The age-class module calculates the distribution of secondary forests and timber plantations based on Poulter dataset. This is used in 32_forestry and 35_natveg for initialization of forest areas.
| Description | Unit | |
|---|---|---|
| im_plantedclass_ac (j, ac) |
Raw Distribution of ageclass in secondary forest as a proxy for planted forest | \(10^6 ha\) |
This realization calculates use the results from Poulter et al. (2018) for secondary forests (and timber plantations) based on MODIS satellite data. This is used in 32_forestry and 35_natveg for initialization of forest areas based on specification of endogenous (or exogenous) forest harvests. These numbers are the most consistent dataset available on spatial scale and are preferred over extarcting such numbers from LUH data due to ease of generating these numbers.
Limitations Forest fires change how the age structures of secondary or human-intervention forests over time. This being a satellite observation data probably includes such disturbances. These disturbances are not modeled extensively in MAgPIE and hence using these numbers directly in the model might generate biases.
| Description | Unit | A | |
|---|---|---|---|
| f28_forestageclasses (j, ac_poulter) |
Poulter age-class area in each cluster | \(1\) | x |
| description | |
|---|---|
| ac | Age classes |
| ac_est(ac) | Dynamic subset of age classes for establishment |
| ac_plantations(ac) | Possible age classes which probably belong to plantations |
| ac_planted(ac) | Young age classes which probably belong to managed forest |
| ac_poulter | Forest age classes in Poulter data set |
| ac_poulter_to_ac(ac_poulter, ac) | mapping between ac and ac_poulter |
| ac_sub(ac) | Dynamic subset of age classes excluding establishment |
| age | Population age groups |
| j | number of LPJ cells |
| t(t_all) | Simulated time periods |
Abhijeet Mishra, Florian Humpenöder