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1. Assessment and monitoring of non-timber forest products

C. Kleinn (chair)
R. Kindt (rapporteur)
Sk. S. Islam
G. Lund
E. Munyanziza
S.P. Sah
K. Schreckenberg
F. Taylor
A.B. Temu
G. Weinland


A wide array of products from plants and animals can be classified as non-timber forest products (NTFPs). This working group focused on plants and plant products, as they had been the main focus of the conference. The first step in assessing and monitoring NTFPs is product identification. This is based on reconnaissance and pilot inventories, market evaluation and indigenous knowledge, as well as on an analysis of what scientific knowledge already exists within the region and what might be transferable from elsewhere. For the purpose of this discussion it was assumed that product identification had been done already and that the status of NTFPs would be assessed and monitored by inventories.

It was agreed that the objective of NTFP assessments is to collect information about the distribution, frequency and seasonality of NTFP so that plans can be made for the sustainable management and utilization of the NTFPs for the improvement of human welfare. It is important to determine, prior to the assessment, for whom is the information being collected-who are the beneficiaries/clients. It is also important to determine that the policies and regulations governing the ownership, management and utilization of NTFPs are conducive to supporting farmers and the rural community and hence the local economy.

Classification of inventories

There is no single technique for assessing and monitoring NTFPs, because of the variety of products. The appropriate methods therefore depend on the objectives of the inventory. The following considerations are important.

The intended use of the inventory: The purpose may be to identify a management plan for an area, or it may be the conservation of an endangered species, or the development of specific products for marketing and processing.

Spatial scale: Inventories may be done at a local, district, national or regional scale, depending on their objectives. Local-level inventories are usually management or market oriented, while regional inventories are usually for planning or policy formulation.

Forest inventories are usual oriented towards specific products-most commonly timber, but increasingly also for some non-timber forest products such as bamboo, medicinal herbs, fruits. The incorporation of many different products in one inventory is complicated by differences in species phenology, scale and spatial distribution.

Inventories of non-timber forest products can be purely to determine the quantity of the product available or to determine the quantity used. The latter involves market studies and the flow of products, which can be age or size dependent. In many cases the biophysical resource inventory would focus on individual products (e.g., bark, fruits), while a socioeconomic flow inventory would concentrate on types of product usage (e.g., food, medicines, gums).

State of the art

Some data and information exist on a few selected NTFPs, for some specific locations. However, the data are scattered in several disciplines and institutions. Furthermore, the data were collected for separate and uncoordinated objectives and using very diverse surveying methodologies, ranging from forest inventories, agricultural crop surveys, participatory rural appraisals (PRA) and socioeconomic studies. Consequently, they lack consistency in terms of:

Designers of the inventories had tailor-made them to suit their needs. The data are therefore difficult to manipulate for other interpretations or uses. There is also limited comparability across disciplines and geographic regions.

The group knew of no references that provide guidance on systematic surveys of NTFP. However, it was recognized that as NTFPs become more significant in the livelihood of local communities, the demand for more precise and comprehensive information will rise. There is, therefore, a need to develop proper inventory technologies to identify, quantify and assess quality of NTFPs.

The group agreed that it is impossible and perhaps futile to search for a generalized technique for NTFP resource assessment because of the major differences in:

An added complication arises when products from a single tree can be used for several purposes; the measurements for a given product could be quite different from those required for a different product. An example is bitter kola (Garcinia kola Heckel), whose fruit pulp is a food and has medicinal properties, the seed is an edible oil-bearing nut, while the wood is used as chewing sticks for dental health because of their bacterial properties and fibrosity. Clearly, assessments of quality and quantity of fruit pulp are unrelated to those for chewing sticks, while nut quantity is probably related to the amount of fruit pulp.

W3735e46.GIF (9940 bytes)

Figure 1. Relationships between products and uses in the West African tree Garcinia kola

In this case, the medicinal uses of each of the products are different. How then can resource flows be monitored and assessed? From the user and the market viewpoints, product flows are probably the most useful. These can be captured by product-flow data-capture forms (fig. 2).

Location/Area: Date
Survey crew name/s:
Codes to monitor resource flow: Supply (sources)

A = Forest; B = Market; C = Commercial area; D = State/Land; E = Farm

Codes to monitor resource flow: Consumption (destinations)

F = Marketplace; G = Process; H = Home; K = Strategic storage



Species 1 Species 2 Species 3 Species 4
  Quantity Code Quantity Code Quantity code Quantity Code
Fibre (kg) 25 AF 13 CG 34 BF    
Fruit (no) 72 EF 19 DH 64 AK    
Bark (kg) 32 AK 25 BK 12 DH    

Figure 2. An example of a NTFP product-flow data-capture form. Quantity could be expressed in weight (kilograms), dimensions (length, diameter, volume) or by number of items. Price per unit may also be included in this column.

