IMAGE - User contributions [en]

Forest management/Data uncertainties limitations

2016-12-13T15:26:52Z

Minnenvj:

{{ComponentDataUncertaintyAndLimitationsTemplate
|Reference=FAO, 2010; IEA, 2012; Brown, 2000; Carle and Holmgren, 2008; UNEP-INTERPOL, 2012; FAO, 2001a; FAO, 2008;
|Description=<h2>Data, uncertainties and limitations</h2>
===Data===
The main data source for the development and calibration of the forest management module is FAO Forest Resource Assessment ([[FAO, 2010]]), 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===
<div class="version changev31">
Timber demand in IMAGE 3.0 is the sum of the demand for sawlogs, pulpwood and fuelwood. This total demand is than used in harvesting forests across the world, without knowing anymore the underlying wood types. So, forest plantations, for example, can used to fulfill the demand for either sawlogs of fuelwood. For specific assessments (e.g. for timber use for modern biomass), it would have been useful to remain the three wood types in the allocation.

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 (which will change the total demand in a region).

The only driver of deforestation modelled in IMAGE 3.0 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 are calibrated in IMAGE. Drivers and extent of deforestation are very
uncertain and subject to debate, yet determine future deforestation and deforestation
emissions in scenario simulations.
</div>
}}

Forest management/Description

2016-12-13T15:08:33Z

Minnenvj:

{{ComponentDescriptionTemplate
|Reference=Kallio et al., 2004; FAO, 2001a; FAO, 2008; Brown, 2000; Carle and Holmgren, 2008; FAO, 2012b; FAO, 2010;
|Description=The forest management module describes regional timber demand and the production of timber in the three different management systems clear felling, selective felling and forest plantations. Deforestation rates reported by {{abbrTemplate|FAO}} are used to calibrate deforestation rates in IMAGE, using a so called additional deforestion.

===Timber demand===
In IMAGE 3.0, the driver for forest harvest is timber demand per region. Timber demand is the sum of domestic and/or regional demand and timber claims by other regions (export/trade). Production and trade assumptions for saw logs and paper/pulp wood are adopted from external models, such as [[EFIGTM model|EFI-GTM]] ([[Kallio et al., 2004]]), and domestic demand for fuelwood is based on the [[TIMER model]] (See Component [[Energy supply and demand]]).

Part of the global energy supply is met by fuelwood and charcoal, in particular in less developed world regions. Not all wood involved is produced from formal forestry activities, as it is also collected from non-forest areas, for example from thinning orchards and along roadsides ([[FAO, 2001a]]; [[FAO, 2008]]). As few reliable data are available on fuelwood production, own assumptions have been made in IMAGE. While fuelwood production in industrialized regions is dominated by large-scale, commercial operations, in transitional and developing regions smaller proportions of fuelwood volumes are assumed to come from forestry operations: 50% and 32% respectively.

===Timber supply & production in forests===
In IMAGE, felling in each region follows a stepwise procedure until timber demand is met, attributed to the three aforementioned management systems. The proportion for each management system is derived from forest inventories for different world regions ([[Arets et al., 2011]]) and used as model input (Figure Flowchart). Firstly, timber is derived from forest land that has been converted to agriculture. Secondly, timber from forest plantations at the end of their rotation cycle are harvested. Finally, trees from natural forests are harvested, applying clear felling and/or selective felling. In all management systems, trees can only be harvested when the rotation cycle of forest regrowth has been completed.

===Selective logging===
Under selective felling, only a - regional and time specific- fraction of the trees is logged and the other trees remain in the forest. After logging, a fraction of the harvested wood is removed from the forest to fulfil the demand. Biomass left behind in the forest represents losses/residues during tree harvesting (from tree damage and unusable tree parts) or left in the forest because of environmental concerns (biodiversity and nutrient supply). This fraction take-away is derived from literature, defined for industrial roundwood (see [[Arets et al., 2011]]) It is further adjusted to account for the demand for wood fuel, for which it equals unity.

