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close this bookAgroforestry in the Pacific Islands: Systems for Sustainability (UNU, 1993, 297 pages)
close this folder9 Institutional agroforestry in the Pacific Islands
View the document(introduction...)
View the documentIntercropping of tree crops/woody perennials with commercial or subsistence ground or tree crops
View the documentPlanting of timber, fuel wood, and general-purpose trees in relation to agroforestry and agriculture
View the documentGrazing with commercial tree cropping and silviculture
View the documentThe future of institutional agroforestry in the Pacific

Planting of timber, fuel wood, and general-purpose trees in relation to agroforestry and agriculture

Because the imminent demise or depletion of commercially usable natural forests can be so readily foreseen in many Pacific Island countries (Watt 1980, 297), governments and development agencies have in several places promoted either some form of restocking or enrichment of commercially logged areas or the establishment of forest plantations on degraded grassland sites. Not all these efforts can be classified as agroforestry, strictly speaking; but in the Pacific context, as in most of the tropical world, the traditional, if transient, shift of land use back and forth between forest and agriculture on any particular site makes it relevant to consider what at first glance appear to be purely forestry projects.

Many of the timber species institutionally promoted have been exotics such as Caribbean pine (Pinus caribaea), West Indian mahogany (Swietenia macrophylla), cordia (Cordia alliodora), and Eucalytus spp., although some indigenous Pacific species such as Albizia falcataria, Agathis spp., Araucaria spp., and Endospermum spp. have been successfully established, often as exotics in areas beyond their natural range. Many other species - including West Indian cedar (Cedrela odorata), the silky oak (Grevillea robusta), teak (Tectona grandis), mahogany (Swietenia mahogoni), toon tree ( Toona australis), cadamba (Anthocephalus chinensis), and Albizia lebbeck along with several indigenous trees - have also been the subject of trials, and planted to various degrees throughout the islands.

Firewood and multi-purpose species that have been successfully introduced include Leucaena leucocephala, Erythrina spp., Casuarina spp., and Gliricidia septum, and, to a lesser extent, Securinega samoana and Adenanthera pavonina. Other species, all of which have been planted experimentally and which seem to grow successfully, but which have not yet become so well established, include Cassia, Acacia, and Calliandra spp. Apart from timber and fuel wood, the major multi-purpose objectives of such plantings are site reclamation and amelioration, erosion control, wind protection, shade, multipurpose construction and handicrafts, nurse cropping, fodder, green manure, and food.

The indigenous casuarinas, particularly Casuarina equisetifolia, have also shown considerable promise for reforestation programmes, and have been planted in Tonga in land reclamation projects, in the Cook Islands for the rehabilitation of degraded lands, and on atolls as sources of fuel wood and to protect coconut plantations from saltwater damage. C. oligodon and C. papuana are traditionally used for reforestation and to enrich fallow land in Papua New Guinea, and are now promoted in some areas for land rehabilitation and as shade plants for coffee.

Pine planting in relation to agroforestry

Of the total area of timber plantations in the Pacific, well over 50 per cent is accounted for by Caribbean pine (Pinus caribaea). The largest area of pine planting is in Fiji, where that country's Pine Commission together with the Forestry Department has established over 50,000 ha of plantation since 1960, mostly on degraded anthropogenic grasslands (Drysdale 1988a, 110; Watt 1980, 301). Some pine timber is used locally, but the wood was intended mainly for export, and a wood-chipping mill is now in operation. In the mid1960s, under a programme now discontinued, woodlots of Pinus caribaea on smallholder sugar-cane farms were promoted by the colonial government.

Sized from 0.4 to 2 ha, these woodlots were planted on steeper non-cane areas of farms to control erosion, provide on-farm supplies of timber and fuel wood, and for undergrazing by farm animals (Eaton 1988b, personal communication). Apart from this woodlot grazing and grazing of cattle in association with larger pine plantations (described below), there has been no institutional support for any form of intercropping or other agroforestry activities in pine plantations (Drysdale 1988b).

Similarly, in the limited areas of pine planting in New Caledonia, Western Samoa, Tonga, and the Cook Islands, there has been little or no link to agroforestry in such programmes, with the main focus being on creating a timber resource, land improvement, erosion control, and employment creation in rural areas.

In highland Papua New Guinea large areas of degraded grassland have been planted with pines (Pinus spp.) and Araucaria spp. Intercropping activities are few and consist of the intercropping of coffee and cardamon on a trial and demonstration basis (Howcroft 1983).

In Vanuatu, P. caribaea var. hondurensis is the main species planted in forest plantations in seasonally dry and highly degraded sites on the southern islands of Aneityum and Erromango, where some 550 ha had been established up to April 1985. The commercial viability of such plantings is still uncertain, however, due to poor access to markets and high transport costs. On Erromango, high costs of clearing land of the indigenous pioneering species Acacia spirobis has stopped the development of pine plantations. Benefits in the form of erosion control and aiding the local economy through wages were the main motives behind these programmes (Neil 1986a).

