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Draft Interim Functional Model For Idaho

DRAFT INTERIM

FUNCTIONAL ASSESSMENT MODEL

IDAHO

Subclass: Low-gradient, broad basin, groundwater fed slope with spring fed riverine inclusion.

Introduction:

The subclass includes montane, low-gradient slope wetlands where the primary water source is groundwater. The slope wetlands occur in broad valleys in mountainous regions of central and eastern Idaho where mineral and organic soils on alluvial sand and gravel deposits typically overlay an impermeable surface. Perennial streams draining the mountains may become intermittent when they reach the alluvial valleys. This water then percolates into the groundwater system and surfaces in the valley bottoms.

Functional Profile:

Geomorphic setting: The mountains of central and eastern Idaho are within the Northern Rocky Mountains Steppe and Southern Rocky Mountains Steppe provinces (Figure 1). The Northern Rocky Mountain Steppe in Idaho includes the Yellowstone Highlands (M331A) and Overthrust Mountains (M331D) (including the Teton Basin) sections. The Southern Rocky Mountains Steppe in Idaho includes the Idaho Batholith (M332A), Bitteroot Valley (M332B), Beaverhead Mountain, Department of Agriculture, (Soil Conservation Service 1991). Adjacent mountain ranges frequently have carbonate and limestone deposits (Bond 1978). Mineral soils are often mildly to strongly calcareous due to precipitation of these deposits and water chemistry may be mildly to strongly alkaline.

Parent Materials:

Fine textured fluvial materials typically overlay restrictive layers such as basalt or other volcanic flows deposited on Paleozoic lake sediments of limestone, siltstone, and sandstone. The alluvial materials of the valley floor are of mixed origin and may be derived from granite, gneiss, sandstone, quartzite, limestone, or rhyolite (U.S. Department of Agriculture, Soil Conservation Service 1969).

Ecological significance of geomorphic setting:

The water holding capacity is high to very high in upper profiles of both the mineral and organic soils. The upper profiles range from 20-72 inches in depth and are underlain by a permeable sand and gravel layer. During the spring, run-off from snowmelt is stored on the soil surface and later moves into the upper profile. The water eventually leaves the system via channels or via underflow through sands and gravels (U.S. Department of Agriculture, Soil Conservation Service 1991, 1969).

Calcareous soils are typically highly to strongly alkaline. Organic peat soils in slope wetlands are moderately to slightly acidic Rare plant species are associated with water chemistry at the extremes of the pH scale (Rabe et al. 1994, Bursik and Moseley 1995). Wetlands of this subclass are floristically rich and frequently provide habitat for plant species of concern.

Functions based on geomorphic setting:

Deep surface soils underlain by permeable sands and gravels result in functions related to storage and movement of water including: surface and subsurface water storage, and moderation of groundwater. Water chemistry of these wetlands often results in unique assemblages of plant species.

Water Source and Climatic Setting:

Winter and spring weather patterns are influenced by westerly winds from the Pacific Ocean. This maritime influence weakens during summer months and continental climatic conditions prevail with air masses from the south producing thunderstorm activity. The area is considered semi-arid with average annual precipitation in the 9 to 24 inch range. Most of the precipitation is in the form of snow during the winter months (Ross and Savage 1967).

Perennial streams draining the mountain systems may become intermittent when they reach the valleys. The water percolates through the groundwater system and surfaces in valley bottoms (Rabe et al 1994). Lesser amounts of water enter the system from direct precipitation in the form of snow.

Ecological significance of water source and climatic setting:

Water quality in these wetlands is high providing habitat for aquatic vertebrates and invertebrates. Throughout Idaho spring fed wetlands have been found to provide habitat for endemic fish and snail species. Streams of these wetlands are often important sport fisheries due to the abundance of invertebrates and optimal water temperatures.

Functions based on water source and climatic setting:

Because the dominant source of water for low-gradient slope wetlands is groundwater the wetlands function to maintain habitat for aquatic species.