===Forest plantations===
Forest plantations are established for efficient, commercially viable wood production. Their regional establishment in IMAGE 3 is scenario driven (see also Input/Output Table at [[Forest management|Introduction part]]), based on FAO. The expectation is that increasingly more wood will be produced in plantations because sustainability criteria may limit harvest from natural forests ([[Brown, 2000]]; [[Carle and Holmgren, 2008]]; [[FAO, 2012b]]). Forest plantations are assumed to be established firstly on abandoned agricultural land. When sufficient abandoned land is not available, forest plantations are established on cleared forest areas. When a forest plantation has been established, the land cannot be used for other purposes or converted to natural vegetation until the tree rotation cycle has been completed.

===Additional deforestation ===
Globally, conversion to agricultural land is the major driver of forest clearing; timber harvest does not result in deforestation, if natural vegetation is regrowing. But there are other causes of deforestation not related to food demand and timber production, such as urbanisation, mining and illegal logging. These activities contribute to loss of forest area, increased degradation risks and a decline in the supply of forest services. To be consistent with the total deforestation rates per world region reported by the FAO ([[FAO, 2010|2010]]), IMAGE 3.0 introduces a category ‘additional deforestation’. IMAGE assumes no recovery of natural vegetation in these areas, and no agricultural activities.
|Flowchart=ForestManagementModel.png
|AltText=Component flow chart forest management
|CaptionText=Flow diagram of forest management
|Model-Database=EFIGTM
}}

Forest management/Description

2016-12-13T15:00:02Z

Minnenvj:

{{ComponentDescriptionTemplate
|Reference=Kallio et al., 2004; FAO, 2001a; FAO, 2008; Brown, 2000; Carle and Holmgren, 2008; FAO, 2012b; FAO, 2010;
|Description=The forest management module describes regional timber demand and the production of timber in the three different management systems clear felling, selective felling and forest plantations. Deforestation rates reported by {{abbrTemplate|FAO}} are used to calibrate deforestation rates in IMAGE, using a so called additional deforestion.

===Timber demand===
In IMAGE 3.0, the driver for forest harvest is timber demand per region. Timber demand is the sum of domestic and/or regional demand and timber claims by other regions (export/trade). Production and trade assumptions for saw logs and paper/pulp wood are adopted from external models, such as [[EFIGTM model|EFI-GTM]] ([[Kallio et al., 2004]]), and domestic demand for fuelwood is based on the [[TIMER model]] (See Component [[Energy supply and demand]]).

Part of the global energy supply is met by fuelwood and charcoal, in particular in less developed world regions. Not all wood involved is produced from formal forestry activities, as it is also collected from non-forest areas, for example from thinning orchards and along roadsides ([[FAO, 2001a]]; [[FAO, 2008]]). As few reliable data are available on fuelwood production, own assumptions have been made in IMAGE. While fuelwood production in industrialized regions is dominated by large-scale, commercial operations, in transitional and developing regions smaller proportions of fuelwood volumes are assumed to come from forestry operations: 50% and 32% respectively.

===Timber supply & production in forests===
In IMAGE, felling in each region follows a stepwise procedure until timber demand is met, attributed to the three aforementioned management systems. The proportion for each management system is derived from forest inventories for different world regions ([[Arets et al., 2011]]) and used as model input (Figure Flowchart). Firstly, timber is derived from forest land that has been converted to agriculture. Secondly, timber from forest plantations at the end of their rotation cycle are harvested. Finally, trees from natural forests are harvested, applying clear felling and/or selective felling. In all management systems, trees can only be harvested when the rotation cycle of forest regrowth has been completed.

===Selective logging===
Under selective felling, only a - regional and time specific- fraction of the trees is logged and the other trees remain in the forest. After logging, a fraction of the harvested wood is removed from the forest to fulfil the demand. Biomass left behind in the forest represents losses/residues during tree harvesting (from tree damage and unusable tree parts) or left in the forest because of environmental concerns (biodiversity and nutrient supply). This fraction take-away is derived from literature, defined for industrial roundwood (see [[Arets et al., 2011]]) It is further adjusted to account for the demand for wood fuel, for which it equals unity.

