Forests and farm trees make significant direct contributions to the food security of rural populations: providing a vast array of foods which supply essential nutrients, especially at times when other food sources are unavailable. However, few studies have focused on the links between forest products and household food security. Nonetheless, information which is available suggests that forests and farm trees' nutritional contribution are often important. It is often assumed that only forest-dwellers and hunter-gatherers still depend on forest foods. The evidence presented here shows this is not the case; many rural agriculturalists also depend on forest foods to supplement their diet.
There is a great range of edible foods which are found in forests including seeds, leaves, fruits, roots, gums, fungi, and wild animals (including insects, rodents, wild game and fish). Often these forest foods have comparable, and in some cases superior, nutritional quality to domesticated varieties. However, these forest foods are generally not dietary staples. But, they do significantly supplement the overall diversity and nutritional quality of rural people's diets. In addition, processed and stored forest food products help insure a year-round food supply. Forest foods can be of crucial importance for seasonally dependent agriculture systems. Forests provide food and fodder during the characteristic "hunger periods." In addition, forests have traditionally provided a source of foods during emergency periods. Foods exploited in emergency periods generally differ from those exploited in other periods; they are characteristically energy-rich (compared with other forest foods such as leaves and fruit), but require complicated processing. The advent of food aid and commercialisation has diminished the importance of emergency foods gathered from the forests.
Forests and farm trees contribute to the quality of rural people's diets indirectly, by providing a habitat for wild animals and fish, providing livestock fodder, a supply of medicines and fuelwood for food processing. There is no conclusive evidence linking fuelwood supply and nutritional status. However, researchers have noted that fuelwood supply may influence the amount of food supplied or cooked; fuelwood shortages can affect the quality of foods consumed; fuelwood supply may affect the amount and quality of processed food. Finally, fuelwood shortages may indirectly affect food security, forcing women to spend more time collecting fuelwood and less time at income generating activities.
This chapter focuses on the importance of forest and farm tree foods in the diets of rural people, especially agriculturalists. In order to understand the role that forests may play in household food security the following key issues are addressed:
-identifying which forest foods are consumed as well as the extent to which they are exploited,
-the linkages between forestry and nutrition,
-the contribution of forest foods to household food security,
-the ways in which forest food exploitation is changing with increasing commercialisation of rural markets as well as increasing forest degradation,
-ways of integrating nutrition issues into forestry activities.
There are vast numbers of foods garnered from the forests; from beetle larvae to nuts and honey. Despite this, the direct contributions of food (both from plants and wild animals) from forests and farm trees is generally thought to be of minor importance. Many botanical and anthropological studies have documented edible forest products gathered by forest dwellers and non-forest dwellers alike (see for example Arnold et al 1985, B.M. Campbell 1986, Connell 1977, FAO 1983a, Gura 1986, Malaisse and Parent 1985). A literature survey done by Becker (1986) revealed 800 edible plant species in the arid and semi-arid Sahelian belt; Grivetti (1976) reported that the Tswana (agro-pastoralists) regularly used 126 plant species and approximately 100 animal species as food sources. In Nigeria, Okafor (1980) reported over 150 species of edible woody plants. Similarly, in Ghana, Irvine (1952) recorded over 100 species of wild plants exploited for their leaves and another 200 wild species valued for their fruits.
Most studies on forest food resources have focused on describing what is consumed or edible. One study in Vindou Tiengoli, Senegal, for example, found that 80% of the woody vegetation had edible parts (B. Becker 1983). More elusive has been determining just how much is consumed and how often. Generalizations can nonetheless be made: for example, there are over 300 million shifting cultivators worldwide who depend on the forests for gathering foods as well as maintaining the productivity of their land; millions of Southeast Asians are dependent to a large extent on fish supplies which are supported by forest vegetation; hunter-gatherers throughout the world rely to a large extent on the forest resources for their food supply.
Few studies, however, focus on the frequency with which they are used, nor the nutritional value they impart. Without this type of analysis it is difficult to assess the magnitude and role of forest and farm tree products in people's diets. The nutrition literature to date appears to focus on the nutrient composition of forest foods (see for example R. Becker 1983, Imbamba 1973, Malaisse and Parent 1985, Ogle and Grivetti 1985). This information is important for those planning for nutritional needs in development projects and especially community forestry projects. However, alone it gives little insight into the contributions forest foods make to the diet.
The information on the nutritional value of forest foods demonstrates that in many cases the nutritional quality of forest foods is comparable and in some cases superior to domesticated varieties. Caldwell and Enoch (1972) for example, found that, on average, wild leaf vegetables have high riboflavin contents (0.4 - 1.2 mg./100 g. edible portion). The values found for wild leaf vegetables are greater than those for eggs, milk, nuts, and fish. Similarly, R. Becker (1983) found that the seed of the chanar tree (Geoffroea decorticans) had a chemical score similar to that of groundnuts and millet. The vitamin C content of an orange is 57 mg./100 g. compared to baobab fruit's 360 mg./100 g., and Ziziphus jujube var.spinosa's 1000 mg./100 g. These examples and the data compiled in Appendices 1-3 illustrate that forest food products are (or can be) nutritionally valuable. However, these comparative values (e.g. "x"/100 g. portion) give no indication of the quantities, frequency and seasonality with which these foods are consumed, and thus give no indication of their relative importance in the diet.
Some researchers have attempted to address the question of the contribution of forest foods to rural diets by calculating potential food production based on scanty species-by-species yield data. Becker (1986), for example, calculates that, in the Sahel, wild plants can supply 10% of the population's food energy needs and, theoretically, 1-5 g./capita/day of wild fruit. Statistical extrapolations (either theoretical or from surveys) do not address the nutritional importance of forest foods nor their seasonal importance.
The examples which illustrate this chapter come principally from site-specific case studies. While case studies do provide more detailed information, it is not clear how much can be extrapolated from them as food consumption is culturally-bound. Nonetheless, the cumulative importance of the following information demonstrates that forest food products are often culturally and nutritionally essential.
