Stage1973

Stochastic individual-tree growth model for lodgepole pine (Pinus contorta) based on the Prognosis Model for Stand Development (Stage 1973). Tracks squared diameter (Dsq = DBH²), total height (HT), height to crown base (HCB), and tree density (N_trees) under four coupled processes: basal area increment (Stage 1973 Eq. 1), height growth (Eq. 2), crown recession (Eq. 3), and endemic mortality (Eq. 4). The upstream Julia source includes a multiplicative Brownian noise term on DDS_rate (gt-kuxo gap); this ESM migrates the deterministic drift equations only. All quantities in SI base units (m, s); upstream regression fitted in imperial units (inches, feet, years) — parameters encode the conversion constants. Migrated from Vegetation.jl@010c3774dc5646d81806c6119c8a029a70f6c9a0:src/stage_prognosis.jl:29.

Stage (1973) static regression model for height to crown base (HCB) of lodgepole pine. Predicts HCB from tree height, stand density (CCF), elevation, relative tree size (DBH/RMSQD), and habitat type. Single explicit-algebraic equation: HCB = one_foot*(b0 + b1*HT_ft + b2*ln(CCF) + b3*EL_100ft + b4*DBH_in/RMSQD_in + HAB). All regression coefficients are in feet-space; result converted to meters. Migrated from Vegetation.jl@010c3774dc5646d81806c6119c8a029a70f6c9a0:src/stage_prognosis.jl:257.