===Forest plantations===
Forest plantations are established for efficient, commercially viable wood production. Their regional establishment in IMAGE 3 is scenario driven (see also Input/Output Table at [[Forest management|Introduction part]]), based on FAO. The expectation is that increasingly more wood will be produced in plantations because sustainability criteria may limit harvest from natural forests ([[Brown, 2000]]; [[Carle and Holmgren, 2008]]; [[FAO, 2012b]]). Forest plantations are assumed to be established firstly on abandoned agricultural land. When sufficient abandoned land is not available, forest plantations are established on cleared forest areas. When a forest plantation has been established, the land cannot be used for other purposes or converted to natural vegetation until the tree rotation cycle has been completed.

===Additional deforestation ===
Globally, conversion to agricultural land is the major driver of forest clearing, and timber harvest does not result in deforestation, if natural vegetation is regrowing. But there are other causes of deforestation not related to food demand and timber production, such as urbanisation, mining and illegal logging. These activities contribute to loss of forest area, increased degradation risks and a decline in the supply of forest services. To be consistent with the total deforestation rates per world region reported by the FAO ([[FAO, 2010|2010]]), IMAGE 3.0 introduces a category ‘additional deforestation’. IMAGE assumes no recovery of natural vegetation in these areas, and no agricultural activities.
|Flowchart=ForestManagementModel.png
|AltText=Component flow chart forest management
|CaptionText=Flow diagram of forest management
|Model-Database=EFIGTM
}}

Forest management/Description

2016-12-13T14:59:24Z

Minnenvj:

{{ComponentDescriptionTemplate
|Reference=Kallio et al., 2004; FAO, 2001a; FAO, 2008; Brown, 2000; Carle and Holmgren, 2008; FAO, 2012b; FAO, 2010;
|Description=The forest management module describes regional timber demand and the production of timber in the three different management systems clear felling, selective felling and forest plantations. Deforestation rates reported by {{abbrTemplate|FAO}} are used to calibrate deforestation rates in IMAGE, using a so called additional deforestion.

===Timber demand===
In IMAGE 3.0, the driver for forest harvest is timber demand per region. Timber demand is the sum of domestic and/or regional demand and timber claims by other regions (export/trade). Production and trade assumptions for saw logs and paper/pulp wood are adopted from external models, such as [[EFIGTM model|EFI-GTM]] ([[Kallio et al., 2004]]), and domestic demand for fuelwood is based on the [[TIMER model]] (See Component [[Energy supply and demand]]).

Part of the global energy supply is met by fuelwood and charcoal, in particular in less developed world regions. Not all wood involved is produced from formal forestry activities, as it is also collected from non-forest areas, for example from thinning orchards and along roadsides ([[FAO, 2001a]]; [[FAO, 2008]]). As few reliable data are available on fuelwood production, own assumptions have been made in IMAGE. While fuelwood production in industrialized regions is dominated by large-scale, commercial operations, in transitional and developing regions smaller proportions of fuelwood volumes are assumed to come from forestry operations: 50% and 32% respectively.

===Timber supply & production in forests===
In IMAGE, felling in each region follows a stepwise procedure until timber demand is met, attributed to the three aforementioned management systems. The proportion for each management system is derived from forest inventories for different world regions ([[Arets et al., 2011]]) and used as model input (Figure Flowchart). Firstly, timber is derived from forest land that have been converted to agriculture. Secondly, timber from forest plantations at the end of their rotation cycle are harvested. Finally, trees from natural forests are harvested, applying clear felling and/or selective felling. In all management systems, trees can only be harvested when the rotation cycle of forest regrowth has been completed.

===Selective logging===
Under selective felling, only a - regional and time specific- fraction of the trees is logged and the other trees remain in the forest. After logging, a fraction of the harvested wood is removed from the forest to fulfil the demand. Biomass left behind in the forest represents losses/residues during tree harvesting (from tree damage and unusable tree parts) or left in the forest because of environmental concerns (biodiversity and nutrient supply). This fraction take-away is derived from literature, defined for industrial roundwood (see [[Arets et al., 2011]]) It is further adjusted to account for the demand for wood fuel, for which it equals unity.

