Chapter 4 the Pine Forests*
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, .._1 Land Resource resources a '•A 'i-,*•''*$•:•'•• *v Land Resources Division, Ministry of Overseas Development Scanned from original by ISRIC - World Soil Information, as ICSU World Data Centre for Soils. The purpose is to make a safe depository for endangered documents and to make the accrued information available for consultation, following Fair Use^ Guidelines. Every effort is taken to respect Copyright of the materials within the archives where the identification of the Copyright holder is clear and, where feasible, to contact the originators. For questions please contact [email protected] Indicating the item reference number concerned. Land resources of the Bahamas: a summary 65^1- Land Resources Division Land resources of the Bahamas: a summary Little B G, Buckley D K, Cant R, Henry P W T, Jeff eriss A, Mather J D, Stark J and Young R N (with a contribution by W T Gillis) Land Resource Study 27 Land Resources Division, Ministry of Overseas Development, Tolworth Tower, Surbiton, Surrey, England KT6 7DY 1977 THE LAND RESOURCES DIVISION The Land Resources Division of the Ministry of Overseas Development assists developing countries in mapping, investigating and assessing land resources, and makes recommendations on the use of these resources for the development of agriculture, livestock husbandry and forestry; it also gives advice on related subjects to overseas governments and organisations, makes scientific personnel available for appointment abroad and provides lectures and training courses in the basic techniques of resource appraisal. The Division works in close cooperation with government departments, research institutes, universities and international organisations concerned with land resource assessment and development planning. IV Contents LIST OF TABLES vi LIST OF PLATES vii LIST OF FIGURES viii LIST OF TEXT MAPS viii LIST OF SEPARATE MAPS •* ABSTRACTS AND KEYWORDS xi GLOSSARY xvii PART1 INTRODUCTION 1 Preface 1 Acknowledgements 2 Origin of project 2 Programme 2 Team composition 3 Reader's guide to the text 3 PART 2 NATURAL RESOURCES Chapter 1 Regions 7 Chapter 2 Climate 9 Chapter 3 Biogeography*and vegetation 13 Chapter 4 Pine forests 23 Chapter 5 Groundwater 33 Chapter 6 Rocks and landforms 45 •Contributed byWT Gillis V Chapter 7 Soils 53 Chapter 8 Rocks and soils of the pine-covered areas 59 Chapter 9 Shorelines 69 PART 3 PEOPLE AND THE LAND Chapter 10 Population, wealth and economic activity 75 Chapter 11 Communications 81 Chapter 12 Land tenure 83 Chapter 13 Land use 87 Chapter 14 Land capability 101 PART 4 RECOMMENDATIONS Chapter 15 General recommendations 109 Chapter 16 Recommendations for large scale groundwater abstraction 113 PART 5 REFERENCES 117 APPENDiX Methods used in the survey 121 LIST OF TABLES 1. Rainfall statistics presented by island 10 2. Incidence of hurricanes in the Bahamas 11 3. Monthly variation in temperature extremes 11 4. Location of forest areas on Crown land in Abaco 26 5. Location of forest areas on Crown land in And ros 26 6. Stocking of regeneration areas in Abaco 27 7. The relationship of lithofacies with texture and primary structure groups 60 8. Characteristics of some lithofacies 60 9. The distribution of private land, Crown land and commonage 84 10. The land capability legend applicable to Abaco 102 11. The original land capability legend modified for use in Exuma and Long Island 104 12. A scheme for zoning land for the purposes of regional planning 104 VI 13. Lithofacies general types, their colloquial names and typical capability class 106 14. Should boreholes or trenches be used for a water supply? 113 15. Rainfall and recommended abstraction rates for years of average precipitation 114 16. Example of a completed pump test form and contract borehole record 125 LIST OF PLATES 1. A section of tall coppice land (Vegetation Community 9) exposed by development near Crossing Rocks Settlement, Abaco 18 2. One of several distinctive vegetation communities on uncemented deposits in Inagua 18 3. View from the coastal sand ridge (with Vegetation Community 2c) over a hypersaline pond or lagoon 19 4. Bulldozed third-order forest tracks prior to felling of the trees 19 5. Haitian forest workers cutting and stacking billets of pine. North Andros 1973 25 6. Mortality of pine seed-trees affected by bark beetle and weevil infestation after the 1962 hurricane and subsequently by fire in South Abaco 25 7. A circular bluehole 450 ft wide and 125 ft deep within a marsh area of Andros 39 8. A section of coastal terrace composed of cemented coral rubble, Mayaguana 39 9. Marshes near a creek called Wide Opening in western North Andros 47 10. Beach ridges near the sea and a low dune (adjacent to the pond) form the Greenwood Barrier in south-east Cat Island 47 11. Panoramic view near Salt Pond, Long Island 49 12. The north part of saline Cormorant Pond seen from Wemyss Bight, Old Estate House, Long Island 49 