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Forest Growth Models in SIMANFOR

SIMANFOR integrates a diverse catalog of forest growth models to simulate stand development and evaluate silvicultural management alternatives (see harvest models).

Models are divided into two main growth categories plus a dedicated suite of silvicultural harvest models:

  1. Individual-tree models: Operate at the single-tree level, simulating tree growth, mortality probability, and ingrowth in a detailed manner, and computing plot attributes based on all individual trees present in the plot.
  2. Stand-level models: Operate at the aggregate plot or stand level, projecting variables such as tree density, basal area, total volume, and dominant height.
  3. Thinning models: Define tree extraction and harvesting according to silvicultural criteria (thinning from below, from above, systematic, by species, or with crop trees) for both tree and stand models.

Individual-tree model calculation flow

In individual-tree models, the simulation engine calculates biological processes considering individual trees and aggregated plot dynamics:

Individual-tree model calculation flow

Tree-level simulation phases:

  1. Read initial inventory: Loads Plots (identifiers, site factors, etc.) and Trees (diameters, heights, species, and tree expansion factors).
  2. Initialization: Estimates missing inventory variables (heights, volumes, crown variables...) and computes aggregate plot metrics.
  3. Scenario simulation loop: According to user-defined silvicultural scenarios:
  4. Time projection: Evaluates individual survival, applies growth, incorporates new trees (ingrowth), and updates tree and plot metrics for the specified time period (this period must follow the recommendations of the model used).
  5. Harvest / Treatments: Removes selected trees (by size, species, or silvicultural rule) and updates remaining stand structure. For more details on thinning options, see the harvest models guide.
  6. Write output: Generates output tables with the state of the stand and trees at each simulation step.

Stand-level model calculation flow

Stand models simplify inventory data input, requiring only aggregate plot-level parameters without tree lists:

Stand-level model calculation flow

Stand-level simulation phases:

  1. Read initial inventory: Loads only the Plots sheet (age, density, basal area, dominant height as required).
  2. Initialization: Imputes required and missing initial stand attributes (volume, site index...).
  3. Scenario simulation loop:
  4. Time projection: Models aggregate stand growth and natural mortality curves, and updates plot variables for the established time period (this period must follow the recommendations of the model used).
  5. Harvest / Treatments: Applies direct reductions to density, basal area, or volume, updating plot metrics afterwards (see harvest models).
  6. Write output: Produces aggregated evolution tables.

Harvest models configuration

Silvicultural interventions are defined in scenarios by selecting the appropriate harvest model, the thinning criterion (density, basal area, or volume), and the percentage intensity:

Harvest configuration in SIMANFOR

For full details on each harvest model, behavior in mixed stands, and parameter descriptions, see the harvest models and silvicultural treatments guide.

