pyforestry.sweden.bark package#

Submodules#

pyforestry.sweden.bark.hannrup_2004 module#

Bark thickness models for Sweden.

This module contains functions implementing the bark thickness equations presented by Hannrup (2004). The models estimate double bark thickness for the two major conifer species in Sweden:

  • Hannrup_2004_bark_pinus_sylvestris_sweden - Scots pine model that uses diameter at breast height, latitude and stem height.

  • Hannrup_2004_bark_picea_abies_sweden - Norway spruce model that relates the diameter at a given point to the breast height diameter.

Both functions return the estimated double bark thickness in millimetres and are derived from:

Hannrup, Björn. (2004). Funktioner för skattning av barkens tjocklek hos tall och gran vid avverkning med skördare. Arbetsrapport 575, Skogforsk.

pyforestry.sweden.bark.hannrup_2004.Hannrup_2004_bark_picea_abies_sweden(diameter_at_height_mm: float, diameter_breast_height_mm: float | Diameter_cm) → float[source]#

Calculates double bark thickness for Norway Spruce in Sweden based on diameter.

Based on the function presented in Skogforsk Arbetsrapport 575-2004.

Parameters:

  • diameter_at_height_mm (float) – Diameter over bark at the point of interest along the stem, in millimeters.

  • diameter_breast_height_mm (Union[float, Diameter_cm]) – Diameter at breast height (1.3m) over bark, in millimeters. Must be in the same units as diameter_at_height_mm. If Diameter_cm is passed, it’s converted to mm.

Returns:

Estimated double bark thickness at the point corresponding to

diameter_at_height_mm, in millimeters. Minimum value is 2 mm.

Return type:

float

Raises:

  • ValueError – If inputs are non-positive or dbh is zero.

  • TypeError – If diameter input types are invalid.

References

Hannrup, Björn. (2004). Funktioner för skattning av barkens tjocklek hos tall och gran vid avverkning med skördare [Functions for estimating bark thickness of Scots pine and Norway spruce at harvester felling]. Arbetsrapport 575. Skogforsk. Uppsala Science Park, Sweden. 34 pp. ISSN: 1404-305X. Available Online [2025-04-17]: https://www.skogforsk.se/contentassets/960ad964391d489785f97f9eaeeaf174/arbetsrapport-575-2004.pdf

Notes

  • This function calculates bark thickness based on the diameter at a given point relative to the breast height diameter. It does not directly use stem height or latitude.

  • The function returns DOUBLE bark thickness in MILLIMETERS.

  • Only applicable to Picea abies in Sweden.

pyforestry.sweden.bark.hannrup_2004.Hannrup_2004_bark_pinus_sylvestris_sweden(diameter_breast_height_mm: float | Diameter_cm, latitude: float, stem_height_cm: float) → float[source]#

Calculates double bark thickness at a given stem height for Scots Pine in Sweden.

Based on the “Sf_tall” function presented in Skogforsk Arbetsrapport 575-2004.

Parameters:

  • diameter_breast_height_mm (Union[float, Diameter_cm]) – Diameter at breast height (1.3m) over bark, in millimeters. If Diameter_cm is passed, it will be converted to mm. Diameters over 590mm are capped at 590mm internally for the calculation.

  • latitude (float) – Latitude in decimal degrees (e.g., 63.82).

  • stem_height_cm (float) – The height along the stem (from ground level) where bark thickness is desired, in centimeters.

Returns:

Estimated double bark thickness at the specified stem_height_cm,

in millimeters. Minimum value returned is 2 mm.

Return type:

float

Raises:

  • ValueError – If inputs are outside reasonable ranges (e.g., negative diameter, invalid latitude, negative stem height).

  • TypeError – If diameter input type is invalid.

References

Hannrup, Björn. (2004). Funktioner för skattning av barkens tjocklek hos tall och gran vid avverkning med skördare [Functions for estimating bark thickness of Scots pine and Norway spruce at harvester felling]. Arbetsrapport 575. Skogforsk. Uppsala Science Park, Sweden. 34 pp. ISSN: 1404-305X. Available Online [2025-04-17]: https://www.skogforsk.se/contentassets/960ad964391d489785f97f9eaeeaf174/arbetsrapport-575-2004.pdf

Notes

  • This function calculates bark thickness at any point along the stem height, not just at breast height.

  • It requires latitude as an input.

  • The function returns DOUBLE bark thickness in MILLIMETERS.

  • Only applicable to Pinus sylvestris in Sweden.

pyforestry.sweden.bark.soderberg_1992 module#

Soderberg (1992) bark thickness model for Swedish trees.

Implements the Söderberg (1992) double bark thickness at breast height (1.3 m). The original equations are reported in:

Söderberg, U. (1992). Functions for forest management. Height, form height and bark thickness of individual trees. Report 52, Department of Forest Survey, SLU, Umeå.

Notes

  • Returns double bark thickness in millimetres (mm).

  • Inputs are explicit and use pyforestry standard units.

pyforestry.sweden.bark.soderberg_1992.soderberg_1992_bark_thickness_bh_mm(*, species: TreeName | str, diameter_cm: float, max_diameter_cm: float, mean_age_total_years: float, site_index_pine_m: float | SiteIndexValue, latitude_deg: float, altitude_m: float, prop_pine: float, prop_spruce: float, prop_birch: float, part_of_sweden: str, south_east: bool = False, region5: bool = False, split_plot: bool = False) → float[source]#

Estimate double bark thickness at breast height (mm) from Söderberg (1992).

Parameters:

  • species (TreeName | str) – Tree species.

  • diameter_cm (float) – Diameter at breast height, cm (over bark).

  • max_diameter_cm (float) – Maximum diameter on plot, cm.

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

  • site_index_pine_m (float | SiteIndexValue) – Pine site index (H100), m. SiteIndexValue inputs must be Hagglund (1970) H100 for pine.

  • latitude_deg (float) – Latitude, degrees.

  • altitude_m (float) – Altitude, m.

  • prop_pine (float) – Pine proportion of basal area (0..1).

  • prop_spruce (float) – Spruce proportion of basal area (0..1).

  • prop_birch (float) – Birch proportion of basal area (0..1).

  • part_of_sweden (str) – north, middle or south.

  • south_east (bool) – Southeast Sweden indicator.

  • region5 (bool) – Region 5 indicator.

  • split_plot (bool) – Split plot indicator (unused by the original model).

Returns:

Double bark thickness at breast height, mm.

Return type:

float

Raises:

ValueError – If diameter or max diameter is non-positive.

References

Söderberg, U. (1992). Functions for forest management. Height, form height and bark thickness of individual trees. Report 52, SLU, Umeå.

Module contents#

Public interface for bark thickness models for Swedish species.