UNIT 3 - FORESTRY

TOPIC 5 – THE BOREAL FOREST

LOCATION Boreal Forests are also known

as TAIGA forests

What portion of forests are BOREAL?

Boreal forests are CIRCUMPOLAR, meaning they circle the earth, spanning the top of Northern Europe, North America, and Asia (Called the “great green scarf” the Earth)

82 % of all Canadian Forests are boreal (Largest Canadian Biome)

100 % of NL forests are boreal

CLIMATE Coldest biome on Earth other

than the tundra Latitude is 50-60 degrees north

of equator Long, cold winters lasting 5-6

months of the year Short, warm summers Precipitation is generally snow Temperatures:

–50 0C to 300C throughout the year

average is less than 10 0C for eight or more months of the year

GROWTH RATE The Boreal forest is the SLOWEST

GROWING FOREST on EARTH WHY?

Shoot/root growth does not occur until temperature is high enough

Short Growing Season – 130 days

Low decomposition rate due to cold temperatures, so nutrient levels in soil are low

Extreme weather is common, killing buds and reducing growth

Cold snaps during growth season can reduce growth for the next season

SOIL CONDITIONS

SOIL is THIN(SHALLOW).

Soils is ACIDIC Due to decomposing needles

Soil has LOW DRAINAGE Evergreens provide permanent

shade, so soil is often waterlogged as a result.

Soils is NUTRIENT-POOR Decomposers are slower in cold,

acidic soil Waxy coating of evergreens

makes for a slower decomposition rate

BIODIVERSITY On a species level, it the LEAST BIODIVERSE

of all forest types Sometimes called the “spruce-moose” forest! Why?

With colder temperatures, and slower decomposition rates, ENERGY AVAILABILITY IS LOW

Recall the FLORA means “plants” and FAUNA means “animals”

BOREAL FOREST FLORA Boreal forests are mostly CONIFEROUS, with a

smaller portion of DECIDUOUS TREES Most common trees are coniferous softwoods

BLACK SPRUCE and BALSAM FIR. Other softwoods include Eastern larch and

pine. The smaller portion deciduous hardwoods

include white birch and trembling aspen.

BALSAM FIR Used in NL for pulp and

lumber Most abundant tree on the

island, 2nd most abundant in Labrador

At maturity, about 12-15 m in height meters in height and 30-50 cm in diameter

Can reach ages of 70-100 yrs old

Favourite snack of MOOSE Most common naturally

disturbance is INSECT DAMAGE

Needles are flat (will not roll in fingers) and grow horizontally on twig

Memory Tool: Flat is Fir

BLACK SPRUCE Provincial tree of NL Used in NL for pulpwood and

for Christmas trees Most abundant tree in

Labrador, 2nd most common on island

At maturity, about 9-12 m in height and 15-30 cm in diameter

Can reach age of 200 years Most common disturbance is

FIRE, cones are adapted to survive fire

Needles are four-sided, will roll in fingers and are spirally arranged

The other common spruce in NL is white spruce.

EASTERN LARCH (TAMARACK) Makes good posts

and poles.

Many locals incorrectly call this tree a juniper in NL

It is an unusual conifer because it drops its needles in winter (deciduous conifer).

WHITE BIRCH Most common birch in NL

and most important HARDWOOD in NL

Also called the paper birch or canoe birch

Used for fuel wood and in value-added wood products

scattered over the island but common in valleys on west coast of island

Other less common birch is YELLOW BIRCH

BOREAL FOREST FAUNA What types of fauna live

in our forests?

Moose Black Bear Woodland Caribou Canadian Lynx Snowshoe Hare Red Squirrel Little Brown Bat

Mink Coyote Beaver Newfoundland Marten Red Fox Masked Shrew Voles Rock Ptarmigan

LINKS http://ca.youtube.com/watch?v=YNG7

_aAhyY4 http://www.youtube.com/watch?v=Xhj

_qVII1Wg http://www.youtube.com/watch?v=RB

9uzMjiYSQ http://fliiby.com/file/130754/cuwxmfpb

fd.html http://www.youtube.com/watch?v=Ifx

RXL0KGXQ&feature=related http://www.hww.ca/media.asp?mcid=2

UNIT 3 - FORESTRY

TOPIC 6 – SURVIVING THE

HARSH ENVIRONMENT of

a BOREAL FOREST

ADAPTATION 1 – PREVENTING DESSICATION)

Coniferous leaves are modified to prevent dessication, which means “drying out”

They are modified into needles or scales that:decrease surface area reduce water loss by transpiration

(evaporation from leaves)

ADAPTATION 2 – WITHSTANDING SNOW LOAD

Conifers have downward sloping of boughs, allowing trees to shed a heavy snow load.

ADAPTATION 3 – WITHSTANDING EXTREME COLD

At low temperatures between 0 to -40 degrees Celsius, other trees might freeze to death.

In conifers, liquids in the tree remain liquid, a process known as super cooling.

Some conifers that can survive below -40 degrees Celsius include white and black spruce, and tamarack

ADAPTATION 4 – MAXIMIZING PHOTOSYNTHESIS

Due to the ALBEDO EFFECT, darker objects absorb more heat energy as compared to lighter–hued objects.

The dark green of conifer needles helps the trees absorb the maximum heat from the sun and begin photosynthesis as early as possible

ADAPTATION 5 - CONES

Example: Black Spruce It produces two types of

seed cones, CLOSED and OPEN CONES.

Open seed cones drop each year and sprout in any area where there is enough light to grow.

Closed cones cannot release their seeds unless heated to a high temperature by fire. The heat of the fire melts the resin that acts like glue to keep the seed cone closed