Roughly, forest plant food products can be catagorized as leaves, seeds and nuts, fruits, tubers and roots, sap, gum, fungi, salt, and medicines. They collectively add diversity and flavouring as well as provide protein, energy, starch, vitamins, and essential minerals to the human diet. Some products are simply gathered and eaten raw, while others must go through complex processing to be made edible. What follows is an overview of the literature about the types of forest foods commonly consumed.
Leaves
Wild leaves, either fresh or dried, are one of the most widely consumed forest foods. Frequently they are used as the base for soups, stews, and relishes which accompany carbohydrate staples such as rice or maize. This combination is important because in addition to increasing the nutritional value, these wild leafy vegetables add flavour to otherwise bland staple diets thereby encouraging greater food consumption.
The nutritional value of leaves varies greatly. Some species provide fats, others are good sources of protein. Perhaps of greatest nutritional value are the minerals and vitamins they provide. Although the fat content of leaves is generally low, some exceptions are Bidens pilosa (22.5%) and Dracaena reflexa (18%). Ogle and Grivetti (1985) found the protein content to average about 4%, whereas Malaisse and Parent (1985) found an average protein content of 13% in the leaves they analyzed. The leaves of baobab are 13% protein (see Appendix 1 for more details). Mineral and vitamin contents also vary: wild leaves can be excellent sources of vitamin A (e.g. Moringa oleifera 11,300 ug./100 g.), Vitamin C, (e.g. Cassia obtusifolia, 120 mg./100 g.), calcium (e.g. Balanites aegyptiaca, 37,010 mg./100 g.), niacin (e.g. baobab, 8.1 mg./100 g.), and iron (e.g. Leptadenia hastata, 95 mg./100 g.). Thus, the nutritional roles of wild leaf vegetables are to increase palatability, to provide essential minerals and vitamins, and to enhance the quality of protein in the diet.
Many tree leaves, forest herbs, and "weeds" of agriculture are consumed. Malaisse and Parent (1985) found that the leaves of 50 species of trees were used as food in Upper Shaba (Zaire). Common "leaf vegetable" species included Pterocarpus spp., Myrianthus arboreus, Gnetum spp., Bidens pilosa, Adansonia digitata, and Cassia obtusifolia.
In her study of wild leaf plants in Lushoto, Tanzania, Fleuret (1979) found that vegetable relishes are an essential element of the Shamba people's diet. She found that introduced cultivated vegetables were not replacing wild leaf relishes because people preferred the taste of wild leaves and they were traditionally important. In addition, wild leaves are valued because they are cheap and accessible.
Fleuret's survey covered three regions. The quantity and frequency of use of wild leaf vegetables corresponded to readily accessible supply. Wild leaves are used in 32% of all meals consumed. They are the most common ingredient (used 81% of the time compared with 17% for cash-crop vegetables) for the traditional side dish. Another interesting point discussed in the study is that wild leaves, meat and fish are viewed as consumptive substitutes for one another, whereas cultivated vegetables are viewed as a cash crop.
Ogle and Grivetti (1985) have conducted the most thorough study on the uses of edible wild plants in Swaziland, examining the cultural, ecological, and nutritional aspects of wild plant use. They found that over three ecological zones, more than 220 wild plant species are commonly consumed by the 394 people interviewed. The inhabitants of the study area were well integrated into the cash economy, 92% of respondents reported purchasing food regularly, all respondents reported using wild foods. Thirty nine percent estimated that wild plants contributed a greater share to the annual diet than domesticated cultivars. Conversely, 37% reported greater annual consumption of domesticated plants.
The study concludes that the dietary use of wild plants is not minor. The nutrient content of leaves compares favourably with that of cultivated varieties. Especially important are the lysine-rich proteins and minerals of the wild leaf vegetables.
In the previous two case studies, wild leaves were generally boiled fresh in stews. Another common method of consuming wild leaves is after they have been dried and powdered. B. Becker (1983) relates that in the Ferio, Senegal, powdered baobab leaves (Adansonia digitata) are commonly eaten with couscous. These pulverized leaves are sold in most village markets in the area. Baobab leaves are good sources of protein (13.4% of calories), energy (1180 kj./100 g.), calcium (2600 mg./100 g.), and vitamin A (1618 ug./100 g. retinol equivalent).
Leaves may also be fermented. Dirar (1984) found that Cassia obtusifolia leaves are fermented and commonly used as a meat substitute
(Kawal). The fermented leaves are made into a paste or are dried and powdered. Kawal is used in stews and soups which accompany a sorghum porridge. The protein content of Kawal is high (19.7% and 21.9% in two study samples).
Seeds and nuts
Seeds and nuts generally provide calories, oil, and protein to the diet. Edible oil (fat) consumption is often low in developing countries, and can be one of the major household food purchases (Truscott 1986). Low fat diets are thought to be detrimental, especially for children, who need energy-dense foods. In addition to the energy they provide, fats and oils are also important for the absorption of vitamins A, D, and E.
There are numerous examples of nutritionally important nuts and seeds, foremost among tham are the palm nuts: coconut, oil palm and babassu palm. Coconuts are of central importance in many cultures. On a world scale, they represent 7% of the world's fat ration. An estimated 8 billion nuts were consumed "raw" in 1965 (Cornelius 1973). In northeastern Brazil, Babassu kernels provide oil for an average 71% of the households in the region (May et al. 1985a).
The kernel and fruits of the palm oil (Elaeis guineensis) provide the main source of oil in the southern regions of West Africa. In Sierra Leone, for example, Smith et al. (1979) estimates that it is consumed by 96% of the rural households. They add that it is also the main source of vitamin A. Similarly, in southeastern Nigeria, Nweke et al. (1985) estimates that 89% of the households consume palm oil regularly.
Sago palm (Metroxylon spp.) is an important food source for many Asian people. Townsend (1971) found that the Sago palm provided 85% of the energy intake for the rural population in Upper Sepik, Papua New Guinea. Ulijaszek (1983) estimates that Sago is a staple food for one-third of a million Melanasians, and that another million consume it regularly. He adds that those consuming Sago as a subsistance crop come from various social groups, including traders, agriculturalists, and hunter-gatherers.
