Environmental Plant Physiology Botanical Strategies for a Climate Smart Planet

Magnitude and quality of life as well as sustainable human progress inescapably depend on the state of our environment. The environment, in essence, is a common resource of all the living organisms in the biosphere as well as a vivacious basis of the evolution of life on Earth. A sustainable future broods over a sustainable environment?an environment encompassing life-originating, life-supporting, and life-sustaining uniqueness. A deteriorating environment haplessly sets in appalling conditions leading to shrinkage of life and a halt in human progress. The current global environment scenario is extremely dismal. Environmental disruptions, largely owing to anthropogenic activities, are steadily leading to awful climate change. Horribly advancing toward mass extinction in the near or distant future and posing a threat to our Living Planet, the unabatedly ongoing climate change, in fact, is an unprecedented issue of human concern about life in the recorded human history.

How to get rid of the environmental mess and resolve environmental issues leading to climate change mitigation is the foremost challenge facing humanity in our times. There are several measures the whole world is resorting to. They are primarily focused on cutting down excessive carbon emissions by means of development of technological alternatives, for example, increasing mechanical efficiencies and ever-more dependence on clean-energy sources. These are of great importance, but there is yet a natural phenomenon that has been, and will unceasingly be, pivotal to maintain climate order of the Earth. For it to phenomenally boost, we need to explore deeper aspects of environmental science. It is the environmental plant physiology that links us with deeper roots of life.

Environmental Plant Physiology: Botanical Strategies for a Climate-Smart Planet attempts to assimilate a relatively new subject that helps us understand the very phenomenon of life that persists in the planet?s environment and depends on, and is influenced by, a specific set of operating environmental factors. It is the subject that helps us understand adaptation mechanisms within a variety of habitats as well as the implications of the alterations of environmental factors on the inhabiting organisms, their populations, and communities. Further, this book can also be of vital importance for policy makers and organizations dealing with climate-related issues and committed to the cause of the earth. This book can be instrumental in formulating strategies that can lead us to a climate-smart planet.

Features:

? Provides ecological basis of environmental plant physiology

? Discusses energy, nutrient, water, temperature, allelochemical, and altitude relations of plants

? Reviews stress physiology of plants and plants? adaptations to the changing climate

? Examines climate-change effects on plant physiology

? Elucidates evolving botanical strategies for a climate-smart planet

Contents

Preface...............................................................................................................................................xi

Acknowledgments .......................................................................................................................... xiii

Author ..............................................................................................................................................xv

Chapter 1 Environment and Ecosystems: Physiological Basis of Ecology ...................................1

The Lumenosphere .......................................................................................................1

The Biosphere ...............................................................................................................2

The Organism-Environment Relationships ..................................................................3

Energy and Nutrient Flows through Ecosystems ....................................................4

Food Chains .............................................................................................................5

Food Web .................................................................................................................6

Ecological Pyramids ................................................................................................7

Ecological Pyramid of Numbers ........................................................................7

Ecological Pyramid of Biomass .........................................................................8

Ecological Pyramid of Energy ...........................................................................9

The Sixth Trophic Level ........................................................................................ 10

The Seventh Trophic Level .................................................................................... 10

What Is Environmental Physiology? .......................................................................... 11

Climate and Its Changing Behavior ........................................................................... 12

Scope of Environmental Plant Physiology ................................................................. 13

Applications in Food Production ........................................................................... 13

Environmental Physiology: The Basis for a Climate-Smart Planet ........................... 14

Summary .................................................................................................................... 17

References .................................................................................................................. 18

Websites ...................................................................................................................... 18

Chapter 2 Energy Relations ........................................................................................................ 19

Energy and Life .......................................................................................................... 19

Trophic Diversity in Nature ........................................................................................ 19

The Light of Life ........................................................................................................20

Leaf and Light ............................................................................................................ 21

Leaf-Energy Balance .............................................................................................22

Energy Inputs and Energy Outputs of a Leaf ...................................................24

Net Radiation ....................................................................................................24

Sensible Heat Loss (Conduction and Convection) ............................................25

Latent and Chemical Energy ............................................................................25

Photosynthetic Pathways ............................................................................................26

C3 Photosynthesis ..................................................................................................27

C4 Photosynthesis ..................................................................................................28

CAM Photosynthesis .............................................................................................29

E = mc2 in the Context of Earth’s Ecosystems...........................................................30

Sun–Soil–Plant: The Evolutionary Ladder of Life .................................................... 31