Constraints and problems

General conditions affecting NTFP assessments

Organizational problems

Cost is always difficult to treat. An assessment will find sources for funding only if the objectives are convincing. Convincing objectives alone, however, are not sufficient. In the ideal case, the economic or socioeconomic benefit of improved information exceeds the cost of the inventory. But in many cases this situation is not given.

Other organizational problems are logistics and the availability of expertise and training possibilities. In local-scale inventories expertise could be provided by the local communities, if they are involved with the inventory planning from the very beginning.

For regional assessments the question of expertise is much more crucial. Local expertise can also be used in this case, but then it must be guaranteed that the level and quality of knowledge of the local experts are comparable throughout the region. Otherwise data consistency is questionable.

Data consistency and quality problems

One of the central problems identified was the valuation of the products, still missing for many products and in many regions.

The identification of many NTFPs is not easy, for example identifying aromatic and medicinal herbs. Special knowledge is required, and it cannot be easily transferred in a training course.

Some NTFPs show a clear seasonality. This means that identification is possible only during a particular time of the year when, for example, above-ground shoots indicate below-ground storage organs. This necessitates a large number of field crews and experts to carry out the inventory in the short time period available.

Measurement of quantitative and qualitative characteristics is problematic, as is the standardization of measurements. For example, to measure or estimate the amount of fruit on a fruit tree in terms of either number or weight is extremely difficult as there are fluctuations depending on tree size, climate, water supply and other interacting factors. The same difficulty of measurement holds for medicinal and aromatic herbs, for which there might also be an interest in the content of particular chemicals. Chemical analysis, however, is beyond the possibilities of a regular inventory.

Research issues

Research issues are relatively easy to identify. A classification into technical/biophysical and socioeconomic research fields appears reasonable.

On the technical side research into specific inventory and monitoring techniques is necessary, especially statistical aspects (statistical design, field plot design, data analysis techniques). The potential for remote sensing should be analysed. Direct assessment of NTFPs by means of remote sensing is possible for some products (trees, bamboo), but it might be possible to identify indicators with which the occurrence of NTFPs can be estimated in an indirect way. Identification of indicators is another very important research issue, as is the development of modelling techniques.

A review of available, proven or not-proven techniques is needed. Two topics are of utmost importance: participatory inventory techniques and the compatibility of different assessment techniques. In many cases a resource inventory has to be combined with a quantitative market study and maybe also with the results of a questionnaire or the evaluation of official statistics.


Many studies and projects on utilization, management, marketing, etc., of NTFPs are ongoing. The methodology used in specific studies to collect data and to create a database should be spelled out clearly and made available to interested researchers and projects.

We need the knowledge about the status quo of the resource now. Interdisciplinary case studies would be helpful-on single products or sets of products, and on sales both locally and regionally. It is difficult to talk in general terms about assessment and monitoring of NTFPs. See tables 1 and 2, summarizing research issues and expertise needed.

Table 1. Research issues in NTFP resource assessment and monitoring

Biophysical Cross-cutting Socioeconomic
Statistical and field plot design

Assessment of land and plant capability

Potential of remote sensing techniques

Review of available techniques

Participatory inventory techniques

Compatibility of different techniques

Indicators and modelling techniques

Information system development (needs and potential).

Demand for and use of inventory data or improved information.

Table 2. Expertise needed to address inventory research

Biophysical Cross-cutting Social
Inventory/statistics (forest, range wildlife, crop)



Remote sensing


Ethnobotany Sociology

Environmental economy


Village-based research

The following research needs have been identified:

Development of product groups; research on inventory techniques by these groups as well as for individual products.

Interdisciplinary case studies based on:

- single products

- sets of different products grouped into compatible classes

Case studies should first be done locally and regionally. The methodologies tested in case studies should be fully documented.

Consideration of market information in inventory planning. Product value is an essential ingredient in any inventory planning. In many cases, the market prices for NFTPs are unknown. In the consideration of how much effort can be put into the assessment of a given product, this is a complicating factor.

Standardization of inventory procedures, especially with regard to units used in product measurement and reporting. This will facilitate comparability as well as regional and global compilation of inventory information.

Development of predictive models using satellite data and aerial photographs; also the development of models estimating product quantity and quality from measurable tree and stand variables.

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