AUSTRALIAN FORESTERS in PAPUA NEW GUINEA 1900 - 1975
PNGAF MAGAZINE ISSUE # 9B - 1 of 17th March 2021 THE PLACE OF RAINFOREST
PNG1
Editor R B McCarthy2 2021
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FAO – FRP2005 District Forester TPNG 1963-1975
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TABLE OF CONTENTS “FORWOOD”
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Place of Rainforest
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World Forest Resources Temperate and Boreal Forests Tropical Forests Moist Deciduous Forests Forests of the Dry Zones
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Papua New Guinea Forest Resources Oceania Ecological Zones Papua New Guinea Ecological Zones PNG’s Woody Vegetation Closed Broadleaved Forests Lowland Rainforest West Papuan Forest System Papuan South Coast Forest System Southeast Coastal Forest System Bismarck Forest System Solomon Forest System Sepik - Ramu Forest System Lower Montane and Montane Forest Mangrove Forest Fresh Water Swamp Forest Swamp Forest - Littoral Forests Swamp Forest- Deciduous Forests Swamp Forest - Dry Evergreen Forests Open Broadleaved Forests Woodlands Savanna Eucalypt Savanna Melaleuca Savanna Mixed Savanna Bamboo Forest Coniferous Forest Scrub Formations Methodology for Assessment of PNG’s Woody Vegetation
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Bibliography
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ACRONYMS
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“FORWOOD” Rainforest, a type of vegetation originally covering nearly a tenth of the world’s land surface is clearly of more than academic interest. When this vegetation happens to coincide with some of the world’s finest growing conditions and to occur in areas of high population growth, it becomes obvious that sound understanding, and proper management of rainforest occupy high priority in the list of problems facing the world. For millions of years, rainforest, particularly the tropical formation, existed in forms little different to that of today, its distribution varying with changes to the world’s climate. The tropical rain forests are so called because they occur in areas with annual rainfall of more than about 2 500 mm. It is a multi-storeyed community containing trees, which are mostly evergreen, luxuriant, and rich in tree species as well as in other plant and animal life. The trees are frequently buttressed and/or stilt rooted, their leaves tend to be mesomorphic, entire, usually mesophylls in size, frequently compound and often equipped with drip trays and pulvini. Heavy vines are often abundant, cauliflory is common, and vascular epiphytes are normally plentiful. The tallest trees usually exceed 30 metres in height. In 2005, the World’s total forest area was estimated at 3,952 million hectares which corresponds to about 30 % of the land area. Within the vast area of the tropics (area between the Tropic of Cancer and the Tropic of Capricorn). the tropical forests (some 1,700 million hectares) cover a wide range of forests, broadly divided into four main types: the lowland formations, comprising the tropical rain forests; the moist deciduous forests; the dry and very dry forest zones; and the upland formations. The area includes most of Africa, Mexico, Central America, and South America to about the latitude of Rio de Janeiro (Brazil); most of the Indian subcontinent, southern China, Southeast Asia, and the northern half of Australia. By far the greatest concentration of the tropical rain forest is in the Amazon Basin. This huge area of forest, which covers north western Brazil and stretches into the neighbouring countries of Colombia, Ecuador, Peru and Venezuela, accounts for two-thirds of the world's tropical moist forest. Asia has the next largest area, mostly in Indonesia, Malaysia, and Papua New Guinea. Africa tropical rainforest is almost entirely in the Congo and Zaire. Approximately 40 million hectares, or 87% of Papua New Guinea, is covered with some form of forest cover which ranges from savanna woodlands, swamps and mangroves to lowland rainforests, hill forests and montane forests. Extensive areas of grasslands are found in the Highlands and in the southwest.
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PLACE OF RAINFOREST In relatively recent times Man entered the rainforest, in the first place as a fugitive from more aggressive and powerful tribes. Here he found shelter and lived by hunting the animal life of the rainforest and by collecting the edible fruits and roots of various rainforest lands. In such a primitive economy Man’s effect on the rainforest was little greater than that of the native fauna, and indeed must have been less than the large animals like the elephant. With the coming of more civilized conditions, the importance of rainforest increased immensely. Plants, particularly those with edible roots or tubers e.g., yams, taro, cassava, which had previously been gathered from the natural forest, were found amendable to cultivation. Once brought into cultivation, they were also exchanged on a worldwide scale and made possible permanent settlement within the rainforest. This settlement was usually accompanied by the development of a shifting or bush fallow system of agriculture, which in some cases led to the degradation of the rainforest, under excessive burning and farming, to grassland or savanna. Other plants of the rainforest, generally used by the native inhabitants but of less local significance than the staple food plants, proved to have considerable economic value in world trade as rubber trees, oil palm and coffee. These have been extensively planted in the tropical regions of the world and contribute a major proportion of the export earnings of the main producing countries. Less widely cultivated but still of immense economic importance include spices (e.g., cloves, pepper, ginger), rattans, resins, essential oils, kapok, ornamental plants, and various medicinal plants etc. Timber does not appear to have been widely used by the original inhabitants of the rainforest. Logs of certain species were utilized to make canoes; small timber provided fuelwood and poles for shelter. The reasons for this little use of timber by the local inhabitants was due to the rapid damage and rot caused by the timber borers and wood destroying fungi, which abound in the tropical rainforest. Further, because the few highly resistant species were difficult to handle in the absence of steel axes etc, they were not utilized by the original inhabitants. Under such circumstances, the relatively permanent mud and the cheaply replaced thatch were an obvious choice. The exploitation of rainforests to provide timber for export commenced shortly after European contact with the rainforest regions. This was as early as 1500’s. From these beginnings nearly 500 years ago, was established the international trade in tropical rainforest hardwoods which continues to the present. The general picture of the utilization of tropical rainforest timbers is thus one of a low domestic demand and of a long history of highly selective exploitation for a few valuable export species. In the last 30 years, the tendency has been for many more species to enter the export trade and for domestic demand to increase. These factors have led to a somewhat more thorough exploitation of the forests in the main producing countries and to a higher yield, both financial and in volume per hectare, though the average yields remain exceptionally low by temperate forest standards. In turn, the rising yields and more complete harvesting have made possible increasingly intensive silvicultural treatment of the rainforests.
