Timber bucking demo#

Notebook Objectives#

  • Show reproducible bucking workflows with timber objects, taper functions, and price lists.

  • Provide runnable, copy-safe snippets that work in the docs build environment.

Prerequisites#

  • Python environment with pyforestry installed from this repository.

  • Execute cells in order; random components should use fixed seeds where shown.

Sources#

  • Näslund (1985) bucking workflow implementation exposed in pyforestry.base.timber_bucking.

  • Package-level timber/taper abstractions in pyforestry.base.timber and pyforestry.base.taper.

This notebook demonstrates timber objects, tapers, pricelists, the Nasberg bucking algorithm and how solution cubes store many results in xarray.

[1]:

from pyforestry.base.pricelist import create_pricelist_from_data
from pyforestry.base.pricelist.solutioncube import SolutionCube
from pyforestry.base.timber_bucking.nasberg_1985 import BuckingConfig, Nasberg_1985_BranchBound
from pyforestry.sweden.pricelist.data.mellanskog_2013 import MELLANSKOG_2013_PRICE_DATA
from pyforestry.sweden.taper import EdgrenNylinder1949
from pyforestry.sweden.timber.swe_timber import SweTimber

Create timber object#

[2]:

timber = SweTimber(species="pinus sylvestris", diameter_cm=18, height_m=25)
timber

[2]:

<pyforestry.sweden.timber.swe_timber.SweTimber at 0x7f46faabbe90>

Load pricelist#

[3]:

pricelist = create_pricelist_from_data(
    MELLANSKOG_2013_PRICE_DATA, species_to_load="pinus sylvestris"
)
pricelist.Timber.keys()

[3]:

dict_keys(['pinus sylvestris'])

Run bucking optimizer#

[4]:

optimizer = Nasberg_1985_BranchBound(timber, pricelist, EdgrenNylinder1949)
result = optimizer.calculate_tree_value(
    min_diam_dead_wood=99, config=BuckingConfig(save_sections=True)
)
result

[4]:

BuckingResult(species_group='pinus sylvestris', total_value=np.float32(116.55982), top_proportion=0.0, dead_wood_proportion=0.0, high_stump_volume_proportion=0.0, high_stump_value_proportion=0.0, last_cut_relative_height=np.float64(1.106), volume_per_quality=[0.0, 0.1061747827409899, 0.10089169267225448, 0.0931144950816689, 0.0, 0.03325533384575725, 0.0], timber_price_by_quality=[0.0, np.float32(374.95026), np.float32(395.25204), np.float32(175.33333), 0.0, 0.0, 0.0], vol_fub_5cm=0.3315022903380483, vol_sk_ub=0.33342746304095644, dbh_cm=np.float64(18.000000000000004), height_m=25, stump_height_m=0.25, diameter_stump_cm=np.float64(20.503363467016907), taper_diameters_cm=[20.50336265563965, 19.994277954101562, 19.61321449279785, 19.30855369567871, 19.054716110229492, 18.83714485168457, 18.646760940551758, 18.47751808166504, 18.325185775756836, 18.186691284179688, 18.059728622436523, 17.942522048950195, 17.833681106567383, 17.732088088989258, 17.6368408203125, 17.547189712524414, 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value=np.float32(12.637021), species_group='pinus sylvestris', timber_proportion=0.0, pulp_proportion=0.0, cull_proportion=0.0, fuelwood_proportion=0.0, quality=<QualityType.LogCull: 5>), CrossCutSection(start_point=np.int16(100), end_point=np.int16(168), volume=0.0931144950816689, top_diameter=np.float32(11.158686), value=np.float32(24.234894), species_group='pinus sylvestris', timber_proportion=1.0, pulp_proportion=0.0, cull_proportion=0.0, fuelwood_proportion=0.0, quality=<QualityType.TopLog: 3>), CrossCutSection(start_point=np.int16(45), end_point=np.int16(100), volume=0.10089169267225448, top_diameter=np.float32(14.508299), value=np.float32(39.877647), species_group='pinus sylvestris', timber_proportion=1.0, pulp_proportion=0.0, cull_proportion=0.0, fuelwood_proportion=0.0, quality=<QualityType.MiddleLog: 2>), CrossCutSection(start_point=np.int16(0), end_point=np.int16(45), volume=0.1061747827409899, top_diameter=np.float32(16.024956), value=np.float32(39.81026), species_group='pinus sylvestris', timber_proportion=1.0, pulp_proportion=0.0, cull_proportion=0.0, fuelwood_proportion=0.0, quality=<QualityType.ButtLog: 1>)])

[5]:

result.plot()
../_images/notebooks_timber_bucking_demo_10_0.png

Generate a small solution cube#

[6]:

cube = SolutionCube.generate(
    pricelist_data=MELLANSKOG_2013_PRICE_DATA,
    taper_model=EdgrenNylinder1949,
    species_list=["picea abies"],
    dbh_range=(20, 22),
    height_range=(15, 15.2),
    dbh_step=2,
    height_step=0.2,
    workers=1,
)
cube.dataset

Generating Solution Cube using 1 parallel processes...
Pricelist hash: 4058af6a860784c4a6ce94f561a4f484a0401624c2f3cc8405c3074570164174
Total trees to process: 4

Generating Solution Cube:   0%|          | 0/4 [00:00<?, ?it/s]/home/runner/work/pyforestry/pyforestry/src/pyforestry/base/pricelist/solutioncube.py:156: UserWarning: Error processing picea abies DBH=20 H=15.0: Provided object is not an instance of Timber.
  (worker_func(task) for task in tasks),
/home/runner/work/pyforestry/pyforestry/src/pyforestry/base/pricelist/solutioncube.py:156: UserWarning: Error processing picea abies DBH=20 H=15.2: Provided object is not an instance of Timber.
  (worker_func(task) for task in tasks),
/home/runner/work/pyforestry/pyforestry/src/pyforestry/base/pricelist/solutioncube.py:156: UserWarning: Error processing picea abies DBH=22 H=15.0: Provided object is not an instance of Timber.
  (worker_func(task) for task in tasks),
/home/runner/work/pyforestry/pyforestry/src/pyforestry/base/pricelist/solutioncube.py:156: UserWarning: Error processing picea abies DBH=22 H=15.2: Provided object is not an instance of Timber.
  (worker_func(task) for task in tasks),
Generating Solution Cube: 100%|██████████| 4/4 [00:00<00:00, 598.63it/s]


Finished parallel computation in 0.01 seconds.
Successfully created xarray Dataset.



[6]:

<xarray.Dataset> Size: 104B
Dimensions:            (species: 1, height: 2, dbh: 2)
Coordinates:
  * species            (species) object 8B 'picea abies'
  * height             (height) float64 16B 15.0 15.2
  * dbh                (dbh) int64 16B 20 22
Data variables:
    total_value        (species, height, dbh) float64 32B nan nan nan nan
    solution_sections  (species, height, dbh) object 32B '[]' '[]' '[]' '[]'
Attributes:
    pricelist_hash:     4058af6a860784c4a6ce94f561a4f484a0401624c2f3cc8405c30...
    taper_model:        EdgrenNylinder1949
    creation_date_utc:  2026-08-11T18:25:42.087472+00:00
    dbh_range:          20-22 cm
    height_range:       15-15.2 m
[7]:

cube.lookup(species="picea abies", dbh=20.0, height=15.0)

[7]:

(0.0, [])