The Hudson Bay Lowlands Flashcards
What are the northern and southern limits of the HBL?
Northern limit=tree line with continuous canopy forest, southern limit= boreal forest
What is the HBL underlain by?
sedimentary limestone
What is the average daily temperature?
-3 to -6 degrees C which = short growing season. Discontinous permafrost
What are the dominant habitats in the HBL?
Peatlands, red sphagnum moss is a dominant moss that colonizes wetlands and creates peatlands.
What is it called if the Peat> 45cm thick and wet
muskeg. The HBL is one of the largest expanses in the world of Muskeg
Stunted black spruce and tamarack are not dwarfs in the HBL, What are they?
they are stunted in growth form
What are the two major categories of peatlands?
Bogs: a true bog receives water and nutrients only by rainfall and are dominated by sphagnum moss.
Fens: receive nutrients from flowing groundwater such as streams and are often sedge dominated.
How do peatlands form?
First there is water left by the melting glaciers, plants grow at the edge of the water in a form called lakefill, sedges colonize and grow out into the water, sphagnum moss then starts growing around the sedges
Sphagnum moss
is one of the most powerful plants in Ontario, it can grow on top of water and it can grow on top of itself.
Sphagnum moss modifies the environment making it more acidic, more nutrient poor, and oxygen deprived. It provides its own water because it is built like a sponge.
Peatland mosses have another unusual feature they form the soil. Slowly the mat grows thicker and spreads, choking the water the lower portion of the moss mat dies and more sphagnum grows on top of it
Heath plants
Dominant group of plants in bogs, have mycorrhizal associations on their roots. Examples: bog laurel, cranberry, bog rosemary, leatherleaf.
What are the three types of carnivorous plants?
Pit fall traps (pitcher plants, Suction traps (bladderwort) and adhesive traps (sun dew)
Eventually the moss fills into the bottom of the pond, trees grow larger on the top of the of the grounded mat, what kind of forests form?
Black spruce forest forms
As a peatland mat _______, diversity ___________
increases; decreases
What does the youngest edge of the mat do?
Its called the sphagnum lawn and it supports the greatest diversity of plants (most of the carnivorous plants grow here)
What is paludification?
An important/common way the peatlands are formed in the HBL. Water is coming in and the habitat is changing and forming.
What’s a climax pattern?
its a general habitat type/ various habitat types that occur during different conditions throughout different time periods.
Shallow ponds
American toad (not freeze tolerant so they burrow into the ground and this is when the discontinuous permafrost benefits them), spring peepers, sandhill cranes, Lesser yellowlegs nest only in HBL,
The stunted spruce provide habitat for:
Birds, northern shrikes nest in the HBL muskeg in the summer they are found primarily in the HBL could be an indicator species
Why are rivers an important habitat?
They move sort and deposit material creating drier substrates for plants. Rising water levels create raise banks along their shores which allows for a greater diversity of plants and animals in the HBL bc the sphagnum moss doesnt dominate here which means access to calcium.
Examples of calciphillic plants that grow on the shoreline of HBL
Alpine Bistort and False asphodel, Butterwort is a northern carnivorous plant that likes calcium, and many kinds of orchids grow on the shoreline like sparrows egg lady slipper.
Birds in the HBL
Orange warbler , Fox sparrow, Pine grosbeak (finch), Black backed woodpecker (not an indicator, found in coniferous trees not in muskeg), Gray jay (in coniferous not all through muskeg, stores food) Spruce grouse
Snowshoe hare
In the HBL, eats spruce bark/needles
What animals eat the seed from spruce cones
white winged cross bills specialized for eating seeds, red squirrels
Hudsonian godwit
indicator species
Maritime plants and animals
Colonizes sand on the edge of the ocean: Beach pea (also grows on shores/sandy area of James bay), jellyfish
HBL is flat with one major exception, what is it?
The sutton hills/ridges: bery new habitat, precambrian (mostly granite), Disjunct populations of plants like rock polypody, greenland sandwort, and alpine saxifrage.
Why is there a lot of relief to the south of the HBL?
The Canadian shield
