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Home-garden urban agroforestry
Urban agroforestry on undeveloped land
Problems of urban agroforestry
Integrating agroforestry into urban planning and policy
With the growth of towns and cities in the Pacific and the resultant increasingly large and dense concentrations of people isolated to varying degrees from rural production, urban agroforestry has taken on ever greater significance, although until recently it has received little official recognition or encouragement. Two main types of Pacific Island urban agroforestry are categorized here as: home-garden agroforestry adjacent to residences; and agroforestry on idle or undeveloped land within urban areas, but usually at a distance from the residence.
Urban agroforestry in home gardens is today a ubiquitous feature of urban landscapes in the Pacific Islands. Even in areas not renowned for agricultural diversity, such as Kiribati and Nauru, urban gardens contain a wide range of food trees, non-tree staple and supplementary food plants, and non-food plants (table 8). Cultivation or protection of trees and non-tree plants on idle or undeveloped land in urban areas is also very widespread and provides an important source of other produce, including limited commercial production (Thaman 1977a; 1977b; 1984a; 1985a; 1987a; 1988e).
As suggested by table 8, more than 20 species of trees are common in the "food trees" category in urban agroforestry gardens. Also common are all the important staple root crops and a great range of supplementary non-tree food plants such as onions, amaranths, pineapple, peanuts, cabbages, a wide variety of legumes and "spinaches," cocurbits, okra, tomatoes, passion-fruit, sugar cane, eggplant, and corn. There are also condiments and spices such as chillies, ginger, coriander, and mint as well as plants producing beverages, stimulants, and depressants (betel-nut, betel pepper, kava [Piper methysticum], tobacco, and lemon grass). Many of the home gardens surveyed contained a large proportion of these plants.
Table 8 Number of species and distinct varieties found in surveys of urban agroforestry systems in Port Moresby in Papua New Guinea; Suva in Fiji; Nuku'alofa in Tonga; South Tarawa in Kiribati; Nauru; and Location, the contract-worker settlement in Nauru
|Crop types||Papua New Guinea||Fiji||Tonga||Kiribati||Nauru||Location|
|Non-tree supplementary foods||48||65||44||35||14||41|
*The totals for Papua New Guinea and Nauru would have been slightly higher for food trees if Musa clones and Citrus spp., respectively, had been differentiated.
As stressed by Soemarwoto et al. (1985, 44), in their study of Javanese home gardens, true plant diversity is far greater than indicated by the presence of many different species since many species are represented by numerous cultivars. In Tonga, for example, there are numerous distinct, named breadfruit cultivars. And in tree gardens in settlements in Yap, as already mentioned in the section on the Micronesian high islands, there are 21 named coconut cultivars, 28 breadfruit cultivars, and 37 banana cultivars (Falanruw 1985, 16). There is similarly great cultivar diversity among other crops such as mangoes, domesticated Pandanus, papayas, and especially among the traditional staple ground crops such as yams, taros, and sweet potatoes. This intra-species diversity adds economic, ecological, and nutritional stability to urban agroforestry systems.
"Weed" species are also myriad in urban agroforestry gardens, but as Soemarwoto et al. (1985,44) caution, "the term 'weed' should be used with extreme care" because of the many uses home gardeners have for weeds - as medicines, fodder, mulch, roofing, fish poisons, toothbrushes, and vegetables. "Weeds" such as Amaranthus spp., black nightshade (Solanum nigrum), purslane (Portulaca oleracea), and water spinach (Ipomoea aquatica), for example, are important pot herbs in Fiji and are often sold at the Suva Municipal Market (Thaman 1976/77), and almost all grass species are used for fodder.
