Hudson Bay Lowland

Question 1

Describe how sphagnum moss contributes to the formation of peatlands.

Answer 1

Sphagnum moss grows on water, anchored to sedges
1. Acidifies its environment
2. Locks up nutrients, making the water nutrient-poor
3. Deoxygenates
4. Holds water with unique cell structure - dead cells allow living cells to form their own water supply
These factors, plus the cold, wet environment, make decomposition difficult; in these areas, growth exceeds decomposition. Over time the sphagnum moss forms a thick mat on top of the water, and as it decays, it forms peat soil.

Question 2

What is muskeg?

Answer 2

Wet area of peat > 45cm thick

Question 3

What kinds of plants grow on muskeg?

Answer 3

Colonizers - lichens - when mat becomes thick enough to support plants
Heath (ericaceae) - bog laurel, cranberry, bog rosemary, leatherleaf, labrador tea
Stunted trees - black spruce, tamarack
Carnivorous plants - sundew (great sundew unique to HBL), bladderwort, pitcher plants

Question 4

What features allow a plant to thrive in peatland?

Answer 4

Leathery, evergreen leaves with hairs to prevent desiccation
Features to assist with nutrition, for example:
1. Mycorrhizal associations - fungus which helps the plants absorb nutrients
2. Carnivorous plants which eat insects
3. Root nodules containing nitrogen-fixing bacteria

Question 5

Name the types of carnivorous plants that live in the Husdon Bay Lowland and describe the traps they utilize.

Answer 5

Pitcher plants: pitfall traps - insects slide down and become trapped by water stored at the bottom of the pitcher, water contains digestive enzymes and plant absorbs the nutrients through the cell wall
Sundew: sticky/adhesive traps - modified hairs with glue-producing nodes on the tip
Bladderwort: suction trap - found in aquatic environments

Question 6

The dominant type of shrub in Hudson Bay Lowland

Answer 6

Alders, which have root nodules containing nitrogen-fixing bacteria

Question 7

Trees that grow in layered colonies on hummocks

Answer 7

Stunted black spruce

Question 8

Which has more biodiversity - a peatland, or a black spruce forest - and why?

Answer 8

A peatland has more biodiversity than a black spruce forest. The sphagnum mat in a black spruce forest has become thick enough to support trees, meaning that it has locked up almost all of the water and nutrients. In a peatland, the mat is less developed, leaving enough water and nutrients for other plants to survive. There is also more sunlight due to the lack of a canopy. The sphagnum lawn - the youngest edge of the mat - supports the most plant diversity.

Question 9

Describe the process of lake succession, or lakefill, in the Hudson Bay Lowland

Answer 9

Sedges grow at the edges of a body of water, providing an anchor for sphagnum moss to grow. The sphagnum moss eventually grows to form a mat floating on top of the water. Over thousands of years, the sphagnum and peat will thicken until the mat reaches the bottom of the water, forming a grounded mat. As a peatland becomes a black spruce forest, its biodiversity drops off.

Question 10

Are any continuous forests found in the Hudson Bay Lowland? Why or why not?

Answer 10

Yes - continuous forests can be found at the southern end of the Hudson Bay Lowland. The glaciers left the southern area earlier, meaning a longer period of isostatic rebound.

Question 11

Describe the physical characteristics of the Hudson Bay Lowland.

Answer 11

1. Sedimentary limestone bedrock
2. Flat, discontinuous permafrost with impervious deposits
3. Wet - poor drainage, lots of water
4. Average daily temperature of -3 to -6 degrees.

Question 12

What differentiates a bog and fen?

Answer 12

Usually unclear, aside from one key difference - water flows into a fen from an external source, water only enters a bog through rainfall. Over time they can change from one to the other.

Question 13

Is the black spruce forest the climax of succession in the Hudson Bay Lowland ecosystem? Explain why.

Answer 13

Not necessarily - it is more of a “climax pattern”. Through pallidification - a process in which water is introduced into an ecosystem and water levels rise - a black spruce forest can become a peatland again. Sphagnum moss chokes the spruce trees and overtakes the forest. This is a major contributing factor in the development of peatlands in the Hudson Bay Lowland due to the hypsithermal warming trend, a warming event 5000 to 7000 years ago.