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WORLD’S FOREST RESOURCES In 2005, the World’s total forest area was estimated at 3,952 million hectares which corresponds to about 30 % of the land area.
The Global Distribution of Forests, by Climatic Domain3.
Temperate and Boreal Forests The temperate and boreal forests together make up almost half the total area of forest in the world. Virtually all the wood harvested from these forests is used for industrial purposes, with only a small proportion used for fuel. In all, the temperate and boreal forests provide over 80 percent of the world's industrial wood supplies. The total area of temperate and subtemperate forest, including plantations, is about 760 million hectares. The proportion of the land area occupied by forests (mainly temperate forest types) in the industrialized countries of the Northern Hemisphere is surprisingly high. In the former USSR, it is over 40 percent; in France, Germany, Italy, and Poland it is 25 to 30 percent each; and in Greece and Austria it is about 45 percent. The United States has about 300 million hectares of forest, covering about one-third of its land area; the area of forest, in fact, is 50 percent greater than that of cropland. 3
FAO 2005
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It is estimated that most of the temperate forests are under some form of management, although there is no reliable figure for the actual area. The Mediterranean region, with a population of around 1000 million, was once heavily forested but now the forest cover is less than 5 percent of the area, concentrated mainly in the northern countries of the region. The boreal forests encircle the northern part of the globe, extending through Alaska (USA) and the northern regions of Canada, Finland, Norway, Sweden, and the former USSR. Their area is vast, a total of about 920 million hectares of closed forest with a further 300 million hectares of open woodland. Almost three-quarters of the total is in the former USSR. A further 20 percent is in Canada and Alaska and about 5 percent in the Nordic countries. Production from the boreal forests accounts for about 50 percent of the world's newsprint, nearly 40 percent of the sawn wood and 20 percent of the paper pulp. Although large areas of forest are harvested every year, the quantities of wood removed are substantially less than the overall annual growth of the boreal forests. Tropical Forests The tropics are, geographically speaking, the area between the Tropic of Cancer and the Tropic of Capricorn, 23 30' south and north of the equator, respectively. The area includes most of Africa, Mexico, Central America, and South America to about the latitude of Rio de Janeiro (Brazil); most of the Indian subcontinent, southern China, Southeast Asia, and the northern half of Australia. Within this vast area there is a wide range of forests, but they can be broadly divided into four main types: the lowland formations, comprising the tropical rain forests; the moist deciduous forests; the dry and very dry forest zones; and the upland formations. In total, the tropical forests cover about 1 700 million hectares, an area roughly that of South America. The tropical rain forests are so called because they occur in areas with annual rainfall of more than about 2 500 mm. It is a multi-storeyed community containing trees, which are mostly evergreen, luxuriant, and rich in tree species as well as in other plant and animal life. The trees are frequently buttressed and/or stilt rooted, their leaves tend to be mesomorphic, entire, usually mesophylls in size, frequently compound and often equipped with drip trays and pulvini. Heavy vines are often abundant, cauliflory is common, and vascular epiphytes are normally plentiful. The tallest trees usually exceed 30 metres in height. They are a major source of the world's hardwoods; mahogany, rosewood, ebony and sapele are the most popularly known but there are dozens of other species which are used in fine furniture, veneers, and other high-grade uses. There are also many other species of lesser commercial value which are used for construction, plywood, and other purposes. The soils on which the rain forests grow tend to be shallow and poor in nutrients. The high growth rates and intense biological activity of the forest is based upon a quick recycling of organic waste material back into the growing plants. In many areas, if the trees are removed and the land is used for agriculture, the nutrient cycle is broken and the inherent lack of fertility of the soil is quickly revealed. By far the greatest concentration of the tropical rain forest is in the Amazon Basin. This huge area of forest, which covers north western Brazil and stretches into the neighbouring 6
countries of Colombia, Ecuador, Peru and Venezuela, accounts for two-thirds of the world's tropical moist forest. Asia has the next largest area, mostly in Indonesia, Malaysia, and Papua New Guinea. Africa tropical rainforest is almost entirely in the Congo and Zaire. Only a small proportion of the world's tropical forests are under management in any meaningful sense. Even where there is management, it is often confined to the collection of revenue from logging operations or the protection of national parks by government forest services. Moist Deciduous Forests The moist deciduous forests occur in areas with annual rainfall of 1000 to 2000 mm. These forests vary greatly depending on factors such as the amount of rain and its distribution throughout the year, the temperature, and the type of soil. They are generally much less rich in tree species and less biologically diverse than the tropical moist forests. The total area of the zone is nearly 1300 million hectares. Because the zone is well suited for human settlement, there has been much greater deforestation than in the rainforest zone. Forests of the Dry Zones The tropical dry forests occur in areas with rainfall of 500 to 1000 mm per year. They are relatively open and, especially in Africa, rich in wildlife. The people living in and around these forests tend to rely heavily on them for livestock grazing as well as for fuelwood, building poles and other products. More than half the world's dry tropical forests and savannah woodlands are in Africa. Dry forest zones are found also in north eastern Brazil and much of India. In many areas, these forests merge into arid or even desert margin zones where the natural tree cover becomes increasingly sparse. The total area occupied by the dry forest zone is roughly one-third that of the rain forest zone, but depletion has reached an advanced stage, especially in Asia where only 15 percent of the zone is now forested.
