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I. Forestry and nutrition

Linkages between forestry and nutrition
Contributions to nutritional well-being
Assessing nutritional well-being

Linkages between forestry and nutrition

The relationship between forestry and nutrition may go unnoticed by development professionals. Yet the connection is important. Forests and trees contribute to the nutritional well-being of many people and are especially important for the poor, who may depend on natural resources for many purposes.

Some nutritional implications of forests and trees

Coconuts produce a good, almost sterile oral rehydration fluid; a high energy food; oil for cooking or soap-making; foliage for roofing; husks and wood for fuel; shade under which other foods grow and animals live.

Plantains, bananas and ensete (false bananas in Ethiopia) may be the staple high carbohydrate food of 30-50 million people in the world; an important supplementary food for millions of others.

Mulberries may form the basis for a silkworm industry, providing income and food for many people.

Fruit orchards may produce most of the carotene (vitamin A) and vitamin C in diets.

Trees may provide a place away from the field and footpath as a designated place for defecating and urinating, as in India. In this way they may lessen transmission of diseases linked to malnutrition (Latham 1988).

Not surprisingly, forests and trees provide many edible products. Although these foods usually are not dietary staples, they play a supplementary role in the diet. Wild leaves and fruits contain necessary vitamins. Seeds, nuts, roots and tubers supply fats and carbohydrates. Mushrooms, gums and saps provide protein and minerals. Wild animals often supply the majority of meat consumed by people living near forest areas. Forest foods also contribute to diet diversity and consequently may improve the quantity and quality of food intake. Forest foods are often seasonally important. Those foods available for longer periods or during the "hungry season" ensure that rural people eat when agricultural products are not yet available and/or when storage facilities have emptied. Finally, tree products such as roots, nuts, honey and stems furnish needed energy during famines or natural disasters.

Forestry also contributes to food production through environmental protection. Various trees with deep rooting systems extract nutrients from deep in the soil and deposit them in the form of leaf litter. This leaf cover enriches the soil and helps retain moisture. Nitrogen fixing trees also contribute to soil fertility as does the shade which lowers surface temperatures. Trees and shrubs planted and managed as wind breaks can help control erosion, thereby stabilizing soil quality and helping agricultural production. Moreover, fodder for animals collected from forests and trees enhances meat and dairy production.

Another linkage between forestry and nutrition is fuelwood. Fuelwood scarcity can influence household nutrition in a number of ways: cooking foods, boiling water and allocation of women's time. If fuelwood is scarce, women may be forced to ration cooking times. This can lead to decreases in food consumption or meal frequency. In turn, the nutritional well-being of household members may suffer. Additionally, fuelwood scarcity may increase the incidence of illness resulting from contaminated water or improperly prepared food. Finally, the amount of fuelwood available for household use influences the time women spend collecting fuelwood and thus the time they have for food production and preparation, income generation, child care and leisure.

Income and medicines also link forestry and nutrition together. Selling fuelwood, wild foods, medicines and forest raw materials or employment in forestry bring essential monetary income to many households. In addition, medicines, which originate from tree products, help keep humans and livestock healthy.

Forestry products and benefits, overall household welfare and household nutritional well-being all affect one another. Their relationship is characterized by a complex web. The diagram in Figure 1 outlines some of the factors that influence one another. The graphic is not all-inclusive and is complicated. It only attempts to indicate the range of factors that interact to form links between forestry and nutrition. It identifies forest products and benefits that can influence nutritional well-being and can often be targeted by forestry projects.

Figure 1 Forestry products and benefits related to nutrition

Contributions to nutritional well-being

In much of the world, individuals and households suffer from problems of undernutrition. The causes of these problems are complex and the consequences often lead to a "vicious circle of malnutrition." On the individual level, food consumption and infection determine nutritional status. However, food consumption and infection are, in turn, affected by many other social, political and economic factors. The most pressing of these is poverty.

