Chapter 9Forest Biomes

Covers 30% of the EarthContains 75 % of Earth’s Biomass

9.1 Coniferous Forest Limited to the

Northern Hemisphere (far from the equator)

High latitudes (closer to the Arctic)

Summers are warm and last 2-5 months

Winters are long and very cold

40-200 cm of precipitation (as rain and snow) per year

9.1 Coniferous Forest Coniferous means

“cone bearing”

Conifers (coniferous trees) producer seeds in cones

Leaves have adapted to conserve water by producing long-thin with a thick waxy coat called needles

9.1 Coniferous Forest Tree is also a cone-

shaped - the needles allow heavy snow to fall through the branches

Conifers are “evergreen” they do not loose all their leaves in winter but keep them all year round

9.1 Coniferous Forest Examples of

conifers: Hemlock, Spruce, Cedar, Pine

Forests are not diverse – usually only one or two types of pine.

Soil is poor and very acidic

Hemlock

Blue Spruce

Scotch Pine

Eastern Cedar

9.1 Coniferous Forest Plants: Ferns,

Lichens and Sphagnum moss grown on forest floor

Animals: Large herbivores – moose, elk

Small herbivores – beaver, snowshoe hare, squirrel, mouse, blue jay

Carnivores – grizzly bear, wolves, fox, weasel, lynx, owl, eagle

9.2 Deciduous Forest Deciduous tree

sheds its leaves during the winter

Temperature ranges from 30oC in summer to -30oC in winter

Precipitation 50 – 300 cm (rain/snow) per year

Forests found in the temperate zones – mostly Europe and North America

Maple tree

9.2 Deciduous Forest Growing season is 6

months long

Sunlight is used by chlorophyll in the leaves to make food

Autumn has shorter days – chlorophyll fades –other pigments show through

All pigments fade, leaves dry up and fall off tree

9.2 Deciduous Forest Deciduous forest has

4 layers:

Canopy – top layer

Understory – third layer

Shrubs – second layer

Floor – bottom

Lots of biodiversity so lots of organic matter in the soil (humus-Ch 8)

9.2 Deciduous Forest Food web has many

organisms:

Decomposers (fungi and bacteria)

Insects (bees, flies) and invertebrates (worms)

Herbivores (deer, rabbits, mice)

Carnivores (mountain lions, wolves, eagles, owls)

9.2 Deciduous Forest Human activity has

shrunk the vast area that was the temperate deciduous forest.

Two reasons: rich soil for farming and the trees for wood, fuel and paper

Replanting trees does not restore the forest ecosystem

9.3 Rain Forest Tropical zone is

located at or near the equator.

Direct rays from the sun keep temperatures warm 25oC or higher

Growing season is 12 months

Precipitation 100-450 cm of rain a year

9.3 Rain Forest Dense canopy of

evergreen broadleaf trees

Contains 70-90% of all species on Earth

Only 6% on the Earth’s surface

40% of the Earth’s biomass

Most biodiverse biome

9.3 Rainforest Several levels:

Emergent trees- top layer, 99% sunlight (50-60 m)

Upper canopy – next layer – less than 1% filtered sunlight

Lower canopy – third layer, less than 1% filtered sunlight

Understory – fourth layer, dense shade

Forest floor – little or no sunlight

9.3 Rainforest Top soil is thin – 99%

of available nutrients in only 5 cm of top layer soil

Tree roots are shallow and trees develop extra roots - Buttresses - to support the immense height

Dead organic matter decomposes and is recycled quickly

9.3 Rainforest Most activity takes

place in the canopy layer

Many rainforest organisms never touch the ground

Vast diversity of plant life leads to vast diversity of animals

Habitats vary from tree to tree and level to level

Complex food webs with many species interactions

9.3 Rainforest Greatest biodiveristy for

plants, animals and insects

Many species haven’t even been discovered yet

Fungus beetle, toucans and howler monkeys spend their time in the upper canopy

Blue bird-of-paradise travels from the lower canopy to the forest floor

Margay cat hunts understory and forest floor

Tapir lives on the forest floor

9.3 Rainforest Deforestation