Louisiana State University LSU Digital Commons LSU Historical Dissertations and Theses Graduate School 1994 Physiological Variation in Loblolly Pine (Pinus Taeda L.) as Related to Crown Position and Stand Density. Dennis Albert Gravatt Louisiana State University and Agricultural & Mechanical College Follow this and additional works at: https://digitalcommons.lsu.edu/gradschool_disstheses Recommended Citation Gravatt, Dennis Albert, "Physiological Variation in Loblolly Pine (Pinus Taeda L.) as Related to Crown Position and Stand Density." (1994). LSU Historical Dissertations and Theses. 5873. https://digitalcommons.lsu.edu/gradschool_disstheses/5873 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]. 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Each original is also photographed in one exposure and is included in reduced form at the back of the book. Photographs included in the original manuscript have been reproduced xerographically in this copy. Higher quality 6” x 9" black and white photographic prints are available for any photographs or illustrations appearing in this copy for an additional charge. Contact UMI directly to order. A Bell & Howell Information Company 300 North Zeeb Road. Ann Arbor. Ml 48106-1346 USA 313/761-4700 800/521-0600 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. PHYSIOLOGICAL VARIATION IN LOBLOLLY PINE (Pinus taeda L.) AS RELATED TO CROWN POSITION AND STAND DENSITY 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 School of Forestry, Wildlife, and Fisheries by Dennis A. Gravatt B.S., University of Kansas, 1988 M.A., University of Kansas, 1991 December 1994 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. DMI Number: 9524453 UMI Microform Edition 9524453 Copyright 1995, by UMI Company. All rights reserved. This microform edition is protected against unauthorized copying under Title 17, United States Code. UMI 300 North Zeeb Road Ann Arbor, MI 48103 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. ACKNOWLEDGMENTS I wish to thank a number of people who contributed to this dissertation and played an important role in my completion of a doctoral degree. Several people provided the muscles needed for the erection of the steel towers and walk-ways on the study site. Dr. Suresh Guddanti engineered, installed and maintained the access towers and data acquisition system with the help of Jim Scarborough and the Johnson Tract Crew. Mark Hebert was greatly appreciated for his field assistance and acting as an outstanding "go-fer", the least of which was to go for another Rolling Rock. Consultations with Drs. Vemon Wright and David C. Blouin assisted me in the correct decisions regarding experimental design and analysis of the mountain of data from the field experiments. I would like to thank my committee members for their efforts and support: Dr. Quang V. Cao, Dr. Sam E. Feagley, Dr. Thomas J. Dean, Dr. Reza S. Pezeshki and Dr. James P. Barnett. I am grateful to my major advisor, Dr. Jim L. Chambers, for accepting me as his student, and allowing me to pursue my research as an independent scientist. A big thank you goes to my past and present office mates: Bill Patterson, Michelle Imbalzano, Jim Allen and Jian Sun. Thanks goes also to Karen Velupillai for her continuous laughter and harassment of Jim Chambers; she acted as a great diversionary tactic. ii Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. I am most grateful to Dr. Stanley B. Carpenter and the faculty/staff in the School of Forestry, Wildlife, and Fisheries at L.S.U. A special thank you to the Gilbert Foundation Fellowship for their financial support throughout my degree program. I want to express my greatest thanks to my family and friends for their support during this often difficult time. Especially Mary, Steve and Sarah Bowen for a sanctuary in which to hide during the home-stretch of my dissertation. A big thank you to Dr. Craig E. Martin and Valerie S. Loeschen, University of Kansas (Go Jayhawks !), for the much needed comaraderie and vacation spot in Germany during the writing of my dissertation. A very special thank you goes to my best friend and kindred spirit, Patti Faulkner, who listened tirelessly to me complain. I will always be thankful for her immeasurable support and understanding. A final thank you goes to my wife Patti. Without her support and understanding I would never have embarked on such a journey, nor would I have succeeded. Finally, a particular note of thanks to my parents, Albert and Helen Gravatt. My parents supported my educational pursuits, especially in biology, since I was old enough to remember. I will always remember, and keep the same sense of wonderment, about the world around me, that my parents first introduced me to while on childhood camping trips. I dedicate this dissertation to their memory. "I am glad I did it. Partly because it was well worth it, but chiefly because I shall never have to do it again" Mark Twain 111 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. TABLE OF CONTENTS ACKNOWLEDGMENTS .......................................................................................................ii ABSTRACT ..............................................................................................................................v INTRODUCTION .................................................................................................................... 1 CHAPTER 1. LITERATURE REVIEW ............................................................................. 5 CHAPTER 2. PHYSIOLOGICAL RESPONSE OF TWELVE-YEAR-OLD LOBLOLLY PINE STANDS FIVE YEARS AFTER THINNING . 31 CHAPTER 3. PHYSIOLOGY AND MORPHOLOGY OF BRANCHES WITH A NORTHERN OR SOUTHERN EXPOSURE IN LOBLOLLY PINE STANDS ................................................................... 67 CHAPTER 4. EFFECTS OF CROWN POSITION, STAND DENSITY AND FERTILIZATION ON TEMPORAL AND SPATIAL VARIATION IN FOLIAR NUTRIENT CONCENTRATIONS AND CHLOROPHYLL LEVELS ......................................................................97 CHAPTER 5. FOLIAR LIGHT RESPONSE CURVE ANALYSIS...........................134 CHAPTER 6. OVERALL CONCLUSIONS .............................................................. 163 BIBLIOGRAPHY............................................................................................................... 170 APPENDIXES A. SITEMAP ........................................................................................................ 182 B. NORTH - SOUTH PARAMETER MEANS ............................................ 183 C. CHLOROPHYLL EXTRACTION (DMF) PROCEDURE........................ 192 VITA ............................................................................. 194 iv Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. ABSTRACT Physiological parameters were measured under natural light conditions and needle orientation from towers and walkways erected in the crowns of loblolly pine {Pinus taeda L.) trees. Photosynthetic light response curves, chlorophyll content, nutrient content and specific leaf area were determined for current-year foliage on detached branches. Two silvicultural treatments were randomly assigned to the twelve plots in the fall of 1988. Plots were thinned to a density of 731 trees per hectare or left unthinned, at a density of 2990 trees per hectare. The plots were left unfertilized or fertilized with 744 kg per hectare of diammonium triple superphosphate was applied. During the fifth growing season (1993) following thinning, light levels were greater in the thinned, fertilized plots than in the unthinned, fertilized plots. However, no effect of thinning on canopy light levels was found in the unfertilized plots. Needle level physiology was not different with respect to thinning treatment for fertilized or unfertilized plots. In contrast, upper crown levels within the fertilized and unfertilized