Crop variation

While commercialization in small-scale farming households is a necessary development, changes in crop variation policies such as monocropping can lead to a decrease in diet diversity and to malnutrition. Hassan et al. carried out research on the extent of malnutrition in two villages in Bangladesh between 1981 and 1982. The first village employs traditional farming practices, is double-cropped and flooded. The second village, on the other hand, is triple-cropped and non-flooded but has irrigation facilities, high yielding variety seeds, and chemical fertilizers and pesticides. Researchers found that in this second, agriculturally modern village which specializes in cereal crops, there is a greater incidence of vitamin A and vitamin C deficiency. The researchers concluded that one of the factors affecting the higher incidence of nutrient deficiencies in this village was decreased food diversity caused by less crop variation (Hassan et al. 1985).

The quality and quantity of an individual's food consumption is predominantly determined by the level and variety of the household's food supply. The food supply consists of foods produced, foods stored, foods gathered, foods given as aid and foods purchased. Many different factors affect the amount and quality of food produced and purchased including agricultural and marketing policies,1 land holding patterns and laws,2 labour availability, women's time3 and cash income. The importance of stored foods should not be underestimated given the seasonal nature of food production and gathering. Food storage facilities and food preservation techniques have a large impact on the household food supply.

1 For example, cash cropping and crop variation.
2 For example, landlessness, land poor families and access to commons.
3 For example, for food production, food preparation and child care.

Infectious diseases also contribute to malnutrition through the synergistic relationship between malnutrition and infection. Malnutrition lowers resistance to infection, and infection increases the likelihood of nutritional deficiencies. Infections often result from poor environmental conditions due to lack of sanitation or clean water. These infections may persist unchecked due to an absence of health facilities. Moreover, activities that modify environments may influence the spread of infection. Water, for such purposes as irrigation, hydro-power or transportation and natural environments of forests or bushlands may constitute habitats for disease-spawning animals and insects. Mosquitos, which thrive in bushland environments, and snails and flies, which thrive in water environments, carry parasites responsible for malaria, schistosomiasis, and onchocerciasis. These infections in turn contribute to malnutrition by affecting the body's ability to consume and absorb foods.

Figure 2 diagrams the factors that, alone or in combination, contribute to malnutrition. The figure indicates that forestry can influence the factors that contribute to household welfare and affect nutritional well-being. Once again the diagram is only illustrative and not all-inclusive.


The concept of vulnerability is often used interchangeably with poverty. However, as Chambers (1989) points out, the concepts are not identical. Poor people lack, but vulnerable people are defenseless, insecure and exposed to risks and shocks. Community members often define security as a priority and projects must begin to consider vulnerability and not just economic poverty.

Nutritional vulnerability is a particular instance of vulnerability. Certain individuals tend to be nutritionally "at risk" especially if their household is at risk. For example, due to rapid growth, children require frequent feedings of foods with high energy and nutrient content. In addition, because children explore and play in many areas and in large groups, they are more prone to infection than adults. Pregnant and lactating women are also vulnerable to nutritional problems as they require additional food for the growth of the fetus and for milk production. Moreover, households that consume monotonous diets of maize or highly milled rice or that are living in particular areas such as those with insufficient iodine in the soil, may be vulnerable to nutritional disorders. Further, communities may be nutritionally at risk because of seasonal variations in the food supply.

Nutritional deficiencies

Vitamin deficiencies are not the major nutritional problems. The overall major nutritional problem is inadequate caloric intake. The four most serious nutritional deficiencies in the world today are those involving a lack of calories (protein-energy), vitamin A, iron and iodine. Protein-energy malnutrition (PEM) may result from inadequate consumption of food or from disease and usually manifests itself in children through inadequate growth, severe loss of weight, and lack of energy. In extreme cases, swelling or changes in skin, hair, face and mental capacity indicate the presence of PEM. Severe cases of PEM can be fatal. Vitamin A deficiency seriously affects the eyes (causing blindness in extreme cases), is often related to PEM, and is frequently precipitated by infectious diseases. Iron deficiency can lead to nutritional anemia, causing tiredness, shortness of breath, heart palpitations and, in extreme cases, death. Finally, iodine deficiency can lead to goitre (swelling of the thyroid gland) and cretinism in children born to mothers with iodine deficiency. Niacin, thiamine, vitamin C, vitamin D and riboflavin deficiencies may be problems in certain communities. A deficiency of a single nutrient alone is rare. For example, although riboflavin deficiency alone is not serious, it usually indicates a deficiency in all the B vitamins.