Hydrodynamics:

The hydrograph of groundwater fed wetlands in mountainous regions of Idaho may experience two pulses. The broad valleys where these wetlands occur typically have accumulations of snow from -- to -- feet during the winter months. A peak in flow in the early spring occurs due to snow melt. The flows are then level and may pulse again in the fall due to lag time in percolation from the mountains, underflow from the ground watershed, or in response to the end of irrigation (Wiley 1977). Overbank flows that occur in most stream systems associated with spring run-off are typically lacking (Rabe et al. 1994). Rather, the wetland complex becomes inundated when the soil profile becomes saturated.

Water entering sloped wetland systems is stored in areas of low topographic relief, in the soil profile, and on the surface. Nearly all of the water leaves the system through surface run-off in spring channels. Lesser amounts may be lost to evapotranspiration and underflow. Portions of the wetland mosaic with shallow surface soils are only temporarily flooded

Ecological significance of hydrodynamics:

The poorly drained soils of this wetland subclass are saturated throughout the growing season and plant productivity is high. A diverse mosaic of native plant communities, including scrub-shrub, forested, emergent vegetation, is correlated with duration of flooding in this subclass. Scrub-shrub vegetation occurs in association with somewhat poorly drained soils lining spring channels. Willows or water birch are dominant scrub-shrub species and are habitat for neotropical migrants, moose, and deer. Soils that dry out seasonally (temporarily flooded) support scrub-shrub vegetation dominated by low shrubs including shrubby cinquefoil and greasewood. Forested vegetation is typically dominated by aspen and may become established on former spring heads. The aspen stands are known to contain bald eagle nests and heron rookeries. Emergent vegetation occurring on very poorly drained soils are dominated by sedges, rushes, and cattails. Temporarily flooded emergent vegetation is dominated by grasses and sedges (Conservation Data Center, Idaho Department of Fish and Game 1997). Semipermanently flooded and open water habitat provide habitat for amphibians. Water is frequently open during winter months and may provide habitat for wintering waterfowl including trumpeter swans. Temporarily flooded emergent and scrub-shrub wetlands provide habitat for sandhill cranes and foraging areas for harriers and great gray owls (Groves et al. 1997). Areas that are temporarily flooded are accessible to humans and livestock and subject to alterations from agricultural conversion, grazing, and development.

Functions based on hydrodynamics:

The distribution of plant communities throughout the wetland is a result of hydrodynamics. In addition to habitat functions, the mosaic of emergent, scrub-shrub, forested, and open water habitat results in functions related to storage and accumulation of organic and inorganic sediments as well as elements and compounds.

Functions:

Definition of functions, variables, and indices:

Hydrologic Functions

Function: Surface water storage

Definition: Storage of water on the surface of the wetland

Rationale:

Model Variables Indicators Pre- Post Comments and notes

Vfreq: frequency of water above the soil surface Frequent (once or more every two years) flooding as indicated by field observation, series of air photos, or soil survey.
1.0
1.0

Flooding occasional (average of once or less in two years) or common (flooding likely under normal conditions) as indicated by series of air photos, or soil survey.
0.5
0.5

Flooding rare(not possibble except under unusual weather conditions) as indicated by series of air photos or soil survey.
0.1
0.1

No evidence or indicators of flooding.
0
0

Vmicro: micro-topographic relief ? >50% of the wetland with topography which stores surface water. Indicators include swales or other areas with low topographic relief which allow water to be stored or hummocks which allow water to flow in rills.
1.0
1.0

25-50%
0.5
0.5

1-25%
0.1
0.1

Wetland is flat and water essentially flows as a sheet.
0
0

Condition
INDICES OF VARIABLES

Index of Function: If Vfreq=0 then FCI=0; otherwise FCI=(Vfreq+Vmicro)/2

Vfreq
Vmicro

Pre-project

Post-project

Change due to project

Function: SUBSURFACE WATER STORAGE (national slope model - draft)

Definition: Ability of a wetland to store subsurface water (national slope model - draft). (Availability of storage for water beneath the wetland surface. Storage capacity becomes available as periodic drawdown of the water table or reduction in soil saturation occurs, making drained pores available for storage of water. Drawdown may be the result of vertical and lateral drainage and/or evapotranspiration. - national riverine guidebook)

Effects On-Site: Maintain biogeochemical processes (national HGM approach)

Effects Off-Site: recharge surficial aquifers and maintain baseflow and seasonal flow in streams (national HGM approach)

