Forest management/Data uncertainties limitations: Difference between revisions

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{{ComponentSubLimitationTemplate
{{ComponentDataUncertaintyAndLimitationsTemplate
|Reference=FAO, 2001; FAO, 2008; Brown, 1990; Carle and Holmgren, 2008
|Reference=FAO, 2010;IEA, 2012;Brown, 2000;Carle and Holmgren, 2008;UNEP-INTERPOL, 2012;FAO, 2001a;FAO, 2008;FAO, 2020
|Description=Several assumption were made to model the future wood produced from forestry management systems, and these pinpoint towards uncertainties in the forestry management model and its data. Better monitoring and reporting of this data allows for better calibration of the present forestry module.  
}}
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==Data, uncertainty and limitations==
===Data===
The main data source for the development and calibration of the forest management module is FAO Forest Resource Assessment ([[FAO, 2020]]), from which data on wood production and deforested areas are derived. In addition, statistics from the International Energy Agency ([[IEA, 2012]]) are used to estimate the regional fuelwood production, based on household fuelwood and charcoal requirements in national energy statistics. Finally, national data were collected to parameterise the type and production parameters of forest management in world regions (see details in [[Arets et al., 2011]])  and establishment of new forest plantations was designed according to planting rates reported and projected by FAO ([[Brown, 2000]]; [[Carle and Holmgren, 2008]]).
 
===Uncertainties===
Several assumptions had to be made to project future production in forest management systems. These pinpoint the uncertainties in the forestry management model. Better data, monitoring and reporting would improve calibration of the IMAGE forest management module.
 
FAO Forest Resource Assessment reports are published regularly on quantities of industrially produced wood and the areas of primary and secondary forests. However, these reports do not include the area from which these wood quantities are harvested, and the forest management system of these areas. The amount of wood produced in deforestation processes is not reported, probably due to the illegal nature of many such operations.
 
Few data are available on the extent of illegal logging, they are not captured in the FAO statistics, but in satellite-based assessments, and only very rough estimates are available ([[UNEP-INTERPOL, 2012]]). In addition, few data are available on informal collection of fuelwood in forests in developing countries ([[FAO, 2001a]]; [[FAO, 2008]]). Estimates of total fuelwood demand are highly uncertain ([[IEA, 2012]]), and fuelwood demand is only partly met by the forestry operations in this IMAGE module.  


In the regularly published FAO Forest Resource Assessment, the amount of industrial produced wood is reported, but not the area from which these amounts are harvested, nor the use of different forest management types. Moreover, the amount of wood produced in deforestation processes is not reported, probably due to the illegal nature of many of such operations.  
Another uncertainty is the starting point, which is the state of forest use by age cohort in 1970. As forests take several decades to a century to regrow after felling, the effect of historic uncertainties in forest-use extends far into the future.


Another shortcoming in available forest-use data is the extent of informal fuelwood collection from forests in developing countries (FAO, 2001, 2008). At present, only part of the fuelwood demand is attributed to industrial forest harvesting. Another uncertainty is the absence of good data on historical forest-use, preceding the usually applied starting year for modelling , i.e. 1970. As forests take several decennia to even a century for regrowth after cutting, the effects of forest-use extends far into the future. To establish a good initial forest-use situation in 1970, forest use from the previous century should be known or at least assumed.  
===Limitations===
Timber demand in IMAGE 3.2 is the total demand of sawlogs, pulpwood (both based on [[FAO]] for the historic period), and fuelwood (based on [[IEA]] and calculated by the [[TIMER model]]). The demand is fulfilled by harvesting wood from any type of forest without specifying the original source of demand. This can be relevant as different types of wood are used for timber, pulp and fuel. For fuelwood we assume that a certain fraction originate from informal sources, like gathering. For specific assessments it would be useful to include this detail in the allocation of forestry.


