Studies on Plant Demography

Transcription

1 Studies on Plant Demography A Festschrift for John L. Harper EDITED BY JAMES WHITE Department of Botany University College Dublin, Ireland 1985 ACADEMIC PRESS Harcourt Brace Jovanovich, Publishers London Orlando San Diego New York Austin Montreal Sydney Tokyo Toronto

2 Contents Contributors Foreword Preface Profile of John L. Harper Scientific Publications of John L. Harper xiii xv xvii xix xxvi I Dynamics and Evolution of Plant Populations in Natural or Seminatural Environments 1. Past, Present and Future: Studies on the Population Dynamics of Some Long-lived Trees John Ogden I. Introduction 3 II. Some Methodological Considerations 4 III. Some Examples 5 IV. Conclusion, 14 References \ Plant Demography: A Community-level Interpretation Jose Sarukhdn, Daniel Pinero and Miguel Martinez-Ramos. I. Introduction 17 II. Plant Demography and the Study of Mosaic Regeneration in Tropical Forests 18 III. Determination of Forest Turnover Rates 22 IV. The Study of the Dynamics of Forest Structure and Composition 23

3 vi Contents V. The Influence of Astrocaryum mexicanum on Forest Diversity 26 VI. Concluding Remarks 29 References Fires and Emus: The Population Ecology of Some Woody Plants in Arid Australia James C. Noble I. Introduction II. The Species and Their Distribution III. Phenology and Reproductive Biology IV. Seed Dispersal and Establishment Biology V. Mallee Coppice Dynamics VI. Concluding Remarks References Differences in Life Histories between Two Ecotypes of Plantago lanceolata L. J. M van Groenendael I. Introduction 51 II. The Differences in Life Histories of Ecotypes 52 III. Tests of Life History Hypotheses 58 IV. Concluding Remarks 64 References Variation and Differentiation in Populations of Trifolium repens in Permanent Pastures Roy Turkington I. Introduction 69 II. Population Differentiation 70 III. Population Variation 76 References 80

4 Contents.- vii 6. Disasters and Catastrophes in Populations of Halimione portulacoides Ad H. L. Huiskes and Atie W. Stienstra I. Introduction 83 II. Materials and Methods 85 III. Results 86 IV. Discussion 90 References Establishment and Peri-establishment Mortality Robert E. L. Naylor I. Introduction 95 II. The Safe Site 96 III. Filling Safe Sites with Seeds 103 IV. Microsite Survival 103 V. Loading the Dice 105 References Population Biology and the Conservation of Rare Species H. J. Harvey I. II. III. IV. Conservation and Demography Demographic Studies Involving Small or Declining Populations Some Generalisations \ Conclusions References II Biology of Invasive and Weedy Species 9. Invading Plants: Their Potential Contribution to Population Biology Richard N. Mack I. Introduction 127

5 viii Contents II. Invaders and the Estimation of Population Parameters III. The Spread of Aliens IV. Invasion and Disturbance V. Competition VI. Extinction VII. Invaders and Future Emphasis in Population Biology References J Proso Millet (Panicum miliaceum L.): A Crop and a Weed Paul B. Cavers and Marguerite A. Bough I. Introduction 143 II. Proso Millet 143 III. Crop and Weed Races 146 IV. Discussion 153 References Population Dynamics of a Few Exotic Weeds in North-east India R. 5. Tripathi I. Introduction 157 II. Exotic Weeds in North-east India 157 III. Population Dynamics of Eupatorium spp. 158 IV. Population Dynamics of Galinsoga spp. 163 V. Conclusion \ 169 References Weeds and Agriculture: A Question of Balance B. R. Trenbath I. Introduction 171 II. Forest Species in a Swidden System 172 III. Tree Species in a Grazing System 175 IV. Annual Grasses and Alternate Husbandry 179 V. Conclusions 181 References 182

6 Contents IX III The Demographic Interpretation of Plant Form: Application to Plant Competition and Production 13. On the Astogeny of Six-cornered Clones: An Aspect of Modular Construction A. D. Bell I. Modular Construction 188 II. Astogeny and Patterns of Growth 189 III. Solitary Patterns: The Effect of Angle 193 IV. Neighbours 196 V. Age 201 VI. Conclusion 205 References The Importance of Plant Form as a Determining Factor in Competition and Habitat Exploitation Peter H. Lovell and Patricia J. Lovell I. The Plant in Its Environment 209 II. Different Forms 211 III. The Prostrate Habit 213 References Modular Demography and Form in Silver Birch Michelle Jones \ I. Introduction 223 II. The Demography of Form in Silver Birch 225 III. Conclusions 235 References Modular Demography and Growth Patterns of Two Annual Weeds (Chenopodium album L. and Spergula arvensis L.) in Relation to Flowering I^ucie Maillette I. Introduction 239

7 Contents II. Experimental Procedure 240 III. Results 242 IV. Discussion 249 V. Conclusions 252 References A Modular Approach to Tree Production Miguel Franco I. Modular Construction and the Growth of Trees 257 II. Definition of Concepts 258 III. A Simple Model of Mass Accumulation 259 IV. Test of the Model Using Forestry Data 262 References 270 IV Plant Interference: The Effects of Neighbours 18. Plant Responses to Crowding A. R. Watkinson I. Introduction 275 II. Yield Density Relationships in Monoculture 275 III. Size Hierarchy Development 277 References The Thinning Rule and Its Application to Mixtures of Plant Populations James White I. Introduction 291 II. Thinning in Single-species Populations 293 III. Thinning in Mixed-species Populations 298 IV. Conclusion 306 References 306

8 Contents ' xi V The Influence of Pathogens.and Predators on Plant Populations 20. Pathogens and the Genetic Structure of Plant Populations J. J. Burdon I. Introduction 313 II. Pathogens as Selective Agents 314 III. Conclusion 323 References Sex Ratios, Clonal Growth and Herbivory in Rumex acetosella Jon Lovett Doust and Lesley Lovett Doust I. Introduction 327 II. Methods 329 III. Results 331 IV. Discussion 336 References The Role of the Grazing Animal Rodolfo Dirzo I. Introduction 343 II. The Effects of Grazing on Plant Performance in a Local Population 344 III. Grazing and Plant Diversity \ 349 IV. Herbivory and Plant Succession 351 V. Conclusion 353 References 353 VI Plant Reproductive Biology 23. Islands and Dioecism: Insights from the Reproductive Ecology of Pandanus tectorius in Polynesia Paul Alan Cox I. The Colonization of Islands by Dioecious Plants 359

9 xii Contents II. The Reproductive Ecology of Pandanus tectorius 362 III. Discussion 370 References The Meaning and Measurement of Reproductive Effort in Plants F. A. Bazzaz and E. G. Reekie I. Introduction 373 II. Carbon Allocation to Reproduction 375 III. Effect of Reproduction on Vegetative Activity 383 References 386 Index 389