Other important oil nut trees are the sheabutter nut, cashew nut, african breadfruit, and the mongongo nut (Ricinodendron rautanenii). In most parts of the Sahelian region of Africa, the seeds of Parkia sp. form an important part of the diet. Campbell-Platt (1980) found that fermented parkia (dawadawa) was the most important ingredient of the side dishes, soups, and stews made to accompany porridges in northern and western Africa. The fermentation process improves the digestibility of the protein and increases the vitamin content of the seeds, thus providing an incredibly nutritious protein and fat-rich food. The protein content ranged from 26-47 g./100 g. and the caloric value ranged from 517-618 Kcal.
Campbell-Platt's literature survey revealed that fermented Parkia bean was used:
90/100 days by the Cabrais (Northern Togo).
60/100 days by the Mobas " "
50% of all meals in Ghana's Upper Region
10% of all meals in the Northern Region.
Fruits
There are thousands of species of wild fruits consumed worldwide. Fruit is most commonly consumed raw, as a snack food. Some fruits, such as Artocarpus communis (breadfruit) are dietary staples. Forest fruits are also widely used for making beverages, most notably beer. Fruits are especially good sources of minerals and vitamins and sometimes contribute significant quantities of calories.
In a study on the use of wild fruits in Zimbabwe, Campbell (1986) found that, though there were many fruit species, three species (Diospyros mespiliformis, Strychnos cocculoides, and Azanza garckeana) were the most frequently consumed and also the most highly prized. He examined fruit use at three different sites, accounting for the three main types of tenure arrangements. He found that while the communal land area was heavily populated and had suffered severe deforestation, the prevalence (density) and use of the three favoured fruit species had not been affected by deforestation. Fruit trees had not been cleared, but had been incorporated into the farms. He also found that the abundance of fruit trees showed no relationship with the frequency with which these fruits were consumed. Fruits were most commonly consumed as snacks, only 23% of those collecting fruits stated they would use them for meals.
The nutritional role and importance of snack food have not been examined. Ogle and Grivetti (1985) noted that in Swaziland most fruits are consumed away from the homestead, when working or walking. They concluded that wild fruits were a major source of Vitamin C. One hundred and ten wild fruit species were identified; of these, 13 species were consumed frequently by more than 25% of those interviewed; 34 species were consumed annually by more than 25% of the population; and 8 species were consumed annually by 80% of the population. They found that there was considerable variation in fruit abundance and consumption between ecological zones. In addition, there were differences in who consumed fruit. Children consumed the greatest quantities of fruit.
Roots and tubers
Roots and tubers provide carbohydrates and some minerals. They are drought and famine foods not only because they can persist under reduced precipitation, but also because they can be an important source of water. In addition, roots and tubers are often important ingredients in traditional medicines. Malaisse and Parent (1985) identified more than 40 root species used for food in Upper Shaba. They did not, however, examine the frequency with which they were consumed. Many roots and tubers require processing (soaking, cooking) in order to be edible, perhaps accounting for their use primarily in times of food shortage. As was noted earlier, in recent years the availability of food aid and commercial food supplies may have reduced their use in times of hardship.
In Swaziland, Ogle and Grivetti (1985) found that about 10% of the wild species identified as edible were bulbs or roots. The only species used frequently were the bulbs of Aloe saponaria. Most edible roots were eaten by cattle herders when they were away from the homestead. Similarly in Kenya, Kabuye (1986) found that roots and tubers were consumed only as snacks while herding livestock. In general, roots were considered too time consuming to find and dig up.
Mushrooms
Mushrooms are favourites in many cultures, where they are added to sauces and relishes for flavouring; often they are consumed as meat substitutes. They are good sources of protein and minerals. Parent (1977) analyzed the nutritional value of 30 edible mushroom species from Upper Shaba, Zaire. He found that the mean protein content was 22.7 g./100 g. dry weight. Mushrooms are also extremely good sources of minerals; he found that the mean calcium content was 349 mg./100 g. and average iron content was 1552 mg./100 g.
Mushrooms are often only available for short seasons. In some cultures mushroom gathering becomes a major activity during this period. Parent (1977) found that the Cantharellus sp. were most frequently gathered. He estimated that during the rainy season at least 20 tons are consumed by the approximately 700,000 inhabitants of Upper Shaba. Mushrooms are gathered by women and children, who frequently spend up to two or three hours a day gathering them in the rainy season. The mushrooms are then often marketed. Similarly, in the Mae Sa Valley in northern Thailand, many species of mushroom are collected in the rainy season for consumption and for marketing (Jackson and Boulanger 1978). Sen Gupta (1980) estimates that 30 tons of mushrooms are annually collected from Jammu, Kashmir, and Himachal Pradesh.
Gums and sap
Sap is frequently tapped for beverages, and is often high in sugars and minerals. Gum is used as food supplement, it can also be a good source of energy. Both saps and gums have many medicinal uses, as well.
In northern Brazil, the sap of Babassu palm is used for making wine. The stumps (left after harvesting) are hollowed out and the sap which collects in the hollow is left to ferment (May et al. 1985a). Similarly, the Palmyra palm (Borassus flabellifer) is widely cultivated in southern India for its sap, or toddy. Unopened inflorescences are tapped for sap. One inflorescence can yield two liters of sap a day. The sap is either drunk fresh or left to ferment, becoming palm wine. Another popular palm wine, in West Africa, is tapped from the Raphia hookeri and Elaeis guineensis palms. In this region it is a particularly important cultural beverage and is served at cultural and ceremonial occasions throughout the region (FAO 1989). In southern Cameroon, for example, Koagne (1986) found that it was consumed in all households several times a week.
The gum of Sterculia sp. is used as a dietary supplement by the Wolofs of northern Senegal. It is added to soups and stews. It is a good source of vitamin C (52 mg./100 g.) and vitamin A (396 ug./100 g. retinol equivalent) (B. Becker 1983). Similarly, gum arabic (Acacia senegal) is also traditionally an important food for pastoralists, agriculturalists, and hunter-gatherers alike. Nomads from Mauritania use it to make N'dadzalla, a mixture of fried gum, butter, and sugar. It is also used as a milk substitute when mixed with sugared water (Giffard 1975). Grieve (1967) notes that six ounces is sufficient to support a man for a day. It is often the staple food for gum collectors in the field. The Senegalese Forest Service estimates that 500 tons are consumed annually by gatherers (Giffard 1975). Wichmann (in New 1984) found that it could be used as a dietary supplement, as it increases the intensity of vitamin synthesis.
