Sustainable Forest Management (SFM) Toolbox

Reducing Forest Degradation

This module is intended for forest and land managers, as well as for stakeholders in all sectors involved in joint efforts to reduce forest degradation. It provides guidance on how to slow, halt and reverse forest degradation within a manager’s sphere of control and influence. Readers may find it helpful to read this module in conjunction with the Reducing Deforestation module.  

Drivers of forest degradation

Globally, the most important activities that cause forest disturbances and – in the longer term – forest degradation include:

  • unsustainable logging and timber extraction;
  • unsustainable fuelwood collection;
  • unsustainable charcoal production;
  • overgrazing in forests;
  • uncontrolled fires; and
  • defaunation (i.e. the loss or reduction of wildlife, which may have major ecological consequences, for example in terms of tree pollination, seed dispersal and pest control).

Underlying drivers are the complex interactions of social, economic, political, technological and cultural factors that affect direct drivers. They include unsound policies; weak governance and a lack of law enforcement; landlessness and the unclear allocation of rights; rural poverty; a lack of investment and financial resources; population growth and migration; and civil conflict.

The distinction between direct and underlying causes, and between human-induced and natural changes, is often not as clear as might first appear. Human and natural causes of degradation are often interdependent, and degradation is the end result of long, complex chains of causation.

Table 2. Main drivers of forest degradation

Table 2. Main drivers of forest degradation

How to address forest degradation

Assessing forest degradation

Assessing forest degradation

It is important to know whether forests are being degraded and, if so, what the causes are, so that steps can be taken to arrest and reverse the process.

Collecting and analysing information on forest condition and the extent of forest degradation will help in prioritizing resources and measures to prevent further degradation, address the root causes, and restore and rehabilitate degraded forest landscapes. It will also allow countries to fulfil their commitments on international reporting.

Quantifying the scale of the problem is difficult, however. Different stakeholders perceive forest degradation differently – one person’s degraded forest may be another’s livelihood – and it can be difficult to find a common approach to defining it. Various criteria may be applied, such as health and vitality, species diversity, production capacity, protection capacity and aesthetic value, but the weighting given to such criteria will influence the perception of degradation. For example, a planted forest may be regarded as “degraded” if consideration is based only on the criterion of biodiversity.

The definition of degradation should be linked to the objectives of forest management and ultimately to society’s goals – “degradation” is thus defined by the capacity of a forest to produce the products and services wanted by stakeholders.

Another issue in monitoring degradation is the potential difficulty in differentiating between natural variations and degradation. A reference state is required for comparing changes in a forest at a given temporal scale.

The SFM thematic elements enumerated in the UN Forest Instrument (and listed in the table) may provide a suitable framework for choosing indicators of forest degradation.

SFM thematic elements

Example of indicators of forest degradation

1.   Extent of forest resources

•  Decrease in canopy-cover percentage

2.   Forest biological diversity

•  Amount of fragmentation and road density

•  Species composition and changes in composition (for an ecosystem type)

•  Existence of or changes in key species (e.g. threatened, old-growth, hunted)

•  Existence or changes and degree of occurrence of invasive species

•  Existence or changes and degree of occurrence of pollinator bees

3.   Forest health and vitality

•  Area affected by pests and diseases

•  Area affected by fire

4.   Productive functions of forest resources

•  Number of commercial timber tree species

•  Number of mature trees

•  Diminished reproductive capacity of commercial species (e.g. number of exhausted coppices)

•  Average distance travelled to collect fuelwood or non-wood forest products

•  Number of game animals

5.   Protective functions of forest resources

•  Soil erosion (e.g. presence of rills, gullies and ravines, and plant root exposure)

•  Water quality and quantity

The assessment of forest degradation implies the selection of a spatial scale (e.g. global, national, subnational, landscape/watershed, forest management unit –FMU, or stand/site), and an assessment methodology. These are discussed further below.

Forest management unit or site level

Forest management unit or site level

Assessing forest degradation at each site or FMU enables forest owners and managers to decide on corrective actions at the local scale.

Forest managers should decide on the degradation indicators to be measured in their regular forest monitoring (see Forest Management Monitoring module). The early identification of local problems can guide the revision of forest management plans so as to prevent further degradation, address the root causes of degradation, take action to restore the damage already done, and invest in rehabilitation.

Forest managers should bear in mind that many indicators of a forest’s capacity to provide goods and services vary over time within a stand without implying forest degradation. Short-term fluctuations may be part of natural cycles or the result of planned human interventions (see Figure 1 in “basic knowledge”).

Subnational, national or global level

Subnational, national or global level

Forest degradation is normally estimated at larger scales to assist in policy and programme design and implementation, including payment mechanisms or other incentive schemes aimed at preventing degradation (e.g. payments for environmental services). Such larger-scale monitoring is also need for national reporting to international processes, such as those related to GHG emissions and biodiversity.

