Frigid Xeric Foothills 30-40 PZ

Description

This site occurs across the landscape as a mosaic of plant community phases characterized by variation in forest structural stage (tree age, density and cover) and plant community composition. Historically, many dry mixed conifer forests would have cycled from a shrub/tree initiation phase (1.1) to a young forest stage (1.3) to a mature forest phase (1.4) with a fire regime characterized by frequent surface and mixed fires. However, some communities would have been shaped by less frequent fire intervals and a mixed intensity fire regime and would have been characterized by a closed canopy and dense understory stocking conditions represented by Communities 1.2 and 1.5. The Reference Community within this state is that of an open mature stand represented by Community Phase 1.4. Historical evidence suggests that this community type was common across the landscape prior to selective logging and widespread fire suppression, which can alter fire regimes and lead to a greater frequency of high severity fire.

Submodel

Description

This alternative state represents the many variations of timber harvesting that can occur on this site. This may result in a number of manipulated community types and pathways depending on strategies surrounding harvest, shrub control, weed control and replanting. Following harvest, some sites with adequate moisture and shrub seed source may be dominated by early seral shrubs. These may persist for decades yet are likely important for providing shade to young conifers, cycling nutrients and providing wildlife forage and cover. Selective removal of large ponderosa pine may advance succession and favor maturation of shade tolerant trees such as grand fir, Douglas fir, and incense cedar.