Figure 2 Contributions to individual nutritional well-being

Assessing nutritional well-being

Nutritionists use many types of information to evaluate nutritional well-being. For example, health statistics, vital statistics, anthropometric data, food science information, diet surveys, agricultural data, economic data, socio-cultural data, clinical examinations and laboratory tests can be helpful.4 In most forestry projects, examination of these types of existing data will improve the project planning process. Ministries, nutrition institutes, local universities, health centres or dispensaries are possible sources of information. Another essential information source is the community itself. Local officials, members of women's groups, traditional midwives and others know what is happening in their community and can offer their own perceptions and state their needs.

4 Often, nutritionists compare anthropometric measurements (such as height and weight) to reference standards to determine nutritional status. In a forestry project with a nutritionist this is an important method for obtaining background nutrition information and for monitoring and evaluating the project. However, it may not be a feasible or adviseable to measure project success by having foresters weigh and measure babies. Thus, because the term nutritional status often reflects anthropometric measurements, the term nutritional well-being is used throughout this guide.

Table 1 describes the different types of information listed above. The table contains possible sources of information and explanations about how forestry project planners might be able to use the information.

Women's role in nutrition

Women are crucial in maintaining the nutritional well-being of family members for several reasons. Most notably, women play a central role in household food security. Their role in food production is well known but often minimized. In Africa it is estimated that women make up 60-80% of the labour force involved in food production. Additionally, some studies indicate that income received by women is more often used for food purchases than is men's income.

Within the household, women have responsibility for food storage, processing, preservation, and preparation in addition to their duties as child rearer, water and fuel carrier, etc. The labour demands on rural women are tremendous. The many demands placed on a woman's time mean that she cannot devote much time to any one activity, thus even her food production function has had to be altered in order for her to meet other demands. For example, in Zimbabwe, rural women have changed their crop production from the nutritious crops of sorghum, millet, and groundnuts to maize because the processing of the former crops is so demanding (Tagwireyi 1987).

Table 1 Assessing nutritional well-being





Health and nutrition information

Health centres, nutritionists and health professionals

Existing information to determine the nutrition and health situation in the area.

Vital statistics


Existing information to determine the nutrition and health situation in the area.

To set project objectives

Food science information nutrient content, biological availability, toxicity, food processing


Existing information to select species based on the community's nutritional needs

Anthropometric data

Nutrition institutions, nutritionists

Existing information to determine the nutritional situation in the area.

To determine the nutritionally vulnerable

Clinical examinations

Health professionals

Requires highly trained medical personnel and thus may be difficult for some forestry projects.

Laboratory tests

Health professionals

Requires highly trained personnel and large hospital facilities and thus may be difficult for forestry use.

To create a pool of baseline data for use in monitoring and evaluation

Dietary surveys

Nutrition institutions, nutritionists

Determines overall food consumption patterns including forest and tree foods eaten.

Agricultural data food production, food balance sheets

Nutritionists, agronomists, ministries, community members

Determines scarcity periods and food storage capacity. Determine food uses of trees and forests including snack foods. Determines the vulnerable.

To develop an idea of the level and types of existent indigenous knowledge

Economic data purchasing power, food prices and distribution

Economists, ministries, community members

Determines income distribution and the nutritionally vulnerable.

Sociocultural data food consumption patterns, food practices and beliefs

Community members, sociologists, universities, anthropologists

Determines child feeding practices, key food consumption, fuelwood use, women's workload.

To select indicators5

5 Only the last four types of information can reliably be used in the selection of indicators

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