Non-pine forestry in relation to agroforestry

To judge from programmes in Papua New Guinea, the Solomon Islands, Vanuatu, Tonga, and Western Samoa, there seems to be greater promise and greater institutionalized promotion of intercropping with other, primarily broadleaved evergreen, species than has been the case with pines.

In Papua New Guinea, where extensive areas of Eucalyptus deglupta have been planted, cocoa and coffee have been successfully grown at 4 m x 4 m and 3 m x 3 m spacing, respectively, in conjunction with E. deglupta planted at 10 m x 10 m (Jacovelli and Neil 1984, 10).

Also in Papua New Guinea, severe environmental degradation resulting from rapid urban expansion and associated subsistence gardening and "fuel-wood mining" prompted the cities of Lae and Port Moresby to institute fuel-wood-planting programmes. In Lae, in 1978, it was decided to plant 200 ha of sloping land (20°-30°) in Leucaena leucocephala for firewood and to intercrop fuel-wood species with annual food crops in zones designated for subsistence food gardening. The project, which was allocated K250,000 (US$275,000) over six years, had a management component coupled with a public education programme and a team of local government rangers to control gardening and to police the area (King 1987). Follow-on projects were planned but not carried out because of lack of funding. By 1988 the project had ceased to operate, and the original plantings of some 100 ha of L. Ieucocephala, Acacia auriculformis, and Eucalyptus spp. and 5 ha of "agroforestry plantings" of fuel-wood species with food crops had been cut down or removed completely (King 1987).

In Vanuatu, Cordia alliodora, a hardwood native to Central America, has been the main commercial silvicultural species since the mid-1970s, with over 1,000 ha planted on 12 islands as of 1984 (Neil 1984). Cordia was first planted on various islands in 5-10-ha blocks called Local Supply Plantations (LSP). As the potential contribution of forestry to rural and national development became evident, larger, export-oriented Industrial Forest Plantations (IFP) were established on the islands of Pentecost, Erromango, and Aneityum (Jacovelli and Neil 1984). The rapid expansion of IFPs, sometimes with plantings of up to 200 ha per year on single sites, led to unprecedented demands for land and aroused fears among landowners, especially on Pentecost, that these silvicultural activities would make land unavailable for planting subsistence and commercial crops. This prompted the Vanuatu Forest Service to establish, on Pentecost in 1984, demonstration plots growing a wider range of subsistence and cash crops within forestry plantations of Cordia alliodora (Jacovelli and Neil 1984).

Crops established between line plantings of Cordia alliodora included 8 sweet potato cultivars, 6 cassava cultivars, 13 aroid cultivars from Colocasia esculenta, Xanthosoma sagittifolium, and Alocasia macrorrhiza, 12 yam cultivars, kava (Piper methysticum), and trials with coffee (Arabica and Robusta), cocoa, and cardamon. In addition to these trials, subsistence gardens have also been established under Cordia alliodora by both local landowners and forest workers alike (Jacovelli and Neil 1984, 8).

Because C. alliodora may be severely attacked by root rot (Phelli nus noxius) in some conditions, and does not perform well on some sites, other species currently being tried in Vanuatu include Terminalia brassii, T. calamansanai, Eucalyptus deglupta, Swietenia macrophylla, Toona australis, and Cedrela odorata. However, the barks of both T. brassii and E. deglupta are palatable to cattle (Jacovelli and Neil 1984, 10; MacFarlane 1980). The species showing greatest potential as an alternative species to C. alliodora may be S. macrophylla, and if grown with nurse species to reduce pest problems, intercropping should be possible during the early years of rotation (Neil 1986b).

Several other systematic experiments on tree species, both exotic and indigenous, have been carried out in Vanuatu in a search for species especially suitable for fuel wood, timber, or pulpwood, but none of this research was connected with agroforestry. Research on agroforestry has focused almost exclusively on "cash crops which appear to have great potential, particularly coffee and cocoa, and possibly kava and cocoa" (Jacovelli and Neil 1984, 11).

In Fiji, some 22,953 ha of tropical hardwood forests have been planted as of mid-1986. Of these, 14,987 ha are West Indian mahogany (Swietenia macrophylla), 3,058 ha are Cordia alliodora, 2,963 ha are cadamba (Anthocephalus chinensis), 928 ha are Maesopsis eminii, 438 ha are Eucalyptus deglupta, and 202 ha are the indigenous species Endospermum macrophyllum (ADAB 1986). Despite such considerable silvicultural activity, in terms of both hardwood and pines, it is essentially monocultural, and, as the General Manager of the Fiji Pine Commission has stated: "Institutionalized agrosilviculture is non-existent in Fiji at present" (Drysdale 1988b, personal communication).

