A list of variables provided by each resource unit.

These variable names are used when binding a tree to a Expression.

## General variables

Name |
Description |

year | current simulation year. |

## Resource unit variables

Name |
Description |

index | unique index of the resource unit. 0-based. |

id | id of the unit provided in resource unit grid mode, or -1 otherwise |

area | total stockable area of the resource unit (m2). The value is determined by the initial stand grid. |

totalEffectiveArea | (0..1). intermediate variable for production calculation. |

nitrogenAvailable | available nitrogen (kg/ha*yr) |

soilDepth | depth of the soil (mm) |

stockedArea | area covered by trees (calculation is based on 2m-pixels) (m2) |

count | number of trees / ha |

volume | sum of volume of the tree bole (m3) |

avgDbh | arithmetic mean of DBH (cm) |

avgHeight | arithmetic mean of tree height (m) |

basalArea | total basal area of all trees (m2) |

leafAreaIndex | total LAI (m2/m2)leaf area weighted average aging factor (0..1) |

aging | total average aging (weighted by LAI) factor. |

cohortCount | total number of cohorts per ha in the sapling phase. |

saplingCount | total number of individuals in the sapling phase per ha. |

canopyConductance | LAI weighted average canopy conductance (m/s) (including the conductance of the "ground cover" layer) |

soilC | total Carbon content (t/ha) in soil (sum of young, refractory and SOM) |

soilN | total Nitrogen content (t/ha) in soil (sum of young, refractory and SOM) |

snagC | total Carbon (kg/ha) present in the standing woody pools (i.e.: carbon in snag diameter classes and carbon in branch/coarse root pools) |

meanTemp | mean annual temperature (daytime) on the resource unit (°C) |

annualPrecip | annual precipitation (mm) on the resource unit |

annualRad | total incoming radiation (MJ) per year |