ISO 8347:2025

Measurement procedures associated with the chain of custody in native tropical forest management areas

This document establishes a process to measure wood being logged in native tropical forest management areas following an approved and documented plan. Such a process includes quantifying and monitoring the harvested area to support the chain of custody assessment, helping to ensure the origin of the logged wood. Wood volume measurement is outside the scope of this document. This document proposes indicators that can be used to reinforce the level of confidence with regards to the correct origin of the logged wood, particularly when assessing the transport and commercial documentation of wood-based products, by means of a consistency check with what can be observed as occurring in the forest area declared as the origin of native tropical timber. The indicators will serve as an alert of any eventual inconsistency detected. These indicators are obtained by means of standardized metrics. These metrics are mathematical models that establish a correlation between the area of subtracted vegetation – detected through remote sensing monitoring tools – and the number of extracted trees that generate the amount of declared logged wood. This document is intended to be used to quantify the impact resulting from native vegetation extraction by selective logging in various tropical forest regions of the world, in order to support the long-term maintenance of these forest assets. The scope of this document is limited to native tropical forests, i.e. forests naturally originated and formed by native species (or group) in tropical regions. This document does not apply to planted forests, regardless of the species (or group) being native or exotic, as those forests are subject to varied and particular management practices which depend on the geographical conditions and rules of the country in which they are located. Regarding the limitations of this document, it is not intended to ensure: — exact origin (geographical coordinates) of each log; — exact volumes of wood extracted from the forest; — species (or group) of wood harvested; — chain of custody compliance; — social and labour compliance of the audited operation; — tax compliance of the audited operation. This document does not focus on, and is not oriented towards, biomass and carbon-balance estimations. This document does not cover any aspects of sustainable forest management and focuses on measurement procedures described above. In addition, it is not intended to be a Management Systems Standard (MSS). Furthermore, the national legal requirements and international policies are not repeated in this document, including those related to sustainability aspects, as well as those related to traditional and indigenous communities contained in the principles/articles of the UN Declaration on the rights of Indigenous Peoples (UNDRIP).

Procédures de mesure associées à la chaîne de contrôle dans les zones de gestion des forêts tropicales indigènes

General Information

• Status: Published
• Publication Date: 03-Dec-2025
• ICS: 65.020.01 - Farming and forestry in general
• Technical Committee: ISO/TC 287 - Sustainable processes for wood and wood-based products
• Drafting Committee: ISO/TC 287 - Sustainable processes for wood and wood-based products
• Current Stage: 6060 - International Standard published
• Start Date: 04-Dec-2025
• Due Date: 30-Jun-2025
• Completion Date: 04-Dec-2025

Overview

ISO 8347:2025 - Measurement procedures associated with the chain of custody in native tropical forest management areas - establishes a standardized process to measure and monitor selective logging in native tropical forests to reinforce traceability of timber origin. The standard uses remote sensing, georeferenced documentation and standardized metrics/indicators to perform consistency checks between declared harvesting (forest management plans and transport/commercial documents) and what can be observed on the ground via spatial monitoring. Wood volume measurement, exact coordinates of each log, species identification and compliance audits are outside the scope.

Key topics and technical requirements

• Scope limitation: Applies only to native tropical forests; planted forests are excluded.
• Documentation requirements: Verification relies on approved forest management plans (FMP), harvesting permits and geospatial documentation submitted by the responsible party.
• Remote sensing data & accuracy: Independent georeferenced information (satellite, airborne, other remote sensing) is used with defined accuracy requirements to detect canopy opening and subtracted vegetation.
• Standardized metrics and indicators: Mathematical models correlate the area of vegetation removed (from remote sensing) to the expected number of extracted trees linked to declared logged wood. These indicators act as alerts for inconsistencies.
• Consistency checking procedures: Methods to compare georeferenced data provided by the responsible party with independent observations, evaluate spatial patterns of production areas and assess temporal alignment with declared harvest periods.
• Limitations and exclusions: The standard explicitly does not ensure exact log coordinates, exact wood volumes, species ID, chain-of-custody compliance, social/labour/tax compliance, biomass/carbon accounting, nor does it function as a Management Systems Standard (MSS).
• Additional clauses: Contains provisions for claims and whistleblowing and references to normative terms and remote sensing accuracy criteria.