It is clear from this very brief overview of forest plant foods that a great range of forest plant species are still consumed in many regions of the world. The case specific studies shed some light on the extent to which they are used, but more research is needed on the frequency and role of these foods in people's diets. It is also not clear how the exploitation of forests for foods is changing. This issue will be discussed in section 2.4.
"Forest foods" are generally thought to include only those foods gathered from forest plants and especially from trees. Wild animals and fish are also important forest food products. Forested areas, mangroves, streams and fallow agricultural fields provide a habitat for many wild animal species and fish. Fish and wild game provide a significant portion of the animal protein consumed in rural areas. While it is beyond the scope of this study to address the "protective" functions of forests, the importance of forests for maintaining the habitat of a great number of forest animals -- thus a rural food resource -- needs to be highlighted.
Fish resources
Forests provide and maintain stream habitats for many fresh water fish species, helping to maintain water temperatures and reduce stream sediment loads. In addition, forests -- notably mangrove forests -- provide an essential habitat for coastal fisheries. Forest clearing may cause increases in stream sedimentation as well as water temperatures. Fine sediments can hinder the movement of oxygen through stream gravel which in turn can lead to fish egg damage. Mangrove forests provide important breeeding habitats for many economic coastal species, most notably shrimp and crabs. Other coastal species such as milkfish, shad, sea perch, mullets and catfish are also believed to depend on mangrove areas during part of their life cycle (Twilley 1986, Turner 1975).
Fish and molluscs provide a significant portion of people's animal protein supply. For example, Olatunbosum et al. (1972) found in a study on animal production in Nigeria that the daily consumption of fish was 29 g. per capita compared with 9.15 g. of beef. The Prescott-Aliens (1982) estimated that in Sarawak, Malaysia, fish make up 60% of the daily animal protein consumed, while in the Philippines they estimate fish provide 53% of the animal protein consumed. A survey in the Peruvian amazon (Dourojeanni 1978) showed that inhabitants consumed 135.6 g. of fish per day (or 60%) out of a total animal meat consumption of 221.7 g. a day per capita.
The fresh water fish catch in Asia has averaged more than 4.25 million tons a year (1975-1980). The average annual catch for Africa is estimated at 1.5 million tons (as great as Europe and the Americas combined). In Asia the mainstay of freshwater fisheries are the rivers. In Africa 60% of the freshwater catch comes from the major lakes (Prescott-Allen and Prescott-Allen 1982).
Wild animal foods from forests and farm trees
Wild animals are another important forest food. The range of species consumed includes birds and their eggs, insects, rodents, and other larger mammals. For people living in close proximity to forests and fallow areas, wild animals are often an important part of their diet; in some cases they supply the only source of animal protein. The information on the consumption of game meat comes principally from West Africa, where its consumption is exceptionally high. There are some important conclusions to be drawn from these studies which are valid elsewhere:
- The most important game meat species are small animals (e.g. rodents); this is due to their natural abundance and unrestricted hunting.
- Consumption of game meat is closely linked with the availability of supply; as a result, there is great regional variation in wild meat consumption.
- In areas with "heavy" poaching of subsistence-type species (e.g. antelope, not rhino), which is often the norm in wildlife reserves worldwide, it can be assumed that there is a great demand for game meat.
It is difficult to calculate the extent to which forests contribute wild meat to local diets. In many areas, hunting is often carried out "under-cover," because of hunting bans and regulations. In addition, the more commonly consumed foods, the small animals such as snails and insects are generally eaten as snacks, and so, much like wild fruits, their consumption goes unrecorded in food consumption studies.
The nutritional value of wild animal meat
Wildlife can provide nutritionally important sources of animal protein. The nutritional value of wild meat is comparable to that of domestic meat. In a few cases, wild species such as antelopes, iguanas and pheasants have higher protein contents. Wild animal meats are good sources of iron, vitamin A and vitamin B.
De Vos (1977) noted that the chemical score of rat meat is in the same range as that of other animal foods. The percent of calories which are protein of some commonly consumed wild game ranges from 21.8 to 24.9% (Asibey 1978) although others report a range of 13.7-30.4% (Ohtsuka 1985). For example, the protein content of the grasscutter is 22.3% and of the giant rat is 22.5%, while that of the antelope is 30.4%.
Insects are amazing sources of protein and vitamins. Poulsen (1982) likened caterpillar consumption to vitamin pills. Mungkorndin (1981) found that 100 g. of termites provided 561 calories and that bee larvae are good sources of vitamin D (10 times greater than fish liver oil) and vitamin A (2 times greater than egg yolk).
Many studies focus on the percent contribution of wild meat to overall animal protein consumed. While this may be significant in some cases, extremely small quantities of meat are consumed in many households. Thus the protein contribution may be minimal. However, even in these instances animal foods may add flavour to the main foods thus encouraging people to eat larger quantities. No studies, however, have focused on this issue.
The importance of wild meat in the diet
Wild animal consumption varies greatly from region to region. In West Africa bushmeat is still a major food item for rural households where it contributes between an estimated 20 and 100% of the animal protein consumed (FAO 1989). For example, in Nigeria bushmeat provides a regular source of meat for 53% of the rural population in the southeastern region (Martin 1983). In three southern regions of Nigeria in 1966, Charter (1973) calculated that 19% of animal food came from bushmeat, 60% from fish, and 21% from livestock. While the quantities of wild meat consumed may be declining, 95% of the population were found to consume bushmeat (Martin 1983). In Accra, Ghana, a minimum 98,100 kg. of fresh bushmeat are consumed annually (based on studies at the main market). Asibey (1978) estimates the actual consumption to be ten times this figure.
The variations in bushmeat consumption usually correspond to variations in conditions of the forest. In Nigeria, Charter (1973) found that in areas with no reserve forests and high population density such as Onitsha, bushmeat contributed only 7% of the total meat consumption, whereas in areas near large forest reserves bushmeat provided the majority of meat consumed, 82% in Benin, and 84% in Uyo, for example. Among the rural population in the tropical moist forest (TMF) zone of the Ivory Coast, 70% of the meat consumed is bushmeat; however, bushmeat only supplies 7.4% of the total animal protein consumed country-wide (Ajayi 1979). Similarly, in Cameroon's TMF zone bushmeat supplies 70-80% of the annual consumption of animal proteins, compared with 2.8% for the entire country (Prescott-Allen and Prescott-Allen 1982).
