COMMERCIAL WILDFLOWER PRODUCTION IN THE FYNBOS BIOME AND ITS ROLE IN THE MANAGEMENT OF LAND-USE BY GEORGE WILLIAM DAVIS A THESIS PRESENTED FOR THE DEGREE OF DOCTOR OF PHILOSOPHY IN THE DEPARTMENT OF BOTANY FACULTY OF SCIENCE UNIVERSITY OF CAPE TOWN FEBRUARY 1990 University of Cape Town The copyright of this thesis vests in the author. No quotation from it or information derived from it is to be published without full acknowledgement of the source. The thesis is to be used for private study or non- commercial research purposes only. Published by the University of Cape Town (UCT) in terms of the non-exclusive license granted to UCT by the author. University of Cape Town To the spirit ofjustice, peace, and co-operation which must prevail for conservation of a viable human environment in South Africa ABSTRACT The wildflower industry of the Cape, South Africa, utilizes ecosystems and vegetation of the Fynbos Biome either directly by harvesting of natural plant populations, or indirectly by land transformation for agro-horticultural production. This thesis reports on a study of conservation and management issues arising from: (a) direct veld-harvesting; and (b) primary annexation of land for controlled production of material. A review of the industry's structure and the controlling legislation, indicated a need for integration of current management strategies. A potential means of anticipating population degradation and local extinction of plant species through over-utilization was investigated by construction of a computer model. Lack of data describing the flow of material and revenue was highlighted as an impediment to resource management by means if modelling. Experimental work investigated the effects of marginal cultivation on mountain fynbos ecosystems as utilized by the industry. Work was conducted at a site in the Highlands Forest Reserve in the south-western Cape. This experimental system was cleared by burning, and tilled as if for commercial production. Disturbance effects on system parameters were monitored. These included energy and water regimes, aspects of community structure, plant growth, and water relations of the natural vegetation. Results showed that tillage altered the system during the dry summer months by increasing reflectivity of the soil surface to solar radiation, reducing soil temperatures, and increasing soil water content. Response of the vegetation included reduction of species richness and diversity, a reduction in projected foliar cover, and an increase in the productivity of some, but not all, of the naturally occurring dominant species. Two commercially favoured species of Protea were also introduced to the site. Survival and productivity of these populations were monitored as responses to substrate disturbance. Results showed that the treatment was significantly associated with better survival for P. cynaroides, but better productivity for P. repens. A concluding review suggests that there are general paradigmatic blocks between the economic and ecological facets of natural resource utilization which prevent implementation of optimal environmental management strategies. The wildflower industry is nominated as a small bridge for that gap. i CAPTIONS TO PHOTOGRAPHS IN FRONTISPIECE 1. Flowers and foliage of the "greens" species Erica longifo/ia are harvested from the veld in the south- west.em Cape (see Chapter 1) · 2. Protea species growing under orchard cultivation in the south-west.em Cape (see Chapter 1) 3. Protea repens inflorescences for sale at a street market in Cape.Town (see Chapter 1) 4. Strip tillage for cultivation of proteaceous floricultural material on a farm near Kleinmond, south­ west.em Cape. This is the same approach as adopted for the experimental work described in Chapters 4 to 7 S. Clearing vegetation at the Highlands study site by fire prior to experimental work (see Chapters 4 to 7) 6. Mature vegetation at the Highlands study site prior to clearing, with the yellow leaves of Leucadendron xanthoconus visible in the foreground (Chapter 3) 7. The Highlands study site following tillage by rotavation, with planted Protea cynaroides visible on the tilled soil at the right (see Chapters 4 to 7) TABLE OF CONTENTS ABSTRACT ............................................................................................................................ .i TABLE OF CONTENTS ..................................................................................................... iv LIST OF FIGURES ........................................................................................................... viii LIST OF TABLES ................................................................................................................. x PREFACE .............................................................................................................................. xi ACKNOWLEDGEMENTS ............................................................................................. xiii GUIDE TO READING THIS THESIS ........................................................................... xv SUMMARY ....................................................................................................................... xvii CHAPTER 1 THE COMMERCIAL WILDFLOWER INDUSTRY IN. THE FYNBOS BIOME ........................................................................................................... 1 A MOTIVATION FOR ACTION .......................................................................... 1 HISTORY AND DEVELOPMENT OF THE WILDFLOWER INDUSTRY .......................................................................................................... 3 Structure of the industry ............................................................................... 4 The volume and content ............................................................................... 6 Conduits and controls ................................................................................. 10 MANAGING RESOURCES ................................................................................ 21 Theoretical considerations ......................................................................... 21 The broader perspective ............................................................................. 22 Resolving conflicts of interest. ................................................................... 23 Models and guides ....................................................................................... 24 Fynbos wildflower resource management ............................................... 25 A FOOTNOTE ON SCIENTISTS ....................................................................... 26 CHAPTER 2 PREDICTING JEOPARDY TO FYNBOS PLANT POPULATIONS EXPLOITED BY THE WILDFLOWER INDUSTRY .......... 27 INTRODUCTION ................................................................................................. 27 MODELLING APPROACH ........................................................................... 28 STRUCTURE OF THE MODEL........................................................................ 31 Phenology submode! ................................................................................... 31 Life cycle submodel ..................................................................................... 32 Response to pruning submode! ................................................................. 33 Population response submodel .................................................................. 33 The combined production component ..................................................... 34 The market demand submodel .................................................................. 34 General operation ....................................................................................... 34 Selection of species .................................................................................... 37 Verification and validation ........................................................................ 41 A SAMPLE RUN - RESULTS ............................................................................. 41 Input data ...................................................................................................... 41 Output. ........................................................................................................... 42 DISCUSSION ........................................................................................................... 49 CONCLUSION ........................................................................................................ 51 iv CHAPTER 3 DESCRIPTION OF THE HIGHLANDS EXPERIMENTAL SITE USED FOR SIMULATION OF MARGINAL CULTIVATION OF TECHNIQUES EMPLOYED BY THE WILDFLOWER INDUSTRY ............ 53 INTRODUCTION.................................................................................................. 53 The study site ................................................................................................ 54 METHODS ............................................................................................................... 54 Development of the study site ................................................................... 54 Climatic data ................................................................................................ 54 The ve~etation .............................................................................................. 55 The SOil. .........................................................................................................55