Although staple ground crops are most numerous, food trees such as coconut, breadfruit, papaya, Citrus spp., mango, Musa clones, guava, Annona and Syzygium spp., avocado, Tahitian chestnut (Inocarpus fagifer), hog plum, or vi-apple (Spondias dulcis), oceanic lychee (Pometia pinnata), and Terminalia spp. are the dominant plants of most urban landscapes, especially in long-settled areas. An exception would be Location, the indentured worker settlement in Nauru, where little or no space for gardening exists, let alone tree cropping, and where a high proportion of plants are grown in artificial boxed beds or containers. The only mature trees are bananas and scattered coconut palms.
Trees constitute a particularly important economic and nutritional resource on low-lying islands such as the atolls of Kiribati, where apart from giant swamp taro (Cyrtosperma chamissonis), which is generally reserved for special occasions, the main staples are all tree crops: coconut, breadfruit, Musa clones, pandanus, and the native fig (Ficus tinctoria). Trees are, nevertheless, very important in home gardens on high islands as well. For instance, as described in chapter 6, the tree gardens around homesteads in Yap contain some 50 species of introduced or indigenous food trees (Falanruw 1985, 15-16). Trees of particular importance to the Indian population of Fiji (who currently make up close to half of Fiji's population) include jakfruit (Artocarpus heterophyllus), horseradish, or drumstick tree (Moringa oleifera), curry leaf, or Indian bay (Murraya koenigii), and tamarind (Tamarindus indicus).
The most common staples include the important root crops, such as cassava, taro, sweet potato, and tannia (Xanthosoma spp.), with giant taro (Alocasia macrorrhiza) important in Tonga, and giant swamp taro (Cyrtosperma chamissonis) particularly important in the harsh environment of the lowlying atolls of Kiribati, as discussed in the previous chapter (Thaman 1984b).
True taro (Colocasia esculenta) is particularly well suited to urban conditions because it can be grown on small plots, either as a staple for its corms or for its leaves, which constitute the most common leafy vegetable, or "spinach," in many areas. It is often found planted in wet conditions along drains, near water taps, or washing areas (Thaman 1977a; 1977b).
Cassava is commonly planted in back and front home gardens in Suva and Port Moresby and along road frontages in Suva, and sweet potatoes commonly occupy large proportions of back and front home gardens in Port Moresby, as well as being found in small plots around homes in densely-settled urban Tarawa. Tannia (Xanthosoma) is also of increasing importance as it seems to be disease-resistant, relatively drought-resistant, and grows well in the shady conditions commonly encountered in older urban areas where mature trees dominate the environment.
Supplementary food crops
Supplementary crops, such as hibiscus spinach (Hibiscus manihot), Amaranthus spp., pineapple, cabbages, chillies, taro (grown especially for its leaves), cucurbits, tomatoes, sugar cane, and a wide variety of edible legumes, are also very common in urban gardens throughout the Pacific. These, plus a wide range of other supplementary, often shortterm crops, constitute a valuable nutritional and economic resource.
In addition to plants for food, drink, or supplementary consumption, many useful non-food plants are also found in home gardens. These include handicraft plants such as Pandanus spp., used in plaited ware, paper mulberry (Broussonetia papyrifera), used for bark or tape cloth, and annatto (Bixa orellana) and Bischofia javanica (both sources of dyes); Leucaena leucocephala, an important renewable fuel-wood resource; a great range of medicinal plants, many of which are trees; plus many other plants with a variety of uses.
Medicinal plants have long been of significance and remain a resource, given the high cost of imported medicines, not to mention their frequent unavailability, misuse, and, in some cases, doubtful efficacy. In Fiji, where extensive areas of tropical rain forest, coastal strand, and mangrove forest still exist, 40 per cent (73) of 183 plant species reportedly used medicinally by the indigenous Fijians (Weiner 1984) are found in home gardens in a cultivated, protected, or weedy state. On the smaller, more densely-populated islands of Tonga and Kiribati, where less natural vegetation remains, approximately 75 per cent of all reported medicinal plants (56 of 77 and 33 of 44 respectively) are found cultivated or protected in home gardens (Luomala 1953; Thaman 1976; Weiner 1971). In Nauru, where over 70 years of open-cast phosphate mining and widespread bombing during World War II have devastated most of the natural and much of the traditional cultural vegetation (Manner et al. 1984; 1985), 28 (85 per cent) of 33 reported medicinal plants are now found in Nauruan home gardens.
