KEY TO THE WETLANDS
Wayne R. Ferren Jr.[1], Peggy L. Fiedler
[2], Robert L. Leidy
[3]
To facilitate the identification and classification of wetlands of the central
and southern California coast and coastal watersheds, we have constructed
dichotomous keys for the systems, subsystems and classes of wetlands. These
keys are modifications of those presented by Cowardin et al. (1979). Keys to
several subsystems that are deepwater habitats rather than wetlands are
included for the purpose of comparison. Various classes for some systems are
not included here because they do not occur in coastal central and southern
California. Conversely, we have expanded the classification and accompanying
keys when wetlands have been found to occur in California that are not
represented in the Cowardin et al. hierarchy. Refer to Section III,
Classification, for an explanation of the methodology for wetland
identification presented herein.
Water regime of habitats is influenced (at least one episode seasonally or
enough to establish functions of system related habitats) by oceanic tides;
salinity due to ocean-derived salts (i.e., ocean-derived sodium chloride) is
0.5 ppt (parts per thousand) or greater:
Habitats are semi-enclosed by land, but are open to, partly obstructed from, or
have sporadic access to the ocean and oceanic tides; halinity (concentration of
sodium chloride) can vary widely within or between examples because of
evaporation or because of mixing with fresh water from runoff from land . . . ESTUARINE SYSTEM
Habitats are not obstructed, or have minor obstruction, to the open ocean;
halinity usually euhaline or temporarily or seasonally less near the mouths of rivers . . . MARINE SYSTEM
Water regime is not influenced by oceanic tides, or if water regime is
influenced by ocean tides the salinity is less than 0.5 ppt (i.e., the
approximate background salinity of runoff from watersheds):
Emergent mosses, persistent emergent vascular plants, shrubs, or trees cover
30% or more of the habitat; if nonpersistent emergents, other non-plant
organisms, or no organisms dominate, the wetland is not a riverine nor a
lacustrine habitat . . . PALUSTRINE SYSTEM
Emergent mosses, persistent emergent vascular plants, shrubs, or trees cover
less than 30% of the substrate, but nonpersistent emergents may be widespread
seasonally:
Habitat situated in a channel or along a channel shore; water when present is
flowing (e.g., streams and rivers and the vegetation when present is
nonpersistent) . . . RIVERINE SYSTEM
Habitat situated in a basin or on level but sloping ground; water when
present is usually not flowing, but if in a channel the vegetation is
persistent or nonpersistent:
Habitat area is generally 8 hectares (20 acres) or greater (e.g., large
lakes) . . . LACUSTRINE SYSTEM
Habitat area is less than 8 hectares (e.g., ponds and pools):
Waved-formed or bedrock-shoreline habitat feature is present, or water depth is 2 meters (6 feet) or greater . . . LACUSTRINE SYSTEM
No wave-formed or bedrock-shoreline habitat feature is present, and water is less than 2 meters deep . . . PALUSTRINE SYSTEM
Marine substrate is continuously submerged (i.e., subtidal habitats, which are
not included in this volume . . . DEEPWATER HABITAT SUBSYSTEM
During the growing season of most years, areal cover by vegetation is less
than 30%:
Substrate formed by the colonization of sedentary (i.e., attached)
invertebrates (e.g., corals, tube worms). . . Reef Class
Substrate composed of rock or sediment; often colonized by invertebrates but
not formed of sedentary types:
Substrate of bedrock, boulders, rubble, or combinations of these covering
70% or more of the habitat . . . Rock Bottom Class
Substrate of organic material, mud, sand, gravel, or cobbles with less than
70% areal cover of bedrock, boulders, or rubble . . . Unconsoliated
Bottom Class
During the growing season of most years, percentage of habitat covered by
vegetation (e.g., algae and marine aquatic flowering plants such as
Zostera) is 30% or greater . . . Aquatic Bed Class
Marine substrate is at least irregularly exposed and flooded by oceanic tides,
or receives wave splash . . . INTERTIDAL SUBSYSTEM
During the growing season of most years, areal cover by vegetation (algae and
marine flowering plants such as Phyllospadix) is greater than
30% . . . Aquatic Bed Class
During the growing season of most years, areal cover by vegetation is less
than 30%:
Substrate is formed by the colonization of sedentary invertebrates (e.g.,
mussels) . . .Reef Class
Substrate composed of rock or sediment; often inhabited by invertebrates but
not formed by the colonization of sedentary types:
Substrate of bedrock, boulders, rubble, or combinations of these covering
70% or more of the habitat . . . Rocky Shore Class
Substrate of organic material, mud, sand, gravel, or cobbles with less than
70% areal cover of bedrock, boulders, or
rubble . . . Unconsolidated Shore Class
Estuarine substrate is continuously submerged (i.e., subtidal habitats,
which are not included in this volume, except where emergent species dominate
in subtidal
channels . . . DEEPWATER HABITAT SUBSYSTEM
During the growing season of most years, areal cover by vegetation is less
