State 1
Reference State

Community 1.1
Sitka spruce-red alder/ salmonberry/American skunkcabbage

Structure: Mosaic of mature overstory and regenerating openings Sitka spruce is the dominant overstory species in the reference community. Western hemlock and Port Orford cedar are in old-growth stands, but they are limited to drier microsites such as nurse logs and mounds. Red alder remains a major component in most mature stands, but it will start to actively decline after 40 to 70 years. Frequent small-scale disturbances will support alder regeneration in pockets where sunlight is abundant (Balian, 2005). The reference community represents a lack of major disturbance for at least 75 years, which allows the pioneering species to form a mature canopy. The overstory canopy closure typically is less than 50 percent, which results in a very dense, productive understory. The lack of disturbance and sparse canopy cover promote the growth of shrubs and forbs. Species common in wet depressions include American skunkcabbage, common ladyfern, water parsley (Oenanthe sarmentosa), and slough sedge. Species prevalent on hummocks and in other drier microsites include Douglas spirea (Spiraea douglasii), cascara (Frangula purshiana), Oregon crabapple (Malus fusca), salal (Gaultheria shallon), evergreen huckleberry (Vaccinium ovatum), California wax myrtle (Morella californica), red elderberry (Sambucus racemosa), and salmonberry. Common disturbances include small gap dynamics (1/2-acre openings or smaller) following windstorms or minor scouring from flooding. The death of one or two trees creates gaps for sunlight to reach the understory, which promotes the growth of forbs and shrubs and regeneration of overstory species, primarily red alder. Soil deposition following periods of ponding or minor scouring from flooding temporarily affects the understory community, but it does not alter the composition of the overstory.

Community 1.2
American skunkcabbage-common ladyfern/slough sedge

Structure: Bare ground with forb and sedge establishment Community phase 1.2 represents a forest that is undergoing regeneration or stand initiation immediately following flooding or windthrow. Scattered remnant mature trees and shrubs may be in some areas, and woody debris is abundant. Loss of the overstory and the fallen trees may impact the hydrology by resulting in more frequent, longer periods of ponding. Successful regeneration is dependent on the local seed source, an adequate seedbed, and sufficient light and water (Nierenberg, 2000). Rapid recolonization is limited to plants that are well adapted to saturated soil conditions for much of the year. American skunkcabbage, common ladyfern, slough sedge, and water parsley will begin to re-establish during this phase.

Community 1.3
Red alder/salmonberry-red elderberry/American skunkcabbage-common ladyfern/slough sedge

Structure: Dense single story Community phase 1.3 is an early seral forest in regeneration. Scattered remnant mature trees may be present. Red alder is dominant in the overstory because it has several competition advantages. It fixes nitrogen in soils, which provides an early competitive advantage (Villarin, 2009). Red alder can establish quickly as compared to conifers. Seeds of deciduous species are light and can be transported long distances by wind and water, allowing for rapid recolonization. An understory of salmonberry and red elderberry establishes in this phase.

Community 1.4
Red alder-Sitka spruce/salmonberry/American skunkcabbage

Structure: Single story with dense understory Community phase 1.4 is a forest in the competitive exclusion stage. Scattered remnant mature trees may be present. Sitka spruce and red alder are dominant in the overstory. Red alder will begin to die 40 to 70 years following disturbance and more light will penetrate the newly nitrogen-rich soil (Naiman, 2009). As a result of several dynamics, conifer regeneration becomes more prevalent in this community phase. Other overstory species may include Port Orford cedar and western hemlock, which typically establish on mounds or downed woody debris. Seedlings of Sitka spruce will begin to establish sporadically, especially in areas that have more shade. They may establish within 4 years of hardwood establishment (Stolnack, 2010). Understory species such as salmonberry, evergreen huckleberry, salal, American skunkcabbage, and common ladyfern flourish under the open canopy. If red alder regeneration is present, it is inferred that frequent minor flooding or windthrow has influenced the site dynamics (Nierenberg, 2000).

Pathway 1.1A
Community 1.1 to 1.2

Sitka spruce-red alder/ salmonberry/American skunkcabbage

American skunkcabbage-common ladyfern/slough sedge

This pathway represents a major 100- or 500-year flood, catastrophic windstorm, or high-intensity, stand-replacing wildfire. Major floods scour and alter the adjacent stream channel, remove understory and overstory vegetation, and may alter the streamflow and subsurface flow. This type of disturbance may completely reconfigure sediment loads and dramatically reduce or eliminate the forest overstory. Catastrophic windstorms may be stand replacing.

