An analysis of the Modeling and Inventory Support Tool: Yield curves vary with Forest Ecosystem Classification

Stand-level growth and yield models are essential to assessing sustainable levels of forest harvest; such assessments are supported in Ontario by the Modeling and Inventory Support Tool (MIST), which combines updated yield estimates and predicted successional trajectories to improve yield forecasts in Ontario. Currently, forest management planning and MIST stratifies the landbase by the Standard Forest Unit (SFU), but not ecosite as defined under the Forest Ecosystem Classification (FEC) system. Here we examined variation in MIST's input and output parameters (site index, top height, and basal area) for ecosites that fall within the definition of the PW1 SFU in Central Ontario (white-pine-dominated sites). Ecosites showed significant differences in site index values and top height, but not basal area, results indicating systematic differences in productivity among ecosites within the SFU. These results show that fine-scale variation in edaphic factors, as indicated by ecosite information, correspond to differences in stand productivity, and suggest the importance of a more harmonized approach between yield modeling, SFUs, and the FEC system in Ontario.