Yukon Wetlands
Bogs
Bogs
Bogs are peatlands that have a
thick layer of poorly decomposed
organic material (peat). Bogs are
raised above the surrounding
ground level. Of all wetlands, bogs
are the most nutrient-poor systems.
They are very widespread across
Canada, particularly in the arctic
and sub-arctic regions.
Identifying Characteristics
• Moisture is received from rain,
snow and fog
• Water table at or near surface
• Nutrient poor
Treed bog, near Ross River—J. Hawkings
• Low diversity of plant species
• Common plants include sphagnum
moss, ground and tree lichens,
low-lying shrubs, and stunted
black spruce
• Deep peat layer formed by slowly
decomposing organic materials
• Acidic environment
Types of Bogs
• Open bogs are comprised mostly of
sphagnum moss and sparse sedges
black spruce
• Shrubby bogs support low-lying
shrubs, bog cranberry, and blueberries
• Treed bogs are identified by stunted
black spruce with a moss and shrub
understory
Benefits and Functions
Drunken Forest
Bogs are commonly associated with
permafrost featuers on the landscape.
Black spruce trees that appear to be
leaning in multiple directions are often an
indication of either melting or heaving
permafrost below the surface. Permafrost
occurs in regions where the soil remains
frozen throughout the year.
• Peatlands store carbon and reduce
the effects of global warming
• Help prevent downstream flooding
by absorbing precipitation
• Support plants commonly used
by people, including cranberries,
blueberries, and Labrador tea
Shrubby bog, near Old Crow—J. Hawkings
Open bog, near Old Crow—J. Hawkings
Black spruce drunken forest
—Yukon Government
Yukon Wetlands
Bogs
1
1 black spruce
3 sphagnum moss
2 bog cranberry
4 Labrador tea
5 cloudberry
4
2
5
3
organic material
water table
mineral soil
Bogs have two distinct peat layers, the top
living layer that can contain and release
large amounts of water to maintain the
water table, and a lower dead layer which
can store large amounts of water. Plants
found in bogs must be very adaptable to
humidity, acidity and nutrient-poor soils.
Bogs are known to be nutrient poor
because minerals are received only by
aerial deposition (pollen, ash, and dust).
Black spruce are often associated with
northern bog systems, however open and
shrubby bogs are also common.
For centuries people
have used bogs
to gather food and
medicinal ingredients.
Top: Cranberries and lichens
—Yukon Government
Middle: Woodland caribou
— C. Eckert
Bottom: Labrador tea
—Yukon Government
Sundew—S. Forest
for more information on wetland conservation visit: www.ducks.ca
Yukon Wetlands
Fens
Fens
A fen is a peatland that is influenced by flowing surface water or
discharged groundwater. The water
moving through fens comes in
contact with mineral soil creating
a more nutrient rich environment
than bogs. Fens vary in wetness
and species diversity, with wetter
fens being richer.
Identifying Characteristics
• Influenced by surface and ground
water flow
• Peat layer greater than 40cm thick
• Water table at or near surface
• Higher nutrient content than bogs
Patterned gramnoid fen, Liard region—C. Eckert
• Higher diversity of plant species
than bogs
Types of Fens
• Usually covered by sedges, mosses,
shrubs, and trees
• Gramnoid fens are dominated by
sedges and are usually the wettest
• Tamarack are generally good
indicators of treed or shrubby fens
• Shrubby fens contain stunted
shrubs such as bog birch and willows
interspersed with sedges and buckbean
Benefits and Functions
• Fens move water and nutrients
through the landscape
• Treed fens are much drier and contain
stunted trees, especially tamarack
and sometimes black spruce
• Sustain water levels and connectivity
of wetlands across the landscape
• As peatlands, fens store carbon and
reduce the effects of global warming
Pools of water that
form at the surface of
fens are called flarks.
Unique Dragonflys
Dragonflies and damselflies are
spectacular flyers, formidable predators,
and eye-catching beauties. The Yukon's
diverse wetlands are home to 40 different
species. Fens offer just the right combination of shallow pools, water chemistry,
vegetation, and a fish-free environment
for species such as the Muskeg Emerald
and the Canada Whiteface.
