6-2 forest biomes. tropical rain forests characteristics: – high humidity – 200-400 cm...

6-2 Forest Biomes

Tropical Rain Forests

Tropical Rain Forests

• Characteristics:– High humidity– 200-400 cm rainfall/year (400 inches)– Warm, constant temperature year-round– Greatest specie diversity (half world’s specie)– Poor soil– Near equator– Helps regulate world climate & mineral cycles

Tropical Rain Forest

• Nutrients:– Decay is rapid– Uptake by plants is rapid for quick growth– Soil is poor in nutrients

Tropical Rain Forest

• Layers:– Plants adapted to growing in layers & to different amounts of sunlight• Emergent layer – top layer grows in direct sun• Canopy layer – gets 95% of sunlight. Primary layer –

most animals live here• Understory – little light, adapted to shade (source of

house plants) large flat leaves

Leaf adaptations

Tropical Rain Forest

• Threats:– Used to occupy 20% of Earth’s surface– Today occupies 7% of Earth’s surface– 100 acres/minute/day lost to logging, agriculture,

oil exploration– Results in habitat destruction & loss of biodiversity

(also exotic plant & animal export)

Temperate Forests

• Two kinds:– Temperate Rain Forests– Temperate Deciduous Forests

Temperate Rain ForestsFound along the northwest coast of the US (N. California, Washington, Oregon), the mountains of North Carolina, Australia, and New Zealand.

Temperate Rain Forest

• Large amounts of precipitation• High humidity• Moderate temperatures• Dominate trees in northwest are evergreens

90 m tall – Sitka spruce, Douglas fir, hemlock• Mosses and ferns cover forest floor

Temperate Deciduous Forest

Temperate Deciduous Forest

Temperate Deciduous Forest

• Eastern Us, Europe, Asia• Located between 30 – 50 degrees north

latitude• Broadleaf trees that change color and lose

their leaves in fall• Wide range of temperatures, seasons (4)• Decomposition slower than rain forest, so soil

is richer

Temperate Deciduous Forest

• Animals: adapted to use forest plants for food and shelter

• Birds are migratory.

Temperate Deciduous Forest

• Plants: dominate trees maple oak birch

Temperate Deciduous Forest

Plants are adapted to seasonal change

Taiga

Taiga

• Northern coniferous forest below arctic circle.• Long winters (6-10months). Summers have

constant daylight• Average temperature below freezing • Plant growth most abundant during summer• Permafrost – ground frozen year round, top

part thaws in summer

Taiga

• Plants:– Conifers: needle-like leaves with waxy covering to prevent water loss– Shape of tree (cone shape) helps trees shed snow without breaking branches

Taiga

• Soil – acidic from decay of needles. Plants & bacteria do not like acidic soil– Decomposition slow– Little plant variety

Taiga

Animals:• Many waterfowl (lots of lakes & marshes)• Birds migrate south in winter• Food scarce, many animals burrow &

hibernate• Some animals (snowshoe hare) shed brown

fur & grow white fur for camouflage