|Agroforestry in the Pacific Islands: Systems for Sustainability (UNU, 1993, 297 pages)|
|2 Pacific Island agroforestry: Functional and utilitarian diversity|
Instead of seeing trees as a basis for stability in agro-ecosystems, modern developers often focus on their disadvantages - e.g., trees take up space, may compete with annual crops, require years to reach maturity, and inhibit the use of some agricultural equipment such as the plough and mechanical harvester. These characteristics have often led to the domination or replacement of trees by more immediately productive annuals. However, in a world where biological stability is increasingly precarious, many characteristics of trees become advantageous. The "frozen" quality of trees - once established they are awkward to replace with other species - and the related lack of a quick turnover of product or land use provide a permanence in ecosystems that slows misuse and provides a wide range of ecological benefits: diversity of habitat, diversity of species, prevention of accelerated erosion, maintenance of soil fertility and arable soil structure, flood retardation, weed suppression, increased slope stability, and wind protection.
Trees for maintenance, insurance, and intensification
Agroforestry is now widely seen as a way to combine production with sustainability. In addition to the cultural and economic contributions already described or listed in table 2, trees also
As populations continue to grow and economic demands on land escalate, the use of land as a resource intensifies - which raises the trenchant question asked by Rambo and Hamilton (1991, 121), with regard to the upland areas of Asia and the Pacific: "How can we devise strategies for intensified resource use that will meet the broadest range of needs of the greatest number of people in the most sustainable way?" Part of their answer is that particular attention needs to be paid to agroforestry as a way to increase the productivity of existing agricultural land while reducing pressures to clear or otherwise exploit remaining forest land. Similarly, Raintree and Warner (1986) discuss the pathways by which agroforestry can aid in the intensification of shifting cultivation.
Antidote to nutritional degradation
The culinary and nutritional values of tree foods were discussed in a previous section. Further mention should be made of their potential to counter the rapid increase in nutrition-related maladies among Pacific peoples; an increase that has been widely documented and includes very high incidences of nutritional disorders such as iron-deficiency anaemia, vitamin-A-deficiency-induced night blindness, obesity, and general micronutrient deficiency, and of nutritionrelated non-communicable diseases such as cardiovascular disease, hypertension, diabetes, various forms of cancer, hyperuricaemia and gout, dental disease, and alcoholism (Cornell 1984; Coyne 1984; Fitzroy 1981; Jansen and Wilmott 1971; Johnson and Lambert 1982; Keith-Reid 1982; Pargeter et al. 1984; Parkinson 1982; Rody 1982; Thaman 1979, 1982c, 1983a, 1985b, 1987).
Although Pacific peoples seem to be genetically predisposed to obesity, diabetes, cardiovascular disease, and gout (Baker 1979), the main cause of the increase of these diseases today seems to be the shift to a diet of imported, highly refined foods from a diet of fresh foods high in fibre, vitamins, and minerals and low in sugar, salt, animal fats, and refined carbohydrates. A diet based on imported, highly refined foods is the reverse - as well as containing carcinogenic food additives. Table 3 is an attempt to assess the degree of correlation between these dietary changes and the major nutritional and nutritionrelated disorders. Cigarette smoking, increasing alcohol consumption, and decreasing physical activity are also contributing factors to the rising incidence of such diseases (Coyne 1984; Thaman 1983a).
As can be seen from table 3, the fresh fruits, nuts, vitamin-rich green leaves, derived juices, and complex-carbobydrate-rich and fibre-rich staple foods such as bananas, breadfruit, and even coconut (which has no animal fat or cholesterol, and the high Pacific-islander consumption of which does not seem to be correlated with the increase in any of these diseases, except possibly gout and hyperuricaemia) are exactly the types of foods needed to stem the Pacific's dangerous nutritional transformation. These foods also constitute the traditional snacks, drinks, and supplementary foods that are now being replaced by soft drinks, candy, and other modern but nutritionally-poor processed foods.
The nutritious local staples, fruits, and vegetables are increasingly scarce (in actual amount and because of their high price) owing to population growth, urbanization, and the emphasis on monocultural production for export. All-but-forgotten by today's youth and in danger of disappearing are ingenious and time-tested strategies of acquiring wild food, of practicing polycultural agriculture and multi-storey agroforestry, and of processing, storing, and preserving traditional foods (Barrau 1958, 1961; Massal and Barrau 1956; Parkinson 1984a; Thaman 1982c, 1985b; Yen 1980a).
Food dependency and decreasing self-reliance
Many countries have become dangerously "food-dependent," with food imports constituting far more, in terms of value, than returns from all export earnings (Carter 1984; Coyne 1984; Heywood 1991; McGee 1975; Parkinson 1982, 1984b; Rody 1978; Thaman 1982c, 1985b). As early as 1968, food imports in the Cooks, Kiribati, Tuvalu, Nauru, Niue, Western Samoa, and Tonga made up between 25 and 35 per cent of import expenditure (Fairbairn 1971; McGee 1975).
Table 3 Degree of correlation between the increasing incidence of major nutritional and nutrition-related disorders and dietary changes (increasing and decreasing consumption of specified nutrients or substances)
|Increasing consumption||Decreasing consumption|
|Marasmus||-||-||-||-||+||-||+ +||+ + +|
|Kwashiorkor||+ +||+ +||-||-||+ +||+||+ +||+ + +|
|Obesity (infant)||+ + +||+ + +||+ +||+ +||-||+ +||+||+ + +|
|Vitamin-B deficiency||+ +||+ +||-||?||+ +||+||+ + +||+ +|
|Infant mortality||+||+||-||-||+||-||+ + +|
|Hypertension||+ +||+ +||+ + +||+ + +||+||+ +||+ +||+|
|Gout/arthritis||+||+||+ + +||+||+ + +||+ +||+ +||+|
|Dental disease||+ +||+ + +||-||-||+||+ +||+ +||+|
|Alcoholism||+||+||-||?||+ + +||?||+||+|
|General morbidity||+ + +||+ + +||+ + +||+ + +||+ + +||+++||+++||+++|
Source: Adapted from Thaman 1983a.