Photosynthesis and Soil Fertilization .................................................................... 32

Energy from Inorganic Molecules ............................................................................. 33

Energy from Organic Molecules ................................................................................ 35

Chemical Composition vis-à-vis Nutrient Requirements ...................................... 35

Herbivory ...............................................................................................................36

Carnivory ...............................................................................................................36

Detritivory ............................................................................................................. 37

Energy Limitations .....................................................................................................38

Optimal Foraging by Animals ..............................................................................38

Optimal Foraging by Plants................................................................................... 39

Energy Flow in the Biosphere .................................................................................... 39

Summary .................................................................................................................... 41

References .................................................................................................................. 42

Websites ...................................................................................................................... 43

Chapter 3 Nutrient Relations ....................................................................................................... 45

The Pedosphere .......................................................................................................... 45

Soil as an Ecosystem .................................................................................................. 45

Diversity of the World’s Soils .....................................................................................46

Soil Types .............................................................................................................. 47

Soil Biodiversity .................................................................................................... 47

Pedodiversity–Biodiversity Relations ....................................................................48

Essential Elements ......................................................................................................49

Sources of Plant Nutrients ..........................................................................................50

Nutrient Availability for Plants .................................................................................. 51

Interactions among Ions ............................................................................................. 51

Cycles in the Soil ........................................................................................................ 53

Ion-Uptake Physiology ...............................................................................................54

Kinetics ..................................................................................................................54

Internal Control ..................................................................................................... 58

Morphological Responses .......................................................................................... 59

Root:Shoot Ratio and Root:Weight Ratio .............................................................. 59

Root Diameter and Root Hairs ..............................................................................60

Root Density and Distribution ...............................................................................60

Soil Microorganisms .................................................................................................. 61

Rhizosphere ........................................................................................................... 61

Impact on Nutrient Uptake .................................................................................... 62

Nitrogen Fixation ................................................................................................... 62

Influence of Environmental Factors ......................................................................63

Mycorrhizas ...........................................................................................................64

Summary ....................................................................................................................65

References ..................................................................................................................66

Websites ...................................................................................................................... 67

Chapter 4 Water Relations ..........................................................................................................69

The Water Planet as Home to Life .............................................................................69

Water Properties Conducive to Life ...........................................................................69

Water Availability to Organisms ................................................................................ 70

Water in Air ........................................................................................................... 70

Water Movement within Water .............................................................................. 71

Water Potential ........................................................................................................... 72

Plant Roots and Water Acquisition............................................................................. 74

Water Relations of Plant Cells .................................................................................... 75

Supply of Water by the Soil ........................................................................................ 76

Water Planet a Climate-Smart Planet.........................................................................77

Summary .................................................................................................................... 78

References .................................................................................................................. 79

Websites ...................................................................................................................... 79

Chapter 5 Temperature Relations ................................................................................................ 81

Microclimatic Variations and Temperatures .............................................................. 81

Atmospheric Trends vis-à-vis Altitudes ..................................................................... 81

Troposphere ...........................................................................................................84

Stratosphere ...........................................................................................................85

Mesosphere ............................................................................................................86

Thermosphere ........................................................................................................86

Exosphere ..............................................................................................................87

Plant–Temperature Relations ......................................................................................87

Ground Color and Temperatures ................................................................................88

Vegetation and Temperatures .....................................................................................88

Slope Aspects and Temperatures ...............................................................................89

Aquatic Environments’ Temperatures ........................................................................89

Photosynthesis in Extreme Temperatures ..................................................................90

Solar Energy–Temperature Interaction ...................................................................... 91

Temperature Regulation by Plants ............................................................................. 91

Arctic and Alpine Plants ....................................................................................... 91

Tropical Alpine Plants ...........................................................................................93

Desert Plants ..........................................................................................................94

Temperature Regulation by Thermogenic Plants ..................................................94

Adaptation to Harsh Environments ............................................................................96

Physiological Strategies for Cooling the Earth ..........................................................97

Summary ....................................................................................................................99

References ................................................................................................................ 100

Websites .................................................................................................................... 101

Chapter 6 Allelochemical Relations ......................................................................................... 103

Competition among Plants ....................................................................................... 103

Defining Competition .......................................................................................... 103

Competition within Plant Populations ................................................................. 104

Asymmetric Competition .................................................................................... 104

Interspecific Competition: Mixed-Species Analysis ........................................... 105

Allelopathy ............................................................................................................... 105