13. Newly prepared 'man made' soils with a crop of maize at Mount Thompson, Exuma 56 14. Two distinct styles of weathering seen in a road cut in the Norman Castle area, Abaco 55 15. Bedded, low-fissility, very muddy grainstone with rare burrows 62 16. Slightly grainy mudstone with moderate or good texture contrast and therefore susceptible to weathering 62 17. Shoreline and offshore details on a high quality vertical airphoto of High Rick Village, Grand Bahama 70 VII 18. Coral reef, well developed lagoon and hypersaline ponds behind a narrow zone of sand along the windward shore of North Acklins 71 19. Scenic coast: cliffs and a coastal bluehole with corals 71 20. Children with their father, Mayaguana 77 21. Many children from the family islands come to Nassau for their secondary education 77 22. Sheep penned in a feed-lot, North Eleuthera 92 23. Low-investment land use: ripped high watertable rockland less many of its larger blocks which have been carried off the field or crushed 92 24. Traditional farmers from Andros discussing with Bahamian project staff the advantages of modern, irrigated vegetable-growing techniques at the BARTAD project 95 25. Establishment of a row of young avocado pear trees in Class 2, Tillage rockland, at the BARTAD project, North Andros 95 26. An imported breed of cattle from Texas grazing in carefully prepared paddocks at the BARTAD project, North Andros 96 27. Owens Town, now dismantled, as it was in 1971 96 28. Typical arrangement of equipment and instruments for testing low specific capacity boreholes; a low-capacity pump, a water level indicator and a conductivity probe suspended over a tripod 128 29. View of the equipment used for conductivity logging 128 LIST OF FIGURES 1. Typical results obtained in the groundwater exploration 37 2. Generalised geological section through Bahama Bank marine sequence 40 3. Lithofacies types and corresponding ground surfaces, BARTAD project, North Andros 63 4. A guide to correct spacing of supply wells and safe abstraction rates in a wellfield in which individual wells penetrate 10 feet into the water and drawdown never exceeds 1/10 foot 115 5. Flow diagram showing the process of groundwater investigation 122 6. Example of pump test results showing drawdown superimposed on the effect of a rising tide at hole GB 45, Grand Bahama 126 LIST OF TEXT MAPS 1. Landform origins illustrated from the Wemyss Bight area, Long Island 43 2. An example of lithofacies mapping from the BARTAD project, North Andros 67 VIII LIST OF SEPARATE MAPS (in map pocket inside the rear cover) 1. Population, economic activities and annual money income (1:1 000 000) 2. Land capability (1:1 000 000) ix Abstracts and keywords ABSTRACT The report summarises eight earlier reports, each of which described one or two major islands in the Bahamas. The text is divided into four main parts: Introduction; Natural resources; People and the land; and Recommendations. These are subdivided into Chapters. A confidential annex contains recommendations for each main island. The report is accompanied by three maps: Population (1:1 000 000),Land capability (1:500 000) and Groundwater (1:500 000). Part 2, Natural resources, summarises the Survey's work and findings on the environ ment, and outlines the physiographic and planning regions. In Chapter 1, regions are defined mainly by reference to rainfall, vegetation type and depositional regimes, past and present. The planning regions recognised in practice by the Bahamian authorities are also explained. Chapter 2 briefly describes the marine tropical climate and relates it to vegetational differences. Chapter 3 reviews the biogeography and vegetation of the islands. Though having a broad regional similarity, each island has its own characteristics, the Crooked Island Passage acting as a major biogeographic boundary within the region. The vegetation communities of Abaco and Eleuthera are outlined, these being typical examples of a pine island and a coppice island, the two major vegetation types. Land developers are cautioned not to destroy vegetation, particularly in the semi-arid south. Chapter 4 summarises a survey of the pine forests by Henry (1974). It deals particularly with the description of the forest vegetation, the location of land suitable for forestry, stocking conditions, growth rates, exploitation and the future development programme. The importance of the Bahamian forests and their potential for rapid growth are emphasised. Chapter 5 introduces the subject of groundwater. It describes how freshwater occurs as a 'lens' within the limestones and the factors which affect the capacity and extent of different lenses. It is underlined that scientific investigation of wellfields is of relatively recent origin and that compre hensive monitoring of extraction has yet to begin. Chapter 6 discusses the relationship between rocks and landforms. Chapter 7 reviews soils and emphasises that Bahamian soils, though in many cases productive, are poor by world standards.