Forest Resources Assessment WP 94

National forest inventory

Field manual


Rome, August 2004

The Forest Resources Assessment Programme

Forests are crucial for the well being of humanity. They provide foundations for life on earth through ecological functions, by regulating the climate and water resources and by serving as habitats for plants and animals. Forests also furnish a wide range of essential goods such as wood, food, fodder and medicines, in addition to opportunities for recreation, spiritual renewal and other services.

Today, forests are under pressure from increasing demands of land-based products and services, which frequently leads to the conversion or degradation of forests into unsustainable forms of land use. When forests are lost or severely degraded, their capacity to function as regulators of the environment is also lost, increasing flood and erosion hazards, reducing soil fertility and contributing to the loss of plant and animal life. As a result, the sustainable provision of goods and services from forests is jeopardized.

In response to the growing demand for reliable information on forest and tree resources at country and global levels, FAO initiated a programme to provide support to national forest assessments (NFA). The programme includes developing a harmonized approach to NFAs, information management and support to policy impact analysis for national level decision-making.

The purpose of the initiative is to introduce countries to an alternative approach designed to generate cost-effective information on forests and trees outside forests, including all benefits, uses and users of the resources and their management. Special attention is placed on monitoring the state and changes of forests, and on their social, economic and environmental functions. Another main objective is to build national capacities and harmonize methods, forest related definitions and classification systems among countries.

The Forest Resources Assessment Programme is organized under the Forest Resources Division (FOR) at FAO headquarters in Rome. Contact person are:

Mohamed Saket, Forestry Officer, [email protected]
Dan Altrell , Forestry Officer, [email protected]
Anne Branthomme, Forestry Officer, [email protected]
or use the e-mail address: [email protected]

Compiled by A. Branthomme
4rd Edition: M. Saket, D. Altrell, P. Vuorinen, S. Dalsgaard & L.G.B Andersson
Rome, 2003, FAO Forestry Department
Version 2. Last Revised 24.08.2004


The Forest Resources Assessment (FRA) Working Paper Series is designed to reflect the activities and progress of the FRA Programme of FAO. Working Papers are not authoritative information sources – they do not reflect the official position of FAO and should not be used for official purposes. Please refer to the FAO forestry website ( for access to official information.

The FRA Working Paper Series provides an important forum for the rapid release of preliminary findings needed for validation and to facilitate the final development of official quality-controlled publications. Should users find any errors in the documents or have comments for improving their quality they should contact [email protected].


1. Introduction

2. Sampling design
2.1 Tract selection and distribution
2.2 Tract description

3. Land use/forest type classification

4. Fieldwork
4.1 Overview of data collection process
4.2 Fieldwork organisation
4.2.1 Organisation structure
4.2.2 Field crew composition
4.3 Preparation for the fieldwork
4.3.1 Bibliographic research
4.3.2 Contacts
4.3.3 Preparation of the field forms
4.3.4 Preparation of maps
4.3.5 Field equipment per crew
4.4 Data collection in the field
4.4.1 Introduction of the project to the local people
4.4.2 Access to plot
4.4.3 Establishment of permanent plot
4.4.4 Data collection in the plot
4.4.5 End of data collection work in the plot and access to the next plot
4.4.6 Interviews

5. Description of field forms
5.1 Form F1: Tract
5.2 Form F2: Plot
5.3 Form F3: Plot - Tree and stump measurements (Dbh>10cm)
5.4 Form F4: Subplots and measurement points
5.5 Form F5: land use/forest type section (LUS)
5.6 Form F6: Forest Products and Services

6. Appendices
6.1 Land cover class definitions
6.2 Tree height and diameter measurements
6.2.1 Tree (Dbh) measurement
6.2.2 Tree height measurement
6.3 Use of receivers for Global Positioning Systems, GPS
6.4 Horizontal distance measurements
6.5 Interviewing and group-discussions techniques
6.5.1 Advice and recommendations
6.5.2 Tool: stakeholder identification and analysis (Venn Diagram)
6.5.3 Tool: Participatory analysis of aerial photographs and maps
6.5.4 Tool: Cross-checking and triangulation
6.5.5 Tool: Direct Observation
6.5.6 Tool: Transect walk to the sample site
6.5.7 Tool: Identifying the forest products, services and their use
6.6 IUCN protected area management categories

7. References

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