Calibration: I think the additional deforestation is part of that. Further, plantation establishment has been designed according to reported and projected planting rates by FAO (Brown, 1990; Carle and Holmgren, 2008).
The timber demand in a region is the sum of local/regional demands and timber claims by other regions. The trade assumptions are adopted from external models, limiting the application of the model for cases with regional timber scarcity.
}}
 
The only driver of deforestation modelled in IMAGE 3.2 is the net expansion of agriculture per region. Many drivers of deforestation are not related to agricultural expansion, but there is no global assessment of these other drivers. Therefore, total deforestation rates in IMAGE are calibrated to FAO and satellite observed deforestation rates. Drivers and extent of deforestation are very uncertain and subject to debate, yet determine future deforestation and deforestation emissions in scenario simulations.
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Latest revision as of 19:16, 22 November 2021

Link to framework components overview

Parts of Forest management/Data uncertainties limitations

  1. Introduction page
  2. Model description
  3. Policy issues
  4. Data, uncertainty and limitations
  5. Overview of references
Component is implemented in:
Components:
Related IMAGE components
Projects/Applications
Key publications
References
Forest management module in IMAGE 3.0
Flowchart Forest management. See also the Input/Output Table on the introduction page. The option of forest plantations in IMAGE and LPJmL is still under development, and expected to be available soon.

Data, uncertainty and limitations

Data

The main data source for the development and calibration of the forest management module is FAO Forest Resource Assessment (FAO, 2020), from which data on wood production and deforested areas are derived. In addition, statistics from the International Energy Agency (IEA, 2012) are used to estimate the regional fuelwood production, based on household fuelwood and charcoal requirements in national energy statistics. Finally, national data were collected to parameterise the type and production parameters of forest management in world regions (see details in Arets et al., 2011) and establishment of new forest plantations was designed according to planting rates reported and projected by FAO (Brown, 2000; Carle and Holmgren, 2008).

Uncertainties

Several assumptions had to be made to project future production in forest management systems. These pinpoint the uncertainties in the forestry management model. Better data, monitoring and reporting would improve calibration of the IMAGE forest management module.

FAO Forest Resource Assessment reports are published regularly on quantities of industrially produced wood and the areas of primary and secondary forests. However, these reports do not include the area from which these wood quantities are harvested, and the forest management system of these areas. The amount of wood produced in deforestation processes is not reported, probably due to the illegal nature of many such operations.

Few data are available on the extent of illegal logging, they are not captured in the FAO statistics, but in satellite-based assessments, and only very rough estimates are available (UNEP-INTERPOL, 2012). In addition, few data are available on informal collection of fuelwood in forests in developing countries (FAO, 2001a; FAO, 2008). Estimates of total fuelwood demand are highly uncertain (IEA, 2012), and fuelwood demand is only partly met by the forestry operations in this IMAGE module.

Another uncertainty is the starting point, which is the state of forest use by age cohort in 1970. As forests take several decades to a century to regrow after felling, the effect of historic uncertainties in forest-use extends far into the future.

Limitations

Timber demand in IMAGE 3.2 is the total demand of sawlogs, pulpwood (both based on FAO for the historic period), and fuelwood (based on IEA and calculated by the TIMER model). The demand is fulfilled by harvesting wood from any type of forest without specifying the original source of demand. This can be relevant as different types of wood are used for timber, pulp and fuel. For fuelwood we assume that a certain fraction originate from informal sources, like gathering. For specific assessments it would be useful to include this detail in the allocation of forestry.

The timber demand in a region is the sum of local/regional demands and timber claims by other regions. The trade assumptions are adopted from external models, limiting the application of the model for cases with regional timber scarcity.

The only driver of deforestation modelled in IMAGE 3.2 is the net expansion of agriculture per region. Many drivers of deforestation are not related to agricultural expansion, but there is no global assessment of these other drivers. Therefore, total deforestation rates in IMAGE are calibrated to FAO and satellite observed deforestation rates. Drivers and extent of deforestation are very uncertain and subject to debate, yet determine future deforestation and deforestation emissions in scenario simulations.

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