Of the 93 medicinal plant species found in urban gardens in these four countries, 51 (55 per cent) were trees and another 10 were woody shrubs. It should be noted that the totals for medicinal plants in Fijian urban gardens would undoubtedly be much higher if data on Indian medicinal plants were also available.
The importance of sacred or perfumed plants to urban agroforestry is also considerable. Of some 49 plant species considered by Tongans to be sacred ('akau kakala), 36 were found present in a survey of home gardens in the capital of Nuku'alofa. Twenty-three of the 36 are trees and five others are woody shrubs. In addition to their sacredness, such plants constitute a very significant economic resource. Their flowers, leaves, fruits, and bark are used in leis and ornamentation for the expanding tourist industry, as well as being the main scents used in body oil (coconut oil), perfumes, and deodorants, the imported substitutes for which are extremely expensive and often not as culturally acceptable. Many of these plants, such as heilala (Garcinia sessilis), langakali (Aglaia saltatorum), feta'u (Calophyllum inophyllum), and sandalwood (Santalum yasi), are chiefly kakala, kakala hingoa, which are reserved for nobility or very special occasions and constitute a very important and sacred cultural resource (Thaman 1987a).
Evidence from Fiji, Kiribati, and Nauru indicates that sacred and perfumed plants are of similar importance there. In Kiribati, for example, where cash incomes are very low, headbands and garlands (primarily from flowers grown in home gardens) are widely sold (often by school children to help their families) to people to wear during work or for dances and other festivities.
Similar analyses of urban agroforestry systems for other plants that yield firewood, dyes, livestock feed, insect repellents, handicrafts, fish poison, etc., would yield equally impressive lists of plants and uses.
Characteristics of urban agroforestry gardens
The commonest plants in the inventory of Pacific urban agroforestry tend to be natives or pre-European introductions, except where the gardeners are from immigrant populations. For example, the Indian population of Fiji prefers species such as eggplant, okra, Amaranthus spp., a wide range of pulses and cucurbits, and tree crops, such as jakfruit, tamarind, mango, Citrus spp., curry leaf (Murraya koenigii), Sebesten plum (Cordia dichotoma), horseradish, or drumstick, tree (Moringa oleifera), and the spiritually and medicinally important neem (Azadirachta indica).
Also of importance, however, is a range of more recently introduced crops, including temperate vegetables, pineapple, papaya, avocado, guava, and improved citrus varieties and banana clones, as well as cassava, which is a ubiquitous staple in most Pacific Island towns (Thaman and Thomas 1985). In fact, Pacific home gardens seem to have been, and will probably continue to be, one of the most effective avenues for the introduction and acceptance of new plant species.
A great diversity exists in the actual area under food crops and in their spatial distribution. Whereas some households have only a few scattered fruittrees and vegetables, many cultivate food crops on over 50 per cent of their allotments. In Port Moresby, for example, in low-income areas settled by migrants, such as Morata and Gerehu, an average of approximately 40 per cent of 450 sq m allotments were under food crops. Similarly, in some cases in Nuku'alofa, up to 75 per cent of 500-1,000 sq m allotments were under food cultivation, mainly root crops, such as taro, tannia, and cassava, amongst Musa spp. and scattered trees. Trees become increasingly dominant in longsettled areas, as cash incomes increase, soils decline in fertility, and tree seedlings mature and increasingly shade garden areas.
Ornamentals are commonly planted closest to the home, often in the front, whereas medicinal plants, sacred or fragrant plants, and other culturally valuable, commonly multi-purpose plants, are scattered amongst the food plants.