In Latin America, use of wildlife for animal protein is still important in forested areas. Surveys carried out in the Peruvian Amazon between 1965 and 1973 found that rural inhabitants obtain more than 85% of their animal protein from wild animals (including fish). In the Pachitea area, 460 g. of wild meat are consumed daily. In Ucayali, by contrast, 52 g. of wild animal and 135 g. of fish, as well as 34 g. of domestic meat are consumed daily. In Iquitos (peri-urban), it was found that 76 g. of wild meat were consumed daily. In 1977, the estimated production of wild meat in the Peruvian amazon region was 13,000 tonnes. Invertebrates represent from three to six percent of the total meat consumed in this region (Dourojeanni 1978).
In some areas of Botswana, 248 g. of wild meat are consumed daily per capita. Butynski and Von Richter (1974) estimated that Batswana pastoralists get 80% of their animal protein from wildlife. They estimated the value of subsistence game meat to be 2,360,000 Rands.
A good indication of the demand for bushmeat comes from the prices recorded in some cities of West Africa (see Table 2.1). In almost all cases the price of bushmeat exceeds prices of domestic meat varieties. While prices do not indicate the prevalence of bushmeat consumption, they do suggest that consumption is limited by supply rather than changes in cultural values.
In a study conducted at the frontier of the trans-Amazon highway, Smith (1976) also found that wild meat consumption was limited by supply rather than preference. In a newly settled region, he found bushmeat supplied 20% (or 21,033 kg.) of the total animal protein consumed (he also noted that these are conservative estimates biased toward large game). However, in another region, fifteen years after settlement, wild meat supplied only 2% of the total animal protein consumed. The decline was due to changes in habitat and overhunting.
In general, it is the smaller animals which are important for subsistence consumption.
Dourojeanni reported that in Peru 41% of animal protein comes from four species of small wild animals. In South America, the capybara, a giant rodent, is an extremely popular wild meat. A comparison of capybara and cattle shows that the capybaras are 3.5 times more efficient in
productivity and 6 times more efficient in reproductive performance. Butynski (in de Vos 1977) estimated that 2.2 million kg. of meat from springhare are consumed in Botswana annually. This is equivalent to the amount of meat obtained from 20,000 head of cattle.
The most important sources of wild meat in West Africa are the giant rat and the grasscutter. A survey of a market in Accra (Ghana) revealed that grasscutters were the most important wild animal species sold. Seventy five percent of bushmeat sold was meat from grasscutters: 117,226 kg. of a total 155,979 kg. sold. Other important rodents consumed in Africa are the squirrel, palm squirrel, porcupine, and several species of mice (Ntiamoa-Baidu 1987).
(US $/Kg) |
(1) |
(2) |
(3) |
(4) |
(5) |
(6) |
(7) |
Hare (Lepus spp.) |
3.75 |
7.2 |
|||||
African giant rat (Crycetomys gambianu) |
5.0 |
0.51 |
2.33 |
||||
Grasscutter (Trovnovmys swinderianus) |
9.6 |
3.33 |
1.06 |
3.96 |
10.00 |
1.00 | |
Brushtailed (Antherarus africanus) |
4.30 |
3.66 |
1.06 |
3.04 |
2.50 | ||
Tree Hyrax (Dendrohyrax arboreus) |
6.4 |
3.66 |
|||||
Grey duiker (Sylvicapra grimmia) |
6.8 |
0.88 |
4.00 | ||||
Maxwell's duiker (Chephalophus maxwelli) |
2.83 |
3.75 |
|||||
Bay duiker (chephalophus dorsalis) |
2.50 |
0.86 |
2.70 |
||||
Black duiker (Chephalophus niger) |
5.2 |
0.79 |
2.91 |
||||
Bushbuck (Tragelaphus scriptus) |
5.2 |
1.33 |
3.07 |
2.50 | |||
Bushpig (Potamochoerus porcus) |
3.33 |
3.26 |
2.50 | ||||
Spot (Cercopithecus ascenius) |
3.47 |
2.50 | |||||
Red colobus (Colobus badius) |
3.75 |
3.00 | |||||
Civets (Mandinia spp.) |
1.88 |
3.35 |
|||||
Beef |
2.50 |
4.2 |
0.45 |
3.00 |
2.50 | ||
Mutton |
3.50 |
2.8 |
0.61 |
6.00 |
4.00 | ||
(1) Cameroon, Sabouang, 1978 (2) Nigeria, Ibadan, 1975 (3) Nigeria, Bendel State, 1977 (4) Ghana, Accra, 1970 |
(5) Ghana, Accra, 1985 (6) Cote d'Ivory, Abidjan, 1978 (7) Liberia, Monrovia, 1979 |
||||||
Source: Asibey, 1986 | |||||||
Despite the importance of small game species it is generally assumed that the prevalence of small game and rodents in the diet is due to the paucity of large game rather than taste (de Vos 1977).
Wild animals on farms and fallow lands:
Agricultural lands, especially fallow lands provide a habitat for many wild animal species. For example, in West Africa the popular grasscutter has expanded its natural range farther south into cleared and fallow farm areas (Asibey 1986). Some studies suggest that one benefit of incorporating trees into the farming system is their provision of a habitat for wild animals. Farmers in northern Brazil's babassu palm region rely to a considerable extent on hunting for animal protein. The babassu palm fruits are important foods for two large rodents, the pacas and the agouti. Stems of fallen palms are often left in situ in order to attract beetle larvae, which are then gathered and cooked (May et al. 1985a).
In a study of the trees in paddy fields of northern Thailand, Grandstaff et al. (1985) found that among the values of trees planted on dikes and in the paddy fields, provision of wildlife habitat was important. Lizards, rats, birds and tree ants were among the species caught and consumed. Similarly in the Peruvian Amazon, farmers set up hunting platforms in old fallow farm areas, near animal feeding trees. Indeed the trees which are managed in the fallow are included in part because they are a food tree of the most favoured wild animals (both for skin and meat) (Padoch et al. 1985).