===Forest plantations===
Forest plantations are established for efficient, commercially viable wood production. Their regional establishment in IMAGE 3 is scenario driven (see also Input/Output Table at [[Forest management|Introduction part]]), based on FAO. The expectation is that increasingly more wood will be produced in plantations because sustainability criteria may limit harvest from natural forests ([[Brown, 2000]]; [[Carle and Holmgren, 2008]]; [[FAO, 2012b]]). Forest plantations are assumed to be established firstly on abandoned agricultural land. When sufficient abandoned land is not available, forest plantations are established on cleared forest areas. When a forest plantation has been established, the land cannot be used for other purposes or converted to natural vegetation until the tree rotation cycle has been completed.

===Additional deforestation ===
Globally, conversion to agricultural land is the major driver of forest clearing, and timber harvest does not result in deforestation, if natural vegetation is regrowing. But there are other causes of deforestation not related to food demand and timber production, such as urbanisation, mining and illegal logging. These activities contribute to loss of forest area, increased degradation risks and a decline in the supply of forest services. To be consistent with the total deforestation rates per world region reported by the FAO ([[FAO, 2010|2010]]), IMAGE 3.0 introduces a category ‘additional deforestation’. IMAGE assumes no recovery of natural vegetation in these areas, and no agricultural activities.
|Flowchart=ForestManagementModel.png
|AltText=Component flow chart forest management
|CaptionText=Flow diagram of forest management
|Model-Database=EFIGTM
}}

Forest management/Data uncertainties limitations

2016-11-04T08:02:59Z

Minnenvj:

{{ComponentDataUncertaintyAndLimitationsTemplate
|Reference=FAO, 2010; IEA, 2012; Brown, 2000; Carle and Holmgren, 2008; UNEP-INTERPOL, 2012; FAO, 2001a; FAO, 2008;
|Description=<h2>Data, uncertainties and limitations</h2>
===Data===
The main data source for the development and calibration of the forest management module is FAO Forest Resource Assessment ([[FAO, 2010]]), 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 3.0 is the sum of the demand for sawlogs, pulpwood and fuelwood. This total demand is than used in harvesting forests across the world, without knowing anymore the underlying wood types. So, forest plantations, for example, can used to fulfill the demand for either sawlogs of fuelwood. For specific assessments (e.g. for timber use for modern biomass), it would have been useful to remain the three wood types in the allocation.

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 (which will change the total demand in a region).

}}

Forest management/Policy issues

2016-11-03T12:23:14Z

Minnenvj:

{{ComponentPolicyIssueTemplate
|Reference=PBL, 2010; Brown, 2000;
|Description=In most baseline scenarios, areas of managed forests increase. The IMAGE forest management model was used in the scenario study ‘Rethinking global biodiversity strategies’ on future biodiversity developments ([[PBL, 2010]]). The study projects that, in the absence of additional forestry policy, the area of forest plantations will increase only slightly between 2000 and 2050 (from 1.1 to 1.2 million km<sup>2</sup>). The total forest area for wood production will increase from 9.5 to 14.5 million km<sup>2</sup> (the figure below, left panel). According to this projection, by 2050, just over a third of the global forest area will be used for wood production and consequently. In the same year, the area of primary forest, defined in IMAGE as established before 1970 and not exploited since, will decrease by more than 6 million km<sup>2</sup> from almost 30 million km<sup>2</sup> in 2000.
|Example=Several policy interventions on forest management can be simulated in the IMAGE model 3.0:
* increase in production on highly productive forest plantations;
* increase in carbon storage to mitigate climate change;
* increasing harvest efficiencies, or using harvest residues for energy;
* more reduced impact logging (RIL) techniques, less conventional selective felling.

The scenario study [[Rethinking Biodiversity Strategies (2010) project|‘Rethinking global biodiversity strategies’]] implemented the following two ambition levels for improved forest management as alternatives for the baseline trend (the figures above and below):
# Moderate ambition level: partial substitution of conventional selective felling in tropical forests with RIL techniques, and forest plantations targeted at supplying 25% of the global wood demand;
# High ambition level: full substitution of conventional selective felling with RIL techniques as of 2010, and forest plantations targeted at supplying 40% of the global wood demand by 2050. This represents a plausible future development of plantation growth ([[Brown, 2000]]).