In the atoll environment of South Tarawa, Kiribati, where the cal careous soils are poor and thin and population densities are very high, traditional staple tree crops, such as coconut, breadfruit, pandanus, the native fig (Ficus tinctoria), and, in some cases, Musa spp., are predominant. In the gardens of the indigenous Nauruans (who, as a result of phosphate mining royalties, have among the highest per capita incomes in the world), ornamental, fragrant, and medicinal plants dominate, along with the ubiquitous coconut, edible pandanus, some Musa spp., and breadfruit.
At the Location contract-worker settlement, where people live in multistorey tenements, and where family gardening is limited to no more than 1530 sq m, most families have only a few plants. In the case of the gardens of Tuvaluans (nationals of Tuvalu, formerly known as the Ellice Islands) and IKiribati, they often constitute juvenile tree seedlings, staple root crops, or a single coconut or stand of bananas.
In the case of gardens made by Chinese (mostly recruited from Hong Kong) and Filipinos, the emphasis is on intensive vegetable gardening, often in containers, reflecting a more intensive system than that practiced by most indigenous Pacific peoples. In Kiribati and Tonga, however, recent emphasis has been placed by the governments and non-governmental organizations on more intensive types of gardening, such as hydroponic techniques in Kiribati because of the highly calcareous and sandy soils there. In Kiribati, where vitamin-A deficiency-induced night blindness and xerophthalmia have become problems, the planting and consumption of the vitamin-rich leaves of two native tree species, Morinda citrifolia and Pisonia grandis, have been encouraged in urban areas.
Undeveloped or idle lands in urban and pert-urban areas are important sources of food and tree products such as timber, fence posts, fuel wood, medicines, leaves, flowers, fruits, and nuts. Such areas include road frontages, empty allotments, river banks and valleys, right-of-ways for proposed or existing paths and roads, and open land such as hillsides and swamp land.
In Port Moresby, over one-third of all households had gardens on idle land in addition to their home gardens. Kilakila villagers, as original inhabitants of the area, had particularly large tracts of undeveloped urban savanna land, and all households had, in addition to their home gardens, from one to four "bush" gardens averaging 1,135 sq m located on urban land within two miles of the urban village of Kilakila.
In Suva, about 20 per cent of all households cultivate "unused" open land, and it has been estimated that on the Suva Peninsula, approximately 5 sq km (over 70 per cent) of the "undeveloped" area (which does not include swamp or mangrove) was under this type of cultivation. The practice was most common in areas where there is a high proportion of Crown and leasehold land (as opposed to freehold land) and a high proportion of Fijian residents. Some 20 per cent of all households also planted along road frontages, despite Suva City Council regulations forbidding the practice.
In Tonga, Kiribati, and Nauru, there is little undeveloped "urban" land, although, in a number of cases, Tongans planted entire adjacent unoccupied "town allotments" ('apt kolo) in sweet potato, taro, tannia, and a mixture of trees, or in traditional mixed yam gardens (ma'ala 'up), where yams, giant taro, plantains, and taro are intercropped, usually under coconuts and other trees. There is virtually no open land in urban Kiribati, but in Nauru, some Chinese, Tuvaluan, and I-Kiribati contract labourers plant food gardens near the Nauru Phosphate Corporation's "topside" workshops, on the phosphate-rich central plateau, and in the swampy area surrounding land-locked Buada Lagoon. In Tuvaluan and I-Kiribati gardens, coconuts and banana clones were dominant.
