pyforestry.sweden.misc package#

Submodules#

pyforestry.sweden.misc.nfi_age_to_bh module#

Age-to-breast-height and dominant mean diameter helpers for Sweden.

These helpers reproduce the Elfving (2009) NFI smoothing for time-to-breast-height (T13) and the dominant mean diameter (Dm) regression.

pyforestry.sweden.misc.nfi_age_to_bh.age_to_breast_height_elfving_years(*, site_index_m: float | SiteIndexValue, latitude_deg: float, species: TreeName) → float[source]#

Estimate time to reach breast height (T13) in years.

Source:

Elfving (2009) NFI smoothing: T13 = 37 – 0.605*LAT – 1121/SIS + 21.92*LAT/SIS + 29.5*ISSPRUCE/SIS

Parameters:

  • site_index_m (float | SiteIndexValue) – Site index (m), typically SIS. SiteIndexValue inputs must be Hagglund (1970) pine/spruce H100.

  • latitude_deg (float) – Latitude in degrees (N).

  • species (TreeName) – Tree species.

Returns:

Years to reach breast height (T13).

Return type:

float

Raises:

ValueError – If site_index_m is non-positive.

pyforestry.sweden.misc.nfi_age_to_bh.dominant_mean_diameter_cm(*, mean_age_total_years: float, field_estimated_basal_area_m2_ha: float, site_index_m: float) → float[source]#

Compute dominant mean diameter (Dm) in centimeters.

Source:

Dominant mean-diameter regression (Lind 2003 / Elfving 2003).

Parameters:

  • mean_age_total_years (float) – Basal-area weighted mean total age (years).

  • field_estimated_basal_area_m2_ha (float) – Field-estimated basal area (m2/ha).

  • site_index_m (float) – Site index (m).

Returns:

Dominant mean diameter (cm). Returns 0.0 when inputs are invalid.

Return type:

float

Module contents#

Miscellaneous Sweden helper utilities.