than 30%:
Substrate formed by the colonization of sedentary (i.e., attached)
invertebrates (e.g., mussels, oysters) . . . Reef Class
Substrate composed of rock or sediment; often colonized by invertebrates but
not formed of sedentary types:
Substrate of bedrock, boulders, stones, or combinations of these covering
70% or more of the habitat . . . Rock Bottom Class
Substrate of organic material, mud, sand, gravel, or cobbles with less than
75% areal cover of bedrock, boulders, or
rubble . . . Unconsoliated Bottom Class
During the growing season of most years, percentage of habitat covered by
vegetation (e.g., algae and estuarine aquatic flowering plants such as
Ruppia) is 30% or greater . . . Aquatic Bed Class
Estuarine substrate is at least irregularly exposed and flooded by oceanic
tides . . . INTERTIDAL SUBSYSTEM
During the growing season of most years, areal cover by vegetation is less than 30%:
Substrate formed by the colonization of sedentary invertebrates (e.g.,
mussels) . . . Reef Class
Substrate composed of rock or sediment; often inhabited by invertebrates but
not formed by the colonization of sedentary types:
Habitat contained within a channel bed . . . Streambed Class
Habitat along a shoreline:
Substrate of bedrock, boulders, rubble, or combinations of these
covering 70% or more of the habitat . . . Rocky Shore
Class
Substrate of organic material, mud, sand, gravel, or cobbles with less
than 70% areal cover of bedrock, boulders, or rubble . . . Unconsolidated
Shore Class
During the growing season of most years, percentage of area covered by
vegetation (e.g., algae, aquatic and emergent vascular plants, or shrubs) is 30% or greater:
Vegetation composed predominantly by macrophytic algae . . . Aquatic Bed
Class
Vegetation composed predominantly of vascular species:
Vegetation herbaceous:
Vegetation tidally-submerged rooted-aquatic, floating-leaved, or
floating types (e.g., Ruppia, Potamogeton, Lemna) . . . Aquatic
Bed Class
Vegetation emergent types:
During the growing season of most years, the vegetation is composed largely of pioneering annuals and seedlings of perennials that occur at the time of substrate exposure:
Vegetation occurs on unconsolidated bottom or bed
habitats . . . Unconsolidated Bottom (Vegetated) Class
Vegetation occurs on unconsolidated shore or bank habitats . . . Unconsolidated Shore (Vegetated) Class
During most years, the vegetation is composed largely of persistent species that dominant the substrate (e.g.,Salicornia, Scirpus, Spartina) . . . Emergent Wetland Class
Vegetation shrubs or trees:
Dominant plants less than 5 meters (15 feet) tall and composed of
shrubs or stunted trees . . . Scrub/Shrub Wetland
Class
Dominant plants 5 meters tall or taller (does not occur in Calif.) . . . Forested Wetland Class
KEY TO THE RIVERINE SUBSYSTEMS AND CLASSES
Water gradient is low and under the influence of oceanic tides (there are no
examples of this subsystem in the study area, but there are in large river
systems to the north) . . . TIDAL SUBSYSTEM
Substrates are continuously submerged (i.e., subtidal habitats):
During the growing season of most years, areal cover by vegetation is less
than 30%:
Substrate of bedrock, boulders, rubble, or combinations of these covering
70% or more of the habitat . . . Rock Bottom Class
Substrate of organic material, mud, sand, gravel, or cobbles with less than
70% areal cover of bedrock, boulders, or
rubble . . . Unconsoliated Bottom Class
During the growing season of most years, percentage cover by vegetation (e.g.,
algae and submerged aquatic vascular plants such as Potamogeton,
Zannichellia, Elodea) is 30% or greater . . . Aquatic
Bed Class
Substrates are at least irregularly exposed and flooded by oceanic tides
(i.e., intertidal habitats):
During the growing season of most years, areal cover by vegetation is less
than 30%:
Substrate of bedrock, boulders, rubble, or combinations of these covering
70% or more of the substrate . . . Rocky Shore Class
Substrate of organic material, mud, sand, gravel, or cobbles with less than
70% areal cover of bedrock, boulders, or rubble . . . Unconsoidated
Shore Class
During the growing season of most years, percentage of area covered by
herbaceous vegetation (e.g., algae, aquatic and emergent vascular plants) is
30% or greater:
Vegetation tidally-submerged rooted aquatic, floating-leaved, or floating
types (e.g., Zannichellia, Najas,
Lemna) . . . Aquatic Bed Class
Vegetation intertidal, non-persistent emergent types (e.g Sagittaria,
Isoetes, Elatine) . . . Emergent Wetland Class
Water gradient is low, high, or intermittent, but there is no influence from
oceanic tides:
Water flows in the channel for only part of the year; when water is not
flowing surface water may be absent, or water may occur as isolated
pools . . . INTERMITTENT
SUBSYSTEMS
Channel occurs within a relatively high gradient (4-10%), where flows are
often flashy and closely tied to specific rainfall events, and is entrenched
with steep banks and poorly defined floodplains . . . UPPER
INTERMITTENT SUBSYSTEM
During the growing season of most years, areal cover by vegetation is less
than 30% . . .
