Durham E-Theses Biology of Prosopis cineraria (Leguminosae) in the Sultanate of Oman Brown, Kevin How to cite: Brown, Kevin (1991) Biology of Prosopis cineraria (Leguminosae) in the Sultanate of Oman, Durham theses, Durham University. Available at Durham E-Theses Online: http://etheses.dur.ac.uk/10282/ Use policy The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that: • a full bibliographic reference is made to the original source • a link is made to the metadata record in Durham E-Theses • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders. Please consult the full Durham E-Theses policy for further details. Academic Support Oce, Durham University, University Oce, Old Elvet, Durham DH1 3HP e-mail: [email protected] Tel: +44 0191 334 6107 http://etheses.dur.ac.uk 2 The copyright of this thesis rests with the author. No quotation from it should be published without his prior written consent and information derived from it should be acknowledged. BIOLOGY OF PROSOPIS CINERARIA (LEGUMINOSAE) IN THE SULTANATE OF OMAN KEVIN BROWN Submitted in fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY University of Durham, Department of Biological Sciences. March, 1991. 1 MAY 1992 For Charlie, Mick, Karin and Kara DECLARATION The material contained in this thesis has been produced only by the author, and has not previously been submitted in any form for a degree in this or any other university. The copyright of this thesis rests with the author. No quotation from it should be published without his prior written consent and information derived from it should be acknowledged. ABSTRACT This thesis presents the results of a four year study from 1986 to 1990 on the biology of the leguminous tree Prosopis cineraria (L.) Druce in the Sharqiya region of the Sultanate of Oman. Descriptive studies were performed on both the woodland habitat and the species. The suitability and methodology of utilising P.cineraria in future forestry programmes in Oman were also examined. Field studies have shown that this drought-tolerant indigenous phreatophyte forms large mono-culture relic woodlands in the sandy deserts of the Shargiya. It is well adapted to the harsh environment of shifting sand dunes, growing vegetatively through accumulated sand to form tree clumps. Ecological studies have shown that the Prosopis woodland micro-environment supports wildlife not necessarily adapted to arid conditions. P.cineraria is an excellent multi-purpose tree for local people, particularly in providing fodder, fuelwood and shade protection. Over- exploitation and the general absence of natural reproductive regeneration has resulted in the decline in the condition of some Prosopis woodlands in Oman. To ensure their continued survival several methods of conservation were recommended. Studies on the mature trees have shown that the morphological variability of this species in the Sharqiya was high, which contributed to its multi-purpose potential. This variability was both phenotypic and genotype in origin. Glasshouse trials of P.cineraria in Durham have shown that seeds sampled from individual trees produced seedlings that were morphologically variable and were particularly tolerant to high salinities. Variation in morphology and salinity tolerance were related to both their geographical and parental origin. Three P.cineraria field trials in Oman have shown that the climate and soil environment greatly affected seedling growth and morphology. Silvicultural recommendations derived from these trials have been proposed for the propagation of this species in Oman. I CONTENTS ABSTRACT I CONTENTS II ACKNOWLEDGMENTS V LIST OF ABBREVIATIONS VII CHAPTER 1: GENERAL INTRODUCTION 1 CHAPTER 2: GENERAL MATERIALS AND METHODS 11 2.1 Navigation in the field 11 2.2 Seed sampling strategies 12 2.3 In situ plots of seedling regeneration 12 2.4 Assessment of genetic variation 13 2.5 Soil analysis 16 2.6 Seed extraction from pods 18 2.7 Seed germination 19 2.8 Sowing seeds 19 2.9 Seed moisture content determination 19 2.10 Seedling harvests 20 2.11 Leaf area determination 20 2.12 Quantitative analysis of plant growth 21 2.13 Statistical and computational methods 22 CHAPTER 3: HABITAT DESCRIPTION OF THE PROSOPIS 24 WOODLANDS 3.1 Introduction 24 3.2 Materials and methods 29 3.2.1 Field methods 29 3.2.2 Tree density and basal area determination 31 3.2.3 Understorey vegetation description and ordination 31 3.3 Results and discussion 34 3.3.1 Description of woodland study areas 34 3.3.2 Woodland structure and tree distribution 38 3.3.3 Prosopis woodland soils 50 3.3.4 Woodland flora 63 3.3.5 Woodland fauna 75 3.3.6 Woodland resources and their