State 1
Reference

Community 1.1
Douglas-fir Mosaic

Structure is a mosaic of mature, large overstory trees of mixed age and canopy position, and occasional canopy openings Douglas-fir is the most common tree species, occupying dominant or emergent canopy positions and often exceeding 100 years of age. Pacific madrone establishes and becomes codominant in some areas that have high exposure to sun and wind. Forest canopy is generally continuous over large areas. Moderate sized (2-5 acres) canopy gaps intermittently interrupt the overstory canopy. These are created by small patches of overstory tree mortality from native pests and diseases, storm damage and surface fires which occasionally exhibit short durations of increased intensity. Standing snags are present both within gaps and occasionally elsewhere; remnants of former trees that were killed by fire, pests or disease. These may persist for decades, especially those of larger stature. Tree seedlings are emerging within canopy gaps and represent the surrounding overstory composition. If present, madrone will often regenerate both from seed and by resprouting from burned or damaged stems. . Gaps also contain shrubs and vines with vigorous new growth or increased density owing to improved light levels. Oceanspray (Holodiscus discolor), Cascade barberry (Berberis nervosa), hairy honeysuckle (Lonicera hispidula), dwarf rose (Rosa gymnocarpa), California hazelnut (Corylus cornuta), California blackberry (Rubus ursinus), and salal (Gaultheria shallon) are common shrubs and vines. When fire occurs, many of these understory species may also resprout from the root collar, rhizomes, or shallow subsurface roots. A rich mix of herbaceous species are present, especially in canopy gaps.

Community 1.2
Early Seral Re-Sprouting Forest

Structure is a single story shrub. This community consists of a mix of regenerating trees, shrubs, forbs and grasses over a large area that has recently experienced a significant overstory tree mortality event, usually high severity fire. Snags and other large woody debris are abundant. Species composition is diverse, with young trees representing pre-fire dominant species of Douglas-fir or madrone, while many shrub and herbaceous species have increased or expanded opportunistically; some species that were not apparent prior to the disturbance may regenerate from persistent seed banks. Vegetation is often very dense and vigorous, and most species exhibit accelerated growth in the high light conditions. Shrub growth response is emblematic of many species’ ability to resprout from the root collar, rhizomes, or shallow subsurface roots. If present, madrone will also regenerate by resprouting from burned or damaged stems with rapid initial growth of many sprouts from each surviving parent stump. This resprouting mix will typically dominate while young Douglas-fir trees have yet to emerge above this tall shrub layer. Shrubs often include oceanspray, California blackberry, salal, California hazelnut, and Cascade barberry. If introduced to the site, non-native Himalayan blackberry (Rubus armeniacus) and Scotch broom (Cytisus scoparius) may become abundant in this phase, usually at the expense of native shrubs and trees. A rich mix of herbaceous species are typically present.

Community 1.3
Douglas-fir Canopy Closure

Structure is single story with diminished understory, infrequent small gaps. This community consists of a forest undergoing canopy closure from natural regeneration. Douglas-fir has overcome early shrub dominance across much of the forest by forcing its way through gaps in shrub cover or occupying space opened up by successive minor disturbances. If present, madrone has occupied the site alongside re-sprouting shrubs since the early seral re-sprouting forest phase but has now overtopped the shrub layer and often exhibits a multi-stemmed tree form in a dominant canopy position. With canopy closure, competition for sunlight has led to a diminished understory that favors more shade tolerant species such as Cascade barberry and salal. Other shrub species resembling the composition typical of the previous early seral re-sprouting forest phase are limited to infrequent small gaps in the canopy where Douglas-fir or madrone were not able to establish. Tree density is variable, but there is minimal vertical overstory differentiation due to the tree layer being relatively even aged. The herbaceous component is limited but present.

Community 1.4
Maturing Douglas-fir

Structure is single story with canopy that is beginning to thin. This community consists of maturing Douglas-fir forest. Madrone may be present in the overstory or regenerating in the understory but has largely been forced into a subdominant position by the increasing height of Douglas-fir. The forest canopy is now fully closed and is starting to differentiate vertically, becoming more complex as some trees are suppressed and die and the canopy has lifted high above the forest floor resulting in a more open understory. A mix of shrubs and herbs has persisted in the understory and some species that do well with dappled light such as dwarf rose are expanding. Shade tolerant species also perform well, such as cascade barberry and salal. Herbaceous species typical of the reference Douglas-fir mosaic phase such as Pacific bleeding heart (Dicentra Formosa) have begun to reappear.

Pathway 1.1A
Community 1.1 to 1.2

This pathway occurs from a stand-replacing fire in which all or nearly all overstory trees are killed.

Pathway 1.2A
Community 1.2 to 1.3

This pathway represents growth over time with only very minor or no additional disturbances.

Pathway 1.3B
Community 1.3 to 1.2

This pathway occurs from a stand-replacing fire in which all or nearly all overstory trees are killed.