During the growing season of most years, percentage of area covered by
vegetation is 30% or greater, composed largely of pioneering annuals and
seedlings of perennials that occur at the time of substrate
exposure . . . Streambed (Vegetated) Class
Channel occurs within a depositional landform, with a moderate gradient
(1.5-4%) and low sinuosity, and is slightly entrenched . . . MID
INTERMITTENT SUBSYSTEM
During the growing season of most years, areal cover by vegetation is less
than 30% . . .
During the growing season of most years, percentage of area covered by
vegetation is 30% or greater, composed largely of pioneering annuals and
seedlings of perennials that occur at the time of substrate
exposure . . . Streambed
(Vegetated) Class
Channel occurs within a depositional landform with a low gradient (1.5% or
less), where the floodplain is moderate to well developed, the valley only
slightly confined, and the channel only slightly
entrenched . . . LOWER INTERMITTENT SUBSYSTEM
During the growing season of most years, areal cover by vegetation is less
than 30% . . . Streambed
Class
During the growing season of most years, percentage of area covered by
vegetation is 30% or greater, composed largely of pioneering annuals and
seedlings of perennials that occur at the time of substrate
exposure . . . Streambed (Vegetated) Class
Some water flows in the channel throughout the year . . . PERENNIAL
SUBSYSTEMS
Channel gradient is high (4-10%) and water velocity is at least seasonally or
temporarily fast;substrates consist of rock, cobbles, or gravel with patches
of sand; a floodplain is usually lacking or poorly developed . . . UPPER
PERENNIAL SUBSYSTEM
During the growing season of most years, areal cover by vegetation is less
than 30%:
Water regimes include permanently or semi-permanently flooded and
intermittently exposed; substrate is usually not a soil; bottoms and
beds:
Substrate of bedrock, boulders, rubble, or combinations of these covering 70% or more of the habitat . . . Rock
Bottom Class
Substrate of sand, gravel, or cobbles with less than 70% areal cover of bedrock, boulders, or rubble . . . Unconsolidated Bottom
Class
Water regimes include seasonally flooded, temporarily flooded,
intermittently flooded, saturated, or artificially flooded; shores and
banks:
Substrate of bedrock, boulders, rubble, or combinations of these covering 70% or more of the habitat . . . Rocky Shore Class
Substrate of sand, gravel, or cobble with less than 70 % areal cover of bedrock, boulders, or rubble . . . Unconsolidated Shore
Class
During the growing season of most years, percentage of area covered by
herbaceous vegetation is 30% or greater:
Vegetation generally permanently-flooded algae, rooted aquatic,
floating-leaved, or floating types . . . Aquatic Bed Class
Vegetation dominated by nonpersistent emergent types:
During the growing season of most years, vegetation is composed largely of nonpersistent pioneering annuals, nonpersistent perennials, and seedlings of perennials that occur at the time of substrate exposure:
Vegetation occurs on exposed, unconsolidated bottom or bed
habitats . . . Unconsolidated Bottom (Vegetated) Class
Vegetation occurs on exposed, unconsolidated shore or bank
habitats . . . Unconsolidated Shore (Vegetated) Class
During most years, vegetation is composed largely of nonpersistent
perennials that dominate the substrate or flooded riverine
habitat . . . Emergent Wetland Class
Channel gradient is moderate (1.5-4%) and sinuosity low, and occurs in a
depositional and form; substrate is variable but dominated by cobbles, gravel,
and sand . . . MID PERENNIAL SUBSYSTEM
During the growing season of most years, areal cover by vegetation is less
than 30%:
Water regimes include permanently or semi-permanently flooded and
intermittently exposed; substrate is usually not a soil; bottoms and
beds:
Substrate of bedrock, boulders, rubble, or combinations of these covering 70% or more of the habitat . . . Rock Bottom Class
Substrate of organic material, mud, sand, gravel, or cobbles with less than 70% areal cover of bedrock, boulders, or rubble . . . Unconsolidated Bottom Class
Water regimes include seasonally flooded, temporarily flooded,
intermittently flooded, saturated, or artificially flooded; shores or
banks:
Substrate of bedrock, boulders, rubble, or combinations of these covering 70% or more of the habitat . . . Rocky
Shore Class
Substrate of organic material, mud, sand, gravel, or cobbles with less than 70% areal cover of bedrock, boulders, or rubble . . . Unconsolidated Shore Class
During the growing season of most years, percentage of area covered by
herbaceous vegetation (e.g., algae, submerged aquatic and nonpersistent
emergent vascular plants) is greater than 30%:
Vegetation generally permanently-flooded algae, rooted aquatic,
floating-leaved, or floating types (e.g., Potamogeton,
Lemna)Aquatic Bed Class
Vegetation dominated by nonpersistent emergent types:
During the growing season of most years, vegetation is composed largely of nonpersistent pioneering annuals, nonpersistent perennials, and
seedlings of perennials that occur at the time of substrate exposure:
Vegetation occurs on exposed, unconsolidated bottom or bed habitats . . . Unconsolidated Bottom (Vegetated) Class
Vegetation occurs on exposed, unconsolidated shore or bank
habitats . . . Unconsolidated Shore (Vegetated) Class
During most years, vegetation is composed largely of nonpersistent perennials that dominate the substrate or flooded riverine habitat . . . Emergent Wetland Class
Channel gradient (1.5% or less) and water velocity are low; substrates are
mostly sand and mud; a floodplain is often well developed . . . LOWER
PERENNIAL SUBSYSTEM
During the growing season of most years, areal cover by vegetation is less
than 30%:
Water regimes include permanently or semi-permanently flooded and
intermittently exposed; substrate is usually not a soil; bottoms and
beds:
Substrate of bedrock, boulders, rubble, or combinations of these covering 70% or more of the habitat . . . Rock
Bottom Class
Substrate of organic material, mud, sand, gravel, or cobbles with less than 70% areal cover of bedrock, boulders, or rubble . . . Unconsolidated Bottom Class
Water regimes include seasonally flooded, temporarily flooded,
intermittently flooded, saturated, or artificially flooded; shores and
banks:
Substrate of bedrock, boulders, rubble, or combinations of these covering 70% or more of the habitat . . . Rocky
Shore Class
Substrate of organic material, mud, sand, gravel, or cobbles with less than 70% areal cover of bedrock, boulders, or rubble . . . Unconsolidated Shore Class
During the growing season of most years, percentage of area covered by
herbaceous vegetation (e.g., algae, submerged aquatic and nonpersistent
emergent vascular plants) is greater than 30%:
Vegetation generally permanently-flooded algae, rooted aquatic,
floating-leaved, or floating types (e.g., Potamogeton, Lemna) . . . Aquatic Bed Class
Vegetation dominated by nonpersistent emergent types:
During the growing season of most years, vegetation is composed
largely of nonpersistent pioneering annuals, nonpersistent perennials,
and seedlings of perennials that occur at the time of substrate
exposure:
Vegetation occurs on exposed, unconsolidated bottom or bed habitats . . . Unconsolidated Bottom (Vegetated) Class
Vegetation occurs on exposed, unconsolidated shore or bank
habitats . . . Unconsolidated Shore (Vegetated) Class
During most years, vegetation is composed largely of nonpersistent perennials that dominate the substrate or flooded riverine habitat . . . Emergent Wetland Class
KEY TO THE LACUSTRINE SUBSYSTEMS AND CLASSES
All habitats (i.e., deepwater habitats) in a lake extending below a depth of 2
meters (6.6 feet) below low water or below the maximum extent of nonpersistent
emergent plants, if these grow below 2 meters (all such habitats are excluded
from this volume, but are included in the key for the purpose of
comparison . . . LIMNETIC SUBSYSTEM
During the growing season of most years, areal cover by vegetation (i.e.,
submerged rooted-vascular, floating-leaved, and floating such as Najas,
Potamogeton, Myriophyllum) is 30% or
greater . . . Aquatic Bed Class
During the growing season of most years, areal cover by vegetation is less
than 30%:
Substrate of bedrock, boulders, rubble, or combinations of these covering 70%
or more of the habitat . . . Rock Bottom Class
Substrate of organic material, mud, sand, gravel, or cobbles with less than
70% areal cover of bedrock, boulders, or rubble . . . Unconsolidated Bottom Class
All habitats (i.e., wetlands) in a lake extending from the shoreline boundary
