State 1
Reference

Community 1.1
Pacific Silver Fir, Western Hemlock, Rusty Menziesia, Black Mountain Huckleberry, Oregon Oxalis and Western Swordfern

Pacific silver fir - western hemlock / rusty menziesia – black mountain huckleberry / Oregon oxalis - western swordfern

Structure: mosaic of mature overstory and regenerating openings

Pacific silver fir and western hemlock are the most common overstory species in this community. Both are considered to be very shade tolerant, and perhaps the most shade tolerant of any tree species in North America (Crawford, 1990). Douglas-fir, noble fir, and western white pine may be present but there will be minimal regeneration under closed canopy forests, at times, entirely absent. The dense canopy created by multiple age groups of hemlocks may block most of the sunlight from the forest floor, leading to sparse understory in some areas. Gaps in the mid-canopy and overstory that allow sunlight to reach the ground are where the majority of the understory plants establish. When there is no mid-canopy, the understory tends to be more continuous. The most common natural disturbance on this site is small gap dynamics following the death of one or two trees or windthrow. Common understory species include twinflower, rusty menziesia, black mountain huckleberry, Cascade Oregongrape, Oregon oxalis, common beargrass, western swordfern, and deerfoot vanilla leaf.

Community 1.2
Douglas-fir, Fireweed, and Western Swordfern

Douglas-fir/fireweed - western swordfern

Structure: open forest with shrubby regeneration and snags

Community phase 1.2 is an early seral plant community that has been impacted by a stand-replacing disturbance such as a wildfire, large scale wind event, mass movement, or major insect pest or disease. Nearly all trees are absent, but some fire-resistant trees may survive in the overstory. Douglas-fir is relatively fire tolerant, and large overstory trees may be present. Snags are prevalent and remain standing and decaying. Large stems may be present on the surface and serve as nurse sites. The understory is predominately early seral tree, shrub, and forb species such as Douglas-fir, fireweed (Chamerion angustifolium), and western swordfern.

Community 1.3
Douglas-fir, Noble Fir, Vine Maple, Cascade Oregongrape, and Western Swordfern

Douglas-fir – noble fir / vine maple – Cascade Oregongrape / western swordfern

Structure: dense single story

Community phase 1.3 is an early seral forest in regeneration, possibly with scattered remnant mature trees. Species composition depends on the natural seed sources present and the intensity of disturbance. When resulting from a moderate to severe fire event, it is probable that shrubs will out-compete tree seedlings. Vine maple, red huckleberry, black mountain huckleberry, and Cascade Oregongrape (which may have been only moderately abundant previously) all have the capacity to rapidly recover and spread when top-killed, slowing successful overstory regeneration. Seed sources for tree species would be from the surrounding, undisturbed forest and any of the survivors of the disturbance and would result in a mixed stand which could include Douglas-fir, western hemlock, western white pine, and noble fir.

Community 1.4
Western Hemlock, Douglas-fir, Cascade Oregongrape, Western Swordfern, and Oregon Oxalis

Western hemlock – Douglas-fir / Cascade Oregongrape / western swordfern – Oregon oxalis

Structure: dense single story with diminished understory

Douglas-fir and noble fir will dominate the overstory canopy, however more shade tolerant species such as Pacific silver fir and western hemlock will increase in basal area as saplings. Canopy closure is almost 100% leading to diminished shrub and forb layers. However, some understory species better adapted to at least partial shade (such as twinflower and black mountain huckleberry) will begin to increase. Over time the forest will begin to self-thin due to the elevated competition. Species composition depends on the original seed source(s) available. The forest could be single or mixed-species including Douglas-fir, western hemlock, noble fir, and Pacific silver fir.

Pathway 1.1A
Community 1.1 to 1.2

This pathway represents a major stand-replacing disturbance such as a high-intensity fire, large scale wind event, major insect pest infestation, timber harvest, or large mass movement event leading to the stand initiation phase of forest development.

Pathway 1.2A
Community 1.2 to 1.3

This pathway represents growth over time with no further significant disturbance.

Pathway 1.3A
Community 1.3 to 1.2

This pathway represents a major stand-replacing disturbance such as a high-intensity fire, large scale wind event, major insect pest or disease infestation, timber harvest, or large mass movement leading to the stand initiation phase of forest development.

Pathway 1.3B
Community 1.3 to 1.4

This pathway represents growth over time with no further major disturbance.

Pathway 1.4B
Community 1.4 to 1.1

Western Hemlock, Douglas-fir, Cascade Oregongrape, Western Swordfern, and Oregon Oxalis

Pacific Silver Fir, Western Hemlock, Rusty Menziesia, Black Mountain Huckleberry, Oregon Oxalis and Western Swordfern

This pathway represents growth over time with no further major disturbance.

Pathway 1.4A
Community 1.4 to 1.2

This pathway represents a major stand-replacing disturbance such as a high-intensity fire, timber harvest, large scale wind event, major insect pest or disease infestation, or large mass movement leading to the stand initiation phase of forest development.