+ + + Very high positive correlation (i.e., a major determinant). + + High positive correlation (i.e., a significant determinant). + Some positive correlation (i.e., a complicating factor). - Not significant, no correlation, or a negative correlation. ? No data.
Although the percentages of total imports of foodstuffs have not changed significantly, the total values of food imports, and their value compared with the value of exports, has increased drastically. In Kiribati, for example, where the dominant locally-grown staple foods are coconut, breadfruit, and pandanus (together with the giant swamp taro Cyrtosperma chamissonis), the 1989 value of food imports was $8,580,000 (Australian), which was 134 per cent of the value of exports. The import percentage increases still more if beverages and tobacco are included. The situation is similar in Tuvalu, Niue, and the Cook Islands, where food-import bills are larger than the total value of locallyproduced exports. The decrease in self-reliance is even greater in American Micronesia, but less in Melanesia, although food dependency in urban areas is increasing rapidly there (Cornell 1984; Forum Secretariat 1991).
A study in Papua New Guinea comparing rural eastern highlanders with those living in urban Lae showed that, whereas sweet potato and other starchy foods provided 85 per cent of the dietary energy and 65 per cent of the protein in the rural area, rice had become the main staple - ahead of sweet potato and taro, with animal protein being eaten almost daily - in Lae (Jeffries 1979). The country's rice imports increased 40 per cent between 1975/76 and 1979, of which approximately one-half was consumed in rural areas (Bourke et al. 1982). Although energy, vitamin, and mineral intakes seem to be sufficient in rural areas where root crops, bananas, and tree foods predominate, the energy intakes in some low-income urban areas in the capital of Port Moresby, where 72 per cent of the energy was provided by flour, rice, sugar, bread, and biscuits, were the lowest ever recorded for the country: 1,200 kilocalories (5.0 MJ) for men and 1,035 kilocalories (4.3 MJ) for nonlactating women (Jeffries 1979). Sugar provided 11 per cent of the energy, whereas root crops provided only 9 per cent (Coyne 1984).
In Fiji, food-balance studies in the late 1970s showed that the total population received only 29 per cent of total energy from root crops and fruits (NFNC 1979). Of particular concern in Fiji is the increasing emphasis on the consumption of cassava; in some areas, its contribution to dietary energy rose from 36 per cent in 1953 to 59 per cent in 1963 (Parkinson 1984; Thaman and Thomas 1982' 1985). The increasing monoculture of cassava, which can be cropped almost continuously on even the poorest soils, has also been a factor in deforestation. Previously, yams, taro, and other traditional staples were more commonly cultivated along with trees as components in integrated agroforestry systems.
In Tonga and Samoa, similar trends are evident. Diets in urban Nuku'alofa contained more bread, sweet potato, cassava, mutton, pork, tinned fish, beef, butter, and tea than diets in rural areas, where more taro, plantain, coconut, ripe bananas, fresh fish, shellfish, green vegetables, and fruits were consumed (Jensen 1973). In Western and American Samoa, taro, green bananas, breadfruit, and coconut contributed 50-64 per cent of the dietary energy in rural areas but only 31 per cent on the more urbanized island of Tutu'ila, and only 20.5 per cent among highly urbanized Samoans in Hawaii (Bindon 1982; Parkinson 1984b).
In the Cook Islands, studies comparing rural Mitiaro with urbanized Rarotonga show that less than half the amount of root crops and one-eighth the amount of coconut, but over thirty times the amount of cereals (flour, bread, and rice) and nine times the amount of sugar were consumed in Rarotonga (Coyne 1984). In French Polynesia, where the trend is well advanced, by 1973 90 per cent of food intake was imported (Jacober 1977).
The changes are, however, most dramatic on some of the atolls, such as in the Tuamotu atolls of French Polynesia, where the traditional foods, such as taro and Polynesian arrowroot, have been all but forgotten and breadfruit and bananas are becoming rare. As early as 1956, Barrau (1961) found that flour, sugar, rice, biscuits, vegetables, fats, and tinned foods accounted for more than 2,000 kilocalories of individual daily food intakes.
In Tuvalu, where the traditional diet consisted of fish, coconut, breadfruit, bananas, and Cyrtosperma taro, by 1976 the island of Funafuti was 80 per cent dependent on imports for its food needs (Zimmet et al. 1981). In Kiribati, the per capita consumption of rice and sugar increased, respectively, three-fold (from 15 to 52 kg per year) and five-fold (from 8 to 40 kg) between 1950 and 1979. Even on rural Maiana, 60 per cent of the population regularly consumed sugar, 90 per cent flour, and 95 per cent rice (Pargeter et al. 1984). Studies on Namu atoll in the Marshall Islands in the late 1960s showed that 93 per cent of all copra income was spent on food, and that sugar, tea, and rice had replaced breadfruit, coconut, and Cyrtosperma taro as the most commonly consumed foods (Pollock 1970, 1974).
In parts of the Pacific, such as Tonga, where the traditional agro forestry system is relatively intact, the per capita bill for imported food has remained fairly modest - US$75 in 1984 (Heywood 1991, 75). Elsewhere, food dependency has reached far more vulnerable levels, as in French Polynesia with per capita annual food imports of US$554 (Hamnett et al. 1981).