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PAPUA NEW GUINEA FOREST RESOURCES The following section in relation to PNG details work undertaken by FAO in their Tropical Forest Resource Assessment Project4 – Forest Resources of Tropical Asia in 1981. It pictures very much the forest resource situation of PNG as of 1975. One must note that the detail methodology follows FAO concepts and classifications with interpretation of satellite imagery (Landsat) which was not available to Australian Foresters `1in PNG before 1975. Oceania Ecological Zones
PNG
FAO Map Oceania Region 1981. Oceania is comprised of Australia, New Zealand, Papua New Guinea, and the Pacific Islands (Micronesian, Melanesian, and Polynesian archipelagos). The climate of the Pacific Islands is dominated by the trade winds and most of islands have ample precipitation. The average annual precipitation generally varies between 1 500 and 4 000 mm and the dry season is seldom severe. Locally, rainfall depends on the relief and the leeward side may be dry. Mean temperature at sea level is about 23°C near the Tropics and 27°C at the equator, with little difference between the hottest and coolest
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Tropical Forest resource Assessment Project – Forest Resources of Tropical Asia UN 32/6.1301-78-04 technical report 3 of 1981. M-35 ISBN 92-5-101105-2
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months. Cyclonic disturbances mainly affect the western Pacific archipelagos (Melanesia and western Micronesia). The coastal area of north-eastern Australia has a tropical wet climate and receives the highest annual rainfall in Australia. It has a mean annual precipitation of 1 500 to 2 500 mm with some areas exceeding 4 500 mm. There is a marked summer maximum (January to March). The mean annual temperature is around 23°C. The rain forests of the tropical Pacific Islands are generally evergreen. Their structure is comparable to that of the Indo-Malayan forests, but the flora of the dominant strata is often relatively poor. The tallest hardwood forests, with heights ranging from 30 to 45 m, are found on deep volcanic soils. About a dozen species (in the genera Calophyllum, Campnosperma, Dillenia, Elaeocarpus, Endospermum, Gmelina, Maranthes, Parinari, Schizomeria and Terminalia) are the main constituents of the canopy, overtopped occasionally by banyan figs (Ficus spp.) and Terminalia calamansanai. In Vanuatu, Fiji, and Samoa this forest type is somewhat lower (about 30 m) and floristically slightly different. New Caledonian flora is totally different from that of the forests in other parts of Melanesia. Clusiaceae (Calophyllum spp. and Montrouziera spp.), Cunoniaceae, Myrtaceae, Myrtoideae, Proteaceae and Sapotaceae predominate in the upper stratum. A poorer forest grows on the limestone atolls. In certain special environments a single species dominates the upper stratum. Examples are the Nothofagus spp. forests in New Caledonia and the Metrosideros collina forest that is found throughout the tropical Pacific. Coniferous forests belonging to the Araucariaceae, Cupressaceae, Podocarpaceae and Taxaceae families have a limited distribution throughout the Pacific. Mangroves cover rather large areas in the Melanesian archipelagos and in the Caroline Islands. They can reach a height of 25 m and the main constituents are Rhizophoraceae together with species of the genera Avicennia, Lumnitzera, Sonneratia and Xylocarpus. Papua New Guinea Ecological Zones Papua New Guinea lies in the southwestern part of the Pacific Ocean and covers a land area of 461 700 km2 between latitudes 0° and 12°S and longitudes 141° and 156°E. The country consists of the eastern half of the island of New Guinea, the Trobriand, Woodlark, d'Entrecasteaux and Louisiade groups of islands, the Bismarck Archipelago with New Britain, New Ireland, and Manus and the Buka and Bougainville islands of the Solomons. The central core of New Guinea is a massive mountain chain with peaks up to 4 500 m (Mount Wilhelm 4 508 m) and forming a natural east-west barrier. The mountain chain is made of a series of ranges divided by large fertile valleys at altitudes between 1 500 and 1 800 m. High rainfall is responsible for the existence of many rivers, which are only navigable in their lower parts. Exceptions however are the Sepik river in the north and the Fly river in the southwest, both with extensive herbaceous grass swamps. Southwestern New Guinea is a flat land covered with dry evergreen forests. The island regions also have prominent mountains, however of much lower elevations: highest peaks on New Britain are up to 2 438 m, on Bougainville up to 2 743 m and New Ireland up to 1 871 m. These islands, with recently latent but still active volcanic