Pathway 1.3A
Community 1.3 to 1.4

This pathway represents growth over time. Minor disturbances may occur without disrupting this pathway, such as low-intensity fires, understory fuels management, pockets of pests or disease, and damage from weather events. These may help accelerate advancement toward pathway 1.4A by opening space for more understory species and creating more structural complexity.

State 2
Timber Plantation

Community 2.1
Mature Douglas-fir Plantation

Structure is single story forest of even-aged trees. This community phase is the management-controlled climax condition for a Douglas-fir plantation. The overstory is exclusively or near exclusively Douglas-fir and is even-aged. Trees are usually less than 100 years old. Trees are relatively evenly spaced, owing to their having been artificially established on a tight grid; there are typically no significant canopy gaps and little complexity in canopy structure. The understory may be somewhat sparse to relatively well-vegetated with a mix of highly shade-tolerant shrubs and herbaceous species, especially Cascade barberry (Berberis nervosa) or salal (Gaultheria shallon). Large snags are very few or absent.

Community 2.2
Regenerating Douglas-fir Plantation

Structure is single story small trees and shrubs. This community consists of regenerating Douglas-fir forest over a large area that has been opened by timber harvest. Species composition is strongly controlled by management actions. The site is typically planted with Douglas-fir while non-timber shrubs and trees are controlled to facilitate planted seedling survival, resulting in a dense, young forest with low tree species diversity. Shrubs and mixed herbaceous species typically occupy space between planted saplings. These may include oceanspray, California blackberry, salal, and Cascade barberry. Introduced Himalayan blackberry (Rubus armeniacus) and Scotch broom (Cytisus scoparius) are often present and may be abundant, usually at the expense of native shrubs or planted trees. Snags are very few or absent. Downed woody debris may be abundant or limited depending on thoroughness of its reduction during the prior timber harvest.

Community 2.3
Stem Exclusion Douglas-fir Plantation

This community is the interim point in a Douglas-fir plantation between regeneration and the mature state. Composition is exclusively or near exclusively Douglas-fir, and the stand is very dense, having been artificially established on a grid and tended with weed control methods to maximize Douglas-fir survival. A pre-commercial thin is often applied at or shortly before this phase to reduce inter-tree competition and maintain high growth rates. The understory is often very sparse, particularly if pre-commercial thinning is not performed, owing to the very limited light that reaches the forest floor. Only highly shade tolerant species such as cascade barberry (Berberis nervosa) occur, if present at all. Snags are very few or absent. Downed woody debris may be abundant or limited depending on thoroughness of its reduction during the prior timber harvest.

Pathway 2.1A
Community 2.1 to 2.2

This pathway represents even-aged harvest of a mature Douglas-fir plantation followed by Douglas-fir planting. This pathway may also result from a stand-replacing fire followed by a salvage harvest and replanting of Douglas-fir. Site preparation and removal of woody material to limit fire hazard is usually performed prior to planting.

Pathway 2.2A
Community 2.2 to 2.3

This pathway represents growth of an even-aged Douglas-fir plantation alongside active weed controls to limit competition with undesired species. Thinning of Douglas-fir saplings and pruning may or may not occur, depending on stand density or fire hazard concerns. Disturbances, such as fire, pests, and disease, are discouraged and controlled if possible.

Pathway 2.3A
Community 2.3 to 2.1

This pathway represents growth of an even-aged Douglas-fir plantation that is maturing and dominates the overstory. Light thinning may or may not occur, depending on stand density or fire hazard concerns. Disturbances, such as fire, pests, and disease, are discouraged and controlled if possible.

Pathway 2.3B
Community 2.3 to 2.2

This pathway results from a stand-replacing fire or a major pest or disease event that kills all or nearly all trees, followed by replanting of Douglas-fir. Salvage harvesting may occur if there is sufficient commercially viable material in the stand. Site preparation and removal of woody material to limit fire hazard is usually performed prior to planting.

State 3
Deforested

Community 3.1
Managed Cropland or Hayland

Structure is annual or perennial non-native species monoculture. This community consists of a range of crops, including annually planted species, short-lived perennial species, and more permanent shrubby crops. Hay and grasses and legumes for silage are included in this community.

Community 3.2
Introduced Grass and Shrub

Structure is annual or perennial herbaceous or shrubby species. Community 3.2 is characterized by low-level or more intermittent management activity such as occasional or light grazing or sporadic mowing. This plant community is dominated by introduced weedy species and the less frequent disturbance supports a more shrubby character. The site is grazed, mowed or burned often enough to prevent re-establishment of forest. Dominant shrubs are typically invasive rhizomatous species that form thickets such as Himalayan blackberry (Rubus armeniacus) or those that develop a robust seedbank and flourish in open conditions such as Scotch broom (Cytisus scoparius). Some tougher native shrub species such as California blackberry (Rubus ursinus) may be interspersed. Wetter areas commonly support non-native rhizomatous grasses. Between shrub thickets introduced pasture species such as tall fescue (Schedonorus arundinaceus), orchardgrass (Dactylis glomerata) and red fescue (Festuca rubra) are common. Fire and soil disturbing activities often favors an increase in western brackenfern (Pteridium aquilinum).