Practical applications

• Strengthening documentation-based traceability for timber buyers, primary processors and downstream supply-chain actors who need independent assurance of timber origin.
• Supporting auditors, third-party verifiers and certification schemes with geospatial consistency checks that flag potential documentary fraud or illegal harvesting.
• Enabling governments, NGOs and responsible forest managers to monitor selective logging impacts and detect discrepancies between declared harvests and observed canopy changes.
• Informing due-diligence processes for market access requirements where “deforestation-free” proof is required.

Who should use ISO 8347:2025

• Forest managers and operators in native tropical regions (for planning and compliance support)
• Remote sensing and geospatial service providers (to supply validated monitoring products)
• Auditors, certification bodies and regulatory agencies (for independent consistency checks)
• Timber traders, importers and large buyers seeking enhanced origin assurance

Related standards and context

ISO 8347:2025 was prepared by ISO/TC 287 (Sustainable processes for wood and wood-based products) and is designed to complement existing chain-of-custody and certification frameworks by providing a remote-sensing-based methodology for origin verification without replacing legal or social requirements.

Standards Content (Sample)

International
Standard
ISO 8347
First edition
Measurement procedures
2025-12
associated with the chain of
custody in native tropical forest
management areas
Procédures de mesure associées à la chaîne de contrôle dans les
zones de gestion des forêts tropicales indigènes
Reference number
© ISO 2025
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 2
3 Terms and definitions . 2
3.1 Terms related to the forest value chain .2
3.2 Terms related to remote sensing technology .5
3.3 Terms related to the accuracy of remote sensing technology .6
4 Forest management documentation and relevant data required from the responsible
party . 7
4.1 Understanding of the native forest area .7
4.1.1 Criterion: wood production capacity .7
4.2 Following an approved forest management plan (FMP) .7
4.2.1 Principle .7
4.2.2 Criterion: harvesting permit .7
4.2.3 Criterion: geospatial documentation related to the forest management plan
(FMP) .8
4.2.4 Criterion: geospatial documentation related to the actual activities .9
4.3 Chain of custody traceability .9
4.3.1 Principle .9
4.3.2 Criterion: chain of custody records .9
5 Information sources and technologies – Independent georeferenced information
derived from remote sensing (and its accuracy requirements) .10
5.1 Consistency checking of the remote sensing technologies availability in the geospatial
industry .10
5.1.1 Principle .10
5.1.2 Criteria .10
5.2 Consistency checking of the remote sensing technologies detection’s relevant capacity.11
5.2.1 Principle .11
5.2.2 Criteria .11
6 Consistency checking procedures .11
6.1 General .11
6.2 Consistency of georeferenced data provided by the responsible party . 12
6.2.1 Principle . 12
6.2.2 Criteria . 12
6.3 Consistency of the production area’s spatial pattern . 13
6.3.1 Principle . 13
6.3.2 Criteria . 13
7 Claims .13
8 Requirements for whistleblowing .13
Bibliography . 14

iii
Foreword
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bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
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related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 287, Sustainable processes for wood and wood-
based products.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

