.2 METHODS 58 3.2.1 Harvest Methods 61 3.2.2 Litter 62 3.2.3 Decomposition 63 3.2.4 Harvest Techniques and Calculations 64 3.2.4.1 Peak Standing Crop 64 3.2.4.2 Harvest 65 3.2.4.3 Harvest Plus Litterfall 65 3.2.4.4 Harvest Plus Litterfall Plus Decomposition 66 3.3 RESULTS 67 3.3.1 Biomass 67 3.3.1.1 Area Along the Shore Effects 69 3.3.1.2 Distance from Shore iii Effects 70 3.3*1.3 Area Times Distance Effects 71 3.3.2 Litter 71 3.3.3 Decomposition 73 3.3.4 Production 75 3.4 DISCUSSION 76 3.4.1 Biomass 76 3.4.2 Litter 77 3.4.3 Decomposition 78 3.4.4 Production 79 3.4.4.1 Methods 79 3.4.4.2 Value of Harvest Results 82 3.5 LITERATURE CITED 85 IV. CHAPTER 4 110 ENVIRONMENTAL AND PHENOLOGICAL CORRELATES OF GROWTH OF THE SEAGRASS Vallisneria americana IN LAKE PONTCHARTRAIN no ABSTRACT 110 4.0 INTRODUCTION 112 4.1 DESCRIPTION OF STUDY AREA U 4 4.2 METHODS 114 4.3 RESULTS 116 4.3.1 Biomass and Net Annual Production Patterns n 6 4.3.2 Environmental Parameters Related to Distance from Shore 117 4.3.3 Environmental Parameters Related to Season ng 4.3.4 Phenology of the Grass Bed 122 4.4 DISCUSSION 124 4.5 REFERENCES CITED 130 V. CHAPTER 5 I57 SIMULATED NITROGEN DYNAMICS DURING GROWTH AND DECOMPOSITION OF A SUBMERGED VALLISNERIA AMERICANA GRASS BED IN LAKE PONTCHARTRAIN, LOUISIANA 157 ABSTRACT I57 5.0 INTRODUCTION I 5 9 5.1 DESCRIPTION OF THE STUDY AREA AND GRASS BED ECOSYSTEM i5g 5 .2 MODEL DEVELOPMENT 1 6 0 5.2.1 Model Boundaries 151 5.2.2 Construction of the Conceptual Model 1 6 2 5.2.2.1 Forcing Functions 152 5.2.2•2 Growth 1 g 4 5.2.2.3 Decay 154 5.2.3 Construction of the Simulation Models 166 5.2.3.1 GROW 1 6 6 5.2.3.2 DECAY 171 iv 5.2.4 Initializing GROW and DECAY 176 5.2.4.1 GROW 176 5.2.4.2 DECAY 176 5.2.5 Calibrating GROW and DECAY 177 5.2.5.1 GROW 178 5.2.5.2 DECAY 181 5.3 RESULTS AND DISCUSSION 134 5.3.1 GROW: Leaf and Root and Rhizome Nitrogen Simulation 185 5.3.2 DECAY: Inorganic and Organic Water and Sediment Nitrogen Simulations 187 5.3.3 Sensitivity Analysis 190 5.3.3.1 GROW Sensitivity Analysis 191 5.3.3.2 DECAY Sensitivity Analysis 193 5.3.4 Validation of GROW 197 5.3.5 Prediction of the Vallisneria Grass Bed's Response to Different Sunlight Conditions 198 5.3.6 Conclusions 199 5.4 REFERENCES CITED 201 VI. CHAPTER 6 264 CONCLUSIONS AND RECOMMENDATIONS TO MANAGERS 264 6.0 SUMMARY OF RESULTS 264 6.1 RECOMMENDATIONS TO ECOSYSTEM MANAGERS 266 6.2 LITERATURE CITED 269 v LIST OF FIGURES Chaoter 1 Figure 1. The physiography of the Pontchartrain Basin (from Saucier, 1963). 13 Figure 2. Origin of the Milton's Island and the Pine Island beach trends (from Saucier, 1963). Figure 3. Distribution of sediment types in Lake Pontchartrain, La., as determined by Bahr, et al., (1980). 17 Figure 4. Comparison of the Milton's Island and Pine Island Beach Trends with the location of submerged grassbeds in Lake Pontchartrain, Louisiana. 19 Figure 5.