Pathway 1.2A
Community 1.2 to 1.3

American skunkcabbage-common ladyfern/slough sedge

Red alder/salmonberry-red elderberry/American skunkcabbage-common ladyfern/slough sedge

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

Pathway 1.3A
Community 1.3 to 1.2

Red alder/salmonberry-red elderberry/American skunkcabbage-common ladyfern/slough sedge

American skunkcabbage-common ladyfern/slough sedge

This pathway represents a major 100- or 500-year flood or catastrophic windstorm. Major floods scour and alter the adjacent stream channel, remove understory and overstory vegetation, and may alter the streamflow and subsurface flow. This type of disturbance may completely reconfigure sediment loads and dramatically reduce or eliminate the forest overstory. Catastrophic windstorms may be stand replacing.

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

This pathway represents no further major disturbance. Continued growth over time and ongoing mortality lead to increased vertical diversification. The community begins to resemble the structure of the reference community, including small pockets of regeneration (both deciduous and coniferous) and a more diversified understory.

Pathway 1.4A
Community 1.4 to 1.2

This pathway represents a major 100- or 500-year flood or catastrophic windstorm. Major floods scour and alter the adjacent stream channel, remove understory and overstory vegetation, and may alter the streamflow and subsurface flow. This type of disturbance may completely reconfigure sediment loads and dramatically reduce or eliminate the forest overstory. Catastrophic windstorms may be stand replacing.

State 2
Converted State

Community 2.1
Managed Cropland or Hayland

Structure: Annual or perennial non-native species monoculture Community phase 2.1 may consist of a range of crops, including annually planted species, short-lived perennial species, and more permanent shrubby species. Hay and grasses and legumes for silage are included in this community phase.

Community 2.2
Non-Native Grassland and Shrubland

Structure: Annual or perennial herbaceous or shrubby species Community phase 2.2 is characterized by low-level agronomic or management activity such as adding soil nutrients, intensive grazing management, regular mowing, or weed control. This plant community commonly consists dominantly of introduced weedy species. Areas that have extremely low fertility or are subject to heavy grazing pressure have a higher proportion of annual, stoloniferous, or rhizomatous species. Wetland areas commonly support dominantly non-native rhizomatous grasses. The plant community may include remnants of introduced pasture species that commonly are seeded.

Community 2.3
Managed Grassland

Structure: Perennial herbaceous species Community phase 2.3 receives regular agronomic inputs, including adding soil nutrients and other soil amendments such as lime, implementing grazing management plans or regular mowing, controlling weeds, and reseeding as needed. This plant community typically includes introduced perennial pasture and hay species that commonly are seeded. In areas of historic native grassland, mixtures of perennial and annual native species may be seeded and managed by appropriate agronomic and livestock management activities. Minor amounts of introduced species that commonly are in non-native grassland and shrub communities (community phase 2.2) are in this phase.

Pathway 2.1A
Community 2.1 to 2.2

In the absence of agronomic and livestock management activities, seeds from surrounding weedy plant communities will be transported to the site by wind, floodwater, animals, or vehicle traffic. Adapted species will become established. Management activities include tilling, adding soil nutrients and other soil amendments such as lime, mowing, burning, harvesting or chemically controlling vegetation, planting to desirable herbaceous species, and implementing grazing management plans.

Pathway 2.1B
Community 2.1 to 2.3

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

Pathway 2.2B
Community 2.2 to 2.1

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

Pathway 2.2A
Community 2.2 to 2.3

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

Pathway 2.3A
Community 2.3 to 2.1

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

Pathway 2.3B
Community 2.3 to 2.2

In the absence of agronomic and livestock management activities, seeds from surrounding weedy plant communities will be transported to the area by wind, floodwater, animals, or vehicle traffic. Adapted species will become established. Management activities include tilling, adding soil nutrients and other soil amendments such as lime, mowing, burning, harvesting or chemically controlling vegetation, planting to desirable herbaceous species, and implementing grazing management plans.

Transition T1
State 1 to 2

This pathway represents a change in land use. Land management includes modifications to the hydrologic function to develop pasture and agriculture. Non-native seed disbursement is introduced (intentionally or unintentionally), which alters the reference community.

Transition T2
State 2 to 1

This pathway represents restoration of the natural hydrologic function and native plant habitat. Native seed sources and extensive management and mitigation of brush and invasive species are needed to restore the community.