EEB 337H - Families of Vascular Plants 

Tundra, southern coast of Hudson Bay

Tundra is ... treeless. Genera that are trees or large shrubs further south (e.g. Betula, Rhododendron, Salix, below) are represented here by species of much smaller stature. In Ontario, tundra occurs along the coasts of Hudson Bay and James Bay. Much of the herbaceous vegetation consists of sedges and grasses. The weight of the most recent continental ice sheet depressed the land here so that, when the glacier melted, seawater flooded in to create the Tyrell Sea. Since that time the land has been slowly rising, so as to produce the modern shoreline of Hudson and James Bays. Even now isostatic rebound is continuing, as can be seen by the succession of beach ridges that parallels the coastline in the image below.
La Perouse Bay - 32549 Bytes
La Perouse Bay, near Churchill MN. Left: willow thicket with polar bear; photo E. R. Chang - © E. R. Chang 1998. Right: sedge meadow; photo T. Handa - © T. Handa 1998.
Stunted arctic tundra develops in the sheltered depressions between the beach ridges at Cape Henrietta Maria, where Hudson Bay and James Bay meet (Riley 2003).
John Riley, photographer; NRC 2003.

Salix arctica - photo: Dawn Davidson
Salix arctica
; photo D. Davidson - D. Davidson 1998.

Salix reticulata - photo: Dawn Davidson
Salix reticulata; photo D. Davidson - © D. Davidson 1998.
Betula glandulosa - photo: E. R. Chang
Betula glandulosa; photo E. R. Chang - © E. R. Chang 1998.
Polygonum viviparum - photo: E. R. Chang
Polygonum viviparum; photo E. R. Chang - © E. R. Chang 1998.
Rhododendron lapponicum - photo: E. R. Chang
Rhododendron lapponicum; photo E. R. Chang - © E. R. Chang 1998.

The photograph of Cape Henrietta Maria appears in Flora of the Hudson Bay Lowland and its postglacial origin (2003) and is used with permission here. It was taken by John L. Riley and is © the National Research Council of Canada 2003.

Northern Ontario Plant Database

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