Along road frontages, fruit-trees such as mangoes and coconuts are common, but ornamental and shade trees such as Plumeria spp., flamboyant (Delonix regia), Cassia spp., monkey-pod (Samanea saman), banyans (Ficus spp.), variegated coral tree (Erythrina variegata var. variegata), and the pride of India (Lagerstroemia speciosa), many of which are systematically planted by city councils or the government, as well as by individual households, are dominant. Living fences of fruittrees and other useful species, such as Polyscias spp., Leucaena leucocephala, Erythrina variegata, Hibiscus tiliaceus, Hibiscus rosasinensis, guava, and the recently introduced madre de cacoo (Gliricidia septum), are harvested, pruned, pollarded, or "grazed" and constitute important sources of food, fodder, firewood, medicines, and flowers, as well as being of considerable ecological importance. The balance of agroforested landscapes in urban areas includes the rare botanical garden or urban forest reserve, public parks, and institutional tree planting throughout cities, often as part of landscaping schemes.
Despite the current importance of agroforestry on undeveloped urban and pert-urban land, it is these areas that are most severely affected by wanton deforestation because of insecure tenure and undefined ownership. It is a classic example of Hardin's "Tragedy of the Commons" (1968), where the urban poor and entrepreneurs clear trees in order to plant crops and to glean the land of scarce fuelwood resources. As Eckholm argues (1976, 101), the "real energy crisis" is the daily scramble by the world's poor to find the wood they need to cook their dinner. This scramble for wood and associated deforestation is clearly visible and rapidly increasing in Pacific Island urban areas (Thaman and Ba 1979).
Animal husbandry and urban agrosilvipastoralism
Small-scale animal husbandry, although playing a minor role compared with plants, is also an important activity. Surveys in Port Moresby found animal-keeping to be minimal, with 11 of 79 households keeping pigs, chickens, or ducks, and a few households keeping tethered cows or goats. There were no pigs kept in Suva. In Tonga over half of all sample households kept tethered or penned pigs, and almost two-thirds kept chickens or ducks. In most cases, poultry were penned or tethered at night and allowed to forage during the day, and pigs and other larger animals were generally tethered or penned at all times. In Kiribati and Nauru, pigs and chickens are also kept on home allotments. In Nauru, there was a large communal pig-rearing area along the beach in Denigomodu District, and, in Betio, the most heavilypopulated area of South Tarawa, there was a large communal pigrearing area with individualized pens, established by the local town council, under coconuts, breadfruit, and other trees.
In terms of agrosilvipastoralism within the wider context of urban areas, livestock depend on trees to a great extent for shade, sustenance, and tethering. Apart from kitchen waste, the main feed for pigs and chickens in most areas is coconut. In Tonga, goats and pigs are commonly fed the leaves of Leucaena leucocephala, Pisonia grandis, and Erythrina variegate, while "living edible pens" for poultry and pigs are made of these same species, plus others such as Hibiscus tiliaceus and Polyscias spp., all of which are easily pruned or pollarded to provide fodder. On open land, horses, cattle, and goats are commonly tethered to trees, which also give them shade. Small animal pens, which are commonly constructed of coconut logs, bamboo, Leucaena, or other local timber, are found occasionally.
On the detrimental side, grazing animals and pigs seem to accelerate deforestation in urban areas through the consumption or destruction of tree seedlings and saplings. Once established, however, trees and animals co-exist well, except where goats eat the bark of trees. Cattle seem to enhance the establishment and spread of guava, which although an important fruit, medicinal, and fuel-wood source - has become a noxious pasture weed in many areas.
Urban agroforesters in the Pacific face a number of problems. Unfavourable climate, poor soils, high cost or unavailability of land and water, insufficient time and labour, theft, and lack of government assistance were most commonly mentioned.
Problems of drought are severe in Port Moresby, and include high cost of water, distance of community taps, and water cancellations in Morata, and fear of City Council regulations against the use of water for gardening purposes between 8.00 a.m. and 6.00 p.m. Restrictions on the use of water in gardens are also imposed during periods of extended drought in Fiji.
Urban gardeners commonly have to contend with poor, infertile soils, such as the very poorly developed rocky or stony lithosols of Port Moresby, the shallow soils that overlay a marl substrate in Suva, hydromorphic soils in low-lying areas, and the notoriously infertile calcimorphic soils of Kiribati. Continual cropping on small urban plots also leads to declining fertility and loss of soil structure, unless ameliorative measures are taken. Both water shortage and poor soils, however, often make trees a more attractive proposition than shortterm ground crops, which require water and higher soil fertility.