Model Variables
Indicators
Pre-
Post-
Comments and notes

VPORE: soil pore space available for storage Higher permeability wetland soils (sandy loam to coarser texture soil) and soil not saturated to surface nor ponded for long durations during the growing season
1.0

Lower permeability wetland soils (soil texture finer than sandy loam) and soil not saturated to surface nor ponded for long durations during the growing season
0.5

Soil saturated to surface or ponded for long durations during the growing season
0.1

Soil saturated to surface or ponded throughout the year
0.0

VWTF: fluctuation of water table Water table falls rapidly to 15-30 cm of surface
1.0

Water table falls slowly and/or to a depth of 15 cm
0.5

Soils stay nearly saturated of fluctuate within a few cm of the surface over several days to a week
0.1

Soil saturated to surface throughout the year or water table at 30 cm or greater for long periods
0.0

Index of Function = (VPORE + VWTF)/2

Condition INDICES OF VARIABLES

Index of Function = (VPORE + VWTF)/2

VPORE
VWTF

Pre-project

Post-project

Change due to project

Biogeochemical Functions:

Function: REMOVAL OF PARTICULATES

Definition: Process of filtering and settling both organic and inorganic particulates

Effects on-site: Sediment accumulation contributes to the nutrient capital of an ecosystem. Deposition increases surface elevation and changes topographic complexity. Organic matter may also be retained for decomposition, nutrient recycling, and detrital food web support.

Effects off-site: Reduces stream sediment load and entrained woody debris that would otherwise be transported downstream.

VARIABLES
INDICATORS
PRE-
POST-
COMMENTS

Vpden
Plant density (75-125%) of reference standard--Hebaceous plants with 50% or greater cover
1.0
1.0

Plant density (25%-75%) of reference standard--Herbaceous plants with 10-50% cover
0.5
0.5

Plant density (0-25%) of reference standard--Litter cover present, but sparse (< 10% cover)
0.1
0.1

No plants present
0
0

Vdherb
Mapped as emergent wetland on NWI maps Emergent cover >___%
Soil survey describes potential habitat type as herbaceous
1.0

Plant stem density <___>___, area is grazed to below 6"stubble height
0.5

No herbaceous layer, area is farmed
0.1

Impervious ground surface
0

Vwetuse
Wetland is part of an acre or larger block of land which is non-fragmented and has few non-natural breaks. If some agricultural uses (e.g. haying, grazing) occur in the wetland and surrounding landscape, no compaction from equipment or evidence of trampling.
1.0

No tillage in saturated wetlands. Outermost zone minimally impacted by light grazing.
0.5

Wetland receives conventional tillage; outermost zone tilled or grazed.
0.1

Wetland severely disturbed by tillage, grazing, and/or water development. Restoration potential questionable and will require replanting and hydrologic restoration.
0.0

Vlitter: Hebaceous plant detritus
(uptake and conversion of nutrients)
Litter density (75-125%) of reference standard--Litter with 50% to continuous cover. Open water <10% of wetland area.
1.0
1.0

Litter density (25%-75%) of reference standard--Litter with 10-50% cover. Open water 10-25% of wetland area.
0.5
0.5

Litter density (0-25%) of reference standard--Litter cover present, but sparse (< 10% cover). Open water >25% of wetland area.
0.1
0.1

No litter present or area dominated by open water.
0
0

Vmicro: micro-topographic relief
? >50% of the wetland with topography which stores surface water. Indicators include swales or other areas with low topographic relief which allow water to be stored or hummocks which allow water to flow in rills.
1.0
1.0

25-50%
0.5
0.5

1-25%
0.1
0.1

Wetland is flat and water essentially flows as a sheet.
0
0

Vmacro
Evidence of macrotopographic features: natural levees, oxbows, meander scrolls, breaks in slope.
1.0
1.0

No evidence of macrotopographic features.
0.0
0.0

Vfreq: frequency of water above the soil surface
Frequent (once or more every two years) flooding as indicated by drift lines, series of air photos, or soil survey.
1.0
1.0

Flooding occasional (average of once or less in two years) or common (flooding likely under normal conditions) as indicated by series of air photos, or soil survey.
0.5
0.5

Flooding rare(not possibble except under unusual weather conditions) as indicated by series of air photos or soil survey.
0.1
0.1

