Group No.3 Boreal Forest

or Taiga

Boreal forest

Biophysical environmentsBiotic interactionsFire regimes & post-fire successionFloodplain succession & paludificationForest clearance and successionClimate change: natural &

anthropogenic

Boreal forest biome-------

Scandinavia70% Russia70% Alaska50% Canada

Fairbanks

Pr. AlbertKapuskasing

Chicoutimi

Note latitudinal variation

Mean annual snowfall (mm)

Boreal forest zone

Boreal forest Tundra

Permafrostpatchy discontinuous continuous

Mean locationPolar FrontJulyJan

150 240 Mean #d <0°C

treegrowth

pollen/seedviability

120 30 Mean #d >10°C

The boreal forest biome in Canada

Boreal forest

“Taiga”

Trees of the N. American boreal forest

Evergreens

Deciduous

non-accessed

spruce

pine

balsam fir

poplar

birch

other

Boreal forest vegetation types

(North America)

Forest structure Boreal forest Taiga

spruce/birch/pine forest mosaic spruce-lichen woodland

Boreal forest soils

south north

Podzols,

regosols

gleysols, cryosols

Underlain by coarse-textured deposits or bedrock. Well-drained, warm fairly rapidly in summer, more rapid breakdown of organics, strongly-leached, acidic, low nutrient availability.

Underlain by fine-textured deposits / permafrost. Poorly-drained, cold in summer; little microbial activity, slow breakdown of organics, low nutrient availability.

boreal forest taiga

% c

over

0

100

OAe

Bf

OBC

Cg

Forest community segregation in the boreal

forest

site: wet mesic drysoil: gleys podzolsactive: thin (<0.3m) thick (>2m)layer (or no permafrost)organic thick thin layer

blackspruce tamarack

white spruce -birch-aspen-

balsam fir

jack pine

mosses

Floodplain succession( pioneer phase)

Floodplain succession( pioneer phase)

Balsam poplarwhite spruce

herbs

Floodplain succession(climax phase)

mature white spruceon scroll bars