Plant Physiological Ecology

1. ASSUMPTIONS AND APPROACHES

Introduction-History, Assumptions, and Approaches

1   What is Ecophysiology?

2   The Roots of Ecophysiology

3   Physiological Ecology and the Distribution of Organisms

4   Time Scale of Plant Responses to Environment

5   Conceptual and Experimental Approaches

6   New Directions in Ecophysiology

7   The Structure of the Book

References

 

2. PHOTOSYNTHESIS, RESPIRATION, AND LONG-DISTANCE TRANSPORT

2A. PHOTOSYNTHESIS

1   Introduction

2   General Characteristics of the Photosynthetic Apparatus

2.1 The 'Light' and 'Dark' Reactions of Photosynthesis

2.2 Supply and Demand of CO₂ in the Photosynthetic Process

3   Response of Photosynthesis to Light

3.1 Characterization of the Light Climate under a Leaf Canopy

3.2 Physiological, Biochemical, and Anatomical Differences between Sun and Shade Leaves

3.3 Effects of Excess Irradiance

3.4 Responses to Variable Irradiance

4   Partitioning of the Products of Photosynthesis and Regulation by 'Feedback'

4.1 Partitioning within the Cell

4.2 Regulation of the Rate of Photosynthesis by Feedback

4.3 Sugar-induced Repression of Genes Encoding for Calvin-cycle Enzymes

4.4 Ecological impacts Mediated by Source-Sink Interactions

4.5 Petiole and Stem Photosynthesis

5   Responses to Availability of Water

5.1 Regulation of Stomatal Opening

5.2 The A-C_i Curve as Affected by Water Stress

5.3 Carbon isotope Discrimination in Relation to Water-use Efficiency

5.4 Other sources of Variation in Carbon isotope ratios in C₃ Plants

6   Effects of Nutrient Supply on Photosynthesis

6.1 The Photosynthesis-Nitrogen Relationship

6.2 Interactions of Nitrogen, Light and Water

6.3 Photosynthesis, Nitrogen, and Leaf Life Span

7   Photosynthesis and Leaf Temperature: Effects and Adaptations

7.1 Effects of High Temperatures on Photosynthesis

7.2 Effects of Low Temperatures on Photosynthesis

8   Effects of Air Pollutants on Photosynthesis

9   C₄ Plants

9.1 Introduction

9.2 Biochemical and Anatomical Aspects

9.3 Intercellular and Intracellular Transport of Metabolites of the C₄ Pathway

9.4 Photosynthetic Efficiency and Performance at High and Low Temperatures

9.5 C₃-C₄ Intermediates

9.6 Evolution and Distribution of C₄ species

9.7 Carbon isotope Composition of C₄ Species

9.8 Growth Rates of C₄ Species

10  CAM Plants

10.1    Introduction

10.2    Physiological, Biochemical and Anatomical Aspects

10.3    Water-use Efficiency

10.4    Incomplete and facultative CAM Plants

10.5    Distribution and Evolution of CAM Species

10.6    Carbon isotope Composition of CAM Species

11  Specialized Mechanisms Associated with Photosynthetic Carbon Acquisition in aquatic Plants

11.1    Introduction

11.2    The CO₂ Supply in Water

11.3    The Use of bicarbonate by aquatic Macrophytes

11.4    The Use of CO₂ from the Sediment

11.5    Crassulacean Acid Metabolism (CAM) in Water Plants

11.6    Variation in Carbon isotope Composition between Water Plants and between aquatic and Terrestrial Plants

11.7    The Role of aquatic Plants in Carbonate Sedimentation

12  Effects of the Rising CO₂ Concentration in the Atmosphere

12.1    Acclimation of Photosynthesis to Elevated CO₂ Concentrations

12.2    Effects of Elevated CO₂ on Transpiration Differential Effects on C₃, C₄ and CAM Plants

13  Summary: What Can We Gain from Basic Principles and Rates of Single-Leaf Photosynthesis?

References

Box 2A.1: Mathematical Description of the CO₂ Response and further Modeling of Photosynthesis