Insufficient land and insecurity of tenure were problems in most areas, with over half of all households in Suva mentioning land shortage as a problem. Insecurity of tenure, especially in Suva, where a number of people had short-term leases or were squatters, is a major problem and a strong disincentive to urban agroforestry. City Council regulations, although not strictly upheld, were also considered a disincentive that discouraged cultivation of ground crops and trees along road frontages and the keeping of pigs, goats, cows, and horses within the city limits. Other problems included disease, insects, birds, rats, dogs, mongooses, and noxious weeds; theft of produce, especially of banana bunches and tree fruit (approximately one-third of all households had experienced theft); insufficient time; high costs of poultry feed and fertilizer; predation of firewood and deforestation on undeveloped urban and pert-urban lands, where most low-income families still depend on firewood to cook their meals (Thaman and Ba 1979); boundary problems with respect to ownership of crops; and neighbours' unfavourable response to gardening or livestock rearing.
In Kiribati and Nauru, where constraints to expanded home gardening are the greatest, the most significant problems are extremely poor soils, limited water availability, and extremely high population densities, especially in South Tarawa and at Location, the contract-worker settlement. Among the indigenous Nauruans, who are considered to be wholly urbanized, extremely high per capita incomes from phosphate royalties and a resulting overdependence on imported foods act as disincentives to expanded urban agroforestry.
The significance of urban agroforestry is not clearly understood by most planners and policy makers in the Pacific Islands because of a lack of quantitative data on its nature, extent, and cultural and economic value. However, interest has been shown by some city planners and administrators. In Port Moresby, for example, the Housing Commission conducted a survey of urban gardening in the early 1970s. The Committee on Food Supplies of the Solomon Islands (1974) conducted studies of the production of major staple crops (primarily sweet potato) in Honiara and stressed the need to increase production per head in both rural and urban areas, and Fitzroy (1981) pointed out the correlation between vitamin deficiency in '`urbanized" people and the absence of garden plots in Honiara. Further studies stressing the importance of urban home gardens in the Pacific have been conducted since the mid-1970s (All 1976; Basha et al. 1974; Harris 1977; Kesavan 1979; Thaman 1977a; 1977b; 1984a; 1985a; 1987a; 1988e; Vasey 1985; von Fleckenstein 1978).
There have been campaigns encouraging the cultivation of food crops in Port Moresby, and, in Fiji, the National Food and Nutrition Committee (NFNC) and The Fiji Times, through their "Feed Fiji First" campaign, have placed major emphasis on home food production and have sponsored competitions in H.A.R.T. (Housing Assistance and Relief Trust) destitute areas, schools, government housing areas, and agricultural resettlement schemes. Major emphasis was placed on the planting and maintenance of food trees in these competitions.
Similar interest in urban agroforestry has recently been shown in Vanuatu, Tonga, Kiribati, the Federated States of Micronesia, and the Marshall Islands, where urban food dependency and increasing incidences of nutritional disorders have become serious. These countries, along with Papua New Guinea, the Solomon Islands, Fiji, and Western Samoa, are now part of a Unicef-sponsored "Pacific Island Regional Family Food Projection and Nutrition Project" (Sommers 1990). In a course entitled "Agriculture, Food and Nutrition in the Developing World" offered at the University of the South Pacific (a regional university located in Suva but serving 11 Pacific Island countries), a major component of the course involves students in the development and maintenance of mixed home gardens; Tonga and Fiji have both promoted tree planting in towns as integral parts of their World Environment Week and Arbor Day programmes, respectively; and, most recently, the Honiara Town Council has actively and successfully promoted home food gardening through its Sup Sup Gaden (soup soup garden) Club.
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