Chemical Interactions among Plants ........................................................................ 106

Nature of Allelopathy ............................................................................................... 107

Allelopathic Plants ................................................................................................... 107

Allelopathy Applications in Agriculture .................................................................. 109

Cropping Systems’ Management ......................................................................... 109

Mulching for Weed Control ................................................................................. 109

Ecologically Healthy Agrochemicals and Microbial Pesticides ......................... 110

Breeding the Allelopathic Cultivars .................................................................... 110

Reducing NO3 Leaching and N2O Pollution........................................................ 111

Allelopathic Mechanisms ......................................................................................... 111

Effect on Soil Ecology ......................................................................................... 111

Effect on Photosynthesis ..................................................................................... 111

Effect on Respiration ........................................................................................... 112

Effect on Enzyme Functions ............................................................................... 113

Influence on Plant-Growth Regulator System ..................................................... 113

Effect on Antioxidant System .............................................................................. 114

Effect on Protein and Nucleic-Acid Synthesis .................................................... 114

Effect on Water and Nutrient Uptake .................................................................. 114

Effect on Cell Division and Elongation ............................................................... 114

Phytosociology for a Greener Planet ........................................................................ 117

Summary .................................................................................................................. 118

References ................................................................................................................ 119

Websites .................................................................................................................... 120

Chapter 7 High-Altitude Physiology ......................................................................................... 121

Altitude Types from Sea Level ................................................................................. 121

High-Altitude Specificities ....................................................................................... 122

Diverse Ecological Niches ................................................................................... 122

Biodiversity .......................................................................................................... 123

Fragility ............................................................................................................... 123

Adaptation Mechanisms ...................................................................................... 125

Marginality .......................................................................................................... 125

Poor Accessibility ................................................................................................ 126

High-Altitude Plant Ecology .................................................................................... 126

Effects of Altitudes on the Physiology of the Plants ................................................ 128

Photosynthesis ..................................................................................................... 128

Respiration ........................................................................................................... 130

Transpiration ........................................................................................................ 130

Chlorophyll Destruction ...................................................................................... 131

Resistance to Ultraviolet Radiation ..................................................................... 131

Frost Resistance ................................................................................................... 132

Water Balance and Avoidance of Desiccation ..................................................... 132

Growth and Development .................................................................................... 133

High Altitudes: Cooling Breeze for Cooling the Mainstream World ...................... 134

Summary .................................................................................................................. 135

References ................................................................................................................ 137

Websites .................................................................................................................... 138

Chapter 8 Stress Physiology ...................................................................................................... 139

Stress to Life as an Inevitable Phenomenon ............................................................. 139

Solar-Radiation Stress .............................................................................................. 140

Temperature Stress ................................................................................................... 141

Effects on Photosynthesis and Respiration.......................................................... 141

Effect on Membranes and Enzymes .................................................................... 141

Effects of Freezing Temperatures........................................................................ 142

Stress of Oxygen Deficiency .................................................................................... 142

Molecular Genetics Aspects of Oxygen-Deficiency Stress ................................. 143

Root Damage in Anoxic Environments ............................................................... 144

Effect of Anoxia-Damaged Roots on Shoots ...................................................... 145

Synthesis of Anaerobic Stress Proteins ............................................................... 145

Salinity Stress ........................................................................................................... 145

Effect on Photosynthesis and Growth ................................................................. 146

Osmotic and Specific Ion Effects ........................................................................ 147

Plants’ Strategies of Saline Stress Management ................................................. 147

Heat Stress ................................................................................................................ 148

Water Deficit and Heat Stress .............................................................................. 148

Effect on Photosynthesis and Respiration ........................................................... 148

Effect on Cell Membrane .................................................................................... 149

Adaptation Mechanisms against Heat Stress ...................................................... 149

Low-Temperature Stress ........................................................................................... 150

Chilling Effects on Cell Membrane .................................................................... 150

Tolerance to Cold Stress ...................................................................................... 151

Pollution Stress on Ecosystems ................................................................................ 153

Heavy-Metal Stress .................................................................................................. 154

Reactive Oxygen Species ..................................................................................... 154

Inactivation of Biomolecules ............................................................................... 155

Primary Stress ..................................................................................................... 155

Secondary Stress ................................................................................................. 155

Signal Transduction ............................................................................................. 155

Effects on Cellular Components .......................................................................... 155

Heavy-Metal Detoxification Methods ................................................................. 155

