# Variable:SiteIndexH (SIH)

Name: | SiteIndexH (SIH) |
---|---|

Description: | SiteIndexH (SIH) |

I/O: | Output variable (prognosis) |

Membership: | Treatment unit |

Type: | real |

Unit/values: | (m) |

Database table: | dbo.Result_ForestData |

## Usage

Variable SiteIndexH (SIH) is a computed value for H100, i.e. dominant height at an "imagined" age of 100 years. SiteIndexH is only used for presentation purposes and is not used as explanatory variable in any function. To be computed, it requires that a dominant species has at least 70 % of the basal area.

## Definition

SiteIndexH is derived from site index equations. The site index equations gives the height *h* at age *a*, given initial height *h0* at age *a0*. For young stands SiteIndexH could be higher that SIS (site index determined from site factors) (cf. ^{[1]}).

SiteIndexH is computed as the arithmetic mean height of dominant trees when each of these tree is 100 years old (50 years for birch). When dominant trees are 100 years old (at a stand age close to 100 years), result variables dominant height and SiteIndeH should be about the same.

## References

- ↑ Elfving B och Nyström K, 1996. Yield Capacity of planted Picea abies in Northern Sweden, Scandinavien Journal of Forest Research 11:38-49.