Measuring and monitoring forest degradation at the subnational or national scale is a challenge, and it can be more time-consuming and costly than assessing deforestation. A combination of on-the-ground forest inventories and remotely sensed data will provide the most reliable estimates. Remote sensing can be used as a cost-efficient option for assessing degradation through proxies – such as canopy-cover percentage (with a decreasing trend implying degradation). Focused field surveys (e.g. biometric field observations, biodiversity assessments and rapid rural assessments) can be undertaken in areas where remote sensing has detected degradation to obtain a more nuanced understanding of degradation trends and their causes and possible solutions.

The most suitable monitoring approach should be determined depending on parameters such as vegetation type, climate and degradation dynamic (e.g. is degradation occurring at a small or large scale? Is it concentrated or diffuse?). Sometimes, degradation may be the direct result of management, and differences in forest condition may be observable on different sides of management boundaries. In other cases, time-series observations may be required to detect change.

In some countries, existing national forest monitoring systems may be suitable – if adapted and expanded – for monitoring forest degradation.

Monitoring forest degradation with a high level of certainty is time-consuming and costly; it should only be considered in the context of REDD+ if forest degradation is likely to be a major contributor to GHG emissions. If such monitoring is considered necessary, it should focus on those areas most likely to be subject to degradation. 

Estimates of degradation are likely to be imprecise (i.e. with wide confidence intervals) because of the large number of variables and the difficulty in measuring many of these. Even with the best measurement and monitoring systems, it may be difficult to estimate degradation rates from year to year, so a long-term approach is required.

Sources of remotely sensed data that can be used in monitoring forest degradation include high-spatial-resolution optical methods (e.g. RapidEye) and active sensors such as radar and lidar. 

Identification and analysis of forest degradation drivers

Identification and analysis of forest degradation drivers

Forest degradation is a complex, highly location-specific phenomenon, and understanding it requires the analysis of both direct and indirect causes. When the scale and areas of forest degradation have been identified, a comprehensive assessment of the drivers of degradation should be undertaken in each area. It is desirable that the key stakeholders associated with degradation drivers participate in such assessments and assist in analysing data to understand the dynamics of change.

Actions and strategies to address forest degradation drivers

Actions and strategies to address forest degradation drivers

Degradation can be – but is not necessarily – a precursor to deforestation. Forests may remain degraded for a long time but never become completely deforested. Moreover, forest degradation can be halted or reversed at many points on the degradation pathway (see Figure 1 in “basic knowledge”) by forest management interventions. In many other cases, however, forest degradation is a precursor to deforestation: for example, selectively logged areas may become deforested within a few years of logging in the absence of SFM and the presence of deforestation pressures.

Actions and strategies to address forest degradation drivers should take into account the potential impacts on food security, local livelihoods, and climate-change mitigation and adaptation. Priority should be given to improving governance; increasing transparency, capacity and law enforcement; providing secure, equitable tenure; and combating illegal activities.

Interventions should consider both direct and underlying drivers and scale (e.g. local, national or global) and include a mix of measures. Forest managers are mainly responsible for actions at the local level, but viewing forest degradation in the context of larger scales may be beneficial. The time needed to design programmes to address drivers and reconcile the interests of multiple stakeholders should not be underestimated.

Example of strategies and actions to prevent and halt forest degradation

Example of strategies and actions to prevent and halt forest degradation

Forest degradation drivers



Unsustainable wood and non-wood forest product extraction and logging

Promote sustainable management practices in production forests, including: 

At local/forest management unit level

At subnational/national level

  • Review concessions policies, management plans and harvesting practices
  • Conduct research, build capacity and pilot experiences
  • Review forestry laws
  • Enter into dialogue and make mutually accountable arrangements with local stakeholders on access to, the use of, and sharing the benefits of, forest resources



Strengthen forest governance and law enforcement (against illegal logging and the illegal harvesting of non-wood forest products; to ensure respect for established quotas; and to guarantee the legality of imports and exports)


Reinforce and expand forest protected areas, considering joint forest management approaches


Encourage agroforestryafforestation and reforestation to address demand for construction materials


Strengthen forest tenure and rights


Unsustainable fuelwood collection and charcoal production

Promote sustainable levels of fuelwood collection (e.g. through awareness-raising, local regulations and law enforcement), and fuelwood efficiency (e.g. efficient stoves and heaters)


Promote sustainable and efficient charcoal production


Promote agroforestryafforestation and reforestation as strategies for addressing demand for fuelwood and charcoal


Assess and promote alternative fuels (e.g. organic briquettes) and alternative energy sources (e.g. solar, biogas)


Provide  local communities with incentives and support as they transition to alternative sources of energy


Livestock grazing and overgrazing

Promote sustainable grazing

Promote sustainable silvo-pastoral systems



Promote integrated fire management


Forest pests and diseases

Promote integrated pest management


Natural disasters

Promote forestry responses to disasters (e.g. to mitigate impacts, prevent future disasters and strengthen resilience)


Prioritization and implementation

Prioritization and implementation

Actions should be selected and ranked according to agreed criteria (e.g. objectives, estimated costs and potential for funding, and existing implementation capacities) through consultation with local stakeholders. The consultation process can be used to determine which drivers should be addressed first, the most suitable actions for addressing them, and the rationale for the choices.