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Sow's ears and silk purses-non-timber forest product identification, assessment, and monitoring

H. Gyde Lund
USDA Forest Service, FIERR
P.O. Box 96090
Washington, D.C. 20090-6090, USA


There are possibly an infinite number of potential products available from the life forms on our forested lands. The `products,' or functions of organisms, such as plants and animals, may provide useful goods or services for human needs. Methods to identify use include observation, inquiries, reading and research. Assessment and monitoring techniques depend on the life form being studied, its abundance, habitat, and whether it is domesticated or not. Where specific commodities have not been identified, using multiple resource inventories is recommended.


The theme of this international conference is `Domestication and Commercialization of Non-timber Forest Products in Agroforestry Systems'. It is appropriate that this conference starts with a paper on product identification, assessment and monitoring. But why are we looking for new products, uses and services from our wild lands? We do this because we want to-

We need new products to feed and shelter our increasing population and to keep people healthy. With more inhabitants, there will be more pressures on the land. Simultaneously, there will be an increasing need to preserve our natural resources for environmental, ecological, social and economic needs. If we can find new uses for the resources on our `wild' lands, we can probably preserve and sustainably use these resources. Simultaneously, we can probably maintain the much needed diversity.

Is it important that we sustain both biological and economic diversity? We need biological diversity to maintain viable populations of plant and animal species, gene pools, and to provide new product sources. Most nations have agreed to conduct biodiversity surveys and to sustain the existing diversity (anon 1992, 1993). We need economic diversity to minimize risk in the event that our primary income sources fail.

If we can find new products from our lands, we can bolster what may be a sagging or nonexistent economy. Development of non-timber forest products can provide a stimulus to conservation and sound resource management through incomes generated by local people, and through its contribution to national incomes and export earnings.

Products and product identification

A product is an outcome of work (including hunting, gathering or manufacturing) or the growth of living things. Labour, study and skill can increase the quantity and quality of products. The source of a product may be animal, vegetable, mineral, or a combination. Harvesting or conversion of plant or animal material into forms suitable for human use is an example of production.

Non-timber products are any from forest lands, other than those used for building or structural purposes. Non-timber products may include minerals, water, fauna and flora (including woody parts used for fuels) used for medicinal, cultural, ornamental, or religious purposes.

Every product on our planet is derived, one way or another, from natural resources. There are over 100 chemical elements and 1000 minerals. The potential number of products from the earth's living organisms is almost countless. This paper focuses on the living (renewable) resources. Failure to recognize the potential of the flora and fauna we have on hand is a serious weakness in our quest to develop new products.

We have an obvious lack of knowledge about the identity of the species there are on earth. There are an estimated 7-20 million species of life on earth-with the real figure probably falling between 13 and 14 million (Hawksworth & Kalin-Arroyo 1995). Of these, some 1.7 million organisms have been described (table 1).

Table 1. Approximate numbers of species in major life forms (in 1000s)

Group Described species (no.) Total species in group (estimated no.)
Viruses 4 400
Bacteria 4 1000
Fungi 72 1500
Protozoa 40 200
Algae 40 400
Plants 270 320
Nematodes 25 400
Crustaceans 40 150
Arachnids 75 750
Insects 950 8000
Molluscs 70 200
Vertebrates 45 50
Others 115 250
Totals 1750 13620

Source: Hawksworth & Kalin-Arroyo 1995

Approximately half of the 13 million species are believed to be insects. For vertebrates, there are about 45 000 described out of an estimated 50 000. There are 240 000 described vascular plants out of an estimated 320 000. Of the 240 000, 25% are believed to be edible. Up to 5000 plants have been used for food, although most of the world's people rely on less than 200 (Stelljes et al. 1995). These 200 plants provide about 90% of human food supplies.

Another information shortcoming we face is how we can use these organisms. There is a potential for any species to be beneficial to humans. To make the situation more complex, we may use the entire life form, just parts of it, or its by-products.

There is an old saying `we use everything from the pig but the squeal'. From animals, we may use the exterior (skins, shells, hides, furs, antlers, horns, hooves), interior-meat, fats, bones, teeth, body liquids (venom, milk, blood, oils, musk), DNA, body parts and organs (eyes, ears, stomachs, livers, intestines), or animal products-such as nests, honey, wax, silk, and even excrement. From plants, we may use fruits, nuts, seeds, leaves, stems, bark, saps and resins, germplasm, roots or even the genes.

Besides products, many life forms can provide services that directly or indirectly benefit humans. For example, we use dogs to herd sheep, provide guard services, detect drugs, etc. We use insects such as the praying mantis (Mantis religiosa) or ladybugs (Hippodamia convergens) to control other insects. Certain fish control algae. We use many plants for their beauty or for their environmental functions of soil stabilization, watershed protection and carbon sequestration.