Many species of trees in the tropics are used for fodder, either for browse or stall feeding. Wickens et al. (1985) estimate that 75% of the tree species (7,000-10,000) of tropical Africa are used as browse. Fodder trees contribute in several ways to the overall food security of households: they make a significant contribution to domestic livestock production which in turn influences milk and meat supply; in addition, fodder contributes to maintaining draught animals and producing manure for organic fertilizer, thereby supporting agricultural production. Tree fodder may consist of leaves, small branches, seed pods and fruits. Generally it supplements other feed. In arid regions, it can be a crucial component of the livestock diet during the dry season. Tree browse can also be a nutritionally important component of livestock feed, providing protein, minerals and vitamins.
Among the main products of domestic animals, milk and meat play an important role in human nutrition. In Keita, Niger (rural area), the daily consumption of meat was. measured as 14 g. per capita, while in urban centers in Senegal (Dakar and Louga) the daily consumption was around 25 g. per capita. On the other hand, daily milk consumption was higher in rural than urban West Africa: 70 g./capita in Keita versus 15 g./capita in Dakar.
In arid regions tree fodder is especially important in the dry season when grasses are no longer available. For example, Acacia albida is an important fodder species in many regions of sahelian Africa. During the dry season, its pods can account for as much as 30-45% of the total feed intake. In many parts of this region, its pods are sold in markets as a special feed for weakened animals (Wentling in New 1984). The Turkana in Kenya use 87% of their surrounding vegetation for fodder for different types of livestock, important among them are browse species (Morgan 1981).
Tree species also provide fodder in humid regions in the tropics. In western Java, for example, trees contributed 15% of the fodder to the diets of small ruminants in the dry season (maximum). This fodder was used for stall feeding. In Nepal, many farmers have incorporated fodder trees onto their farm lands (Heuch and Shrestha 1986). The relative importance of farm versus forest land sources of browse varies greatly from region to region. In some areas farmers have as many as 90 fodder trees on their land. In southeastern Nigeria, fodder species are of growing importance on farm and fallow lands: the most popular species are Ficus sp., Baphia nitida, Acioa barteri and Newbouldia laevis (Okafor and Fernandes 1987).
Honey is a much-valued product from forested areas around the world. Trees often play an important role in honey production as they collectively (because of different flowering times) provide year-round fodder for bees. Newman (1975) found that honey is a very important food for the Sandawe agriculturalists. It is collected three times a year. Local honey is highly esteemed and highly priced in Oman: 450 g. may cost over 20 Rials (ca. £41) (Lawton 1984).
Honey is nutritionally valuable, especially for the energy it provides: 100 g. of honey has over 280 calories (Sen Gupta 1980). Honey production is an important small industry in India. In 1975-76, 33,000 villages produced 32,000 tonnes of honey and 13 tonnes of wax. These data only represent the reported cultured honey production. Honey production from the wild can be assumed to be much greater (Sen Gupta 1980). Suryanarayana et al. (1984) reported that 5 million kg. of honey was produced from colonies of Apis cerana in India. They also noted that yields from oilseed, pulse and fruit production can be greatly improved through beekeeping in field areas -- this however requires the presence of "honey trees" for year-round bee food sources.
The first section of this chapter examined the various foods which are gathered from forests and farm trees. The following two sections explore the importance of forest products for overall nutrition as well as their role in household food security. Figure 2.1 illustrates the linkages between forestry and household food security. Products such as forest foods (discussed in the last section), fodder and protective functions (such as ameliorating soil conditions) all contribute directly to the quantities of food available to the household. In addition to these products, fuelwood and raw materials for enterprises (discussed in chapter 3) provide cash income for food purchases. Finally, forest products such as fuelwood and medicines may have an impact on people's health and thus their nutritional well-being. The Figure illustrates the essential link between people's food supply and health status. While the linkages between health and nutrition can be fairly complicated, there are some nutrition related health problems which are common in many developing countries (a few examples of these are summarized below). It goes beyond the scope of this study to examine these linkages in detail. However, it is clear that identifying key nutrition problems is an important first step for assessing the potential role of forestry for improving household diets and overall nutritional well-being.
Low energy intake and low protein-energy ratios:
Perhaps the most serious nutrition problem is a deficiency of calories resulting in what nutritionists call protein-energy deficiency. In most cases this problem is best addressed by increasing the quantities of food, especially energy rich foods, available. In many cases these food shortfalls are highly seasonal. In northern West Africa, for example, Annegers (1973c) noted that energy shortfalls were seasonal. Annegers found that, though the diets of many peoples in the northern regions were low in calories, they were high in protein. In southern regions, diets based on tuberous crops generally had low protein and energy contents. There were higher incidences of protein-calorie malnutrition in the South compared with the North. The same phenomenon has been noted by several authors, notably Chambers and Longhurst (1986). In these cases forest foods high in oils would make appropriate additions to the diet. In general, with the exception of oil rich seeds and fruit, forest foods can do little to address the energy needs of rural populations, at least on a large scale.
Low levels of vitamin A intake:
This is one of the more notorious diet problems. Low levels of vitamin A intake can result in blindness; some 250,000 children go blind in Southeast Asia yearly because of lack of vitamin A (FAO 1983b). Many forest fruit species, as well as leaves, are good sources of this vitamin. One good source of vitamin A is palm oil which is widely consumed throughout West Africa. Longhurst (1985) estimates that it provides 14% of the total energy intake in the Sierra Leonean diet, as well as being the primary source of vitamin A. In addition to the quantity of vitamins consumed, other factors influence the body's ability to use vitamin A. Vitamin A needs fats in order to be digested and synthesized; thus, a low fat diet can contribute to problems of vitamin A deficiency. Therefore, nuts and oil seeds, in addition to fruits, could help to ameliorate this nutrition shortfall.