Box 2A.2: Fractionation of Stable Carbon isotopes in Plants

Box 2A.3: Carbon-fixation and Light-Absorption Profiles inside Leaves

Box 2A.4: Chlorophyll fluorescence

Box 2A.5: The Measurement of Gas Exchange

 

2B. RESPIRATION

1   Introduction

2   General Characteristics of the Respiratory System

2.1 The Respiratory Quotient

2.2 Glycolysis, the Pentose Phosphate Pathway, and the Tricarboxylic (TCA) Cycle

2.3 Mitochondrial Metabolism

2.4 A Summary of the Major Points of Control of Plant Respiration

2.5 ATP Production in isolated Mitochondria and in vivo

2.6 Regulation of the Partitioning of Electrons between the Cytochrome and the Alternative Paths

3   The Ecophysiological Function of the Alternative Path

3.1 Heat Production

3.2 Can we really Measure the Activity of the Alternative Path?

3.3 The Alternative Path as an Energy Overflow

3.4 NADH Oxidation in the Presence of a High Energy Charge

3.5 NADH Oxidation to Oxidize Excess Redox Equivalents from the Chloroplasts

3.6 Continuation of Respiration when the Activity of the Cytochrome Path is Restricted

3.7 A Summary of the Various Ecophysiological Roles of the Alternative Oxidase

4   Environmental Effects on Respiratory Processes

4.1 Flooded, Hypoxic, and anoxic Soils

4.2 Salinity and Water Stress

4.3 Nutrient Supply

4.4 Irradiance

4.5 Temperature

4.6 Low pH and High Aluminum Concentrations

4.7 Partial Pressures of CO₂

4.8 Effects of Nematodes and Plant Pathogens

4.9 Leaf Dark Respiration as Affected by Photosynthesis

5   The Role of Respiration in Plant Carbon Balance

5.1 Carbon Balance

5.2 Respiration Associated with Growth, Maintenance, and Ion Uptake

6   Plant Respiration: Why Should it Concern Us from an Ecological Point of View?

References

Box 2B.1  Measuring Oxygen-isotope fractionation in Respiration

2C. LONG DISTANCE TRANSPORT OF ASSIMILATES

1   Introduction

2   The Major Transport Compounds in the Phloem: why not Glucose?

3   Phloem Structure and Function

3.1 Symplastic and Apoplastic Transport

3.2 Minor Vein Anatomy

3.3 Phloem-Loading Mechanisms

3.4 Variation in Transport Capacity

4   Evolution and Ecology of Phloem Loading Mechanisms

5   Phloem Unloading

6   The Transport Problems of Climbing Plants

7   Phloem Transport: Where to Move from here?

References

 

3. PLANT WATER RELATIONS

1   Introduction

1.1 The Role of Water in Plant Functioning

1.2 Transpiration as an Inevitable Consequence of Photosynthesis

2   Water Potential

3   Water Availability in Soil

3.1 The field Capacity of Different Soils

3.2 Water Movement toward the Roots

3.3 Rooting Profiles as Dependent on Soil Moisture Content

3.4 Roots Sense Moisture Gradients and Grow toward Moist Patches

4   Water Relations of Cells

4.1 Osmotic Adjustment

4.2 Cell-Wall Elasticity

4.3 Osmotic and Elastic Adjustment as Alternative Strategies

4.4 Evolutionary Aspects

5   Water Movement through Plants

5.1 The Soil-Plant-Atmosphere Continuum

5.2 Water in Roots

5.3 Water in Stems

5.4 Water in Leaves and Water Loss from Leaves

5.5 Aquatic Angiosperms

6   Water-use Efficiency

6.1 Water-use efficiency and carbon-isotope discrimination

6.2 Leaf Traits That Affect Leaf Temperature and Leaf Water Loss

7   Water Availability and Growth

8   Adaptations to Drought

8.1 Desiccation-Avoidance: Annuals, Drought Deciduous Species

8.2 Desiccation-Tolerance: Evergreen Shrubs

8.3 'Resurrection Plants'