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phenomena, have highly fertile soils and they concentrate most of the agricultural activity and production of the country. The climate is moist and tropical except in the southwestern and central southern areas. The southwestern monsoon, which is hot and humid and brings most of the rain, occurs from December to May. High mountains and insular nature of part of the country have a strong effect on the local climates. The central mountain chain is a rain shelter for the southwestern part during the northwest monsoon and so this part is much drier and covered with savannas. There is a considerable variation in annual rainfall which ranges from 980 mm in Port Moresby to more than 5 000 mm on places in the central mountains, where rainfall is distributed all over the year. Temperatures are about 30°C on average along the coasts in the north and show a marked seasonal tendency southwards: in the highlands they range between 9° and 32° C (with frost and higher elevations) and at Port Moresby between 23° and 32°C. The population can be estimated at 3.1 million in 1980 with an overall density of 6.6 inhabitants/km2. The highlands with more than one million people have a density of nearly 18 inhabitants/km2 while the Papuan coast has only less than 3 inhabitants/km2. The population growth is approximately 2.5%. Agricultural population amounts to 83% of the total population, growing at an annual rate of 21% (FAO Production Yearbook - 1979).
Gogol timber area 1974. Photo credit Ian Whyte.
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PNG’s Woody Vegetation
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Vegetation Map PNG by Dept of Forests 1970. Published New Horizons 1973.
Approximately 40 million hectares, or 87% of Papua New Guinea, is covered with some form of forest cover which ranges from savanna woodlands, swamps and mangroves to lowland rainforests, hill forests and montane forests. Extensive areas of grasslands are found in the Highlands and in the southwest. Closed Broadleaved Forests Lowland rainforest (up to 1,500 m) Unlike the forests of southeast Asia, dipterocarps are not the dominant family in the canopy of the evergreen rainforests and are replaced by a greater number of other species among which Pometia pinnata (especially on the plains), Ficus spp., Alstonia scholaris and Terminalia spp. are constantly present in the upper storeys. Locally predominant according to drainage and soil are, among others, kwila (Intsia spp.), New Guinea rosewood (Pterocarpus indicus) and the dipterocarp Anisoptera thurifera (or A.
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Vegetation PNG Map published New Horizons Jacaranda Press 1973 ISBN0701681845. Source Dr R Robbins Dept of Forests PNG data 1970
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polyandra) which, together with Hopea spp., forms a widespread association on ridges and foothills. On well drained sites with deep soils canopy is well over 30 m and emergents may reach over 50 m. Undergrowth usually consists of vines, many palms, scrubs, and rattans. On poorly drained soils, an open forest occurs with Planchonia papuana, Bischofia javanica, Terminalia complanata, Cananga odorata, Intsia and others. An interesting feature of the composition of the lowland forests is the large component of species of secondary succession types. These fast-growing light demanders reach large sizes and are the most valuable wood species in the forest. Their presence is dependent on natural disturbing phenomena like landslides or intervention by man. The most important species of this group are Pometia spp., Anisoptera thurifera, Alstonia scholaris, Spondias dulcis, Terminalia spp., Octomeles sumatrana and others. These forests can be divided into reasonable homogeneous systems: The “West Papuan Forest System,” is where the Fly river emerges from the mountain. It is a belt of rainforest in which dipterocarps like Anisoptera, Hopea and Vatica spp. are mixed with many non-dipterocarp species, principally of the genera Canarium, Eugenia and Lithocarpus. On the steep slopes Vatica rassak is the commonest tree species in all layers.
Western Province. Middle Fly LLG. Photo credit Dick McCarthy.
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The “Papuan South Coast Forest System” has Pometia spp. as dominant species, and its composition varies greatly according to the relief. On hilly terrain Hopea and Anisoptera spp. are more abundant. Growing stock is moderate.
Cloudy Bay Timber Area Abau Papuan Coast. Photo credit Dick McCarthy. The “Southeast Coastal Forest System” extends along the generally narrow coastal plain and foothill area. The forests are dominated by Anisoptera thurifera, especially in the foothills where they form nearly pure stands. They extend virtually into the permanent swamp areas. Other important species are Pometia spp., Hopea spp., Pterocarpus indicus, Planchonella spp. and others. The “Bismarck Forest System” dominates at present the forest logging activities with approximately 80% of all log export in 1969/70. The forest is dominated by Pometia spp. with sometimes nearly monospecific stands of kamarere (Eucalyptus deglupta), especially near the Hoskins, Bialla, Open Bay and Tairua Pandi areas. Other main species are malas (Homatium foetidum), Terminalia spp., New Guinea basswood (Endospermum medullosum), amberoi (Pterocymbium becoarii), Spondias dulcis, erima (Octomeles sumatrana) and New Guinea walnut (Dracontomelum manniferum).
