The first national results produced by INCAS are based on a series of international and national definitions, using best available data and assumptions. In the absence of clear policy decisions, some definitions have been developed by the INCAS team, in consultation with relevant experts. Every effort has been made to ensure these inputs are as accurate as possible, and that any limitations and uncertainties are clearly acknowledged for full transparency. The key definitions and assumptions used in generating the results are summarised below. More detailed descriptions can be found in National Inventory of Greenhouse Gas Emissions and Removals on Indonesia’s Forest and Peatlands (Krisnawati et al 2015).


INCAS uses the Indonesian definition of forest, as specified in the Forestry Ministerial Decree No. P.14/2004 regarding Afforestation and Reforestation under the Clean Development Mechanism (A/R CDM). This states that forest represents land with a minimum area of 0.25 hectares and that contains trees with canopy cover of at least 30 per cent, capable of reaching a minimum height of 5 metres at maturity.

Biomass Classes

Biomass classes represent forests with similar initial quantities of carbon that respond in similar ways to forest management events. Stratification of forest into biomass classes reduces variation and uncertainty of carbon stock estimates.

INCAS defined biomass classes based on the type and condition of forests including natural forests (i.e. primary dryland forest, secondary dryland forest, primary swamp forest, secondary swamp forest, primary mangrove forest, and secondary mangrove forest) and timber plantations. These forest categories follow the classification of forest lands included in the land-cover map of the Ministry of Environment and Forestry.

Biomass refers to all living material in the above-ground and below-ground pools of forests. The above-ground biomass includes trees (covering all diameter classes) and understorey vegetation. This includes stems, branches, bark and leaves. The below-ground biomass includes coarse and fine roots.

Litter and coarse woody debris belong to the debris pool, but are related to biomass classes through turnover and site conditions.

Non-forest land

Non-forest lands include cropland and other lands including settlement, grassland, and wetland as defined by the Ministry of Environment and Forestry’s land-cover class.


INCAS has used a definition of peatland as lands with organic soil and included in the Ministry of Agriculture’s peat map. Peatland represents areas with an accumulation of partly decomposed organic matter, with ash content equal to or less than 35 per cent, organic carbon content (by weight) of at least 12 per cent, and peat depth of the carbon-rich layer equal to or more than 50 centimetres (Wahyunto et al., 2004; Agus et al., 2011). A peat depth of 50 centimetres was used by INCAS as the quantitative measure to define the peat area, in accordance with the Indonesian National Standard (SNI) 7925 regarding peatland mapping (National Standardisation Agency, 2013).


Deforestation is defined as the permanent change of forested land into non-forested land as a result of human activities. For the national GHG inventory, the deforestation account represents the sum of annual GHG emissions and removals resulting from deforestation related events on forest lands for the time period analysed and reported. Net emissions from subsequent land uses are included where known. For example, where establishment of estate crops occurs on cleared forest lands, these are included in the deforestation account. Emissions from decay of forest debris arising from deforestation events are included, resulting in emissions for many years after each event. This also included ongoing emissions from the events that occurred before the years of analysis.

Forest degradation

Forest degradation is defined as:

  • Conversion of primary forest lands to secondary forest lands. For example, human-induced fire, or logging or clearing followed by natural regeneration resulting in areas of temporarily unstocked forest;
  • Ongoing selective harvesting using conventional technique in secondary forests;
  • Conversion of natural forest lands to plantations;
  • Where forest disturbance was detected in an area but the land still met the minimum threshold for forest lands (forest lands remaining forest lands).

For the GHG inventory, the forest degradation account represents the sum of annual GHG emissions and removals from these events. Emissions from decay of forest debris arising from the forest degradation event are included, resulting in emissions for many years afterwards. This also includes ongoing emissions from the forest degradation events that occurred before the years of analysis.

Sustainable management of forests

Sustainable management of forests is defined as activity occurring on areas where no permanent forest-cover loss was detected from remote-sensing imagery, but concession data indicate harvesting with a Reduced Impact Logging (RIL) technique, as well as ongoing harvesting and replanting of timber plantations. For the GHG inventory, the sustainable management of forests account represents the sum of annual GHG emissions and removals resulting from ongoing management using RIL technique of land classified as secondary forest at the start of the reporting period (i.e. forest land remaining forest land), and ongoing harvesting and replanting of timber plantations.

Enhancement of forest carbon stocks

INCAS defines the enhancement of forest carbon stocks as the establishment of new plantation lands resulting in the conversion of non-forest lands to forest lands. The enhancement of forest carbon stocks may also occur within existing forests. For the GHG inventory, the enhancement of forest-carbon stock account represents the sum of annual emissions and removals, those resulting from the replanting on non-forest land (i.e. conversion of non-forest land to forest land) and subsequent management of these forests. Plantings intended to enhance forest carbon stocks are included in this category.

Role of Conservation

There is no agreed definition on the role of conservation in the context of REDD+ activities. The role of conservation is not defined in the IPCC 2003 Good Practice Guidance nor the IPCC 2006 Guidelines nor the GFOI Methods and Guidance Document. The role of conservation could be viewed as an activity to protect and conserve forests and their ecosystem services. In this context, conservation aims to maintain forest carbon stocks. The role of conservation as a REDD+ activity is not included in the first national GHG inventory for Indonesia due to insufficient data about these kinds of activities on forest lands.