Material
Wood production​
Description​
Both natural and planted forests are used for wood production. The availability of wood as a renewable natural resource is important for a number of applications: as a construction material in the building sector, as a solid product or in processed form (e.g. boards), for packaging and for the production of windows, doors, and furniture; as a basic raw material for paper; as a renewable insulation material; and as a renewable source of energy. In this chapter only the production of round wood is valued.
The calculation is based on knowledge tables available in Sim4Tree, a simulation tool that models forest development and the provision of ecosystem services (including wood production and carbon storage in biomass) over time (Borremans, Jacxsens et al. 2014). These knowledge tables were supplemented with knowledge available within KULeuven. For more information about how the knowledge tables were drawn up, please refer to the ECOPLAN-SE manual (Vrebos et al. 2017).
Required information:
trans- Number of hectares of forest, broken down by tree species: dominant species or otherwise mixed type with a choice of: Beech, poplar, birch, oak, maple, ash, elm, alluvial forest, other deciduous trees/mixed, silver fir, Scots pine, larch, Norway spruce, Austrian pine, Corsican pine, Douglas fir, other conifers/mixed, mixed forest
- Soil texture, drainage class and profile development of the forest soil can be found in the information sheet on the soil map of Belgium (https://dov.vlaanderen.be/page/grondkaart). You can also view derived maps among the background maps in the scenario tab and measures tab of the web tool.
Qualitative valuation​
We use the different categories in the SIM4Tree model. To complete this, the land use map can partly be used to qualitatively evaluate the wood production service. We use score 1 for land use other than forest. The specific tree type and soil suitability determine the score of the forest types. The identification does not take into account current management objectives and wood harvesting regimes.
Soil texture and soil moisture largely determine the extent to which the physical system is suitable for wood production. In addition, the profile development of the soil provides an added or negative value in this suitability. These three factors are bundled in the soil-core series. In addition, there are other factors such as parent material variants, substrates, humus phases and profile development variants that make the soil more or less suitable (Baeyens L. 1992). This knowledge is contained in the BOBO database (Soil Suitability of Forest Trees; https://www.inbo.be), which indicates the suitability of some 35 tree species for all soils occurring in Flanders by stating five scores, ranging from not suitable to very suitable. The Nature Value Explorer works with the most important tree species of these 35.
For species or mixtures of deciduous trees not listed, we use the average score of the deciduous tree species within a soil type. For other species or mixtures of coniferous trees, we use an average score of the coniferous tree species within a soil type. For a mixed forest (coniferous and deciduous tree species without dominance of one or the other) we use an average score of all species used.
These scores have been translated into the scale used in the manual ranging from 1 (not suitable) to 10 (very suitable). The score indicates the suitability of a specific soil for a specific tree species. How this is translated into m³ growth depends on the type of tree species. This means that the score and the m³ increase are not always in the same ratio.
Quantitative valuation​
The productivity of a forest is determined by a combination of independent growth site factors such as soil type and climate, and dependent growth site factors such as humus type. Depending on the choice of tree species and the management applied, different volumes of wood of a specific quality are produced. The production tables of Jansen et al. (1996) allow to estimate the potentially produced wood volumes based on the suitability of the physical system. This exercise was done in Moonen et al. (2011).
The average operating time is also taken into account. It is the time that elapses between forest rejuvenation (e.g. planting) and the final cutting of the mature tree. Depending on the tree species and the desired dimensions of the trees, the operating time varies from tens to sometimes hundreds of years. The faster the trees grow and the smaller the desired size, the shorter the operating time. Within ECOPLAN, a minimum and maximum operating time has been estimated for each tree species. Depending on the management of the forest (production versus nature management), the minimum or maximum operating time will be taken respectively.
To derive the actually produced volumes from the potentially produced volumes, we use a harvest factor. The harvest factor is calculated as the ratio between the actual harvest and the potential harvest (which is equated with the potential annual growth mentioned above).
The harvest factor in domain and other public forests is 0.70, while that of private forests is estimated at 0.6 (Vrebos et al. 2017). If there is more detailed information about the harvest factor, you can of course use it. For example: all forests in a project are managed according to a clear-cutting system: the harvest factor is 100%. Half of the forests are managed according to a clear-cutting system, the other half are unmanaged: the harvest factor is 50%.
Here too, the averages of deciduous tree species and coniferous tree species per soil type are used for other deciduous tree species or mixtures and other coniferous tree species or mixtures, respectively. For mixed forests, an average is taken of all tree species used in the Nature Value Explorer.
Monetary valuation​
The value of the current wood production is obtained by multiplying the wood volumes by the average prices per m³ and per type (see sales prices table).
These prices were determined (expert judgement) based on the sales results of wood sales in the domain forests and other public forests and on average wood prices according to the FNEF for 2019. The prices are based on stock. Standing means that at this price the buyer still has to fell and export the wood himself. We can therefore speak of the net added value of wood production. We use the average of the prices per girth class per tree species.
By combining the prices with the potential production volumes and the harvest factor, we calculate the total annual value of wood production. The yield is expressed as an amount per hectare per year.
Assumptions​
- This only concerns the production of round wood (stems),
- The methods used for wood production are only based on the economically most important tree species that occur in SIM4TRee. If there are data on other species, figures can be used for mixed deciduous/coniferous forests or mixed forests.
- The increase is the so-called 'Maximum Mean Annual Increment'. This is the total volume growth divided by the age at the moment the 'Mean Annual Increment (MAI)' becomes maximum. We therefore assume that stocks are harvested when the MAI reaches its highest point (mature forest) and we further assume that the age structure complies with that of a so-called 'normal forest' (i.e. a forest with a natural distribution of age classes). We therefore take the average annual growth over the age of the forest and assume that wood is harvested from forests at mature age.