The ambitious improvements in forest management will result in considerably less land used for forestry by 2050 (about 10 million km<sup>2</sup>, or one third smaller area than under the baseline scenario) (see the figure above). With the reduced forest area, and the assumed positive effects of {{abbrTemplate|RIL}} techniques, biodiversity loss caused by forestry will be reduced. For the lower ambition level, gains will be smaller with forestry area expanding well over 3 million km<sup>2</sup>, and less biodiversity loss prevented.
|IMAGEComponent=Biodiversity
}}

Forest management/Description

2016-11-02T15:47:28Z

Minnenvj:

{{ComponentDescriptionTemplate
|Reference=Kallio et al., 2004; FAO, 2001a; FAO, 2008; Brown, 2000; Carle and Holmgren, 2008; FAO, 2012b; FAO, 2010;
|Description=The forest management module describes regional timber demand and the production of timber in the three different management systems clear felling, selective felling and forest plantations. Deforestation rates reported by {{abbrTemplate|FAO}} are used to calibrate deforestation rates in IMAGE, using a so called additional deforestion.

===Timber demand===
In IMAGE 3.0, the driver for forest harvest is timber demand per region. Timber demand is the sum of domestic and/or regional demand and timber claims by other regions (export/trade). Production and trade assumptions for saw logs and paper/pulp wood are adopted from external models, such as [[EFIGTM model|EFI-GTM]] ([[Kallio et al., 2004]]), and domestic demand for fuelwood is based on the [[TIMER model]] (See Component [[Energy supply and demand]]).

Part of the global energy supply is met by fuelwood and charcoal, in particular in less developed world regions. Not all wood involved is produced from formal forestry activities, as it is also collected from non-forest areas, for example from thinning orchards and along roadsides ([[FAO, 2001a]]; [[FAO, 2008]]). As few reliable data are available on fuelwood production, own assumptions have been made in IMAGE. While fuelwood production in industrialized regions is dominated by large-scale, commercial operations, in transitional and developing regions smaller proportions of fuelwood volumes are assumed to come from forestry operations: 50% and 32% respectively.

===Timber supply & production in forests===
In IMAGE, felling in each region follows a stepwise procedure until timber demand is met, attributed to the three aforementioned management systems. The proportion for each management system is derived from forest inventories for different world regions ([[Arets et al., 2011]]) and used as model input (Figure Flowchart). Firstly, timber is derived from forests that have been converted to agriculture. Secondly, timber from forest plantations at the end of their rotation cycle are harvested. Finally, trees from natural forests are harvested, applying clear felling and/or selective felling. In all management systems, trees can only be harvested when the rotation cycle of forest regrowth has been completed.

===Selective logging===
Under selective felling, only a - regional and time specific- fraction of the trees is logged and the other trees remain in the forest. After logging, a fraction of the harvested wood is removed from the forest to fulfil the demand. Biomass left behind in the forest represents losses/residues during tree harvesting (from tree damage and unusable tree parts) or left in the forest because of environmental concerns (biodiversity and nutrient supply). This fraction take-away is derived from literature, defined for industrial roundwood (see [[Arets et al., 2011]]) It is further adjusted to account for the demand for wood fuel, for which it equals unity.

===Forest plantations===
Forest plantations are established for efficient, commercially viable wood production. Their regional establishment in IMAGE 3 is scenario driven (see also Input/Output Table at [[Forest management|Introduction part]]), based on FAO. The expectation is that increasingly more wood will be produced in plantations because sustainability criteria may limit harvest from natural forests ([[Brown, 2000]]; [[Carle and Holmgren, 2008]]; [[FAO, 2012b]]). Forest plantations are assumed to be established firstly on abandoned agricultural land. When sufficient abandoned land is not available, forest plantations are established on cleared forest areas. When a forest plantation has been established, the land cannot be used for other purposes or converted to natural vegetation until the tree rotation cycle has been completed.

