Productivity Catalog Gaps

Arnvik Appendix 8 scope

The Appendix 8 tables that power data/productivity/arnvik_forwarder.json only list single-grip harvesters, feller-bunchers, and harwarders (per the thesis framing). Forwarder and grapple-skidder regressions are absent, so the parsed JSON should be treated strictly as a harvester/harwarder validation set. For primary-transport roles we must fall back to the external references already logged in notes/reference_log.md and the public notes under notes/reference (Ghaffariyan et al. 2019, Kellogg & Bettinger 1994, Allman et al. 2021, etc.). Full-text working copies live in the optional, DataLad-backed reference-documents submodule for authorized collaborators.

Implications

  • Continue using the Appendix 8 extracts for harwarder QA only; do not attempt to infer forwarder performance or grapple-skidder coefficients from the current dump.

  • Build the forwarder helper stack (fhops.productivity.forwarder_bc) on top of the published AFORA/ALPACA equations and Kellogg regressions, with BC caveats called out in the dataset plan.

  • Document any future FPInnovations payload/slope confirmations in this file so the planning crew can see when the primary-transport gap is genuinely closed.

Forwarder equation stack (BC roll-out)

Sources in hand

  • Ghaffariyan et al. 2019 (AFORA/ALPACA) – logged in notes/reference_log.md with the source extract retained in reference-documents/notes/reference/sb_202_2019_2.txt for authorized collaborators. Equations 2 (14 t) and 3 (20 t) predict m³/PMH₀ from extraction distance. We already added the slope multipliers (flat = 1.0, 10–20 % = 0.75, >20 % = 0.15) to the CLI.

  • Kellogg & Bettinger 1994 – fhops.productivity.kellogg_bettinger1994 exposes the western Oregon FMG 910 regression (sawlog/pulpwood/mixed offsets) covering multi-product CTL thinning.

  • Allman et al. 2021 – logged in notes/reference_log.md with the source extract retained in reference-documents/notes/reference/forests-13-00305-v2.txt for authorized collaborators. It includes the tethered harvester-forwarder Monte Carlo payload-vs-slope/distance regressions we plan to translate into slope penalty/payload-cap helpers once FPInnovations validates the coastal BC analogues.

Caveats and pending confirmations

  • The AFORA/ALPACA equations are calibrated on Australian pine/eucalypt thinnings with gentle terrain; document this in notes/dataset_inspection_plan.md and warn users that >20 % slope behaviour is extrapolated via the simplistic ×0.15 multiplier until FPInnovations publishes a BC dataset.

  • The Kellogg regression assumes west-side Oregon extraction distances (<350 m) and a specific forwarder configuration (FMG 910). We need payload tables from FPInnovations or the ALPACA dataset to confirm whether the linear distance coefficients hold for heavier BC stems.

  • FPInnovations payload/slope confirmations (ongoing). Once we have those, add them here along with any new helper references so the forwarder_bc module can toggle between “Scandinavian/Australia baseline” and “BC validated” sets.