9   Winter Water Relations and Freezing Tolerance

10  Salt Tolerance

11 Final Remarks: The Message that Transpires

References

Box 3.1: The Water Potential of Osmotic Solutes and of the Air

Box 3.2: Positive and Negative Hydrostatic Pressures

Box 3.3: Oxygen and Hydrogen Stable isotopes

Box 3.4: Methods to Measure sap Flow in Intact Plants

 

4.  PLANT ENERGY BUDGETS: ENVIRONMENTAL EFFECTS

 

4A. THE PLANT'S ENERGY BALANCE

1   Introduction

2   Energy inputs and outputs

2.1 A Short Overview of a Leaf's Energy Balance

2.2 Short-wave Solar Radiation

2.3 Long-wave Terrestrial Radiation

2.4 Convective Heat Transfer

2.5 Evaporative Energy Exchange

2.6 Metabolic Heat Generation

3   Modeling the Effect of Components of the Energy Balance on Leaf Temperature

4.  A Global Perspective of Hot and Cool topics

References

 

4B. EFFECTS OF RADIATION AND TEMPERATURE LEVEL

1   Introduction

2   Radiation

2.1 Effects of Excess Irradiance

2.2 Effects of Ultraviolet Radiation

3   Effects of Extreme Temperatures

3.1 How Do Plants Avoid Damage by Free Radicals at Low Temperature?

3.2 Heat-shock Proteins

3.3 Are isoprene and Monoterpene Emissions an Adaptation to High Temperatures?

3.4 Chilling Injury and Chilling Tolerance

3.5 Carbohydrates and Proteins Conferring Frost Tolerance

4   Global Change and Future Crops

References

 

5. SCALING-UP GAS EXCHANGE AND ENERGY BALANCE FROM THE LEAF TO THE CANOPY LEVEL

1   Introduction

2   Canopy Water Loss

3   Canopy CO₂ Fluxes

4   Canopy Water-Use Efficiency

5   Canopy Effects on Microclimate: a Case Study

6   Aiming for a Higher Level

References

Box 5.1: Optimization of Nitrogen Allocation to Leaves in Plants Growing in Dense Canopies

 

6. MINERAL NUTRITION

1         Introduction

2   Acquisition of Nutrients

2.1 Nutrients in the Soil

2.2 Root Traits that Determine Nutrient Acquisition

2.3 Sensitivity Analysis of Parameters Involved in Phosphate Acquisition

3   Nutrient Acquisition from 'Toxic' or 'Extreme' Soils

3.1 Acid Soils

3.2 Calcareous Soils

3.3 Soils with High Levels of Heavy Metals

3.4 Saline Soils: an Ever-increasing Problem in Agriculture

3.5 Flooded Soils

4   Plant Nutrient-use Efficiency

4.1 Variation in Nutrient Concentration

4.3 Nutrient Loss from Plants

4.4 Ecosystem Nutrient-use Efficiency

5 Mineral Nutrition: as vast Array of Adaptations and Acclimations

References

Box 6.1:  Phosphorus Fractions in Leaves and Photosynthetic Phosphorus-Use Efficiency)

 