===Additional deforestation ===
Globally, conversion to agricultural land is the major driver of forest clearing, and timber harvest does not result in deforestation, if natural vegetation is regrowing. But there are other causes of deforestation not related to food demand and timber production, such as urbanisation, mining and illegal logging. These activities contribute to loss of forest area, increased degradation risks and a decline in the supply of forest services. To be consistent with the total deforestation rates per world region reported by the FAO ([[FAO, 2010|2010]]), IMAGE 3.0 introduces a category ‘additional deforestation’. IMAGE assumes no recovery of natural vegetation in these areas, and no agricultural activities.
|Flowchart=ForestManagementModel.png
|AltText=Component flow chart forest management
|CaptionText=Flow diagram of forest management
|Model-Database=EFIGTM
}}

Forest management

2016-11-02T15:25:41Z

Minnenvj:

{{ComponentTemplate2
|Application=Rethinking Biodiversity Strategies (2010) project; Shared Socioeconomic Pathways - SSP (2014) project; EU Seventh Framework Programme - FP7;
|IMAGEComponent=Drivers; Land-use allocation; Carbon cycle and natural vegetation; Energy supply and demand;
|Model-Database=EFIGTM model;
|KeyReference=Arets et al., 2011;
|Reference=FAO, 2010; Carle and Holmgren, 2008; Putz et al., 2012; FAO, 2006b; Alkemade et al., 2009; Hartmann et al., 2010;
|InputVar=Demand traditional biomass; Land cover, land use - grid;
Forest plantation demand; Land suitability - grid; Harvest efficiency; Timber demand ; Carbon pools in vegetation - grid; Fraction of selective logging;
|Parameter=Traditional biomass from non-forest land; FAO deforestation rates;
|OutputVar=Timber use fraction; Forest residues; Forest management type - grid; Regrowth forest area - grid; Harvested wood; Degraded forest area;
|Description=The global forest area and wooded land area has been estimated for 2010 at just over 40 and 11 million km<sup>2</sup>, respectively ([[FAO, 2010]]). Forest resources are used for multitude of purposes, including timber, fuel, food, water and other forest-related goods and services. In addition, (semi-) natural forests are home to many highly valued species of interest for nature conservation and biodiversity.

The total global forest area is continuing to decline at difference rates in different world regions. Although the rate of global deforestation has decreased in the last decade, deforestation is still occurring on a significant scale in large parts of Latin America, Africa and Southeastern Asia. At the same time, the net forest area is expanding in some regions, such as in Europe and China ([[FAO, 2010]]). Sustainable management of global forest resources may contribute to preserving forests, slowing down or reversing degradation processes, and conserving forest biodiversity and carbon stocks ([[FAO, 2010]]).

Several types of forest management systems are employed in meeting the worldwide demand for timber, paper, fibreboard, traditional or modern bioenergy and other products. Management practices depend on forest type, conservation policies and regulation, economics, and other, often local, factors. Practices differ with respect to timber volume harvested per area, rotation cycle, and carbon content and state of biodiversity of the forested areas.

Modelling of forests and forest management is an integral part of the IMAGE 3.0 framework, with a simulated forest area in 2010 at about 47 million km<sup>2</sup> , somewhat larger than observed by {{abbrTemplate|FAO}} as this area includes fractions of other wooded land (see Component [[Carbon cycle and natural vegetation]]). To manage these forests, three forest management systems are defined in IMAGE 3.0 in a simplification of the range of management systems implemented worldwide ([[Carle and Holmgren, 2008]]; [[Arets et al., 2011]]).
# The first forest management system is clear cutting or clear felling, in which all trees in an area are cut down followed by natural or ‘assisted’ regrowth, as widely applied in temperate regions.
# The second forest management system is selective logging of (semi)natural forests, in which only trees of the highest economic value are felled, commonly used in tropical forests with a high heterogeneity of tree species. An ecological variant of selective logging is reduced impact logging ({{abbrTemplate|RIL}}) directed to reducing harvest damage, stimulating regrowth and maintaining biodiversity levels ([[Putz et al., 2012]]).
# The third forest management system considered in IMAGE 3.0 is forest plantations, such as hardwood tree plantations in the tropics, and poplar plantations in temperate regions. Selected tree species, either endemic or exotic to the area, are planted and managed intensively, for example through pest control, irrigation and fertiliser use, to maximise production. Forest plantations generally have a high productivity level ([[FAO, 2006b]]). By producing more wood products on less land, plantations may contribute to more sustainable forest management by reducing pressure on natural forests ([[Carle and Holmgren, 2008]]; [[Alkemade et al., 2009]]). However, the ecological value of biodiversity in many forest plantations is relatively low ([[Hartmann et al., 2010]]).
|ComponentCode=FM
|AggregatedComponent=Agriculture and land use
|FrameworkElementType=pressure component
}}