- For the choice of minimum or maximum operating time, we assume that most privately managed forests have a minimum operating time, while publicly managed forests have a maximum operating time.
- The prices were determined based on the sales results of wood sales in the domain forests and other public forests for the service years 2019-2021. The prices were only available per lot, so the price per type and per girth class had to be derived via a statistical model.
- We assume that we will get a realistic estimate of the real gross revenue if we average the revenues from wood sales for a given area over a sufficiently long period of time.
- We assume that the specific management and maintenance costs (parking, nursing, etc.) are negligible.
Numbers to use​
The figures from the above paragraphs have been combined into a look-up table that can be consulted on the website of the Nature Value Explorer in the background documents. These values are automatically looked up in the tool based on the type and soil core series entered.
A qualitative score, quantity and value can be derived for each combination of the soil core series and tree species. Below is an excerpt of this table.
Table: extract from table for a specific soil core series to be used for qualitative, quantitative and monetary valuation of wood production.
| Tree species | English name | Soil-core series | Qualitative | average growth without thinnings minimum operating time (m³/ha.year) | average growth without thinnings maximum operating time (m³/ha.year) | value (€/ha.year) minimum operating time | value (€/ha.year) maximum operating time |
|---|---|---|---|---|---|---|---|
| 2 | beech | AAx | 2 | 2 | 1.5 | 110 | 82.5 |
| 2 | beech | Aba | 10 | 4 | 2.3 | 220 | 126.5 |
| 2 | beech | AbB | 10 | 4 | 2.3 | 220 | 126.5 |
| 2 | beech | ABC | 8 | 3.6 | 2.1 | 198 | 115.5 |
| 2 | beech | Abp | 10 | 4 | 2.3 | 220 | 126.5 |
The quantification and valuation in these tables are based on growth. Depending on management, different harvest factors are taken into account. The harvest factor in domain and other public forests is set at 0.70 based on historical figures, while the harvest factor in private forests is equated to 0.60.
Formulas
quantitative valuation: quantity of wood (m³ growth/ha.year) x harvest factor x number of ha= m³/year monetary valuation: value of wood (€/ha.year) x harvest factor x number of ha = €/year
Table: sales prices by stem (average across girth classes, 2020 prices)
| Tree species | €/m³ |
|---|---|
| Beech | 55 |
| Scots pine | 38 |
| Poplar | 40 |
| Maple | 25 |
| Alder | 20 |
| Birch | 20 |
| Common ash | 45 |
| Sessile oak | 85 |
| Pedunculate oak | 85 |
| American oak | 60 |
| Deciduous trees other or mixed | 30 |
| Larch | 50 |
| Norway spruce | 40 |
| Corsican pine | 50 |
| Douglas fir | 55 |
| Conifers other or mixed | 35 |
| Mixed forest | 40 |
Source: Natuurinvest communication 2021
Translation to indicator​
The total amount of sustainable wood production in m³ is used as an indicator. This is the same as the quantitative valuation.
An example​
For the example, we refer to the Dutch version of the manual.
More detailed models/tools​
The Sim4Tree software Sim4Tree is a decision support software for sustainable forest management. With Sim4Tree, the future delivery of a number of ecosystem services from forests under different management and climate scenarios can be calculated and compared. The software can be used at three levels of decision-making: strategic policy planning ('N1', Flanders scale), strategic and tactical management planning ('N2' and 'N3', scale of a forest complex). For the time being, only N1 and N2 are operational.
The emphasis of Sim4Tree is primarily on projections of production services (standing stock, wood harvest by species and range, harvest of woody biomass, C storage in biomass, etc.) and a number of biodiversity indicators (age class distribution, species diversity, proportion of thick trees, etc. .). In principle, other ecosystem services can also be included, provided that appropriate models are linked. The software also allows for a cost-benefit analysis. Sim4Tree brings together existing models and geodatasets in an intuitive user interface and adds additional functionality. The software was primarily developed for use in Flanders and uses the usual yield tables and forest mapping from 2000. The results are therefore only as accurate or correct as these sources. Sim4Tree is available in a free test version from January 2014. For contact about possible use and conditions: Inverde (info@inverde.be).
Other plant and animal materials​
Description​
Various natural ecosystems produce products that we can use as materials such as reed, willow twigs, fur, ... Usually the quantities produced are small or the sales market is small, as with reed, so this is a negligible benefit in Flanders.
However, people are looking for markets for residual flows from management. On the one hand, this can be done for energy (see Energy from biomass) but options are also being explored for using biomass from grassland and tall herbs in paper production, replacing fossil raw materials in numerous [products](https://www .ecopedia.be/pagina/inleiding-kruidige-biomass). It is also used as bedding in livestock cubicles. To properly quantify this, a good inventory is required of all residual flows, their quality and the time of availability. The INTERREG project GrasGoed (2020) mapped out that 40,000 tons (dry matter) of natural grass and heath are available in Flanders. Sod and chopper material from heathland and forest litter are good for the production of substrates in plant cultivation. For the Nature Value Explorer, we should be able to relate those flows to specific areas. There is no generic method for this yet.
Plant materials from agricultural production that are not suitable for food, such as flax, are included under the ecosystem service 'agricultural production'. Animal materials (skins) from agricultural production are not included in the Nature Value Explorer.
Some plants and animals are important from a genetic, medical or cosmetic point of view. For example, pharmaceutical companies pay large sums of money to be allowed to do bio-prospecting in parts of the rainforest. This is probably a less important benefit for Flanders.