Spatial distribution of modeled PSD surfaces (original vs. revised) for balsam fir, black spruce, eastern larch, and red pine.

<p>Original PSD represents species' potential distribution in responses to photosynthetically active radiation (PAR), soil water content (SWC), and growing degree days (GDD); revised PSD (right) indicates distribution in response to PAR, SWC, GDD, and species competitive ability simulated with JABOWA-III forest gap model. Dark blue colors represent least favorable growing conditions and potential absence of species (legend), whereas brown and yellow represent the most favorable conditions and probable presence of the species; green represents intermediate growing conditions and associated species presence.