Photosynthetic Rate and Dynamic Environment

Photosynthetic Rate and Dynamic Environment

Photosynthetic Rate and Dynamic Environment by Kazutoshi Yabuki Professor Emeritus, Osaka Prefecture University, Sakai, Japan SPRINGER-SCIENCE+BUSINESS MEDIA, B.V.

A C.I.P. Catalogue record for this book is available from the Library of Congress. ISBN 978-90-481-6530-8 ISBN 978-94-017-2640-5 (ebook) DOI 10.1007/978-94-017-2640-5 Printed on acid-free paper All Rights Reserved 2004 Springer Science+ Business Media Dordrecht Originally published by Kluwer Academic Publishers in 2004 No part of this work may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, microfilming, recording or otherwise, without written permission from the Publisher, with the exception of any material supplied specifically for the purpose of being entered and executed on a computer system, for exclusive use by the purchaser of the work.

v Contents Preface ix I. A Closer Look at Wind Bibliography 6 II. C0 2 Exchange between the Air and the Leaf C0 2 Diffusive Resistance Theory and Leaf Boundary Layer Resistance Structure of the Leaf Boundary Layer 1. Analysis of the leaf boundary layer with a schlieren optical system a. Schlieren optical system b. Method of determining the boundary layer thickness c. Boundary layers of cucumber and cabbage leaves 2. Wind speed distribution in the leaf boundary layer a. Breeze tunnel b. Wind speed distribution in the leaf boundary layer (1) When a leaf surface is parallel to the main flow (2) When a leaf has attached angle to wind direction at its leading edge Near-surface Airflow 19 1. Visual identification of water flow in the water channel 19 2. Boundary layer of the model leaf parallel to the laminar flow 21 3. Boundary layer of the model leaf with an attack angle to the laminar flow 22 4. Boundary layer of the model leaf freely vibrating in the turbulent flow 24 a. Method of measurement 25 b. Method of analyzing photographs 25 c. Boundary layer of the freely vibrating model leaf 26 d. Free vibrations of model leaves with an attack angle 28 e. Change of shape of the boundary layer of the freely vibrating model leaf 30 f. Vibration of the model leaf and state of the boundary layer 31 g. Relationship between boundary layer thickness and the diffusive resistance value 32 h. C0 2 diffusive resistance value of the boundary layer and photosynthetic rate 33 Bibliography 35 7 7 9 10 10 10 11 15 15 16

Vl ill. Photosynthetic Rate in the Aspects of the Leaf Boundary Layer A. Demonstration of the Significance of the Leaf Boundary Layer 1. Diffusive resistance value rb 2. Stomatal resistance valuers and mesophyll resistance value rm 3. Calculation of the photosynthetic rate B. Measurement of the Effect of a Wind on the Photosynthetic Rate Using a Wind Tunnel for Plant Growth 1. The wind tunnel for plant growth 2. Photosynthetic rate of a cucumber leaf and wind speed 3. Effect of wind speed and humidity on the photosynthetic rate 4. Effect of wind speed and light intensity on the photosynthetic rate 5. Leaf shape and photosynthetic rate a. Leaf length (characteristic length) and photosynthetic rate b. Photosynthetic rates of the leaves with the same area but different widths c. Characteristic length/leaf area of each of four different crops and the photosynthetic rate d. High-yield variety of lowland rice with narrow leaf width C. Attack Angle and Photosynthetic Rate 1. Attack angle and photosynthetic rate 2. Attack angle and dry matter production or NAR D. Leaf Vibration and Photosynthetic Rate E. Distribution of photosynthetic rate on the leaf surface 1. Method of measuring the vertical distribution of photosynthetic rate on the leaf surface 2. Distribution of photosynthetic rate on the leaf surface a. In a calm wind b. When the leaves are fixed at a zero degree attack angle to the laminar flow c. When the leaves are fixed at± 15 and ± 30 attack angles to the laminar flow d. When the leaves are fixed at ± 60 attack angles to the laminar flow e. When the leaves vibrate in a turbulent flow Bibliography 37 37 37 38 39 40 40 41 42 46 47 47 47 50 51 52 52 53 54 56 56 58 58 59 60 62 63 65 IV. Photosynthetic Rate of a Plant Community and Wind Speed A. Methods of Measuring the Photosynthetic Rate of a Plant Community 1. Aerodynamic method 67 67 68

vii 2. Heat balance method 72 3. Method of measuring soil respiration rate 73 B. Photosynthetic Rate of a Paddy Field in Japan 74 1. Photosynthetic rate of a lowland rice community (paddy field) and changes in its growth process 74 2. Relationship between the photosynthetic rate of a lowland rice community and wind speed 76 C. Photosynthetic Rates of Five Different Vegetative Patterns in Thailand 79 1. Introduction 79 2. Climates in the measurement areas 80 a. Vegetation (1) Tropical dry evergreen forest 80 (2) Sugarcane (Saccharum officinarum L.) 80 (3) Lowland rice (Oryza sativa L.) 80 (4) Oil palm (Elaeis guinensis Jacq.) 80 (5) Mangrove forest 80 b. Climate in Thailand 81 3. Methods of measuring the photosynthetic rates of plant communities 82 4. Photosynthetic rates of five plant communities in their natural environments 82 a. Tropical dry evergreen forest 82 (1) Photosynthetic rate during the wet season 82 (2) Photosynthetic rate during the dry season 85 b. Sugarcane field 87 c. Paddy field 91 d. Oil palm field 94 e. Mangrove forest 97 5. Vegetative variation and photosynthetic rate of a plant community 100 6. Conclusion 103 Bibliography I 04 V. Gas Exchange between the Pneumatophores and Roots of Mangroves by 105 Photosynthesis of Pneumatophore A. Pneumatophores with Chlorophyll 106 B. Pneumatophore Variation and Gas Exchange with the Roots 108 C. Gas Exchange between the Pneumatophores and Roots in a Growing Field 111 1. Measurements of photosynthetic and respiration rates of pneumatophores 1 1 2 2. 0 2 diffusion from the pneumatophore to the root 113