of the system to a depth of 6 meters (6.6 feet) below low water or to the
maximum extent of nonpersistent emergent plants, if these grow at depths
greater than 2 meters . . . LITTORAL SUBSYSTEM
During the growing season of most years, areal cover by vegetation is less
than 30%:
Water regimes include permanently or semi-permanently flooded and
intermittently exposed; substrate is usually not a soil:
Substrate of bedrock, boulders, rubble, or combinations of these covering
70% or more of the habitat . . . Rock Bottom Class
Substrate of organic material, mud, sand, gravel, or cobbles with less than
70% areal cover of bedrock, boulders, or rubble . . . Unconsoliated
Bottom Class
Water regimes include seasonally flooded, temporarily flooded, intermittently
flooded, saturated, or artificially flooded:
Substrate of bedrock, boulders, rubble of combinations of these covering 70%
or more of the habitat . . . Rocky Shore Class
Substrate of organic material, mud, sand, gravel, or cobbles with less than
70% areal cover of bedrock, boulders, or
rubble . . . Unconsoidated Shore Class
During the growing season of most years, percentage of area covered by
herbaceous vegetation (e.g., algae, submerged aquatic and nonpersistent
emergent vascular plants) is 30% or greater:
Vegetation generally consists of algae, submerged rooted aquatic,
floating-leaved, or floating types (e.g., Najas, Potamogeton, Myriophyllum) . . . Aquatic Bed Class
Vegetation dominated by nonpersistent emergent types:
During the growing season of most years, vegetation is composed largely of
nonpersistent pioneering annuals, nonpersistent perennials, and seedlings of
perennials that occur at the time of substrate exposure:
Vegetation occurs on exposed, unconsolidated bottom or bed habitats . . . Unconsolidated Bottom (Vegetated) Class
Vegetation occurs on exposed, unconsolidated shore or bank habitats . . . Unconsolidated Shore (Vegetated) Class
During most years, vegetation is composed largely of nonpersistent
perennials that dominate the substrate or flooded littoral habitat . . . Emergent Wetland Class
KEY TO THE PALUSTRINE CLASSES (there are no subsystems)
During the growing season of most years, areal cover by vegetation is less than
30%:
Water regimes include seasonally flooded, temporarily flooded, saturated, or
artificially flooded; substrate is often a soil . . . Unconsolidated Shore
Class
Water regimes include permanently or semipermanently flooded or intermittently
exposed; substrate is usually not a soil:
Substrate of bedrock, boulders, rubble, or combinations of these covering 70%
or more of the habitat . . . Rock Bottom Class
Substrate of organic material, mud, sand, gravel, or cobbles with less than
70% areal cover of bedrock, boulders, or rubble . . . Unconsolidated Bottom Class
During the growing season of most years, percentage of area covered by
vegetation is 30% or greater:
Vegetation composed predominantly of nonvascular plants (e.g., algae or
bryophytes):
Vegetation predominantly macrophytic algae, mosses, or lichens in water or
the splash zones of shores . . . Aquatic Bed Class
Vegetation predominantly mosses or lichens usually growing on organic soils
and always outside the splash zone of shores . . . Moss-Lichen Wetland Class
Vegetation composed predominantly of vascular plant species:
Vegetation herbaceous:
Vegetation generally consists of submerged rooted aquatic, floating-leaved,
or floating types (e.g., Najas, Potamogeton, Myriophyllum) . . . Aquatic Bed Class
Vegetation dominated by emergent types:
Vegetation composed of pioneering annuals, nonpersistent perennials, or seedlings of perennials that often are not hydrophytes and occur only at the time of substrate exposure:
Vegetation occurs on exposed, unconsolidated bottom or bed
habitats . . . Unconsolidated Bottom (Vegetated) Class
Vegetation occurs on exposed, unconsolidated shore or bank
habitats . . . Unconsolidated Shore (Vegetated) Class
Vegetation predominantly perennials or nonpersistent hydrophyte species occurring in natural, restored, or recreated habitats . . . Emergent
Wetland Class
Vegetation shrubs or trees:
Dominants plants generally less then 5 meters (15 feet)
tall . . . Scrub-shrub Wetland Class
Dominants plants generally 5 meters (15 feet) tall or
taller . . . Forested Wetland Class