Notes on the Silviculture of Major N.S.W. Forest Types - No. 11 Rainforest Types NOTES ON THE SILVICULTURE OF MAJOR N.S.W. FOREST TYPES 11. RAINFOREST TYPES Contents Page 1. Introduction 4 2. Forest Ecology and Botany 5 2.1 Features of Rainforest 5 2.1.1 Life-Forms 5 2.1.2 Structure 6 2.1.3 Disturbed Patches 12 2.2 Floristics 13 2.3 Rainforest Types 14 2.4 Environmental Factors 15 2.4.1 General Comment 15 2.4.2 Climate 15 2.4.3 Microclimate 17 2.4.4 Soil 18 2.4.5 Topography 20 2.4.6 Fire 20 2.5 Other Ecological Effects 21 2.6 Relationships with other Communities 22 3. Occurrence and Distribution. 23 4. Values and Utilisation 27 5. History of Use and Management 29 5.1 Prehistory 29 5.2 Aboriginal Use 29 5.3 Early European Use 30 5.4 Recent Use 32 6. Natural Regeneration 38 6.1 Sources of Regeneration 38 6.2 Flowering and Fruiting 40 6.3 Germination and Establishment 42 6.3.1 Patterns of Seedling Establishment 42 6.3.2 Species with Short Viability Seed 43 6.3.3 Soil Seed Bank Species 45 6.3.4 Seed establishing in Low Light Intensities 46 6.4 Natural Regeneration 47 6.4.1 Reprise 47 6.4.2 Undisturbed Patch 47 6.4.3 Gap Phenomenon 49 6.4.4 Clearings 51 6.4.5 Regeneration in Logged Stands 52 6.4.6 Growth of Regeneration 53 6.5 Regeneration Damage 53 7. Artificial Regeneration 54 7.1 Role of Artificial Regeneration 54 7.2 Planting Stock 54 7.3 Open Plantings 55 7.4 Enrichment Planting 59 7.5 Underplanting 61 1 Notes on the Silviculture of Major N.S.W. Forest Types - No. 11 Rainforest Types 8. Growth and Yield 62 8.1 Rainforest Stand Dynamics 62 8.2 Growth in Even-aged Stands 63 8.3 Growth in Uneven-aged Stands 64 8.3.1 Data 64 8.3.2 Cool Temperate Rainforest 65 8.3.3 Warm Temperate Rainforest 66 (a) Bo Bo Plot 66 (b) Styx River Plot 67 (c) Moonpar Plots 68 8.3.4 Subtropical Rainforest 69 8.3.5 Dry Rainforest 72 8.3.6 Patterns in Rainforest Growth 73 8.4 Size, Longevity and Mortality 73 9. Damage to Older Stands 75 9.1 Damage Agencies 75 9.2 Crown Dieback 76 9.3 Logging Damage 77 10. Silvicultural Treatments 79 10.1 Explanation 79 10.2 Subtropical Rainforest 80 10.3 Dry Rainforest 81 10.4 Warm Temperate Rainforest 81 10.5 Cool Temperate Rainforest 83 10.6 Perspective 84 11. Environmental Effects of Rainforest Treatment 85 12. Preservation 87 12.1 Preserved Areas 87 12.2 Rare and Threatened Species 88 12.3 Global Perspective 89 13. Management Aspects 90 13.1 Objectives of Management 90 13.2 Management Options 91 13.3 Guidelines 95 13.4 Future Research 95 14. Acknowledgements 96 15. References 97 2 Notes on the Silviculture of Major N.S.W. Forest Types - No. 11 Rainforest Types Appendices 1. List of Species referred to in Text 104 2. Rainforest Life Forms 109 3. Rainforest Leagues and Types recognised in Classification 113 of Forestry Commission of N.S. W. 4. Detailed Rainforest Classification for N.S.W. (Floyd) 117 5. Climatic Summaries 119 6. Rainforest Stumpage Groups (1981) 121 7. Flowering and Fruiting in N.S.W. Rainforest Trees 122 8. Regeneration in Logged Rainforest Stands 123 9. Growth Rates - Cumberland S.F. Arboretum 126 10. Records of Large Rainforest Trees in N.S.W. 127 11. Preserved Areas on State Forest. 129 Forestry Commission of N.S.W. 28th September, 1989. 3 Notes on the Silviculture of Major N.S.W. Forest Types - No. 11 Rainforest Types NOTES ON THE SILVICULTURE OF MAJOR N.S.W. FOREST TYPES 11. RAINFOREST TYPES The question is often raised by those concerned with the conservation of tropical forest ecosystems: do we have enough knowledge to formulate working plans for the sustainable management and development of tropical moist forests and thus to marry efficiently conservation and development of forests? The question is, intentionally or unintentionally, wrongly put. In this field the problem is not so much one of knowledge - although we all recognize that not sufficient is known at present of the functioning and “handling” of tropical moist forest ecosystems - as, primarily, one of the political will. It was political will, spurred by the need or shortage of timber for the Navy, or of wood for domestic and industrial energy, that was at the origin of the first working plans in Europe several centuries ago, at a time when there were no forestry schools or forest research institutes. Since then, many substantial improvements have been made to these plans, and continue to be made on the basis of research results. Does this mean that the states, communes and other entities who designed and implemented the first working plans were wrong and should have waited (how long?) to know more? Certainly not. It is also certain that more knowledge is needed and will have to be acquired gradually through research and