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Open Bay Timber area 1974. Photo credit Ian Whyte. The “Solomon Forest System” has a composition like that of the Bismarck system but with local concentrations of Vitex cofassus. The “Sepik - Ramu Forest System” is formed by lowland rain forests dominated by kwila (Intsia spp.) with local concentrations of Agathis labillardierei, especially in the Torricelli mountains and south of the Sepik river. Other species are the usual lowland species such as Pometia spp., Terminalia spp., Palaquium spp., Eugenia spp, and Planchonella spp. Block 6 Vanimo Timber Area Coastal landscape. Photo credit Ian Whyte 1974.
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Middle Ramu Lowland Rainforest PNG. Photo Credit Dick McCarthy.
Backswamp forest, Calamus and windthrow Gogol 1971. Photo credit Ian Whyte.
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Block 6 Vanimo Timber Area landscape 1974. Photo credit Ian Whyte. With increasing altitude, the forest canopy becomes less variable in height (25–30 m), closure (60–80%) and crown size. Emergents except for Araucaria are lower, reaching 40 m. Trees with large diameters and buttresses become less common but the total number of trees above 30 cm is greater. This forest is very mixed floristically. Locally a small-crowned hill forest occurs corresponding to particular soil conditions. In this type of forest, frequent species are Castanopsis acuminatissima, Hopea papuana and the drought-tolerant Casuarina papuana.
Bush Work Vanimo 1974. Photo credit Ian Whyte.
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Lower Montane and Montane Forest This type of forest is generally found above 900–1 000 m and extends up to 3 500 m. The canopy height decreases to 15–25 m and emergent trees are often absent except for the Araucaria spp. Undergrowth is abundant. Oaks (Castanopsis acuminatissima) and laurels (Cryptocarya) become prevalent. Upwards, generally above 2 000 m, beech forest prevails, with the valuable southern beech (Nothofagus spp.) in mixed stands occupying the ridges. In the upper zone, above 3 000 m, an Ericaceae forest develops with the Papuacedrus locally present. The canopy is only 12–18 m high. At higher elevations, the height of the canopy gradually decreases with on Mount Wilhelm, between 3 500 and 3 900 m, subalpine scrub forest 4–5 m high.
Bulolo Forestry College Mensuration Classes lower montane forest Bulolo. Photo credit Leon Clifford. 17
Mangrove Forest Mangrove forests fringe large parts of the coasts and form very extensive stands along the Gulf of Papua, near Lae and Madang and in the Sepik estuary. They also occur elsewhere in smaller stands. Most of the mangrove area is very sparsely populated and almost virgin. The general zonation of the mangrove communities appears to be like that of southeast Asia and is dominated by Rhizophoraceae. In the Papuan Gulf Rhizophora spp. and Bruguiera spp. are most common and frequently attain large dimensions.
Gulf of Papua Delta Western Province. Photo Credit Dick McCarthy. Fresh Water Swamp Forest Fresh water swamp forests occur in southwestern New Guinea along the Fly river and in northern New Guinea along the Sepik river, but also in the back of the mangrove and along several river courses in the intermontane basins. These swamps are regularly inundated by mineral rich fresh water. One tree species often dominates the canopy which is 20–30 m high, with emergents reaching 40 m. Throughout New Guinea Campnosperma brevipetiolatum is common and occurs in pure or nearly pure stands as well as the sago palm (Metroxylon sagu) which form large stands, sometimes in combination with the former species. Other frequent swamp species CampnospermaauriculatumNaucleacoadunata, Syzygium spp, Alstonia spp, Terminalia spp., Dillenia papuana and Planchonia timorensis.
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Village and Sac-sac swamp West Sepik 1974. Photo credit Ian Whyte. Large areas of southern Bougainville, in the regions of Tonolai, of the Luluai river and of the Empress Augusta Bay, have extensive swamps with almost pure stands of Terminalia brassii in association with Campnosperma brevipetiolatum forests. “The MONEY IN THE SWAMP” photo Ken Granger assessment in Terminalia brassii swamp forests Empress August Bay Bougainville Survey Sept-Oct 1964. Photo published in November 1964 Courier Mail and New Guinea Times Courier. Photo credit Ken Granger September 1964.
Itam with a girth stick measuring T. brassii Mom Hill swamp, September 1964. Photo Credit Ken Granger.
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Swampy Forests - Lowland Forest In the northern part of Papua pure stands of 50 m tall Casuarina cunninghamiana occur as pioneer vegetation on swampy alluvial soils. Throughout New Guinea Melaleuca spp., which are understorey species in the primary swamp forest, become gregarious after disturbance and then often dominate the swamps.