Community 3.3
Managed Perennial Grassland

Structure is perennial herbaceous species. This community is an introduced grassland that receives regular grazing or mowing disturbance and may include soil amendments such as fertilizers or lime. Weeds are aggressively controlled and desired herbaceous species are reseeded as necessary. Grazing, mowing and other weed control actions prevent the phase from transitioning to a forested state. This plant community is typically dominated by introduced perennial pasture species that are seeded after clearing. Common species include tall fescue (Schedonorus arundinaceus), orchardgrass (Dactylis glomerata) and red fescue (Festuca rubra).

Pathway 3.1A
Community 3.1 to 3.2

This pathway occurs by a reduction in frequent agronomic management disturbance (e.g. discontinued seedbed preparation, harvesting, mowing, etc.) which provides opportunity for grasses, forbs, shrub and bramble-forming species to establish. Intermittent disturbances, such as periodic grazing, targeted mowing or prescribed fire may maintain this community, preventing it from advancing to a forested state.

Context dependence. This pathway occurs by a reduction in frequent agronomic management disturbance (e.g. discontinued seedbed preparation, harvesting, mowing, etc.) which provides opportunity for grasses, forbs, shrub and bramble-forming species to establish. Intermittent disturbances, such as periodic grazing, targeted mowing or prescribed fire may maintain this community, preventing it from advancing to a forested state.

Pathway 3.1B
Community 3.1 to 3.3

This pathway occurs by intentional establishment of a perennial grass-dominated plant community. Often, the site will be prepped for seeding and desired pasture species artificially sown. In some cases, simply discontinuing crop production activities may allow the site to transition to grass, provided emergence of woody shrubs or trees is actively controlled with mowing, fire, or chemical treatment. Consistent grazing is essential to the maintenance of this community and to prevent development of woody shrubs. Other maintenance practices, such as targeted mowing, prescribed fire, chemical treatment, or other mechanical treatment are utilized as needed.

Pathway 3.2B
Community 3.2 to 3.1

This pathway represents agronomic activities. Examples include tilling; adding soil nutrients and other soil amendments, such as lime; mowing; burning; harvesting or chemically controlling vegetation; and planting desirable crop species.

Pathway 3.2A
Community 3.2 to 3.3

This pathway represents agronomic and livestock management activities. Examples include tilling; adding soil nutrients and other soil amendments, such as lime; mowing; burning; harvesting or chemically controlling vegetation; planting desirable herbaceous species; and implementing grazing management plans.

Pathway 3.3A
Community 3.3 to 3.1

This pathway represents agronomic activities. Examples include tilling; adding soil nutrients and other soil amendments, such as lime; mowing; burning; harvesting or chemically controlling vegetation; and planting desirable crop species.

Pathway 3.3B
Community 3.3 to 3.2

This pathway occurs by a reduction in grazing and associated management disturbance (e.g. discontinued seedbed preparation, harvesting, mowing, etc.) which provides opportunity for shrubs and bramble-forming species and other weedy, invasive species to establish. Intermittent disturbances, such as periodic grazing, targeted mowing or prescribed fire may maintain this community, preventing it from advancing to a forested state.

Transition T1A
State 1 to 2

This transition represents a shift to a Douglas-fir timber plantation management system. This transition is typically initiated by clear cut of old forest in the reference state but can be initiated after a large stand-replacing fire in the reference state. Management actions include even-aged harvests and replanting of evenly spaced Douglas-fir. Other tree species, especially non-conifers such as madrone, are heavily controlled to promote maximum dominance and growth of Douglas-fir.

Transition T1B
State 1 to 3

This transition is caused by an intentional clearing of land or a stand replacing fire in state 1, followed by intense, frequent disturbance such as grazing, mowing, crop production, or frequent fire to prevent trees from re-establishing. This transition can be initiated from any community phase in state 1.

Transition R2A
State 2 to 1

This restoration occurs by artificial or natural re-establishment over time of species resembling overstory and understory diversity typical of the reference state. This transition can be initiated from any community phase in state 2.

Transition T2A
State 2 to 3

This transition is caused by an intentional clearing of land or a stand replacing fire in state 2, followed by intense, frequent disturbance such as grazing, mowing, crop production, or frequent fire to prevent trees from re-establishing. This transition can be initiated from any community phase in state 2.

Restoration pathway R3A
State 3 to 1

This restoration occurs by artificial or natural re-establishment over time of species resembling overstory and understory diversity typical of the reference state. Intentional planting, site preparation, and control of competing invasive weeds will accelerate this transition. This transition can be initiated from any community phase in state 3.

Restoration pathway T3A
State 3 to 2

This transition occurs with a change in land management from a cleared non-forest state to a Douglas-fir plantation. The site is typically treated mechanically or with fire to prep the seed bed before planting Douglas-fir on an even spacing. Competing species are heavily controlled to improve seedling survival and growth. This transition can be initiated from any community phase in state 3.