Tonga's silvicultural activities are more diverse, some being significantly agrosilvicultural. More purely silvicultural activities include a major reforestation programme begun on the island of Eua in the mid-1960s. Over 40 ha of mixed exotic species including Toona australis, Cedrela odorata, Cordia alliodora, Grevillea robusta, Agathis robusta, Pinus caribaea, and Eucalyptus spp., as well as suitable indigenous species, such as Casuarina equisetifolia, Terminalia catappa, and Dysoxylum tongense, were planted on the Eua Forest Farm. Tests of seed stock from throughout the world were also carried out on the farm. Larger areas were subsequently planted, with 104 ha alone being planted in 1979 (Thaman 1984e, 3).

The species most commonly planted in 1984 were Eucalyptus saligna, E. tereticornis, Toona australis, and Pinus caribaea. Seedling pro auction for these species and other timber species, such as Cupressus lusitanica, amounted to 77,491 seedlings (42,427 of which were planted) in 1979 (MAFF 1985, 100-102). Reforestation continues, as the small areas of remaining indigenous forest on Eua are exploited, with the local mill "approaching the end of its productive life as the local hardwood timber supply is cut out and cannot be replaced from the Forest Farm for at least another 10 years" (MAFF 1985, 99). The only truly agroforestry aspect of the Eua silvicultural activities, a taungya system of combined tree-planting and temporary gardens, was phased out because "it has greatly increased pressures for settlement of unsuitable land, and is thus clearly not in the national interest" (MAFF 1985, 100).

A second and continuing agroforestry activity has been the Forestry Extension Programme, which began in the 1960s to produce seedlings for distribution to smallholder farmers for planting in small woodlots or as windbreaks around their agricultural allotments (see chapter 5 on Tongan agroforestry). The major species distributed included Casuarina equisetifolia, Grevillea robusta, Cedrela odorata, Eucalyptus spp., Agathis spp., and Gmelina arborea (Thaman 1984e, 3).

With the establishment of the Extension Nursery at Mataliku on the main island of Tongatapu in 1978, the programme was expanded to include the propagation and distribution of a wide range of timber trees, "cultural" species, and species providing food, medicine, and ornamentation. The considerable interest shown by the people for planting on both rural and town allotments led to a "blossoming of forest extension work" to the point that, in 1978, the nursery could not cope with the demand, which exceeded 8,000 trees per month (MAFF 1979, 99).

According to programme records, as of 1984, at least 155 species had been tested and/or propagated for distribution on Eua and Tongatapu. Of these, 66 were timber species, 45 ornamentals, 32 "cultural" plants of particular importance to the Tongan society, 11 food plants, 6 plants used for coastal protection or land reclamation, 4 for living fences or hedgerows, 3 medicinal plants, and 2 each for windbreaks and firewood. Among the most popular nontimber species were Casuarina equisetifolia (planted as an ornamental, living fence, or wind-break); culturally important sacred or fragrant plants, known locally as akau kakala, such as heilala (Garcinia sessilis), langakali (Aglaia saltatorum), sandalwood, or ahi (Santalum yasi), pua (Fagraea berteriana), pipi (Parinari glaberrima), huni (Phalaria disperma), perfume tree, or mohokoi (Cananga odorata), allspice (Pimenta doica), and Pandanus cultivars; fruit-trees, such as mango, Malay apple (Syzygium malaccense), and macadamia nut (Macadamia integrifolia); and ornamental or shade plants, such as flamboyant, or poinciana (Delonix regia), hibiscus (Hibiscus rosa-sinensis), Cordyline fruticosa, copperleaf, or beefsteak, plant (Acalypha amentacea), bougainvillea (Bougainvillea spp.), poinsettia (Euphorbia pulcherrima), gardenia (Gardenia spp.), and the hedge panaxes (Polyscias spp.) (Thaman 1984e).

The final major area of activity has been the testing and establishment of trees for land reclamation, such as the project to rehabilitate low-lying areas at Sopu to the west of the capital of Nuku'alofa on Tongatapu. Reclamation work at Sopu began in the 1960s, with the planting of Casuarina equisetifolia to stabilize the area, and has continued to the present with extensive plantings of Lumnitzera littorea, Rhizophora mangle, Bruguiera gymnorhiza, Xylocarpus granatum, and other selected species. As recently as 1980, 6 acres of Lumnitzera littorea, 4 acres of Terminalia catappa, and 3 acres of Queensland kauri (Agathis robusta) were planted. The vegetation has reportedly been well-established, with the operation becoming more maintenance than reclamation.