Sagari Gadaisu Timber Area. Melaleuca in grassland and rainforest intrusion. Photo credit Ian Whyte 1976. Coniferous swamp forest with Podocarpus, Dacrycarpus and Dacrydium occur locally above 1,700 m. Swampy Forests - Littoral Forests They are confined to coastal sandy beach plains and are characterized by a canopy of medium height and an abundance of palms in the shrub and lower tree layers. Common trees are Pterocarpus indicus, Terminalia spp., Planchonia papuana, Nauclea coadunata, Pongamia pinnata, Syzygium spp., Melaleuca, Casuarina equisetifolia and in the southwest Acacia. Swampy Forests - Deciduous Forests A belt of slightly deciduous forest is present inland from the south central coast, as a transition between savannas and the evergreen forests. This belt is probably due to a combination of seasonal drought stress and shallow soils. Frequent deciduous trees are Garuga floribunda, Brachychiton carruthersii, Intsia bijuga, Terminalia spp., Protium macgregorii and Sterculia spp.
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Forests with a marked deciduous character exist in the coastal limestone hills near Port Moresby where the annual rainfall is less than 1 200 mm. Additional to the species mentioned above are Gyrocarpus americanus, Bombax ceiba, Albizia sp., Maniltoa sp., Adenanthera pavonina and Erythrina sp. This forest has a low and open canopy and in places grades into woodlands. Swampy Forests - Dry Evergreen Forests They are restricted to the relatively low rainfall areas in the southwest on imperfectly drained and gently undulating land. Most common trees are mainly non-deciduous, and the tree stratum is relatively open. Epiphytes are poorly developed. Frequent tree species are Acacia, Tristania, Syzygium, Rhodamnia, Xanthostemon, Maranthes, Mangifera, Rutaceae such as Halfordia and Flindersia and Proteaceae as Oreocallis and Grevillea. Near the Indonesian border dry evergreen forest locally grades into woodland with a dense understorey of tall bamboo. Frequent fires lead to the replacement of dry evergreen forest by woodland and ultimately savanna with firetolerant species. Open Broadleaved Forests Woodlands Dry woodland mainly replaces marginal forest after the forest's delicate balance has been disturbed by fire, but also occurs naturally on sites where adverse conditions of climate and soil have prevented the development of forest. It is found on a variety of landforms mainly in the monsoonal areas of the south-central coast and south-west Papua New Guinea. Woodland has a low and open canopy, but the shrub layer is usually dense and thin woody climbers often abound. Grasses, ferns, and sedges form a sparse ground cover. The most frequent trees are those of the forest it replaces or grades into, i.e., smallcrowned lowland hill forest, dry evergreen forest and littoral forest. Woodland that is subject to periodic flooding occurs on poorly drained flats mainly in south-west Papua New Guinea, and throughout the country forms narrow bands around permanent swamp, lakes and lagoons that have a fluctuating water-table. Frequent trees in such woodland are Carallia brachiata, Nauclea coadunata and, in south-west Papua New Guinea, species of Melaleuca, Acacia and Tristania. Gallery woodland lines small streams within savanna and grassland. Many of its canopy trees are deciduous and bamboo is a common feature in the undergrowth. It is probably the remnants of more extensive forest or woodland cover. Woodland on beach ridges occupies a zone between pioneering herbaceous vegetation and scrub to seaward, and forest to landward. It characteristically contains pantropic trees such as Calophyllum inophyllum, Barringtonia asiatica, Terminalia catappa and Pandanus tectorius. Swamp woodland occurs in permanent and near-permanent shallow swamp. It is extensive in swamps associated with the lower courses of large rivers, such as the Mambare, Lakekamu and Purari rivers. Except for a more open tree canopy it is similar 21
in structure to swamp forest, and many of the frequent trees are common to both types. On sites that have a strongly fluctuating water level many trees develop adventitious roots and Carallia brachiata and Syzygium sp. are common. Near the coast, trees characteristic of brackish swamp predominates and the fern Acrostichum appears in the ground layer. Where the environment is brackish as well as monsoonal, trees such as Excoecaria agallocha and Melaleuca spp. are common. Savanna Three different types of savanna can be distinguished: Eucalypt Savanna This is the most common type, occurring from sea level to about 1 700 m on a variety of landforms that are never flooded. In hilly terrain eucalypt savanna is commonly confined to crests and upper slopes, while the lower slopes and valley bottoms remain under forest. In areas with an annual rainfall of less than about 1 300 mm and a severe dry season during which up to seven months have less than 100 mm, eucalypt savanna completely covers hills, undulating terrain, and plains. Eucalypt savanna is most extensive along the south-central coast but is also present in intermontane valleys in the central range some 150 km east of Port Moresby and, probably in these valleys has reached the central north coast near Popondetta. Eucalypt savanna consists of a tree layer of one or more of the species Eucalyptus alba, E. confertiflora, E. papuana and E. tereticornis, and a ground layer of mid-height grasses, the most frequent of which are Themeda australis and Imperata cylindrica. Eucalyptus tereticornis is present over the whole altitudinal range of eucalypt savanna and tends to dominate on sites having deep soils. It usually has a straight bole and grows to a height of over 30 m. The other savanna eucalypts are present at the lower levels only; they usually have crooked stems and do not normally grow over 20 m high.