Vacuolar Compartmentalization.......................................................................... 157

Pollution Stress Impacts on Ecological Processes ................................................... 157

Water Stress .............................................................................................................. 158

The Etiology of Water Stress ............................................................................... 159

Multidimensional Nature of Water Stress ........................................................... 159

Morphological, Anatomical, and Cytological Changes ................................. 160

Photosynthesis ................................................................................................ 160

Protein Synthesis ............................................................................................ 161

Proline Accumulation ..................................................................................... 161

Lipids .............................................................................................................. 162

Mineral Nutrition ............................................................................................ 162

Abscisic Acid Accumulation .......................................................................... 162

Oxidative Stress .............................................................................................. 162

Summary .................................................................................................................. 163

References ................................................................................................................ 164

Websites .................................................................................................................... 166

Chapter 9 Physiological Effects of Climate Change ................................................................. 167

Living in an Age of Climate Change ....................................................................... 167

The Factors Affecting the Earth’s Climate .............................................................. 168

Enhanced Greenhouse Effect ................................................................................... 169

Overriding the Earth’s Potencies .............................................................................. 171

Impact of Climate Change on Plant Physiology ...................................................... 173

Microevolutionary Responses of Plant Physiology to Climate Change .............. 175

Phenotypic Plasticity ...................................................................................... 176

Adaptive Evolution ......................................................................................... 176

Gene Flows ..................................................................................................... 176

Macroevolutionary Responses of Plant Physiology to Climate Change ............. 177

Species Interactions and the Evolution of Plant Physiology in Response to

Climate Change ........................................................................................................ 179

Effects of Climate Change on Forest Ecosystems ................................................... 180

Forest Productivity .............................................................................................. 180

Forest Distribution ............................................................................................... 181

Forest Ecosystem Disturbances ........................................................................... 181

Forest Pests .......................................................................................................... 182

Impact on Forest Community .............................................................................. 182

Climate Change and Agriculture ............................................................................. 183

Coping with Climate Change ................................................................................... 189

Preparedness ........................................................................................................ 189

Adaptation ........................................................................................................... 190

Mitigation ............................................................................................................ 190

Climate-Smart Planet: A Sustainable Planet ........................................................... 191

Ecological Integrity and Ecological Security ...................................................... 191

Living Soil to Nurture the Roots of Life ............................................................. 192

Forests for a Healthy, Vibrant, and Sustainable Planet ....................................... 193

Climate-Smart Agriculture ...................................................................................... 196

Why an Agroecosystem Approach to Food Production? .................................... 197

Agroecology: The Philosophy of Food Production ............................................. 198

Enhanced Biodiversity Complexity ................................................................ 199

Treating Soil as an Ecosystem ........................................................................ 199

Maintaining Cyclic Flows of Nutrients .......................................................... 199

Vegetarianism: The Philosophy of Earth-Caring Nutrition ..................................... 201

Summary ..................................................................................................................203

References ................................................................................................................204

Websites ....................................................................................................................207

Index ..............................................................................................................................................209

Dr. Vir Singh is Professor of Environmental Science at GB Pant University of Agriculture & Technology. He has more than three decades' experience of teaching and research in forest ecology, environmental science, agroecology, animal sciences, environmental physiology, and natural resources management. Holding triple Masters (M.Sc. Botany, M.Sc. Ag. Animal Nutrition, and M.A. Sociology) and dual Ph.D. degrees (Botany with specialization in Ecology, and Animal Sciences), he has been educated and trained in many universities and institutes: Meerut University (now Chaudhary Charan Singh University), GB Pant University of Agriculture & Technology, HNB Garhwal University, Indira Gandhi National Open University (IGNOU), MP Bhoj (O) University, and Galilee College in Israel (now GIMI, Israel). He has been a Research Fellow at International Centre for Integrated Mountain development (ICIMOD) based in Kathmandu and participated in courses in Geoinformatics at Friedrich Schiller University (FSU) based in Jena, Germany. He has worked on many projects in collaboration with international institutes including ICIMOD, ILRI and the INNO-ASIA project sponsored by the German Federal Ministry BMBF. He has conducted several national and international conferences, symposia and workshops. He has published several books, including recently in limelight, Fertilizing the Universe, and more than 200 research articles and book chapters. Prof. Vir Singh is also a Climate Reality Leader committed to creating awareness about the on-going climate change and its long-term implications on every walk of life and is also formulating programmes and projects for climate change mitigation.