No evidence or indicators of flooding.
0
0

Vflood ??
Evidence of frequent overland flooding: accumulation of recently deposited sediment, layering of leaves and sediment, silt layers on vegetation, high water marks, gage data, aerial photos indicating flooding
1.0

Some evidence of overland flow: runoff, snowmelt, irrigation
0.5

No evidence of overland flooding.
0

Vbuff:zone surrounding the wetland that protects its structural and functional integrity
Buffer is in native vegetation with almost no disturbance
1.0
1.0

Buffer is in native vegetation with light to moderate grazing.
0.5
0.5

Buffer receives conventional tillage or is in non-native monoculture.
0.1
0.1

Urban, semi-pervious, or impervious surfaces immediately adjacent to the site.
0.0
0.0

Condition
INDICES OF VARIABLES

Index of Function= (Vpden +Vwetuse+Vlitter+Vmicro+Vmacro+V freq+ Vbuff)/7

Vdherb
Vwetuse
Vdetrtus
Vmicro
Vmacro
Vflood
Vbuff

Pre-project

Post-project

Change due to project

Function: Removal of dissolved elements and compounds

Definition: The process by which nutrients, contaminents, and other elements and compounds imported into the wetland are removed via nutrient cycling and brought into long-term storage.

Rationale:

Model Variables
Indicators
Pre-
Post-
Comments and notes

Vfreq: frequency of water above the soil surface
Frequent (once or more every two years) flooding as indicated by drift lines, series of air photos, or soil survey.
1.0
1.0

Flooding occasional (average of once or less in two years) or common (flooding likely under normal conditions) as indicated by series of air photos, or soil survey.
0.5
0.5

Flooding rare(not possibble except under unusual weather conditions) as indicated by series of air photos or soil survey.
0.1
0.1

No evidence or indicators of flooding.
0
0

Vmacro
Contour maps indicate gross relief such as breaks in slope and/or closed contours. Abandoned channels, oxbows, swales or hummock and depression surface present.
1.0
1.0

Indicators above are much less well developed and the area has low surface gradient.
0.5
0.5

Indicators above suggest variable is nearly absent from assessment area.
0.1
0.1

All above indicators are absent and area has a moderate to steep gradient.
0
0

Vmacro
Evidence of macrotopographic features: natural levees, oxbows, meander scrolls, breaks in slope.
1.0
1.0

No evidence of macrotopographic features.
0.0
0.0

Vmicro: micro-topographic relief
? >50% of the wetland with topography which stores surface water. Indicators include swales or other areas with low topographic relief which allow water to be stored or hummocks which allow water to flow in rills.
1.0
1.0

25-50%
0.5
0.5

1-25%
0.1
0.1

Wetland is flat and water essentially flows as a sheet.
0
0

Vpden
Plant density (75-125%) of reference standard--Hebaceous plants with 50% or greater cover
1.0
1.0

Plant density (25%-75%) of reference standard--Herbaceous plants with 10-50% cover
0.5
0.5

Plant density (0-25%) of reference standard--Litter cover present, but sparse (< 10% cover)
0.1
0.1

No plants present
0
0

Vlitter:
Hebaceous plant detritus (uptake and conversion of nutrients)
Litter density (75-125%) of reference standard--Litter with 50% to continuous cover. Open water <10% of wetland area.
1.0
1.0

Litter density (25%-75%) of reference standard--Litter with 10-50% cover. Open water 10-25% of wetland area.
0.5
0.5

Litter density (0-25%) of reference standard--Litter cover present, but sparse (< 10% cover). Open water >25% of wetland area.
0.1
0.1

No litter present or area dominated by open water.