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Eucalypt Savanna Papua savannah. Photo credit Dick McCarthy. Melaleuca Savanna. This is the next most common type of savanna. Occurring from sea level to 500 m Melaleuca savanna is characteristic of seasonally inundated or waterlogged plains and 23
fluctuating river back swamps although it also grows on permanently dry, hilly terrain. It is found mainly in regions with a relatively low and seasonal rainfall in freshwater environment, on brackish sites behind mangroves and on slightly alkaline soils of beach plains. Although most extensive in south-west Papua New Guinea it also occurs along the south-central coast and, rarely, on the north side of the central ranges. Melaleuca savanna is also found on hilly terrain on the d'Entrecasteaux islands, which have an evenly spread rainfall in places as high as 2 500 mm or more. Various species of Melaleuca are present, all of which tolerate burning, prolonged inundation and periodic drought. Most frequent are M. cajuputi, M. leucadendron and, particularly in south-west Papua New Guinea, M. viridiflora. Individual stands consist predominantly of one species. Mixed Savanna. This type of savanna is restricted to south-west Papua New Guinea and occurs on undulating to flat terrain varying from permanently dry to seasonally waterlogged or inundated. Its structure and floristics vary with the depth and duration of inundation and with the frequency of burning. On well to imperfectly drained terrain mixed savanna is 20 to over 30 m high and is relatively dense. Shrubs are relatively tall and dense and compete with the grasses Imperata cylindrica, Ophiuros tongcalingii and Ischaemum barbatum in the ground layer. The most frequent of the many trees present are Tristania, Melaleuca, Acacia and Xanthostemon. Eucalypts, except Eucalyptus alba but including E. polycarpa, are present in many places but are nowhere dominant. Bamboo Forest Although bamboo often is an important undergrowth in the drier forests, in no report is mentioned that it forms pure stands other than scrub ones and therefore bamboo forests are not considered separately in this study. Bamboo scrub with emergent tree ferns is extensive on steep, ash-covered slopes in central and northern Bougainville mainly between 600 and 1 200 m. The type appears to be rather stable and may form an arrested successional stage. Coniferous Forest Conifers are widespread in the forests of Papua New Guinea but in most cases, they do not constitute the dominant part of the forests. However, Araucaria spp. in the upper lowland and montane forests, and a community of several conifers in the upper montane forests sometimes form pure stands or are dominant. Two species of Araucaria occur in the upper lowland and montane forests of Papua New Guinea: the klinki pine (A. hunsteinii) and the hoop pine (A. cunninghamii). The hoop pine is present between 90 m and 2 800 m elevations and the klinki pine occurs between 500 and 2 100 m mainly in the valleys and on the slopes of the central cordillera. Both species are most abundant in the Wau and Watut valleys of the Bulolo river. Here in the rain shadow of the inland valley klinki forms dense stands on the valley floor in the discontinuous emergent stratum of the semi-evergreen forests.
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In the montane forest the hoop pine replaces klinki with increasing elevations. Elsewhere both occur in a very wide ecological range but generally in smaller groups. The trees can form giant columns of one metre in diameter and 60 to 75 m in height. In the New Guinean montane forests conifers are frequent. Podocarpus is common in the lower montane forests and, above 2 400 m, belts of some metres wide and up to 36 m tall occur mainly composed of Dacrydium novoguineense, Papuacedrus spp., Phyllocladus hypophyllus and Podocarpus spp. Patches of either Myrtaceae or Dacrydium elatum and Podocarpus papuanus are found in the boggy depressions.
Mid Mountain Forests including Araucaria forests of Bulolo Wau depicting Bulolo Airstrip and the mountain “Su Su’s” covered with natural Araucaria forest. Photo credit Ian Whyte 1979.
The Bulolo Gorge between Wau and Bulolo 1960. Photo Credit Des Harries.
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Bulolo Forestry College Mensuration Classes Natural A. hunsteinii (klinkii) tree. Photo credit Leon Clifford.
Scrub formations Scrub occurs on sites that are unsuited to the growth of forest and woodland because of harsh climatic conditions and/or soil deficiencies. In lowland regions that have a strongly monsoonal climate scrub occurs on coastal limestone hills, beach ridges, and periodically inundated, often alkaline, plains. In high mountain regions it occurs above the tree line and on steep summit ridges that have shallow stony soils. Scrub consists of dense shrubs up to about 6 m high. Scattered low trees are usually present. In coastal monsoonal scrub Hibiscus tiliaceus, Desmodium umbellatum and, on temporarily inundated terrain, Pluchea indica are frequent and Flagellaria indica is a common climber. Sinoga lysicephala scrub, in mosaic with low sedge-grassland, covers large areas of seasonally inundated plain in south-west Papua New Guinea. Styphelia suaveolens locally forms a low, heath-like scrub, in mosaic with grassland, on intermontane valley flats.