• Help prevent downstream flooding
by absorbing precipitation, and
excess water from adjacent uplands
Shrubby fen, near Meister River—C. Eckert
Treed fen, near Watson Lake
Canada Whiteface—C. Eckert
Yukon Wetlands
Fens
1
1 tamarack
6 brown mosses
2 willow
7 meadow horsetail
3 sphagnum moss
8 bog cranberry
4 dwarf bog-rosemary
9 bog birch
5 water sedge
10
10 black spruce
2
9
5
4
3
water table
7
6
8
organic material
mineral soil
Sandhill cranes are a
common bird species
found nesting and
feeding in Yukon fens.
Fens are complex ecosystems that
have formed over thousands of years.
Depending on wetness and nutrient
availability, fens are normally categorized
as rich or poor. Poor fens are more similar
to bogs, are nutrient poor, and often
have plants more associated with drier
conditions. Sphagnum mosses and shrubs
are common in poor fens. Rich fens are
more mineral rich and dominated by
sedges and brown mosses.
Top: Red fox
—C. Eckert
Middle: Cotton-grass
—A. Aasman
Bottom: Tamarack
Sandhill crane—D. Baccus
for more information on wetland conservation visit: www.ducks.ca
Yukon Wetlands
Marshes
Marshes
Marshes are often a transition zone
between open water and shorelines
of lakes and river systems. They are
shallow wetlands with water levels
that fluctuate seasonally. Marshes
receive water from precipitation,
groundwater, and stream inflow.
Identifying Characteristics
• Permanently or seasonally flooded
• Displays an abundance of submerged
and emergent aquatic vegetation
• High nutrient content and low acidity
• Plants are adapted to fluctuating
water levels
• High diversity of aquatic invertebrates
• Commonly associated with shallow
open water wetlands
Freshwater marsh near Pickhandle Lakes—D. van de Wetering
Benefits and Functions
Aquatic Invertebrates
• Plants filter and trap pollutants from
the water
• Great place for wildlife viewing
• Provides food and shelter for many
different species of birds and mammals
giant water bug
freshwater shrimp
whirligig beetle
leech
Aquatic Invertebrates are an important part
of the food chain for birds and fish. They can
be used as an indicator for water quality.
For example, caddisly larvae are present in
healthy water systems.
• Moderates flooding and erosion by
slowing down water flow
• Provide habitat for wildlife species
important for trapping, such as muskrat
Types of Marshes
caddisfly larva
• Freshwater marshes are very
productive and a variety of plants
thrive on the high nutrient levels
• Saltwater marshes are normally
associated with coastlines and fewer
plants can tolerate the saline conditions
Coastal marsh, Pauline Cove on Herschel Island—P. Sinclair
Swallow—J. Jantunen
Yukon Wetlands
Marshes
1 slough grass
5 spiked water-milfoil
2 water sedge
6 bulrush
3 small yellow pond-lily
7 scouring rush
4 clasping leaf pondweed
8 marsh ragwort
1
8
2
6
3
7
4
5
water table
organic material
Ducklings face extraordinary odds to
survive different predators. Foxes and
coyotes stalk ducklings at the water’s edge,
northern pike ambush from below, and
gulls and raptors swoop from above.
Marsh vegetation provides excellent cover
for ducklings to escape these predators.
Marshes make great
outdoor classrooms with
an abundance of plants,
invertebrates, birds, and
mammals.
Mallard ducklings
mineral soil
Emergent and submergent plants
including rushes, sedges, and milfoil
grow in flooded and exposed marsh soil.
Floating vegetation like pond-lilies are
also present. Vegetation is arranged in
zones delineated by water depth, water
chemistry or disturbance.
Top: Muskrat
—J. Jantunen
Middle: Submergent plants
—J. Hawkings
Bottom: Emergent plants
—J. Hawkings
for more information on wetland conservation visit: www.ducks.ca
Yukon Wetlands
Shallow Open Water
Shallow Open
Water
Shallow waters are distinct
wetlands that represent a
transition from marshes to
deeper aquatic ecosystems such
as lakes or rivers. They include
shallow lakes and ponds, as well
as wetlands found beside rivers,
coastlines and shorelines.
Identifying Characteristics
• Water is less than 2 meters deep
• Usually permanently flooded
• Contains submerged vegetation and
floating-leaved plants like pond-lilies
• Less than 25% of the wetland area
is covered by emergent or submergent
vegetation
Pond near the MacMillan River—J. Hawkings
Slimy Sculpin
Benefits and Functions
Slimy sculpins are widespread and live at
the bottoms of lakes and streams. They
are one of the few fish species in the
Yukon that spend their entire life in the
same location. Because of this, they can
be used as indicators of wetland health.