Vwetuse: dominant landuse and condition
Wetland is part of an acre or larger block of land which is non fragmented and has few non-natural breaks. If some agricultural uses (e.g. haying, grazing) occur in the wetland and surrounding landscape, no compaction from equipment or evidence of trampling.
1.0
1.0

No tillage in saturated wetlands. Outermost zone minimally impacted by light grazing.
0.5
0.5

Wetland receives conventional tillage; outermost zone tilled or grazed.
0.1
0.1

Wetland severely disturbed by tillage, grazing, and/or water development. Restoration potential questionable and will require replanting and hydrologic restoration.
0.0
0.0

Vbuff:zone surrounding the wetland that protects its structural and functional integrity
Buffer is in native vegetation with almost no disturbance
1.0
1.0

Buffer is in native vegetation with light to moderate grazing.
0.5
0.5

Buffer receives conventional tillage or is in non-native monoculture.
0.1
0.1

Urban, semi-pervious, or impervious surfaces immediately adjacent to the site.
0.0
0.0

Condition
INDICES OF VARIABLES

Index of Function= (Vfreq*(Vmacro+Vmicro+Vpden+Vlitter+Vwetuse+Vbuff)/6)1/2

Vfreq
Vmacro
Vmicro
Vpden
Vlitter
Vwetuse
Vbuff

Pre-project

Post-project

Change due to project

Function: Moderation of groundwater flow (frank)

Definition: Capacity of wetland to moderate the rate of groundwater flow by interception, water is discharged into down fradeint sources. VARIABLE INDICATORS PRE POST COMMENTS

Vsubin: subsurface flow into wetland
Seeps present at edge of wetland. Springs within wetland. Saturated soils present during the entire year. Gleyed or organic soils present. Vegetation dominated by FACW or OBL species. Low permeability soils present.
1.0
1.0

Soils meet hydric criteria and are saturated to the surface during the entire growing season, Vegetation is dominated vy FACW or drier species. Moderately permeable soils present.
0.5
0.5

No seeps present at the edge of the wetland. No springs in wetland. Soils meet hydric criteria but are not saturated to surface during the entire growing season. Soils not gleyed. Vegetation dominated by FAC or drier species.
0.1
0.1

Above indicators absent.
0
0

Vsubout: surface flow from wetland to other surficial aquatic environment Subsurface and surface flow from wetland to offsite aquatic environment throughout the year. Offsite aquatic environment (creek or stream) with 0.25 miles of wetland. Low gradient in wetland (0 to 0.5%).
1.0
1.0

Subsurface and surface flow from wetland to offsite aquatic environment throughout the growing season. Offsite aquatic environment (creek or stream) 0.25 to 0.5 miles from wetland.
0.5
0.5

Surface flow from wetland to offsite aquatic environment for part of the growing season. Offsite aquatic environment greater thatn 0.5 miles from wetland. High gradient in wetland 2.0% or greater.
0.1
0.1

Above indicators absent.
0
0

Vpore this is opposite of Vpore for subsurface H20 storage--did we resolve this? Check Frank's notes High soil porosity. Poorly drained soil.
1.0
1.0

Intermediate soil porosity.
0.5
0.5

Low soil porosity. Well drained soil.
0
0

Condition
INDICES OF VARIABLES

Index of Function = (Vsubin* Vsubout)1/2

Pre-project
Vsubin
Vsubout

Post-project

Change due to project

Habitat Functions

Function: MAINTAIN CHARACTERISTIC NATIVE PLANT COMMUNITY

Definition: Capacity of a wetland to produce and support characteristic native plant communities. (Emphasis is on location, dynamics and structure of the plant community within the slope wetland and the mosaic of similar wetlands in the area. This is controlled by the dominant species of tree, shrubs, and ground cover and by the characteristics of vegetation regeneration)

Effects On-Site: Converts solar radiation and carbon dioxide into complex organic compounds that provide energy to drive food webs. Provides seeds and propagules for regeneration. Provides habitat diversity for nesting, resting, refuge, and escape cover for animals. Creates microclimate conditions that support completion of life histories of plants and animals. Provides organic matter for soil development and soil related nutrient cycling processes. Creates both long-term and short-term habitat for resident or migratory animals.

Effects Off-Site: Provides a source of seeds and propagules to maintain species composition and /or structure of adjacent wetlands and supplies propagules for colonization of nearby degraded systems. Provides food and cover for animals from adjacent ecosystems. Contributes to landscape connectivity, habitat, and food for migratory species. Enhances species diversity and ecosystem stability. Organic matter supports secondary production in associated aquatic ecosystems. Contributes leaf litter and coarse woody debris habitat for animals in associated aquatic habitats.