7. GROWTH AND ALLOCATION

1   Introduction: What is Growth?

2   Growth of Whole Plants and of Individual Organs

2.1 Growth of Whole Plants

2.2 Growth of Cells

3   The Physiological Basis of Variation in RGR Plants Grown with Free Access to Nutrients

3.1 SLA is a Major factor Associated with Variation in RGR

3.2 Leaf thickness and Leaf Mass Density

3.3 Anatomical and Chemical Differences Associated with Leaf-mass Density

3.4 Net Assimilation Rate, Photosynthesis, and Respiration

3.5 RGR and the Rate of Leaf Elongation and Leaf Appearance

3.6 RGR and Activities per Unit Mass

3.7 RGR and Suites of Plant Traits

4   Allocation to Storage

4.1 The Concept of Storage

4.2 Chemical Forms of Stores

4.3 Storage and Remobilization in Annuals

4.4 The Storage Strategy of biennials

4.5 Storage in Perennials

4.6 Costs of Growth and Storage: Optimization

5   Environmental Influences

5.1 Growth as Affected by Irradiance

5.2 Growth as Affected by Temperature

5.3      Growth as Affected by Soil Water Potential and Salinity

5.4 Growth at a Limiting Nutrient Supply

5.5 Plant Growth as Affected by Soil Compaction

5.6 Growth as Affected by Soil Flooding

5.7 Growth as Affected by Submergence

5.8 Growth as Affected by Touch and wind

5.9 Growth as Affected by Elevated Atmospheric CO₂ Concentrations

6   Adaptations Associated with Inherent Variation on Growth Rate

6.1 Fast growing and Slow growing Species

6.2 Growth of Inherently Fast and Slow growing Species under Resource-limited Conditions

6.3 Are there Ecological Advantages Associated with a High or Low RGR?

7   Growth and Allocation: the Message about Plant Messages

References

Box 7.1:         Phytohormones

Box 7.2:         Phytochrome

 

8. LIFE CYCLES: ENVIRONMENTAL INFLUENCES AND ADAPTATIONS

1   Introduction

2   Seed Dormancy, Quiescence, and Germination

2.1 Hard Seed Coats

2.2 Germination Inhibitors in the Seed

2.3 Effects of Nitrate

2.4 Other External Chemical signals

2.5 Effects of Light

2.6 Effects of Temperature

2.7 Physiological Aspects of Dormancy

2.8 Summary of Ecological Aspects of Seed Dormancy and Germination

3   Developmental Phases

3.1 Seedling Phase

3.2 Juvenile Phase

3.3 Reproductive Phase

3.4 Fruiting

3.5 Senescence

4   Seed Dispersal

4.1 Dispersal Mechanisms

4.2 Life-history Correlates

5   The Message to Disperse: Perception, Transduction and Response

References

 

9. BIOTIC INFLUENCES

 

9A. SYMBIOTIC ASSOCIATIONS

1   Introduction

2   Mycorrhizas

2.1 Mycorrhizal Structures: Are they Beneficial for Plant Growth?

2.3 Phosphate Relations

2.4 Effects on Nitrogen Nutrition Water Acquisition 

2.5 Role of Mycorrhizas in Defense

2.6 Carbon Costs of the Mycorrhizal Symbiosis

2.7 Agricultural and Ecological Perspectives

3   Associations with Nitrogen fixing Organisms

3.1 Symbiotic N₂ Fixation is Restricted to a fairly Limited number of Plant Species

3.2 Host-guest Specificity in the Legume-rhizobium Symbiosis

3.3 The Infection Process in the Legume-rhizobium Association

3.4 Nitrogenase Activity and Synthesis of Organic Nitrogen

3.5 Carbon and Energy Metabolism of the Nodules

3.6 Quantification of N₂ Fixation in situ

3.7 Ecological Aspects of the Symbiotic Association with N₂ Fixing Microorganisms that do not Involve Specialized Structures

3.8 Carbon Costs of the Legume-rhizobium Symbiosis

3.9 Suppression of the Legume-rhizobium Symbiosis at Low pH and in the Presence of a large Supply of Combined Nitrogen

4   Endosymbionts

5   Plant Life among Microsymbionts

References

 