Question 14

What is unique about sphagnum moss?

Answer 14

The structure of sphagnum moss is unique. The lowermost parts of the plant are dead and decomposing. Sphagnum also has two distinct types of cells: normal photosynthesizing cells and retort cells. The retort cells have pores which enable them to soak up water.

Question 15

What is a string bog/ribbed fen and what causes it?

Answer 15

A special formation of peatlands that has the appearance of stripes. A gradual slope causes “ribs” in the moss to run perpendicular to the slope.

Question 16

What species of birds are found in peatlands? Which are indicator species?

Answer 16

Sandhill crane, palm warbler, greater yellowleg (sandpiper)

Indicator species - lesser yellowleg (sandpiper), northern shrike

Question 17

Amphibians found in peatlands

Answer 17

American toad - brightly colours
Spring peeper - very small freeze-tolerant frog
Freeze-tolerant frogs are the dominant group of herps in peatlands

Question 18

Why are rivers important for plants, and what effect do they have on biodiversity in the Hudson Bay Lowlands?

Answer 18

Rivers rise in the spring and recede in the summer, sorting, moving, and depositing material, creating riverbanks with improved drainage and nutrient-density for plants to grow. In the Hudson Bay Lowland, river banks are the areas with the highest level of biodiversity. Boreal forest habitat can be found near rivers, providing areas for boreal forest animals to live.

Question 19

Describe the plants that live on the edges of rivers in the Hudson Bay Lowlands.

Answer 19

Rivers in the HBL are home to calciphilic (calcium-loving) plants that have adapted to the cold - alpine bistort, false (or sticky) asphodel, butterwort (carnivorous, sticky trap), sparrow’s-egg lady’s-slipper (carnivorous, pitfall trap), other orchids

Question 20

What boreal forest species can be found in HBL boreal-like habitat areas?

Answer 20

Shade-loving plants such as bunchberry; black-backed woodpecker, Canada jay, spruce grouse, boreal chickadee, snowshoe hare

Question 21

Name the dominant canopy-forming trees of the HBL rivers’ forest layer?

Answer 21

Poplar, black spruce

Question 22

What is the significance of the presence of boreal-type habitat species in HBL?

Answer 22

Their presence indicates the northern range limit for boreal-type habitat species, where riverbanks in HBL create a habitat similar to the boreal forest

Question 23

What sources of food does the forest habitat provide for boreal-type habitat species?

Answer 23

Spruce grouse and snowshoe hare eat the needles. Red squirrels eat the seeds, stashing the cones in winter. White-winged crossbills eat the seeds using their specialized crossed bill. Predatory animals feed on these small mammals and birds: great grey snowy owl, northern hawk owl, and weasels - fisher, American marten, and wolverines

Question 24

In which physiographic region can you find the Attawapiskat River, and what are some of its interesting characteristics?

Answer 24

Hudson Bay Lowland - glacial striations, steep riverbanks created by the Tyrrel sea

Question 25

What are the physical characteristics of the James Bay region of the HBL?

Answer 25

Salt water diluted by rivers, freezes in winter, salt marshes, mud flats

Question 26

Why is the James Bay region important?

Answer 26

At low tide, the mudflats, which are rich in invertebrates, provide an important source of food for sandpipers and other migratory birds, including the endangered red knot “rufa” subspecies. Salt marshes provide habitat for LeConte’s sparrows and Nelson’s sparrows.

Question 27

James Bay sand colonizer

Answer 27

Beach pea

Question 28

Name two marine animals found in James Bay

Answer 28

Jellyfish and beluga whales

Question 29

Describe the two layers of the HBL river ecological zone, and name the animals and plants found in each.

Answer 29

Tree layer: dominant canopy of poplar and black spruce, northern shade-loving plants such as bunchberry, black-backed woodpecker, spruce grouse, Canada jay, snowshoe hare
Shrub layer: dominant shrub is willow, including wolf willow (not really a willow), orange-crowned warbler, fox sparrow, pine grosbeak