Model Variables
Indicators
Pre-
Post-
Comments and notes

VPDOM: number of dominant (>10% cover) wetland plant species)
Number of dominant wetland plant species is greater than 8
1.0
1.0

Number of dominant wetland plant species is 5 to 7
0.75
0.75

Number of dominant wetland plant species is 3 to 4
0.5
0.5

Number of dominant wetland plant species is 1 to 2
0.25
0.25

Site devoid of vegetation
0.0
0.0

VREGEN: herb, shrub, and tree species as seedling/sapling and/or clonal shoots or with mature seeds
Obvious seedling/sapling and/or clonal shoots or mature seeds; dominated by native wetland species
1.0
1.0

Some seedling/sapling and/or clonal shoots native and non-native species
0.5
0.5

Significant regeneration by non-native species and/or increasers; soil disturbance activities
0.1
0.1

No seedling/sapling and/or clonal shoots present
0.0
0.0

VBUFF: zone surrounding the wetland that protects its structural and functional integrity
Buffer is in native vegetation with almost no disturbance
1.0
1.0

Buffer is in natural vegetation with light to moderate grazing
0.5
0.5

Buffer receives conventional tillage or heavy grazing or is in non-native monoculture
0.1
0.1

Urban, semi-pervious, or impervious surfaces immediately adjacent to site
0.0
0.0

VWETUSE: dominant land use and condition of the wetland
Wetland is part of an acre or larger block of land which is non-fragmented and has few non-natural breaks. If some agricultural uses (e.g., haying, grazing) occur in the wetland and surrounding landscapes, no compaction from equipment or evidence of trampling.
1.0
1.0

No tillage in saturated wetlands. Outermost zone minimally impacted by light grazing.
0.5
0.5

Wetland receives conventional tillage. Outermost zone tilled or grazed.
0.1
0.1

Wetland severely disturbed by tillage, grazing, and/or water development. Restoration potential questionable and will require replanting and hydrologic restoration.
0.0
0.0

VRATIO: ratio of native to non-native plant species
3 of the 4 most dominant plant species in the wetland are native species and/or 75-100% of the species surveyed are native species.
1.0
1.0

1 of the 4 most dominant plant species in the wetland are native species and/or 25-50% of the species surveyed are native species.
0.5
0.5

0 of the 4 most dominant plant species in the wetland are native species, however at least 1-25% of the species surveyed are native species.
0.1
0.1

Wet meadow zone unvegetated or dominated by planted or escaped cultivars.
0.0
0.0

Index of Function = [(VPDOM + VREGEN + VBUFF + VWETUSE)/4 x VRATIO]1/2

Condition
INDICES OF VARIABLES

Index of Function = [(VPDOM + VREGEN + VBUFF +VWETUSE)/4 x VRATIO]1/2

VPDOM
VREGEN
VBUFF
VWETUSE
VRATIO

Pre-project

Post-project

Change due to project

Function: Maintain habitat for native aquatic invertebrates and vertebrates.

Definition: Capacity of the wetland to support characteristic aquatic animal populations.

Rationale:

Model Variables
Indicators
Pre-
Post-
Comments and notes

Vratio: ratio of native to non-native plant species
Three of the four most abundant plant species in the wetland are native species and/or 75-100% of the species surveyed are native species.
1.0
1.0

One of the four most abundant plant species in the wetland are native species and/or 25-50% of the species surveyed are native species.
0.5
0.5

None of the four most abundant plant species in the wetland are native species, however at least 1-25% of the species surveyed are native species.
0.1
0.1

Wet meadow zone unvegetated or dominated by planted or escaped cultivars.
0
0

Vmosaic: number and proportion of cover types
Wetland includes 3 or more vegetation classes based on Cowardin's classification or 3 or more cover types within a single vegetation class.
1.0
1.0

Wetland with 2 or more vegetation classes based on Cowardin's classification or 2 or more cover types within a single vegetation class.
0.5
0.5

Vegetation absent, a monoculture, or essentially a single plant community with little diversity.
0.1
0.1

Vegetation as above with little possibility of restoration or consisting of planted cultivars.
0
0

Vlink: proximity and connectivity to other wetlands in the area
Wetland is adjacent to or connected to other wetlands within a mile radius via subsurface or surface flows (including channels) which have not been altered by diversion, channel straightening, conversion or grazing.
1.0
1.0