experience. But there is need and room, now already, for cautious and conservative forms of forest management for the sustainable production of wood and non-wood products and services. And newly acquired knowledge will, in the future, allow for the improvement and refinement of these first plans. Director, Forest Resources Division. J.P. LANLY Forestry Department, F.A.O., Rome (From Guest Editorial, For. Ecol. & Mgt. 24 (4), p. 311, 1988) 1. INTRODUCTION With possibly a minor exception in the case of those dealing with the Cypress Pine types (Silv. Notes No. 10), all previous Notes on the Silviculture of N.S.W. Forest Types have dealt with communities that are, both botanically and visually, distinctively Australian. These present Notes, however, concern a group of forest types that share many features - at times even tree species, and commonly tree genera - with forests found in other parts of the world. A N.S.W. forester with local rainforest experience does not find conditions particularly strange or different in most of the World’s tropical rainforest areas (the “tropical moist forest ecosystems”, referred to by Lanley in the opening quotation), nor in the temperate rainforests of the Southern Hemisphere or of tropical mountains. Because of these similarities, much experience and research concerning rainforest in other countries has fairly direct application to the understanding of the local rainforest areas. Within historic times, rainforest has not made up more than about 2 per cent of the total forested area of N.S.W., yet this relatively small area (often colloquially known as brush or scrub) has played a disproportionately important role in the development of forestry in N.S.W., and indeed of the State generally. The Australian timber industry had its origins in 1790 in the Red Cedar1 brushes of the Hawkesbury River; exploitation of the valuable Cedar logs led to the subsequent settlement of the coastal river systems; cleared of their rainforest cover, these river flats and nearby basalt plateaux provided some of the State’s finest farmlands; efforts to re-establish Cedar in the 1880s were among the first attempts at silviculture in N.S.W. Besides Cedar, rainforest has yielded many of the State’s 1 For botanical names of species mentioned in text, see Appendix 1. 4 Notes on the Silviculture of Major N.S.W. Forest Types - No. 11 Rainforest Types most beautiful or valuable woods - White Beech, Hoop Pine, Coachwood and many others - and for decades more than 10 per cent of the State’s wood production came from its limited rainforest area, along with a continuing supply of minor products. At the same time rainforest had other notable features - its obviously different appearance from the otherwise almost ubiquitous eucalypt forest; its rich floristic diversity, with nearly half of all the native tree species present in N.S.W.; the apparent strangeness of many of its life-forms; its often distinctive fauna. These combined to give the rainforest high recreational and scientific appeal, and certainly from the 1930s areas of rainforest were being preserved as national parks or, within State Forests, as Flora Reserves. Until the 1950s it was conventional wisdom that the N.S.W. rainforests could not be managed for sustained timber production. During the 1930s this belief led to a policy of creating Hoop Pine plantations on land carrying cut-over rainforest - primarily to demonstrate that the land was being gainfully used, and to forestall agitation for its conversion to farm land. Even when it was finally realised that the stands could be managed as rainforest, the political will, stressed by Lanley, was lacking. Royalty rates for many of the rainforest timbers were pitched way below the true worth of those timbers; industries, utilising these timbers, were established with appetites far in excess of the capacity of the stands to sustain; in some, though not all, areas the intensity of logging was much greater than was silviculturally desirable, aesthetically acceptable or politically wise. The stage was set for events that had the inevitability of a Greek tragedy. As environmental awareness in the community increased, so did concern over rainforest logging, and in 1982 the Government, after long deliberation, decided to transfer large areas of rainforest (and even larger areas of eucalypt forest) from State Forest to national park, and to accelerate the phasing out of routine rainforest logging. In the process some of the most potentially manageable areas of rainforest, much of it previously harvested, were lost from the State Forest estate, and the skills in the techniques of rainforest harvesting rapidly decayed.