• Provides conditions for dense
submergent vegetation
• Habitat for a variety of aquatic
insects and fish
• Provides food for many different birds
• Can recharge groundwater supplies
Osprey—J. Jantunen
slimy sculpin
Red-necked Grebe and Pond-lilies
Red-necked grebes use floating vegetation like pond-lilies
to build their nests, anchoring them to emergent vegetation.
Both adults take responsibility for tending to nests of 4-6
eggs and raising the young. Parents carry chicks on their
backs soon after they hatch.
Red-necked grebe and pond-lilies
—J. Jantunen
Yukon Wetlands
Shallow Open Water
1 water sedge
2 bulrush
3 scouring rush
4 small yellow pond-lily
5 spike water-milfoil
1
2
3
4
5
water table
mineral soil
Waterfowl are most commonly associated
with shallow open water as a place to feed
and raise young, but this habitat is also
important for a diversity of other birds.
Raptors such as bald eagles and ospreys
use open water as a place to hunt. This
habitat is also important for lesser
yellowlegs, a species of shorebird which
feeds on small aquatic insects and worms
in the substrate.
Another species, Bonaparte’s gull,
commonly nests in colonies at the tops
of spruce trees near open water.
Shallow open water
provides the opportunity
to view a variety of birds
and wildlife.
Top: American wigeon, male
Middle: White-winged scoter, male
—J. Jantunen
Bottom: Lesser yellowlegs
—J. Jantunen
Birdwatcher in wetland near Elsa
for more information on wetland conservation visit: www.ducks.ca
Yukon Wetlands
Swamps
Swamps
Swamps are often a transition
between upland forest and other
wetland types. They are normally
associated with river floodplains,
lakes, and ponds. Swamps are
typically dominated by tall trees
and shrubs, with densities greater
than 60%. They can occur in either
mineral or organic soil.
Identifying Characteristics
• Usually found adjacent to rivers,
lakes, and ponds
• Stagnant or slow-flowing water
• Fluctuating water levels; sometimes dry
for years before being flooded again
• Saturated soils are rich in nutrients
and decomposed woody material
Thicket swamp near Nisutlin River
• Trees and shrubs are dominant
vegetation
Types of Swamps
• Trees and shrubs are generally tall due
to high nutrient content
• Thicket swamps are characterized
by tall shrubs, like willow
• Ground is often hummocky with small
pools of water present
• Coniferous swamps are dominated
by white or black spruce
Benefits and Functions
• Hardwood swamps feature
balsam poplar and white birch
Willows
• Moderate floods by slowing water flow
Willows are found in very moist soil and
like to be seasonally flooded. There are
many different willow species in the Yukon.
They are a primary food source for moose
and provide nesting habitat for a number
of bird species. Traditionally, humans have
harvested willows for medicine and
craft-making.
• Fertile soils support a diversity of
trees, shrubs, and other plants
• Snags, standing dead trees, provide
homes for cavity-nesting species like
goldeneye, American kestrel, and
northern flicker
• Recycle nutrients from decaying
plant matter
Hardwood swamp complex, Peel River
Yellow warbler on willow branch
— J. Jantunen
• Vegetation protects shoreline areas
from erosion and sedimentation
Coniferous swamp, near Liard River
Yukon Wetlands
Swamps
1
2
3
1 tamarack
5 meadow horsetail
2 black spruce
6 Labrador tea
3 balsam poplar
7 alder
4 willow
8 Alaska birch
4
8
7
6
5
water table
organic material
Swamps are bursting with bugs like
mosquitoes, beetles, and caddisflies. Little
Brown Bats, common to the Yukon, can’t
resist this bounty of food and often make
their homes close to water in places like
hollow logs and trees. Most feeding
activity occurs within two meters of the
mineral soil
water’s surface and bats will snatch the
insects either from the air or from the
water. Bats are a migratory species that
arrive in the Yukon in June, some going
as far north as Dawson City.
Top: Lesser scaup, male
Swamps provide important
riparian habitat for a
variety of waterfowl and
other wildlife species.
moose—Yukon Government
Middle: Little brown bat
—J. Talerico
Bottom: Milbert’s tortoiseshell
—J. Jantunen
for more information on wetland conservation visit: www.ducks.ca