Forestry - WITNESS
The forests model tracks global forest surface evolution, wood harvested, and CO2 captured by dividing the forest into managed, protected, and unmanaged parts. Managed forests are for long-term biomass production, protected forests are legally preserved, and unmanaged forests can be altered by human activities. Reforestation increases unmanaged forest surface, deforestation reduces it, and managed wood production involves long-term biomass management. These activities collectively impact the global forest surface and biomass production.
It tracks the global forest surface evolution, the wood harvested (more generally biomass) and CO2 captured.
To do this, the following assumptions are made and the global forest surface is divided into 3 parts:
- Managed forest. These are the forests dedicated to long term biomass production thanks to management plans.
- Protected forest. These are the forests that are legally protected, and they will stay as they are. No management plan allowed, no harvesting allowed.
- Unmanaged forest. These are forests that are now unused but they are not protected. As a result, they can be transformed by human activities.
Then, 3 different activities will impact these surfaces taken into account.
- Reforestation. This activity consists in planting trees, and thus increases the unmanaged forest surface, as the global forest surface. In witness, no distinction is made between reforestation and afforestation (see definitions above)
- Deforestation. This activity cuts trees and reduce unmanaged forest surface as the global forest surface. Deforestation can not impact protected forest. Deforestation produces biomass as a one-time activity.
- Managed wood. This activity consists in managing forest to produce biomass regulary on a long term period. Investing in managed wood will increase managed forest surface and so the global forest surface.
Note: The documentation of WITNESS is 'in preparation' and is not yet 'published'!| Corresponding documentation | |
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| Previous versions | |
| No previous version available | |
| Model information | |
| Model link | |
| Institution | Open-Source for Climate (OS-C), N/A, https://os-climate.org/transition-analysis/., Linux Foundation (LF), N/A, https://www.linuxfoundation.org/. |
| Solution concept | Systems dynamics based approach |
| Solution method | OptimizationSimulation-based optimization |
| Anticipation | |
In this model, the quantity of CO2 captured by ha of forest is assumed to be the same all over the world. However, the CO2 captured change with the climate condition. Forest in tropical regions are more effective than forest in cold regions. As a result, cutting trees of the Amazon forest does not have the same impact than cutting trees in cold region, in term of captured CO2. Furthermore, the forest surface is assumed to increase instantaneously when investments are made in managed wood or reforestation. The age of the forest is not taken into account which does not affect the yield. Wood production may therefore be overestimated in case of drastic deforestation, namely if the young reforested forests are deforested or in case of drastic afforestation in managed forest since the new forest cannot produce instantaneously.