Low levels of riboflavin intake:
A common nutrient-related health problem is riboflavin deficiency which is responsible for several eye and skin disorders and usually indicates a deficiency of all the B vitamins. Caldwell and Enoch (1972) noted that riboflavin deficiency is widespread throughout Southeast Asia. Campbell-Platt (1980) noted that it is also a common problem throughout Africa. Many forest foods, especially leaves are good sources of this vitamin. Caldwell found that wild leaf vegetables had significantly higher riboflavin contents than cultivated varieties, 0.4-1.2 mg./100 g. compared with 1-0.3 mg./100 g. The leaves of the cashew nut were found to have the highest values (comparable to that of eggs, milk, and fish). Information on the nutrient contents of specific forest food species is presented in the Appendices.
Iron deficiency and low intake of other minerals:
Iron is essential for the manufacture of blood haemoglobin. Low levels of iron intake pose a major health problem in many regions, particularly in Africa, often leading to aenemia. Iron is of particular importance for pregnant and lactating women. Many forest foods, especially leaves, supply dietary iron (see Appendix 1 for information on nutrient composition of different forest leaves) (Latham 1979).
Other minerals are also essential for a well-balanced diet. Though brief and undoubtedly simplistic, what follows gives some meaning to the term "essential":
- Calcium is necessary for bone formation.
- Copper and Magnesium are needed in the conversion of iron to
haemoglobin, and the functioning of enzymes.
- Magnesium is needed for enzyme function.
- Phosphorus is essential for kidney functioning and niacin
assimilation.
- Zinc is essential for protein syntheses, insulin formation, and blood stability.
Lack of diet diversity:
The quantities of foods consumed are not adequate measures of nutritional "adequacy." A diverse diet is more likely to be a nutritionally well-balanced diet. More important, the use of different foods, even in small quantities improves the flavour of bland staples such as rice or millet and thus tends to increase the overall consumption of the staple
foods.
One of the most common causes for dietary deficiencies and food insecurity in general appears to be the decreasing diversity of traditional diets (Parkinson 1982, Thaman 1982, Fleuret 1979, Truscott 1986). Both Parkinson and Thaman have found that the diets of Pacific Islanders have become less diverse, more dependent on imported cereals, and show preference for introduced vegetables with lower nutrient quality. Fruit and leaf vegetable use has been greatly reduced, with a consequent reduction in vitamin and mineral consumption.
It is often assumed that increased income and assimilation into the cash economy will have a positive impact on people's nutrition situation. However, several studies have shown that this is not always the case (see section 2.4 for further discussion). In rural Bangaladesh, Hassan et al. (1985) found that while "modern" villagers who grew three rice crops had greater food availability throughout the seasons, they suffered higher occurrence of malnutrition than those in traditional villages which only had two rice crops. Hassan et al. surmised that this was due to a reduced diversity of foods in the diet, higher energy expenditure (because of the third crop production), and poorer hygiene. Some interesting comparisons emerged. While the modern villagers consumed more rice and wheat and thus more calories, as well as more protein per capita per day, the traditional villagers consumed more roots and tubers (89 g./cap., compared with 26 g./day/cap. before "aus" (one of the harvests)), more pulses (21 g./day/cap. compared with 14 g./day/cap. before "aus"), more vegetables (especially leafy vegetables) and more fruit (191 g./day/cap. compared with 52 g./day/cap.). Over the year, the mineral and vitamin content of the diet was significantly greater in the traditional compared with the modern village.
The links between health and nutrition are clear. The links between forestry, medicines and nutrition are extremely important although little research has been done in this area. Many intestinal diseases, for example, can lead to malnutrition as food simply is not properly absorbed by the body. In addition, diseases can be debilitating or can reduce labor efficiency in periods crucial to agricultural production, such as during
the planting period.
Forests often provide the only medicines available to the vast majority of the world's population (75-90% of the developing world). Many studies have catalogued the use of medicinal products gathered from the forests (see for example Burkhill 1985, Kerharo and Adam 1974, Heinz and Maguire 1974, and Von Maydell 1986). It is beyond the scope of this paper to address the effectiveness of these systems. However, a few points can be made. Some plants contain high concentrations of different chemicals which are the base for modern drug equivalents. Secondly, many plants chosen for their medicinal qualities are high in particular vitamins and minerals which can counteract illnesses caused by vitamin shortages or meet a need for additional quantities of a particular vitamin or mineral.
The quality of water can directly influence disease prevalence. Forests and forest products can indirectly and directly affect the quality of this supply. Forests act as water supply regulators, ensuring higher levels of year-round water. They also protect against high sedimentation by acting as filters. Fuelwood shortages may negatively affect the quality of water used, as cooking time is often reduced and boiling water is curtailed.
A few forest tree species have interesting properties which can affect the quality of water supplies. Moringa sp. are used by women in Egypt and the Sudan to clarify turbid water. The seeds of the tree contain natural coagulants which can clear water to tap water quality in 1 to 2 hours. The elimination of turbidity is accompanied by a 98-99% elimintation of indicator bacteria. Thus the use of moringa seeds can provide a low cost water treatment technology, thereby improving the health of rural communities (Jahn et al. 1986).
The fruits of Balanites aegyptiaca and Swartzia madagascariensis contain saponins, which are lethal to the snails which act as the intermediary host of bilharzia, as well as to the water flea, which harbors the guinea worm. Planting these species along irrigation banks could do much to prevent the occurence of the diseases (Wickens 1986). Other species with important molluscicidal properties include the bark and fruit of Balanites aegyptica, the shell of Anacardium occidentale, and the seeds of Phytolacca dodecandra and Swartzia madagascariensis.
Forests may provide habitats for several endemic disease carriers. Notorious among them is the tsetse fly, which causes trypanosomiasis infecting humans and livestock. The range of livestock use in Africa is directly related to the tsetse fly areas. This phenomenon can directly affect human populations by making them more susceptible to diseases or, as in the case of tsetse, indirectly affecting nutrition by limiting the supply of animal protein and milk.
Fuelwood is the main energy source in most Third World rural communities. All cooking and most food processing is dependent on fuelwood. As such, fuelwood supplies indirectly affect the stability and quality of food supplies. With fuelwood supplies diminishing in many rural areas, the possible impacts on nutrition need to be examined. While there are few studies which have examined the links between nutrition and fuelwood and thus little evidence from which to draw conclusions, a few important relationships have been identified. Figure 2.2 summarizes the linkages between the conditions of the forest resource, fuelwood availability, women's labour and household nutrition.