Available individual-tree models

Model Target Species Region
Height calculation for Spain Todas las especies forestales arbóreas de España Spain
IBEROPS (calibrated) Pinus sylvestris Iberian Mountain Range and Central System (Ávila, Burgos, Segovia, and Soria; Spain)
IBEROPS (original) Pinus sylvestris Iberian Mountain Range and Central System (Ávila, Burgos, Segovia, and Soria; Spain)
IBEROPT (calibrated) Pinus pinaster, Pinus pinaster mesogeensis Southern Iberian Mountain Range (Cuenca, Guadalajara, Teruel, and Soria; Spain)
IBEROPT (original) Pinus pinaster, Pinus pinaster mesogeensis Southern Iberian Mountain Range (Cuenca, Guadalajara, Teruel, and Soria; Spain)
Mixed stands of Spain Pinus sylvestris, Pinus uncinata, Pinus pinea, Pinus halepensis, Pinus nigra, Pinus pinaster, Quercus robur, Quercus petraea, Quercus pyrenaica, Quercus faginea, Quercus ilex, Quercus suber, Fagus sylvatica Spain
PINEA Andalucía Pinus pinea Andalusia (Huelva, Cádiz, and Seville; Spain)
PINEA Central System Pinus pinea Central System (Palencia, Zamora, Valladolid, Burgos, Salamanca, Ávila, Segovia, and Madrid; Spain)
PINEA in Catalonia Pinus pinea Catalonia (Girona, Lleida, Barcelona, and Tarragona; Spain)
Pinus halepensis in Aragón Pinus halepensis Aragón (Zaragoza, Huesca and Teruel; Spain)
Pinus halepensis in Cataluña and Aragón Pinus halepensis Middle Ebro Valley (Aragón) and Catalonia (Huesca, Zaragoza, Girona, Barcelona, Lleida, and Tarragona; Spain)
Pinus nigra in Cataluña Pinus nigra Catalonia (Girona, Lleida, Barcelona, and Tarragona; Spain)
Pinus sylvestris Catalonia natural stands Pinus sylvestris Catalonia (Girona, Lleida, Barcelona, and Tarragona; Spain)
Pinus sylvestris Catalonia plantations Pinus sylvestris Catalonia (Girona, Lleida, Barcelona, and Tarragona; Spain)
Pure stands of Spain Pinus sylvestris, Pinus uncinata, Pinus pinea, Pinus halepensis, Pinus nigra, Pinus pinaster, Pinus canariensis, Pinus radiata, Abies alba, Juniperus thurifera, Quercus robur, Quercus petraea, Quercus pyrenaica, Quercus faginea, Quercus ilex, Quercus suber, Populus nigra, Eucalyptus globulus, Eucalyptus camaldulensis, Fagus sylvatica, Castanea sativa, Quercus pubescens, Populus x canadensis, Betula alba Spain
Quercus pyrenaica in Castille and Leon Quercus pyrenaica Castille and Leon (León, Palencia, Burgos, Zamora, Valladolid, Soria, Salamanca, Ávila, and Segovia; Spain)
Quercus pyrenaica in Castille and Leon - LifeRebollo+ Project Quercus pyrenaica Castille and Leon (León, Palencia, Burgos, Zamora, Valladolid, Soria, Salamanca, Ávila, and Segovia; Spain)
RAP-ORGANON, Alnus rubra plantations in Oregon and Washington (USA) Alnus rubra Oregon and Washington (USA)
SiTree - Norway model spruce, pine, beech, others Norway
Yield model (Spain) Todas las especies forestales de España Spain

Available stand-level models

Model Target Species Region
Betula pubescens in Galicia Betula pubescens Galicia (Spain)
Cistus ladanifer in Zamora Cistus ladanifer Zamora (Spain)
Pinus nigra in Castilla y León Pinus nigra Castilla y León (Spain)
Pinus pinaster in coastal areas of Galicia Pinus pinaster, Pinus pinaster atlantica Galicia (Spain)
Pinus pinaster in inland areas of Galicia Pinus pinaster, Pinus pinaster atlantica Galicia (Spain)
Pinus pinaster mesogeensis in the Iberian Peninsula Pinus pinaster, Pinus pinaster mesogeensis Iberian Peninsula
Pinus radiata in Galicia Pinus radiata Galicia (Spain)
Pinus sylvestris in Galicia Pinus sylvestris Galicia (Spain)
Pinus sylvestris in the High Ebro Basin Pinus sylvestris High Ebro Basin (Spain)
Pinus sylvestris in Ukraine Pinus sylvestris Ukraine
Populus sp. in Northeast Spain Populus sp. Northeast Spain
Quercus petraea in the Cantabrian Mountains Quercus petraea Cantabrian Mountains (Spain)
Quercus robur in Galicia Quercus robur Galicia (Spain)
RETECHFOR - Castilla y León Pinus sylvestris, Pinus pinaster Castilla y León (Spain)
SILVES - Pinus sylvestris in Iberian System and Central System Pinus sylvestris Iberian System and Central System (Spain)
SILVES - Pinus sylvestris in Madrid Pinus sylvestris Madrid (Spain)
Stand models for Romania Todas las especies Romania
Stand models for Romania (BAU) Todas las especies Romania
Tectona grandis in Campeche (Mexico) Tectona grandis Campeche (Mexico)