How do we go about learning what organisms will be useful? There are several ways:

· Ask someone, especially people in the local area; this is the simplest method for finding out what is useful or not.

· Observe by visiting local markets, or go with hunter-gatherers in the woods.

· Check the literature.

· Consult historical records and archeological sites. These sources may reveal past and forgotten uses.

· Do research and development.

Indigenous knowledge and ethnobotany are discussed in another session in this conference. As we seek new plants and animals to meet our needs, we need to keep in mind that similar species may have similar uses. Thus, if we find that one species meets a need, a closely related one may also. A single species may have also several uses. Another possibility is that those species that are unrelated but thrive together in similar environments or ecological niches may also have similar uses or functions.

As we search for potential applications, we may find that although local people use most species for something, many plants or animals may have no obvious commercial value. This may not mean that the organism is not useful or a potential product source. (Techniques to actually develop a product will be covered in another session in this meeting.) It could mean that-

Besides products, forest lands can also provide functions or services that may yield economic returns to the local community.

A service is a useful result that is not a tangible commodity. Water storage and watershed protection are examples of two types of services. One benefit that is on the increase is recreation-especially ecotourism. For this use, we need to assess why people would want to come to the location -it may be to see unusual or abundant plant or animal life, scenic beauty, historical or cultural interest, etc. Visitors need to be assured of adequate access, living conditions and security. As we search for new uses of our forest resources, we should not overlook opportunities to recycle what we have already developed. Except for a handful of space probes, every product created on earth and every life form that ever existed is still here in some form or another. The recycling potential is unlimited.

Commercialization and domestication


Commercialization is the development of a product or service that is suitable or fit for a wide public market. It is one's intent to profit by commercialization. This may or may not be true for domestication. For plants or animals, the resources may be maintained in natural settings, such as a forest, or in domesticated environments such as a farmer's garden, chicken coop, or a pine plantation. Commercialization should be carried out on a sustained basis, but often it is not.

Non-timber forest products can be extracted on a sustainable basis only under certain circumstances. These situations usually involve climate, soils and numbers of the organisms. To ensure that the product can be sustained, it is necessary to develop a checklist of attributes and requirements for successful and sustainable development for extraction. Methods are also needed to apply this checklist in land-use planning. The Tropenbos Foundation (Lawickse Allee 11, Wageningen, The Netherlands) is developing such a checklist. It will enable the identification of areas where commercial extraction of non-timber forest products is promising as a conservation strategy (anon. 1995).


Domestication is the act or process of converting animals or plants to household use (see Leakey and Newton 1994 for other definitions). That often means moving an organism from its natural habitat, introducing it to a modified habitat, and providing the means for it to maintain itself in its new location. This may involve genetic modification and breeding. An example may be removing a fruit-producing plant from the wild, planting it near one's house, harvesting the crop, and planting the seeds for a future crop. The domesticated plant or animal may be used for one's own enjoyment or consumption, or it may be domesticated for commercial purposes. Techniques for product domestication are discussed in another session in this conference.

We domesticate because it is amicable to have that particular life form around, because it is easier to deal with at home, or because through cultivation it can be improved. Frequently it is also because it is more economical to produce the product than to continually collect it from the wild. If we do not domesticate, the reasons are probably that there is no need-the organism is plentiful in the wild-or else the habitat requirements are too difficult to duplicate on a farm or garden.

Commercialization can change an area's ecology by favouring or exploiting one species instead of another. This is not necessarily bad, as many creatures modify their environment to suit their needs. We just have to be aware that we are shaping the future by our management activities and plan accordingly.

Together, domestication and commercialization may lead to monocultures. While monocultures may not be desirable from a diversity perspective, they may be economically, and perhaps environmentally, acceptable. Agroforestry systems may be more diverse and environmentally acceptable, but they are not necessarily as productive and profitable as plantations. However, if the environment and the external benefits are costed, agroforestry systems may be the most beneficial in the long run.


Market development involves the estimation of demand, analysis of supplies, and assessment of problems and economics of transportation. One must be able economically and effectively to move goods from the producer to markets. Besides economic considerations, one must also consider the ability to deliver in a timely manner. There are three general approaches to market development:

· find out what is out there and then try to find a use for what is abundant

· identify a need and then find a product that will meet that need

· identify what is used locally then determine if the demand can be expanded

The second and third options are desirable, but the first is more common. Successful commercialization depends on market demand. There is an old saying that `you cannot make a silk purse out of a sow's ear' ( note that both pigs and silkworms are natives from the forest). In other words, you cannot make something valuable out of something that is worthless. However, what is worthless to one person may be valuable to another. This value may exist or be created through good marketing strategies.

To commercialize, it is necessary to have or create a demand. One should show that the product-

An opportunistic approach can be used when the product is truly needed. In product development, it is often necessary to look at what is currently used on a small-time basis, then explore needs and opportunities to expand the market.