Wetland is connected to other wetlands within a mile radius via subsurface or surface flows (including channels). Wetlands may be impacted by grazing and conversion but hydrologic manipulations are minor and not fragmenting connectivity.
0.5
0.5

Wetland connectivity is fragmented by periphery ditches or channelization. Adjacent wetlands are impacted by grazing, conversion, or development
0.1
0.1

Wetland is isolated from adjacent wetlands due to dewatering (ditches, diversions) or filling.
0
0

Vupuse: dominant land use and condition of the upland watershed that contributes to the wetland

Uplands never grazed, or at most infrequently and lightly grazed. Never tilled.
1.0
1.0

Surrounding upland in a combination of land uses in which there is moderate grazing on steep and long slopes and/or tillage on short and moderate slopes.
0.5
0.5

Moderate tillage or heavy grazing on high slopes.
0.1
0.1

Urban, semi-pervious, or impervious surfaces resulting in maximum overland flow and high sediment delivery rate to the wetland.
0.0
0.0

Vwetuse: dominant landuse and condition Wetland is part of an acre or larger block of land which is non fragmented and has few non-natural breaks.
If some agricultural uses (e.g. haying, grazing) occur in the wetland and surrounding landscape, no compaction from equipment or evidence of trampling.
1.0
1.0

No tillage in saturated wetlands.
Outermost zone minimally impacted by light grazing.
0.5

0.5

Wetland receives conventional tillage; outermost zone tilled or grazed.
0.1
0.1

Wetland severely disturbed by tillage, grazing, and/or water development. Restoration potential questionable and will require replanting and hydrologic restoration.
0.0
0.0

Condition

INDICES OF VARIABLES

Index of Function = (Vpratio + Vmosaic + Vlink + Vupuse + Vwetuse)/5

Vpratio
Vmosaic
Vlink
Vupuse
Vwetuse

Pre-project

Post-project

Change due to project

Function: Maintain Characteristic Bird Populations

Definition: The abundance and species richness of birds is related to habitat complexity because birds have evolved to fill most available terrestrial niches. They partition habitats temporally (day versus night feeders), spatially (ground feeders, mid- and top-canopy feeders), and trophically (frugivores, insectivores, piscivores). Birds are sensitive to alterations in the structure and function of wetland ecosystems. Species richness and relative abundance can be measured. Bird richness increases with: vegetation/open water interspersion, increased layers of vegetation, and complexes of small and diverse wetlands.

Effects On-Site: Maintain habitat for birds that has characteristic species composition, abundance, and structure containing diversity, nesting, resting, refuge and escape cover.

Effects Off-Site: Maintain corridors between habitat islands and landscape biodiversity.

Model Variables

Indicators
Pre-
Post-
Comments and notes

Vstrata
Dense overstory, with at least 3 vegetative layers.
1.0
1.0

Moderately dense overstory with at least 2 layers. Mix of shrub vegetation near emergent habitat.
0.5
0.5

Overstory with at least 1 layer. No shrub vegetation near emergent habitat.
0.1
0.1

No overstory. No shrub vegetation or emergent habitat.
0.0 0.0

VMOSAIC: number and proportion of cover types within the wetland

Large structurally diverse wetland >10 acres, , open water pools interspersed within wetland, 3 Cowardin vegetation types (Above should be in Vlanduse)
1.0
1.0

Medium sized somewhat structurally diverse wetland 5-10 acres, 2 Cowardin vegetation types
0.5
0.5

Wetlands <5 acres, with little vegetation, 1 Cowardin vegetation type, no open water.
0.1
0.1

Wetlands <0.5 acre in size, with little vegetation, no seasonal saturation to surface.
0.0
0.0

VT&E: presence of threatened or endangered species

Documented presence within wetland of threatened or endangered species.
1.0
1.0

Area sometimes used by threatened or endangered species.
0.5
0.5

Area provides habitat for threatened or endangered species. No documented presence.
0.1
0.1

No habitat or documented presence of threatened or endangered species.
0.0
0.0

VBIRDUSE: number of species using the area within the wetland

Wetland used by 10 (?) or more species of birds. Use nests, calls, tracks, feathers, skeletons, bird lists and field sightings.
1.0
1.0