viii D. Relationship between the Variety of Pneumatophores and the Tidal Level 115 E. Mechanism of Gas Exchange between Pneumatophores and the Roots Active Transport across a Membranous Structure of the Pneumatophore 116 F. Experimental Planting of Mangrove 116 Conclusion 120 Bibliography 120 Index 123

ix Preface The association between plants and wind that first comes to mind might be plant damage from a strong wind such as a typhoon or monsoon. The winds this book will discuss, however, are not this strong at all, but rather are only 2 m s 1 or weaker, like a breeze that gently blows over a farming area. Such a breeze, in fact, instills vitality into plants and increases their growth rates. This book is an attempt to explain these beneficial effects on plants from a field perspective. One fundamental process necessary for plant growth is photosynthesis. Since it is a photochemical reaction, this synthesis has been studied with emphasis on light. Yet to shed light on dry-matter or carbohydrate production by plants, it is indispensable to pursue research not only into the mechanism of photosynthesis but also into photosynthetic production itself. I have observed various phenomena occurring in the production field, and have thereby realized it necessary to recognize photosynthesis as a phenomenon that carbon dioxide (C0 2) in the air diffuses into chloroplasts in the leaves, and to study which environmental factors promote C02 diffusion into the leaves. In this book, I am going to describe the effects of the natural environment on photosynthetic production, placing focus on the leaf boundary layer as an environmental factor for plant production. As a wind blows, the air becomes viscous through friction with the leaf surface, creating a layer along the surface with a lower-velocity airflow. This air layer, termed the "leaf boundary layer, has great effect on the amount of atmospheric C02 diffusion into the leaf (photosynthetic production), as well as on the rate of transpiration or heat transmission. In this respect, the layer is a dominant element of plant dry-matter production. The adoption of the boundary layer as a factor for C02 diffusion into the leaf has enabled quantitative analysis into a variety of phenomena, and new suggestions of dry-matter production. Atmospheric C0 2 diffuses into chloroplasts through physically and chemically diverse organs and substances, all of which act to resist C0 2 diffusion. Compared to electrical currents, the amount of C0 2 diffusion (photosynthetic production) is proportional to the difference in C02 concentration between the air and the chloroplast, while being inversely proportional to the resistance values. This idea is the so-called "diffusive resistance theory" first advanced in 1900 by Brown and Escombe. Further research was conducted by Penman and Schofield (1951), and Gaastra (1959), who all presented several resistances. In addition, there have been many treatises and books published on wind or diffusive resistance in relation to

X plants and photosynthesis. Among them, Grace's Plant Response to Wind (1977) provides further details on this subject. This selection of my readings will provide: (I) a background to why I adopted the leaf boundary layer as a resistance to C0 2 diffusion; (II) the details of the structure of the layer disclosed by a series of experiments; and (III) the relationships discovered between the layer of each type and its photosynthetic rate. The book will then describe about (IV) various phenomena observed in relation to wind by measuring aerodynamically the photosynthetic rate of the plant community in the natural environment, and will conclude with (V) another perspective on photosynthesis, different from that found in the previous chapters. The last chapter will discuss the research project that I conducted on a type of mangrove with chlorophyll in their pneumatophores. The research discovered that photosynthesis in the pneumatophores produces oxygen (02) that is transported to the roots for respiration. This kind of photosynthesis was found to be considerably different from the previously believed method of dry-matter production. It was also disclosed that the pneumatophore exchange gases with the roots in a complicated mechanism involving active transport across a membranous structure of aerenchyma. I decided to include an additional chapter in the book to explain the specificity of this type of photosynthesis. The book is a comprehensive compilation of studies that I have pursued since 1961. It can therefore be called a history of my research including the concepts, experiments, and observations that have supported my studies along the way. During my career, I could not have conducted such studies without cooperation and support from many fellow researchers and assistants. I wish to take this opportunity to thank all of them for their help. Their names are omitted here but will be listed in the papers contained in the book. I owe deep appreciation to Dr. S. Suzuki, Dr. Y. Mihara, Dr. R. Yakuwa, Dr. H. Nishiuchi, Dr. T. Kira, Dr. T. Imazu, and Dr. J. Sugi, who have all provided me with invaluable guidance since I first started treading the path of agricultural science. I also offer great thanks to Dr. Sanga Sabhasri, Dr. Watna Stienswat, Dr. Kasem Chunkao, and Dr. Vipak Jintana for graciously extending use of their various facilities and cooperation when I worked on a research project in Thailand. Also, I am sincerely grateful to Mrs. T. Sakurai for her 20-year cooperation in filing documents and papers for me. Finally, I owe deep appreciation to Dr. T. Kozai for his great efforts to edit this book, and to Mr. Y. Ohmura and Ms. H. Toida for his technical help to edit the book. K.Yabuki, Sakai, Japan, September 25, 2003