Oregon East Cascades, Volcanic Uplands and Mountainbases (Ponderosa pine - Douglas-fir - (Grand fir) / Snowbrush) 20-30 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 pine 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. Fire exclusion can lead to closed canopy and dense understory stocking conditions represented by communities 1.2 and 1.5 which can be more vulnerable to stand replacing fires. The reference community within this state is that of an open, mature, savanna like ponderosa 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.

Dominant plant species

1. ponderosa pine (Pinus ponderosa), tree

2. snowbrush ceanothus (Ceanothus velutinus), shrub

3. greenleaf manzanita (Arctostaphylos patula), shrub

Submodel

Description

This alternative state represents the many variations of timber harvesting that can occur in 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. 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.

Dominant plant species

1. ponderosa pine (Pinus ponderosa), tree

2. Douglas-fir (Pseudotsuga menziesii), tree

3. incense cedar (Calocedrus decurrens), tree

Submodel