Forest Growth Models


SORTIE is a mechanistic, spatially explicit, stochastic model of forests in the northeastern United States that describes local competition among nine species of trees in terms of empirically derived responses of individuals. The nine species modeled are all dominant or subdominant species found in mid- and late-successional stands: American beech (Fagus grandifolia; Be), eastern hemlock (Tsuga canadensis; Hm), sugar maple (Acer saccharum; SM), red maple (Acer rubrum; RM), yellow birch (Betula alleghaniensis; YB), white pine (Pinus strobus; WP), red oak (Quercus rubra; RO), black cherry (Prunus serotina; BC), and white ash (Fraxinus americana; WA). (For more detailed species descriptions, see Pacala et al. 1993. Data for the model were collected in northwestern Connecticut at elevations between 350 and 550 m. [source website]