Difference between revisions of "Forest management"

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{{ComponentTemplate2
 
{{ComponentTemplate2
|IMAGEComponent=Scenario drivers; Agricultural systems; Natural vegetation and carbon cycle
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|Application=Rethinking Biodiversity Strategies (2010) project; Shared Socioeconomic Pathways - SSP (2014) project; EU Seventh Framework Programme - FP7;
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|IMAGEComponent=Drivers; Land-use allocation; Carbon cycle and natural vegetation; Energy supply and demand;
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|Model-Database=EFIGTM model;
 
|KeyReference=Arets et al., 2011;
 
|KeyReference=Arets et al., 2011;
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|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;  
 
|InputVar=Demand traditional biomass; Land cover, land use - grid;  
Forest plantation demand; Suitability - grid; Harvest efficiency; Timber demand ; Carbon pools in vegetation - grid; Fraction cut down and selective cut;
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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;
 
|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;
 
|OutputVar=Timber use fraction; Forest residues; Forest management type - grid; Regrowth forest area - grid; Harvested wood; Degraded forest area;
|Description==== Global context ===
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|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 world’s total forest area and other wooded land area of 2010 was estimated at just over 40 and 11 million km2 , respectively (FAO, 2010). People use these forests as resources for a multitude of purposes, such as for timber, fuel, food, water and other forest-related goods and services. Notwithstanding the undisputed market and non-market value of forests, the total global forest area continues to decline, with distinct differences between world regions. Total global deforestation has decreased over the last decade, but still occurs at a significant scale in large parts of Latin America, Africa and Southeast Asia. At the same time, net forest expansion takes place in other regions, such as in Europe and China. Agricultural expansion is the main pressure that drives deforestation. In addition to the loss of forest area, degradation processes and a decline in the supply of services may occur as a result of the human use of forests. Managing global forest resources in a sustainable way may help to preserve forests, slow down or reverse the degradation process, while conserving their biodiversity and carbon stocks (FAO, 2010).  
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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 in use to meet worldwide demand, for timber, paper, fibre board, biofuel and other products. Management practices depend on forest type, conservation policies and regulation, economics, and other –often local– factors. Practices differ with respect to the volume of wood harvested per area, the rotation cycle and the carbon content and state of biodiversity of the forested areas. Harvested wood  is  used for various purposes, such as for timber, pulp, paper, traditional fuel wood and modern forms of bio-energy.
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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.  
 
  
=== Forestry in the IMAGE 3.0 model ===
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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]]).  
 
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# 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.  
Because of the importance of forest management for the functioning and state of forests, its modelling has become an integral part of the IMAGE 3.0 model. The model simulates an forest area in 2010 of total about 46 million km2. As such the area is somewhat larger than observed, due to the fact that the model does not include other wooded land (see Carbon Cycle and Natural Vegetation module for details). To manage these forests three types of systems are defined in IMAGE 3.0 as a simplification of the whole range of existing forest management systems (Carle and Holmgren, 2008; Arets et al., 2011). The purpose of Sustainable Forest Management (SFM) is to preserve forests and their production capacity and biodiversity for future generations, and to counteract forest degradation processes. In IMAGE, several elements of SFM can be included, subject to policy options,  consisting for example of shifts in the mix of  forest management systems.  
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# 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]]).  
 
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# 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]]).
The first type of forest management included in IMAGE, is that of clearcutting (or clearfelling). This is a management system by which all trees in an area are cut down, after which regrowth can take place, either naturally or ‘assisted’. It is applied often in temperate regions, where stands are often monocultures of specific endemic species.  
 
 
 
The second type is that of selective logging, in which only the trees with the highest economic value are felled. This is more common in tropical forests with a high heterogeneity of tree species. Reduced impact logging (RIL) is an ecological variant of selective logging, to reduce harvest damage, stimulate regrowth and maintain biodiversity levels (Putz et al., 2012). As such, the RIL system is a more ecological and sustainable forest management system, which is promoted under SFM schemes.  
 
 
 
The third system is that of forest plantations, such as hardwoodtree plantations in the tropics and poplar plantations in temperate regions. Selected tree species, either endemic or exotic to the area, are planted and managed more intensively for example, through irrigation and fertilizer use to maximise production and/or wood quality. After the trees are harvested, new ones are planted, and management is put in place. Forest plantations generally have a high productivity level (Del Lungo et al., 2006). By producing more wood and wood products on less land, plantations may contribute to more sustainable forest management by reducing the pressures on natural forests (Carle and Homgren, 2008; Alkemade et al., 2009). At the same time, the ecological value of biodiversity in many forest plantations is relatively low (Hartman et al., 2010).
 
 
|ComponentCode=FM
 
|ComponentCode=FM
 
|AggregatedComponent=Agriculture and land use
 
|AggregatedComponent=Agriculture and land use
 
|FrameworkElementType=pressure component
 
|FrameworkElementType=pressure component
 
}}
 
}}

Revision as of 16:25, 2 November 2016

Key policy issues

  • How can management influence forest capacity to meet future demand for wood and other ecosystem services?
  • What are the implications of forest management for pristine and managed forest areas, and on biomass and carbon stocks and fluxes of relevance for climate policy?
  • What are the prospects for more sustainable forest management and the role of production in dedicated forest plantations?

Introduction