9B. ECOLOGICAL BIOCHEMISTRY: ALLELOPATHY AND DEFENSE AGAINST HERBIVORES

1   Introduction

2   Allelopathy (interference Competition)

3   Chemical Defense Mechanisms

3.1 Defense against herbivores

3.2 Qualitative and Quantitative Defense Compounds

3.3 The Arms race of Plants and herbivores

3.4 How Do Plants Avoid being Killed by their own Poisons?

3.5 Secondary Metabolites for Medicines and Crop Protection

4   Environmental Effects on the Production of Secondary Plant Metabolites

4.1 Abiotic factors

4.2 Induced Defense and Communication between Neighboring Plants

4.3 Communication between Plants and their Bodyguards

5   The Costs of Chemical Defense

5.1 Diversion of Resources from Primary Growth

5.2 Strategies of Predators

5.3 Mutualistic Associations with ants

6   Detoxification of Xenobiotics by Plants: Phytoremediation

7   Secondary Chemicals and Messages that Emerge from this Chapter

References

 

9C. EFFECTS OF MICROBIAL PATHOGENS

1.    Introduction

2   Constitutive Antimicrobial Defense Compounds

3   The Plant's Response to Attack by Microorganisms

4   Cross-talk between Induced Systemic Resistance and Defense against herbivores

5   Messages from One Organism to Another

References

 

9D. PARASITIC ASSOCIATIONS

1   Introduction

2   Growth and Development

2.1      Seed Germination

2.2      Haustoria Formation

2.3      Effects of the Parasite on Host Development

3   Water Relations and Mineral Nutrition

4   Carbon Relations

5   What Can We Extract from this Chapter?

References

9E. INTERACTIONS AMONG PLANTS

1   Introduction

2   Theories of Competitive Mechanisms

3   How Do Plants Perceive the Presence of Neighbors?

4   Relationship of Plant Traits to Competitive ability

4.1 Growth Rate and Tissue Turnover

4.2 Allocation Pattern, Growth Form and Tissue Mass Density

4.3 Plasticity

5   Traits Associated with Competition for Specific Resources

5.1 Nutrients

5.2 Water

5.3 Light

5.4 Carbon Dioxide

6   Positive Interactions among Plants

6.1 Physical benefits

6.2 Nutritional benefits

6.3 Allelochemical benefits

7   Plant-microbial Symbiosis

8   Succession and Long-term Ecosystem Development

9   What Do We Gain from this Chapter?

Box 9E.1: Plant Ecology Strategy Schemes

References

9F. CARNIVORY

1. Introduction

2. Structures Associated with the Catching of the Prey and Subsequent Withdrawal of Nutrients from the Prey

3. Some Case Studies

3.1 Dionaea muscipula

3.2 The Suction Traps of Utricularia

3.3 The Tentacles of Drosera

3.4 Pitchers of Sarracenia

3.5 Passive Traps of Philcoxia

4. The Message to Catch

References

 

10. ROLE IN ECOSYSTEM AND GLOBAL PROCESSES

 

10A. DECOMPOSITION

1   Introduction

2   Litter Quality and Decomposition Rate

2.1 Species Effects on Litter Quality: Links with Ecological Strategy

2.2 Environmental Effects on Decomposition

3   The Link between Decomposition Rate and Nutrient Supply

3.1 The Process of Nutrient Release

3.2 Effects of Litter Quality on Mineralization

3.3 Root Exudation and Rhizosphere Effects

4   The End-product of Decomposition

References

 

10B. ECOSYSTEM AND GLOBAL PROCESSES: ECOPHYSIOLOGICAL CONTROLS

1   Introduction

2   Ecosystem Biomass and Production

2.1 Scaling from Plants to Ecosystems

2.2 Physiological Basis of Productivity

2.3 Disturbance and Succession

2.4 Photosynthesis and Absorbed Radiation

2.5 Net Carbon Balance of Ecosystems

2.6 The Global Carbon Cycle

3   Nutrient Cycling

3.1 Vegetation Controls over Nutrient Uptake and Loss

3.2 Vegetation Controls over Mineralization

4   Ecosystem Energy Exchange and the Hydrological Cycle

4.1 Vegetation Effects on Energy Exchange

4.2 Vegetation Effects on the Hydrological Cycle

5   Moving to a Higher Level:  Scaling from Physiology to the Globe

References

GLOSSARY

SUBJECT INDEX