iv
Introduction
This document is developed in the context of the challenges that have arisen from the international
commercialization of tropical wood, such as deforestation of native tropical forests through illegal
harvesting and documentary fraud in the chain of custody of tropical wood products. The document is
not intended to be a comprehensive solution to these challenges, but rather offers a methodology that can
be used to monitor these challenges within specific contexts for native tropical forests. Data from remote
sensing increases the validity of volume and areas harvested from which tropical wood products originate,
as described in the text below. The focus of this document is the methodology for using remotely sensed
data and the appropriate contexts in which to do so, rather than the use of a specific remote technology for
data collection. Traceability of the origin of wood extracted through selective logging of native forests in
tropical regions of the world has become a standard requirement by consumers of these wood products,
who increasingly favour purchasing products from areas that have been legally authorized and are managed
and harvested more sustainably. Particularly in markets such as the EU, the USA, Australia and Japan, the
lack of reliable information regarding the practices adopted at the origin of wood extraction and throughout
industrialization can hinder the commercialization of such wood-based products.
[ ]
The upcoming demand in the EU, 10 for instance, for these products that are “deforestation-free” requires
strong evidence that they have originated from a specific location where the forest area under management
has not been subject to forest degradation. In this document, native tropical forests are addressed.
Typically, forest management and chain of custody certification of native tropical forests is based on the
periodic auditing of detailed documentation and a sample of evidence collected on site covering the various
stages of production, from receiving the logged wood originated at the forest management unit (FMU),
through primary processing of logs, further industrialization, and final commercialization of wood-
based products. However, because not all the logged wood from native tropical forests commercialized
internationally will be covered by certification, questions can potentially be raised by consumer markets
with respect to the effectiveness of available information and supporting documentation in ensuring the
origin of the wood-based products being commercialized.
In the last decades, remote sensing technologies have been frequently utilized for native tropical forests with
the purpose of detecting changes in forest coverage and of determining the extent of land use conversion.
As an example, satellite remote sensing integrated into alert mechanisms has helped detect deforestation
in areas of native tropical forest in Brazil. Likewise, progressive effort in monitoring and evaluating canopy
opening by remote sensing tools during selective logging (within a previously informed time period)
suggest the possibility of finding an effective way to correlate the amount of retrieved trees from a declared
origin with the information that accompanies the logged wood that arrives at a mill for primary processing
to support the chain of custody of resulting wood-based products (hence commercialized to a variety of
destinations).
Adding geospatial referenced information at the source of the wood extracted from native tropical forest
areas will strengthen the link between the documentation provided as “proof of origin” of the logged wood
at the mill (beginning of the process) to the documentation that accompanies the wood-based products to
the end of the chain of custody. As a result, remote sensing technologies can then be used to analyse the
native tropical forest management areas and verify consistency between the declared amount of logged
wood and the related selective logging features (geographical location, dates, logged areas, canopy opening
associated to logged trees or infrastructure). Therefore, the field of work of this document is to establish
the guidelines of a methodology to assess the impact on forest coverage resulting from the implementation
of a selective harvest under a forest management plan (FMP) by using remote sensing tools, within a pre-
established region in space and a similarly delimited time interval. The magnitude of the impact thus
determined will be compared to the logged wood’s documentation (formal and georeferenced) extracted
by the organization interested in the commercialization of its wood-based products, to verify consistency
between the two distinct sources of information. This proposed verification methodology will be an
independent means for a variety of stakeholders to monitor the selective logging forest areas, and hence will
significantly enhance the credibility of the overall process. Implementation of this document would generate
a robust data set describing where harvesting activity has occurred. It is highly recommended that this data
set be used to check the potential overlap of harvesting on protected areas, indigenous lands, the described
distributions of IUCN Red List endangered species (or group), and other relevant spatial data layers that

v
exist for the purpose of preventing or observing impacts on conservation areas or areas related to social
justice. However, these additional analyses are not required for conformance to this document.
This document is based on cross checking data from remote sensing with official information, relating to
the planning of management activities approved by the competent authorities (management plan, harvest
authorizations and/or similar). The competent authorities have official information that reports what was
carried out in the harvest (invoices and/or any other documents that have official support that indicate the
movement of logs out of the forest). Nevertheless, the use of this document cannot state that the official
information presented has a high probability of being true and of correctly reporting the origin of the log, as
well as that the forest manager respected the environmental legislation in force in the country.

