So what did the Sierra, Sequoia and Inyo do to apply this planning rule requirement to terrestrial ecosystems? I’ve just reviewed the draft plan and DEIS, and I don’t think I’ve got a good answer. They don’t directly say what NRV is or how they determined it (at least in the places I’ve looked).
The Bio-Regional Assessment says this (p. 39): “NRV only was not used because at this time conditions are far removed from them in terms of fire regime, and even a modest shift toward that level of resiliency would benefit ecological integrity and is more feasible in a short period of time. The planning rule specifically provides for using ecological integrity based on measures other than NRV where this is the case.”
This view is supported by the Planning Handbook (1909.12 FSH 12.14b) (but again, the Handbook does not appear to be supported by the Planning Rule): “In some situations, there is not enough information to understand the natural range of variation under past disturbance regimes for selected key ecosystem characteristics or the system is no longer capable of sustaining key ecosystem characteristics identified as common in the past based upon likely future environmental conditions. In these cases, the Interdisciplinary Team should establish an alternative ecological reference model for context for assessing for integrity by identifying the conditions that would sustain these key ecosystem characteristics.” However no “alternative ecological reference model” was documented.
For terrestrial vegetation the Bio-Regional Assessment then apparently ignores itself (p. 98): “Under the 2012 Planning Rule, “natural range of variability” is a key means for gauging ecological integrity. Ecosystem sustainability is more likely if ecosystems are within the bounds of natural variation, rather than targeting fixed conditions from some point in the past (Wiens et al. 2012, Safford et al. 2012). Safford et al. (2013a) compiled comprehensive, scientific literature reviews on natural range of variability, and these are the primary basis for the summary below.” The summaries conclude whether ecosystems are within or outside of NRV, but they don’t say what NRV is.
The Sierra Assessment says this (p. 17): “Comprehensive, scientific literature reviews on natural range of variability were compiled. The following is an overview. Consistent with trends across the entire assessment area, terrestrial ecosystems in the Sierra NF are predominantly outside the natural range of variability (NRV) for key indicators of ecological function, structure, and composition. First, nearly half (44 percent) of the area of the Sierra NF dominated by woody vegetation (or 76 percent of montane coniferous forests) is in a highly departed condition with respect to the historic fire return interval, burning at frequencies that are significantly longer than pre-settlement fire regimes (Safford and van de Water 2013). The Sierra NF has missed an average of three to four fire return intervals across all vegetation types dominated by trees or shrubs (Safford and van de Water 2013). Subalpine forests are the exception, burning at intervals that within one or two fire return intervals.”
The Bio-Regional Assessment describes fire history on p. 33, and the Sierra Assessment appears to use historic fire intervals as a reference, but what are the vegetation conditions that would produce the desired fire intervals (which would be the NRV for vegetation)? I didn’t find a document that says what what vegetation NRV is or how it was determined, or even what the “key indicators” are. The draft plan does have desired conditions for vegetation, and the DEIS says those are or are based on NRV. The quickest way to get a feel for these DC=NRV is Tables 1-7 in the draft revised forest plan.
What is NRV for vegetation characteristics? Are they based on the best available science? Did they properly use historic reference conditions? What was the reference period? Did they consider climate change? Are these sustainable desired conditions? Do they comply with the requirement for ecological integrity? Do they provide conditions needed for at-risk species? You’d think the answers to these important questions would be easier to find, but I’m out of time. Maybe someone else can find some answers on the revision website somewhere.