In our quest to develop new products, we need to keep in mind that unforeseen problems may occur. Commercialization, for example, can lead to a depletion of the resource. Any time we favour one species we do it at the expense of another. Domestication, on the other hand, may lead to the creation of monocultures. While monocultures may be acceptable economically, socially and perhaps even environmentally, they may not be wanted from an ecological perspective. In any case, we must weigh our losses with our gains. Policy and institutional aspects of commercialization and domestication will be discussed in another section of this workshop.

Assessments and monitoring

An assessment is the act of determining the amount or value of a resource. We need to assess both the supply of the resource and its demand. This paper examines only the supply end of the process. We make inventories to determine the extent of the supply of the plants or animals available to us. An inventory can help decide if a plant or animal requires domestication by revealing its apparent abundance and habitat.

As we make our enquiries, we need to decide what organisms are used, how we use them, and if and how they need to be processed. To learn how to domesticate the plant or animal, we need to know what are the habitats or environments in which it is found, when it is usually found (season, time of day, time of year), what is its reproductive requirement, and under what environmental variations can it successfully survive. Such information will be useful in developing the inventory and monitoring systems.

When we have a clear picture of the products we intend to produce and the biotic source of those products, making an inventory is straightforward. Since nearly all life forms depend on vegetation, it makes sense that flora is the focal point of many of our inventories. Inventory techniques are different depending on whether the potential product is domesticated or occurs in the wild.

If we have domesticated the plant or animal, the task is very simple. In all probability `domesticated' plants are found in fields or plantations. Domesticated animals are usually confined to pens or pastures. In other words, we know where the organisms are. For vegetation or animals confined to a small area, we can merely do an enumeration. Where large areas are involved, some type of sampling may be necessary. This again may not be a major problem, especially with vegetation. Most domesticated vegetation is grown in even-aged monocultures or relatively simple mixtures. The expected variation among plants is small. Therefore we can get by with fewer samples than we would need with the same plant in the wild. Finally, fields, plantations and pastures are usually close to some transportation network (roads, trails). With easy access, we can inventory and monitor the resource more frequently and economically.

If the resource occurs in the wild, an inventory becomes more complex. Variation will be greater; we will need more rigorously selected samples. In addition, access may be more difficult, thus costs will be greater. Remote sensing may be required, especially for large areas. If we know the habitat requirements, we can save some money by mapping and stratifying the forest and concentrate our data collection efforts on where the organism is likely to occur. If we do not know the habitat requirements, then we may have to use a systematic sample.

In areas where potential uses and products are anticipated but not well defined, consider using a multiple resource inventory (MRI). In an MRI, one collects sample information on major vegetation types, soils and terrain features. A minimum set of vegetation information to collect is life form (tree, shrub, herb, grass), its numbers, average height, and percentage of ground cover of each. Optimally, one should try to detect and record the genus and species of each plant present and the average dimension of each. From this we can compute biomass, which can then be equated to nearly any product anticipated, by use of a harvest index.

An MRI may also be appropriate where there are known multiple uses of the land. For example, a piece of land may be used for grazing, timber, fuelwood, etc. Rather than collecting data on these uses in separate efforts, a combined inventory may be more economical. A common glossary of terms is a first step in developing an MRI (Resource Inventory Coordination Task Group 1989). Guidance on how to design a multiple resource inventory may be found in Lund (1986), Lund (1995) and Lund & Wigton (1994).

Monitoring is the process of observing changes according to a set of standards or protocols. As with assessments, we need to monitor both the supply and the demand end of the resource. Changes in demand will affect the need to supply. At the supply end, we monitor-

For such monitoring, it would help to know the history of any trends in the availability of the resource. This would help decide monitoring methods and frequency. Again, asking village elders, consulting historical records, etc., may help. Monitoring requires making the same observations at the same location, but at different times.

For naturally occurring vegetation, we often use permanent plots. Guidance on how to establish permanent plots for monitoring forest conditions is found in Päivinen et al. (1994). For animal populations it is essential to monitor habitat as well as the animal numbers. Monitoring should include collecting data on changes in numbers, condition, success of reproduction, and habitat. This information is essential for sustainable forest management. If the organism is not domesticated, it is essential to leave enough individuals and habitat for successful reproduction. To monitor demand, one must not only keep track of changes in number of consumers but also changes in competition, transportation methods, etc.


I have introduced the subjects of product and product identification, commercialization and domestication, and assessment and monitoring. The possibility of creating new products and uses from our wildland resources are nearly limitless and indeed exciting. It has been conservatively reported that one species becomes extinct every three hours (Center for Plant Conservation 1995). What could have gone for good is gone for good. Yet, we do not know how many species there are on earth and how they can be used. Given these facts, I believe we can reach these conclusions:

. . .in that order; local support is essential for success in the meeting these needs.


My thanks to Drs. Roger Leakey and August Temu for their kind invitation to participate in this most important workshop.


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