vi
International Standard ISO 8347:2025(en)
Measurement procedures associated with the chain of
custody in native tropical forest management areas
1 Scope
This document establishes a process to measure wood being logged in native tropical forest management
areas following an approved and documented plan. Such a process includes quantifying and monitoring the
harvested area to support the chain of custody assessment, helping to ensure the origin of the logged wood.
Wood volume measurement is outside the scope of this document.
This document proposes indicators that can be used to reinforce the level of confidence with regards to the
correct origin of the logged wood, particularly when assessing the transport and commercial documentation
of wood-based products, by means of a consistency check with what can be observed as occurring in the
forest area declared as the origin of native tropical timber. The indicators will serve as an alert of any
eventual inconsistency detected.
These indicators are obtained by means of standardized metrics. These metrics are mathematical models
that establish a correlation between the area of subtracted vegetation – detected through remote sensing
monitoring tools – and the number of extracted trees that generate the amount of declared logged wood.
This document is intended to be used to quantify the impact resulting from native vegetation extraction
by selective logging in various tropical forest regions of the world, in order to support the long-term
maintenance of these forest assets.
The scope of this document is limited to native tropical forests, i.e. forests naturally originated and formed
by native species (or group) in tropical regions. This document does not apply to planted forests, regardless
of the species (or group) being native or exotic, as those forests are subject to varied and particular
management practices which depend on the geographical conditions and rules of the country in which they
are located.
Regarding the limitations of this document, it is not intended to ensure:
— exact origin (geographical coordinates) of each log;
— exact volumes of wood extracted from the forest;
— species (or group) of wood harvested;
— chain of custody compliance;
— social and labour compliance of the audited operation;
— tax compliance of the audited operation.
This document does not focus on, and is not oriented towards, biomass and carbon-balance estimations.
This document does not cover any aspects of sustainable forest management and focuses on measurement
procedures described above. In addition, it is not intended to be a Management Systems Standard (MSS).
Furthermore, the national legal requirements and international policies are not repeated in this document,
including those related to sustainability aspects, as well as those related to traditional and indigenous
communities contained in the principles/articles of the UN Declaration on the rights of Indigenous Peoples
(UNDRIP).
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1 Terms related to the forest value chain
3.1.1
native forest area
forest area which comprises native tree species (or group) composition and shows natural dynamics,
occurrence of dead wood, complex age structure and natural regeneration processes
Note 1 to entry: In a native forest area, the naturally regenerated trees are expected to constitute the major part of the
growing stock at stand maturity. If portions of these forests are modified by humans through their actions, they are
expected to be naturally regenerated.
3.1.2
forest management unit
FMU
area of a forest where wood is sourced for wood-based products
Note 1 to entry: An FMU has clearly defined boundaries and can cover different sizes. It can include sites which are not
adjoining.
Note 2 to entry: An FMU can be subject to different land ownership arrangements.
Note 3 to entry: An FMU can be characterized by areas with similar ecology and under similar management practices
(see ISO 13391-2:2025, 4.3).
Note 4 to entry: Forest areas not primarily used for wood production, or set-aside areas for nature conservation or
other purposes, can be included in the FMU.
Note 5 to entry: National definitions or practices can lead to inclusion of additional areas where wood is sourced,
subject to, for example, agroforestry or tree plantations.
Note 6 to entry: The terms “land ownership” and “set-aside areas” are defined in ISO 13391-2:2025, 3.3 and 3.1.
[SOURCE: ISO 13391-1:2025, 3.20]
3.1.3
forest management plan
FMP
document translating forest policies into a coordinated programme for a forest management unit (3.1.2) and
for regulating production, environmental and social activities for a set period of time through the use of
prescriptions, targets, and action and control arrangements
Note 1 to entry: In this document, FMP denotes a set of documents that contains the data required to implement the
methodology described in this document.
Note 2 to entry: The name of the FMP varies regionally.
EXAMPLE Native tropical FMP (used in Brazil).
[9]
[SOURCE: FAO Terminology Portal ]

