Yukon Wetlands Bogs - Environment Yukonspectacular flyers, formidable predators, ... 4 dwarf...
Transcript of Yukon Wetlands Bogs - Environment Yukonspectacular flyers, formidable predators, ... 4 dwarf...
Types of Bogs • Open bogs are comprised mostly of sphagnum moss and sparse sedges • Shrubby bogs support low-lying shrubs, bog cranberry, and blueberries • Treed bogs are identified by stunted black spruce with a moss and shrub understory
Yukon WetlandsBogs
BogsBogs 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 • 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
Benefits and Functions • 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
Treed bog, near Ross River—J. Hawkings
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.
Open bog, near Old Crow—J. Hawkings Black spruce drunken forest—Yukon Government
black spruce
Shrubby bog, near Old Crow—J. Hawkings
for more information on wetland conservation visit: www.ducks.ca
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.
Top: Cranberries and lichens—Yukon Government
Middle: Woodland caribou
— C. Eckert
Bottom: Labrador tea—Yukon Government
For centuries people have used bogs to gather food and medicinal ingredients.
1 black spruce
2 bog cranberry
3 sphagnum moss
4 Labrador tea
5 cloudberry
Yukon Wetlands Bogs
Sundew—S. Forest
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Types of Fens • Gramnoid fens are dominated by sedges and are usually the wettest • Shrubby fens contain stunted shrubs such as bog birch and willows interspersed with sedges and buckbean • Treed fens are much drier and contain stunted trees, especially tamarack and sometimes black spruce
Yukon WetlandsFens
FensA fen is a peatland that is influ-enced 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 • Higher diversity of plant species than bogs • Usually covered by sedges, mosses, shrubs, and trees • Tamarack are generally good indicators of treed or shrubby fens
Benefits and Functions • Fens move water and nutrients through the landscape
• Sustain water levels and connectivity of wetlands across the landscape • As peatlands, fens store carbon and reduce the effects of global warming • Help prevent downstream flooding by absorbing precipitation, and excess water from adjacent uplands
Patterned gramnoid fen, Liard region—C. Eckert
Treed fen, near Watson Lake Canada Whiteface—C. Eckert
Shrubby fen, near Meister River—C. Eckert
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 combina-tion of shallow pools, water chemistry, vegetation, and a fish-free environment for species such as the Muskeg Emerald and the Canada Whiteface.
Pools of water that form at the surface of fens are called flarks.
for more information on wetland conservation visit: www.ducks.ca
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.
Sandhill cranes are a common bird species found nesting and feeding in Yukon fens.
Yukon Wetlands Fens
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Sandhill crane—D. Baccus
1 tamarack
2 willow
3 sphagnum moss
4 dwarf bog-rosemary
5 water sedge
6 brown mosses
7 meadow horsetail
8 bog cranberry
9 bog birch
10 black spruce
Top: Red fox—C. Eckert
Middle: Cotton-grass
—A. Aasman
Bottom: Tamarack
water table organic materialmineral soil
Yukon WetlandsMarshes
MarshesMarshes 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
Benefits and Functions • 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 • Moderates flooding and erosion by slowing down water flow • Provide habitat for wildlife species important for trapping, such as muskrat
Types of Marshes • 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
Aquatic Invertebrates 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.
Swallow—J. Jantunen
whirligig beetle leech
freshwater shrimpgiant water bug
caddisfly larva
Freshwater marsh near Pickhandle Lakes—D. van de Wetering
Coastal marsh, Pauline Cove on Herschel Island—P. Sinclair
for more information on wetland conservation visit: www.ducks.ca
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.
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.
Marshes make great outdoor classrooms with an abundance of plants, invertebrates, birds, and mammals.
Mallard ducklings
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2 water sedge
3 small yellow pond-lily
4 clasping leaf pondweed
5 spiked water-milfoil
6 bulrush
7 scouring rush
8 marsh ragwort
Yukon Wetlands Marshes
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Top: Muskrat—J. Jantunen
Middle: Submergent plants—J. Hawkings
Bottom: Emergent plants—J. Hawkings
organic material mineral soil
Osprey—J. Jantunen
Red-necked grebe and pond-lilies—J. Jantunen
Shallow OpenWaterShallow 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.
Slimy Sculpin 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.
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.
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
Benefits and Functions • 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
Pond near the MacMillan River—J. Hawkings
slimy sculpin
Yukon WetlandsShallow Open Water
for more information on wetland conservation visit: www.ducks.ca
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.
Birdwatcher in wetland near Elsa
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2 bulrush
3 scouring rush
4 small yellow pond-lily
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Yukon Wetlands Shallow Open Water
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Top: American wigeon, male
Middle: White-winged scoter, male—J. Jantunen
Bottom: Lesser yellowlegs
—J. Jantunen
Yukon WetlandsSwamps
SwampsSwamps 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 • Trees and shrubs are dominant vegetation
• Trees and shrubs are generally tall due to high nutrient content
• Ground is often hummocky with small pools of water present
Benefits and Functions
• Moderate floods by slowing water flow
• 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 • Vegetation protects shoreline areas from erosion and sedimentation
Willows 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.
Yellow warbler on willow branch— J. Jantunen
Types of Swamps • Thicket swamps are characterized by tall shrubs, like willow • Coniferous swamps are dominated by white or black spruce • Hardwood swamps feature balsam poplar and white birch
Hardwood swamp complex, Peel River
Coniferous swamp, near Liard River
Thicket swamp near Nisutlin River
for more information on wetland conservation visit: www.ducks.ca
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
Swamps provide important riparian habitat for a variety of waterfowl and other wildlife species.
moose—Yukon Government
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Yukon Wetlands Swamps
water table
Top: Lesser scaup, male
Middle: Little brown bat—J. Talerico
Bottom: Milbert’s tortoiseshell
—J. Jantunen
1 tamarack
2 black spruce
3 balsam poplar
4 willow
5 meadow horsetail
6 Labrador tea
7 alder
8 Alaska birch
organic materialmineral 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.