Hemstrom unpublished data) compared
to stand exam and plot data. All size class and s-class assignments were made using custom Python scripts (Python Software Foundation) within ArcMap 10.1 (Environmental Systems Resources Institute, 2013). We assessed forest restoration needs based on the present-day relative abundance of s-classes compared to NRV reference conditions. Within each biophysical setting and landscape unit (stratum), we determined which s-classes were overrepresented and which were underrepresented, then how many hectares would need to transition to a different s-class in order to move the present-day distribution see more of all s-classes to within the NRV reference distribution (mean ± 2 SD). We categorized these specific transitions between s-classes as resulting from implementation of “disturbance only”, “succession only”, or “disturbance then succession” restoration categories based upon the identity of the excess and deficit classes (Fig. 2). Our analysis considered the following possible restoration categories and the resulting transitions between s-classes. Thinning/low severity fire: Transitions Bcl-xL protein between mid and late development closed canopy to open canopy s-classes through the removal of small and medium
sized trees. May be accomplished through fire or mechanical treatment. Thinning/low fire + grow with fire: This is a two-step transition that first requires fire or mechanical treatment to transition from mid development closed Plasmin canopy to mid development open canopy followed by growth with fire to transition to a late development open canopy s-class. Growth with fire: Transitions from “Early Development” to “Mid Development
Open Canopy” or from “Mid Development Open Canopy” to “Late Development Open Canopy” in Fire Regime Group I or III biophysical settings. These transitions are considered succession only as fire disturbance is not immediate required to alter the successional trajectory. We defined all possible transitions between s-classes within each biophysical setting (Fig. 2) described in terms of the unique characteristics of each biophysical setting’s state-and-transition model and s-class descriptions. All transition definitions for a biophysical setting are captured in that setting’s “rules table” (Table 2, Appendix A.5). When a transition between s-classes required more than one discrete step based upon that biophysical setting’s state-transition model, we defined both a “primary” and a “secondary” transition (Fig. 2 and Table 2). The restoration needs calculations were conducted in a stepwise fashion for each strata. For each strata, we first calculated the excess or deficit abundance of each s-class when compared to that biophysical settings’ NRV reference condition.