3.1.4
production area
geographical limits of a subdivision of the native forest management unit (3.1.2) which have been authorized
for harvest during a predetermined period of time, expressed as a polygon of harvestable area where a
consistency checking analysis will be conducted
Note 1 to entry: The consistency checking analysis is explained in Clause 5.
3.1.5
harvesting permit
logging permit
documentation that has been issued by the applicable authorities specifying the level of allowed harvest
within the geographical limits of a specified production area (3.1.4) and a specified duration period (defined
by issue and expiration dates)
Note 1 to entry: The harvested material can be identified by species (or group) and the level of allowed harvest can be
indicated with a metric appropriate to the context of the harvest (e.g. total volume removed, number of trees removed,
residual basal area).
3.1.6
forest access
main roads and logging deck through which the forest management unit (3.1.2) and subdivisions [production
areas (3.1.4)] are accessed and through which the logged wood is moved and stored prior to transportation
to the mills
Note 1 to entry: Forest access also serves for a variety of forest management activities.
3.1.7
harvesting infrastructure
secondary roads and logging deck within a production area (3.1.4) that are directly and specifically
associated with the harvesting (3.1.8) activities
Note 1 to entry: The data captured by remote sensing technologies typically indicate exposed soil, as an area from
which the forest coverage has been removed. However, unlike clearcutting, these changes are clearly associated, on
a temporal and geographical basis, to distinct moments before and after the forest management and logging (3.1.8)
activities have taken place.
3.1.8
harvesting
logging
set of consecutive operations to convert standing trees to desired products for further processing at
manufacturing facilities
Note 1 to entry: The operations of moving the logged wood to outside of the production area (3.1.4) and onwards will
be referred to as transportation.
[SOURCE: ISO 8965:2022, 3.1.1, modified — Note 1 to entry was replaced.]
3.1.9
selective logging
extracting a few trees belonging to one or a few tree species (or group)
Note 1 to entry: Selective logging can maintain the existing canopy structure, age distribution, and species (or group)
mix of the harvest area in a way that does not change the habitats' ecological functioning or prevent the natural
regeneration of the forest to its pre-harvest state.
3.1.10
forest canopy opening due to logging
reduction in vegetation coverage over time directly associated with individually logged trees
Note 1 to entry: When changes are assessed using remote sensing data (3.2.1), misclassifications are possible where
natural changes, such as the natural seasonal fall of leaves or the natural death of a tree, are mistaken for logging
(3.1.8).
3.1.11
harvesting cycle
period of time, commonly in years, between successive harvests of wood within the same production area
(3.1.4)
Note 1 to entry: The extent of this cycle will define the authorized logging intensity (3.1.12) and subsequent annual
allowable cut.
3.1.12
logging intensity
amount of commercial tree species (or group), expressed in terms of trees per hectare, that can be logged
from the production area (3.1.4)
Note 1 to entry: Its value is estimated on the basis of volumetric equations specified within the forest management
plan (FMP) (3.1.3) and based on the full forest inventory.
Note 2 to entry: 1 hectare is equal to 10 000 m .
3.1.13
overharvested area
area in which the logging intensity (3.1.12) estimated through remote sensing-based
consistency analysis surpasses the logging intensity, as specified in the forest management plan (FMP) (3.1.3)
or declared by the responsible party (3.1.17) (within an “agreed percentage” level of tolerance)
3.1.14
underharvested area
area in which the logging intensity (3.1.12) estimated through remote sensing-based
consistency analysis is below the logging intensity, as specified in the forest management plan (FMP) (3.1.3)
or declared by the responsible party (3.1.17) (within an “agreed percentage” level of tolerance)
3.1.15
chain of custody
process by which information linked to materials is transferred, monitored and controlled throughout the
entire supply chain or parts of the supply chain
[SOURCE: ISO 38200:2018, 3.1]
3.1.16
origin
geographical name of a country, region or specific place which serves to designate a product originating
therein, the characteristic qualities of which are due exclusively or essentially to the geographical
environment, including natural and human factors
Note 1 to entry: For the purposes of this document the scale of the origin will be considered the forest management
unit (3.1.2), which can cover different sizes.
[9]
[SOURCE: FAO Terminology Portal ]
3.1.17
responsible party
organization (3.2.5) that will be providing the necessary information related to forest management and
logging (3.1.8) activities and a product’s chain of custody (3.1.15) process that will be subject to consistency
analysis within the scope of this document
Note 1 to entry: This type of organization includes but is not limited to: forest managing and logging companies;
mills and other logged wood processing companies; wood industrialization companies; and product trading or
commercialization companies.
3.2 Terms related to remote sensing technology
3.2.1
remote sensing data
set of georeferenced information pertaining to a given area, collected or processed, or both collected and
processed, remotely
Note 1 to entry: The definition refers to both the raw collected data and the post-processed data.
3.2.2
remote sensing technology
set of defined procedures for remote sensing data (3.2.1) collection, pre-processing, and analysis, which make
use of one or several types of data to obtain a set of results related to a specific region and period, and have
peer-reviewed established attributes of planimetric (3.3.1), temporal (3.3.2), and thematic accuracy (3.3.3)
3.2.3
spatial resolution
level of detail or granula
...