exploitation 86 3.4 Conclusions and recommendations 89 II CHAPTER 4: MORPHOLOGICAL DESCRIPTION OF MATURE 93 P.CINERARIA 4.1 Introduction 93 4.2 Materials and methods 97 4.2.1 Tree mensuration 97 4.3 Results and discussion 99 4.3.1 Field classification of tree morphology 99 4.3.2 Morphometric analysis of P.cineraria 105 4.3.3 Inter-provenance classification of tree morphology 109 4.3.4 Intra-provenance classification of tree morphology 116 4.3.5 Multi-purpose properties of classified trees 124 4.3.6 Morpho-geographical influences on seed regeneration and infestation 126 4.4 Conclusions and recommendations 130 CHAPTER 5: PROPAGATION, GROWTH AND MORPHOLOGY OF 135 P.CINERARIA SEEDLINGS 5.1 Introduction 135 5.2 Materials and methods 140 5.2.1 Seed morphology 140 5.2.2 Seed storage viability 141 5.2.3 Preparation of glasshouse trials in Durham, U.K. 143 5.2.4 Glasshouse accession trial 144 5.2.5 Glasshouse salinity trial 144 5.2.6 Seedling morphology 146 5.3 Results and discussion 147 5.3.1 P.cineraria seeds and seedlot accessions from Oman 147 5.3.2 Factors affecting natural seedling establishment 157 5.3.3 Glasshouse accession trial of P.cineraria 162 5.3.4 Salinity trial of P.cineraria 176 5.3.5 Quantitative analysis of glasshouse grown seedlings 192 5.4 Conclusions and recommendations 196 III CHAPTER 6: SEEDLING FIELD TRIALS OF P.CINERARIA 200 IN OMAN 6.1 Introduction 200 6.2 Materials and methods 206 6.2.1 Preparation of field trials 206 6.2.2 Seedling preparation 211 6.2.3 Environmental assessment 212 6.2.4 Seedling harvests 213 6.2.5 Seedling morphology 214 6.3 Results and discussion 215 PART 1: ASSESSMENT OF THE TRIAL AND SOIL ENVIRONMENT 215 6.3.1 Environmental variation between trials 215 6.3.2 Physical differences between soil types 218 6.3.3 Chemical differences between soil types 220 PART 2: ENVIRONMENTAL EFFECTS ON SEEDLING GROWTH 223 (SQU-1 & AL-K) 6.3.4 Statistical analysis of data 223 6.3.5 Seedling size 227 6.3.6 Seedling morphology 237 PART 3: SHADE EFFECTS ON SEEDLING GROWTH 248 (SQU-1 & SQU-2) 6.3.7 Statistical analysis of data 248 6.3.8 Seedling size 251 6.3.9 Seedling morphology 258 PART 4: DEVELOPMENTAL VARIATION IN SEEDLING GROWTH 266 (13 & 34 WEEKS) 6.3.10 Statistical analysis of data 266 6.3.11 Developmental variation between 13 & 34 week old seedlings 267 6.3.12 Environmental effects on developmental variation 273 6.4 Conclusions and recommendations 280 6.4.1 Trial effects 280 6.4.2 Soil type effects 282 6.4.3 Soil supplement effects 283 IV CHAPTER 7: GENERAL CONCLUSIONS AND RECOMMENDATIONS 289 7.1 Summary conclusions 289 7.1.1 The woodland habitat 289 7.1.2 The mature trees 293 7.1.3 Seeds and seedling establishment 295 7.1.4 Glasshouse trials in Durham 297 7.1.5 Field trials in Oman 298 7.1.6 Comparisons of seedling growth in Durham and Oman 303 7.2 Recommendations 30 4 7.2.1 Conservation and research 304 7.2.2 SiIvicultural methods 307 7.3 Future of P.cinci aria in Oman 3*ul> REFERENCES 311 APPENDICES 327 A. Prosopis cineraria slide reference collection 327 B. Botanical names of Prosopis species used in the text 331 C. Prosopis cineraria seed data bank 332 D. Statistical summary of data not presented in Chapters 3, 4, 5 and 6 336 E. Well water data from bore holes in the Central Prosopi s Zone 343 ACKNOWLEDGEMENTS I would first like to express my thanks to His Majesty Sultan Qaboos bin Said for giving permission for me to work in the Sultanate of Oman. I would also like to thank Ralph Daly, Conservation Advisor, Diwan of Royal Court, Oman, for funding and sponsorship, and Dr. Roderic Dutton and the Centre for Overseas Research and Development, Durham, U.K., for administrational support throughout the duration of my stay in Oman. I would like to thank Dr. Phil Gates for his supervision of this work, and to Dr. Michael Bradbury for his enthusiasm and constructive comments during the preparation of this thesis. In the U.K., I would like to thank: Nigel de N. Winser and the Royal Geographical Society for the opportunity to V participate in the Oman Wahiba Sands Project; and the staff of the Department of Biological Sciences, University of Durham for advice and for looking after plant material. In Oman, I would like to thank: His Excellency Mohammad Abdulla Al-Hinai, Minister of Agriculture and Fisheries, for providing materials, land, labour, accommodation, transport and climatological data; His Excellency Yahya Mahfoud Al-Manthery, Acting Vice Chancellor of Sultan Qaboos University for accommodation and use of laboratory and computer facilities; the Sultan's Armed Forces for logistical support during the first four months field work; Andrew Pearce of George Dew Ltd.