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Kunai savannah near Wanigela River Sagarai Gadaisu. Photo credit Ian Whyte 1976. In high mountainous areas scrub consists of true shrubs such as Coprosma divergens, Epacridaceae and Ericaceae, and trees that are reduced to a shrub form, such as Pittosporum pullifolium, Xanthomyrtus and Papuacedrus papuanus. Methodology for Assessment of PNG’s Woody Vegetation The assessment of the forest areas of Papua New Guinea has used as a baseline the 1/1 000 000 scale “Vegetation Map of Papua New Guinea”, published in 1975 but established from aerial photographs of years 1943 to 1972. All the areas of the various vegetation types have been measured from the map using a 2 mm × 2 mm dot grid, and, as an average, 1965 has been chosen as the base date. At that time forests covered an area of 39.9 million ha, a figure close to the one often quoted in the reports of 40 million ha. Of these 40 million ha, 21 million ha are considered inaccessible or unproductive because located in the high mountains, on steep slopes and in isolated valleys or covered by fallow forest). The woodlands and savannas are a part of the accessible forest but most of these (3.85 million ha) are unproductive (according to FAO document “Forest Resources in the Asia and Far East Region” - 1976). Parts around Port Moresby are utilised for fuelwood production.
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Bibliography FAO Tropical Forest Resource Assessment Project – Forest Resources of Tropical Asia UN 32/6.1301-78-04 technical report 3 of 1981. M-35 ISBN 92-5-101105-2. FAO document “Forest Resources in the Asia and Far East Region” - 1976. FAO Forestry Paper 147. “Global Forest Resources Assessment 2005”. Minister for Forests 1973 “New Horizons - Forestry in Papua New Guinea” – Brisbane. Paijmans, K. 1975 “Vegetation Map of Papua New Guinea” and “Explanatory Notes to the Vegetation Map of Papua New Guinea” - Land Research Series No. 35 – Melbourne.
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ACRONYMS ACT AEC AFS AFPNG AIF AMF ANBG ANGAU ANU APMF APPM ASIO ASOPA BCOF “Beer Time” BFC BGD BUC C cm CALM CFA CNGT CRE CRE
CSIRO CHAH DASF DEPT DOF FAO F &TB FPRC Forkol GIS ha IBRD IFA ITTO LLG L of N m3 MM
Australian Capital Territory Administrators Executive Committee Australian Forestry School Association of Foresters of PNG Australian Infantry Forces Australian Military Forces Australian National Botanical Gardens Australian New Guinea Administrative Unit Australian National University Australian Paper Manufacturers Forestry Pty Ltd Australia Paper and Pulp Manufacturers Australian Security Intelligence Organisation Australian School of Pacific Administration British Commonwealth Occupational Force 1945-52 Any time. Bulolo Forestry College Bulolo Gold Dredging Company Bulolo University College Commonwealth Centimetre Western Australian Department of Conservation and Land Management Commonwealth Forestry Association Commonwealth New Guinea Timbers Bulolo Commander Royal Engineers CRE is a term inherited by RAE from RE and is the term for the Commanding Officer of a RAE unit which is headed by a Lt Col. Although the officer is called the CRE the name is also used for the name of his unit. E.g., CRE Aust Forestry Group or 1(NG Forests). Commonwealth Scientific and Industrial Research Organisation Council of Heads of Australasian Herbaria Dept of Agriculture, Stock and Fisheries Department Department of Forests Food and Agriculture Organisation Forest and Timber Bureau Canberra Forest Products Research Centre Hohola Bulolo Forestry College Geographic Information Systems Hectare International Bank for Reconstruction and Development Institute of Foresters of Australia International Tropical Timber Organization Local Level Government Area League of Nations cubic metre Military Medal 29
NAA NARI NB no. NG NGF NGIB NGVR NZ NSW P or p PIB PIR PNG PNGAA PNGAF PNGFA PNGFIA PNGRIS PNGUT POM Q QF RAE RPC SFM SP UK UN Unasylva UNE UNI UNITECH UNRE UPNG UQ US USA TPNG TUBL TA TA TRP VSF WA WB WW2
National Archives Australia National Agriculture Research Institute New Britain Number New Guinea New Guinea Forces (relates to plant collection of Lae Herbarium) New Guinea Infantry Battalion New Guinea Volunteer Rifles New Zealand New South Wales page Papuan Infantry Battalion Pacific Islands Regiment Papua New Guinea Papua New Guinea Australia Association Papua New Guinea Australian Foresters Magazine Series Papua New Guinea Forest Authority PNG Forest Industries Association Papua New Guinea Resource Information System PNG University of Technology Port Moresby Queensland Queensland Forestry Royal Australian Engineers/Australian Army Royal Papuan Constabulary Sustainable Forest Management South Pacific United Kingdom United Nations Journal of FAO of UN University of New England Armidale NSW University University of Technology Lae PNG University of Natural Resources and Environment University of Papua New Guinea University of Queensland United States United States of America Territory of Papua and New Guinea Territory United Brewery Ltd Timber Area Timber Authority Timber Rights Purchase Victorian School of Forestry Western Australia World Bank WORLD WAR 2
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