Wetland used by 5 to 10 species of birds.
0.5
0.5

Wetland used by less than 5 species of birds.
0.1
0.1

No bird use evident.
0.0
0.0

VLANDUSE: how the surrounding upland or wetland is being managed

(This is similar to Vbuffer and Vwetuse...we should standardize the use of the three variables in all functions)

Uplands never grazed or tilled. Wetland never grazed and is part of an acre or larger block of land which is not drained. No compaction from any agricultural use.
1.0
1.0

Surrounding upland having light grazing or tilling. No tilling in the wetland
0.5
0.5

Moderate grazing or tilling in the upland. Wetland with moderate tilling. Possible restoration potential.
0.1
0.1

Urban upland use, impervious surface with overland flow and high sediment delivery rate to the wetland. Heavy grazing and tilling in the wetland. Little restoration potential.
0.1
0.1

Vupuse: dominant land use and condition of the upland watershed that contributes to the wetland

Uplands never grazed, or at most infrequently and lightly grazed. Never tilled.
1.0
1.0

Surrounding upland in a combination of land uses in which there is moderate grazing on steep and long slopes and/or tillage on short and moderate slopes.
0.5
0.5

Moderate tillage or heavy grazing on high slopes.
0.1
0.1

Urban, semi-pervious, or impervious surfaces resulting in maximum overland flow and high sediment delivery rate to the wetland.
0.0
0.0

Index of Function = (VCOVER + VMOSAIC + VT&E + VBIRDUSE + VLANDUSE)/5

Condition

INDICES OF VARIABLES

Index of Function = (VCOVER + VMOSAIC + VT&E + VBIRDUSE + VLANDUSE)/5

VCOVER
VMOSAIC
VT&E
VBIRD-USE
VLANDUSE

Pre-project

Post-project

Change due to project

References:

Bond, J. G. and C. H. Wood. 1978. Geologic Map of Idaho. Idaho Department of Lands, Bureau of Mines and Geology. Moscow.

Bursik, R. J., and R. K. Moseley. 1995. Ecosystem conservation strategy for Idaho Panhandle peatlands. Cooperative project between Idaho Panhandle National Forests and Idaho Department of Fish and Game, Conservation Data Center, Boise. 28 pp. plus appendix.

Groves, C. R., B. Butterfield, A. Lippincott, B. Csuti, and J. M. Scott compilers, 1997. Atlas of Idaho's Wildlife, Integrating Gap Analysis and Natural Heritage Information. Cooperative project of Idaho Department of Fish and Game, The Nature Conservancy, and Idaho Cooperative Fish and Wildlife Research Unit. Published by Idaho Department of Fish and Game. Boise. 372 pp.

Idaho Conservation Data Center, Idaho Department of Fish and Game. April, 1997. Element Occurrence Database. Boise.

McNab, W. H. and P. E. Avers, comps. 1994. Ecological subregions of the United States: Section Descriptions. Administrative Publication WO-WSA-5. Washington, DC: U. S. Department of Agriculture, Forest Service. 267 p.

National Slope Team. no date. Slope wetland model draft. Unpublished document prepared by the National Slope Assessment Team.

Rabe, F. W., C. Elzinga, and R. Breckenridge. 1994.Classification of meandering glide and spring stream natural areas in Idaho. Natural Areas Journal 14(3): 188-202.

Ross, S. H., and C. N. Savage. 1967. Idaho earth science: Geology, fossils, climate, water, and soils. Idaho Bureau of Mines and Geology Idaho Earth Science Series No. 1, Moscow.

U.S. Department of Agriculture, Soil Conservation Service. 1969. Soil survey of Teton Area, Idaho-Wyoming. In cooperation with Idaho and Wyoming Agricultural Experiment Stations. U.S. Government Printing Office, Washington D.C. 95 pp. plus maps.

U.S. Department of Agriculture, Soil Conservation Service. 1991. Soil survey of Blaine County area, Idaho. National Cooperative Soil Survey. U.S. Government Printing Office, Washington D.C. 368 pp. plus maps.

Utah Assessment Team no date. Documentation on slope wetlands functions and operational models. Unpublished document developed by the Utah functional assessment team.

Wiley, K. 1977. A preliminary biophysical inventory and management plan for the Silver Creek Biological Preserve. Unpublished report prepared for The Nature Conservancy. 73 pp.