Forest management

2016-11-02T13:27:43Z

Minnenvj:

{{ComponentTemplate2
|Application=Rethinking Biodiversity Strategies (2010) project; Shared Socioeconomic Pathways - SSP (2014) project;
|IMAGEComponent=Drivers; Land-use allocation; Carbon cycle and natural vegetation; Energy supply and demand;
|Model-Database=EFIGTM model;
|KeyReference=Arets et al., 2011;
|Reference=FAO, 2010; Carle and Holmgren, 2008; Putz et al., 2012; FAO, 2006b; Alkemade et al., 2009; Hartmann et al., 2010;
|InputVar=Demand traditional biomass; Land cover, land use - grid;
Forest plantation demand; Land suitability - grid; Harvest efficiency; Timber demand ; Carbon pools in vegetation - grid; Fraction of selective logging;
|Parameter=Traditional biomass from non-forest land; FAO deforestation rates;
|OutputVar=Timber use fraction; Forest residues; Forest management type - grid; Regrowth forest area - grid; Harvested wood; Degraded forest area;
|Description=The global forest area and wooded land area has been estimated for 2010 at just over 40 and 11 million km<sup>2</sup>, respectively ([[FAO, 2010]]). Forest resources are used for multitude of purposes, including timber, fuel, food, water and other forest-related goods and services. In addition, (semi-) natural forests are home to many highly valued species of interest for nature conservation and biodiversity.

The total global forest area is continuing to decline at difference rates in different world regions. Although the rate of global deforestation has decreased in the last decade, deforestation is still occurring on a significant scale in large parts of Latin America, Africa and Southeastern Asia. At the same time, the net forest area is expanding in some regions, such as in Europe and China ([[FAO, 2010]]). Sustainable management of global forest resources may contribute to preserving forests, slowing down or reversing degradation processes, and conserving forest biodiversity and carbon stocks ([[FAO, 2010]]).

Several types of forest management systems are employed in meeting the worldwide demand for timber, paper, fibreboard, traditional or modern bioenergy and other products. Management practices depend on forest type, conservation policies and regulation, economics, and other, often local, factors. Practices differ with respect to timber volume harvested per area, rotation cycle, and carbon content and state of biodiversity of the forested areas.

Modelling of forests and forest management is an integral part of the IMAGE 3.0 framework, with a simulated forest area in 2010 at about 46 million km<sup>2</sup> , somewhat larger than observed by {{abbrTemplate|FAO}} as this area includes fractions of other wooded land (see Component [[Carbon cycle and natural vegetation]]). To manage these forests, three forest management systems are defined in IMAGE 3.0 in a simplification of the range of management systems implemented worldwide ([[Carle and Holmgren, 2008]]; [[Arets et al., 2011]]).
# The first forest management system is clear cutting or clear felling, in which all trees in an area are cut down followed by natural or ‘assisted’ regrowth, as widely applied in temperate regions.
# The second forest management system is selective logging, in which only trees of the highest economic value are felled, commonly used in tropical forests with a high heterogeneity of tree species. An ecological variant of selective logging is reduced impact logging ({{abbrTemplate|RIL}}) directed to reducing harvest damage, stimulating regrowth and maintaining biodiversity levels ([[Putz et al., 2012]]).
# The third forest management system considered in IMAGE 3.0 is forest plantations, such as hardwood tree plantations in the tropics, and poplar plantations in temperate regions. Selected tree species, either endemic or exotic to the area, are planted and managed intensively, for example through pest control, irrigation and fertiliser use, to maximise production. Forest plantations generally have a high productivity level ([[FAO, 2006b]]). By producing more wood products on less land, plantations may contribute to more sustainable forest management by reducing pressure on natural forests ([[Carle and Holmgren, 2008]]; [[Alkemade et al., 2009]]). However, the ecological value of biodiversity in many forest plantations is relatively low ([[Hartmann et al., 2010]]).
|ComponentCode=FM
|AggregatedComponent=Agriculture and land use
|FrameworkElementType=pressure component
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