Fuelwood supply can influence the amount of food supplied or cooked.
Cecelski (1984) reported that, in Somalia, refugees fed their bean rations to their livestock or discarded them because they could not afford the fuelwood to cook them. While this is an extreme case, it serves to illustrate the fact that whole grains and legumes are inedible without cooking.
In a fuelwood study in Ghana, Ardayfio (1986) found that, over a year's survey period, the proportion of the household budget taken up by fuelwood purchases rose from 1% to 16.3% in one village. Thus, money that shad otherwise been spent on food had to be spent on fuelwood. Many authors report a reduction in the number of meals cooked (Agarwal 1986, Alcantara et al. 1985, Cecelski 1984). It is not clear whether the total amount of food consumed is reduced. Nor is it clear that fuelwood scarcity is the cause for this decline. Generally fuelwood scarcity is associated with other problems such as food scarcity, increased work loads, commercialization and and the availability of processed foods.
Source: Soemarwoto and Soemarwoto 1984 based on Danoesastro 1980
In Rwanda, 62% of all families cook only once a day. Thirty three percent cook even less (Lidju and Bamuhiga 1982). In the Sudan, Hammer (1982) reports that food is cooked once a day instead of the customary three times because of fuelwood shortages. The reduction in cooked meals has a negative effect on children's nutritional status. If the staple foods are starchy, a child cannot digest adequate calories in one meal alone (Cecelski 1984).
Fuelwood shortages can affect the quality of foods consumed.
Fuelwood scarcity reduces the quality of the diet if women have to cook for less time; in some instances the food may be undercooked, in others the consumption of reheated foods may increase. In Peru, Alcantara et al. (1985) found that, in one study area, the consumption of half-cooked food was common and affected the nutritional status of families, especially during the rainy season. Similarly, in Nepal, diets include more raw food because of fuel scarcity (Cecelski 1984). Undercooking and reheating leftovers can have a serious impact on disease incidence. This is especially true of meats (because of parasites), tubers, and legumes (because of toxic substances lost in cooking).
Also associated with fuelwood shortages are changes in the diet. In particular, several authors have noted that an increase in consumption of fast foods and purchased snack foods is a reaction to increasing fuelwood shortages (Cecelskí 1984, Agarwal 1986). Generally, it is assumed that these foods are of lower nutritional quality than traditional foods, though little has been said to support this claim. There are many factors associated with the dietary changes discussed above, including income, labor demands, and changing cultural values. However, it is also clear from these observations that fuelwood supply is linked to nutritional needs and problems.
Several authors have suggested that there is a limited amount of time women can afford to spend on fuelwood collection and cooking. As fuelwood gathering takes increasing amounts of time, it leaves less time for cooking. In Peru, an average of five hours was spent daily on cooking and fuelwood gathering. As the amount of time spent gathering fuelwood increased (from 10% to 33%), the amount of time spent cooking was reduced (from 90% to 67%), (Alcantara et al. 1985).
Fuelwood is an important "ingredient" in food processing.
Food processing is of central importance to nutritional stability, as it serves to extend the supply of a food resource into a non-productive period. Traditionally, products are smoked, dried, or cooked. In a study on fuelwood use in Sierra Leone, Kamara (1986) found that 13.4% of the household firewood energy was expended on processing farm produce. Mascarenhas et al. (1983) found that 90% of the fish catch from Lake Victoria (Tanzania) was smoked. The fuelwood scarcity in the region has meant that the cost of processing has gone up and has been passed on to the consumers. In other fishing regions, lower percentages of fish were smoked: in Arusha 35% of the catch was smoked, in Dodoma 50% was smoked, and in Singida 57% was smoked. They also found that 80% of the households brewed beer using firewood. In another study of Lake Victoria fisheries, Mnzava (1981) reports that 59,000 tonnes (of a total 65,415 tonne catch) of fish were smoked in 1977. It is also assumed that an additional 30% were consumed and were not recorded. Of these, some were smoked. He also estimated that between 1975 and 1981 an estimated 152,000 m3 of wood was used to cure 759,000 tonnes of fish.
An important issue for social forestry projects as they relate to nutrition is the extent to which farm trees meet nutritional needs of the households. Trees are left in the fields and planted around homesites, usually for the food and income they provide (See section 4.2 for a more detailed discussion of home gardens). In a study of home gardens raised by women in Puerto Rico, Immink et al. (1981) found that home gardens positively affected the overall nutritional status of the associated households. The home gardens appear to increase the total food supply during certain seasons. In particular, intakes of vitamin A and vitamin C were improved, especially in children.
Similarly, from a survey of 40 households of the Philippines
home gardens, Sommers (1978) found that nearly all the households could meet the recommended daily requirement for vitamin A, vitamin C, iron and calcium; over half could obtain a sizeable contribution towards their thiamine, riboflavin and niacin requirements and one in four households could meet their protein and energy requirements, with the outputs and resources from the home gardens. Okafor and Fernandes (1987) reported from an analysis of the edible parts (fruits, seeds, nuts) of some trees in the compound farms in southeastern Nigeria that most of them contained substantial quantities of fat and protein. They found that seeds of Irvingia gabonensis, nuts of Tetracarpidium conophorum and fruit pulp of Dacryoides edulis are rich (44-72%) in fat, whereas nuts of T. conophorum and Pentaclethra macrophylla contain high quantities (15-47%) of protein.
Widagda (1981) reports that home gardens in West Java produced 4.5 million calories and 58.5 kg. of protein per hectare, which compared favorably with the 5.15 million calories and 113.5 kg. of protein per hectare of irrigated rice. Soemarwoto (1987) found that rice fields produced foods with higher protein and caloric contents than home gardens, but the latter produced foods with higher levels of calcium, vitamin A and vitamin C.
In northern Thailand, Grandstaff et al. (1985) found that a vast majority of the trees planted in paddy fields and on dikes, as well as many naturally occuring species, had food uses. Gielen (1982) found that an increasing number of farmers in Machakos, Kenya, were growing fruit trees. Sixty-nine percent of the farmers grew bananas for food in the lean season.
