2.4 Biomes

Assessment Statements Define the term biome Explain the distribution, structure, and relative productivity of tropical rainforests, deserts, tundra, and any other biome

2.4.1 Define the term biome A collection of ecosystems sharing similar climatic conditions.

BIOME is the collection of ecosystems sharing similar climatic conditions.

Cell 3 South Cold, dry air falls Moist air rises — rain Cell 2 South Cool, dry air falls Cell 1 South Moist air rises, cools, and releases moisture as rain Cell 1 North Cool, dry air falls Cell 2 North Moist air rises — rain Cell 3 North Cold, dry air falls Polar cap Arctic tundra 60° 30° 0° 30° 60° Polar cap Evergreen coniferous forest Temperate deciduous forest and grassland Desert Tropical deciduous forest Equator Tropical rain forest Tropical deciduous forest Desert Temperate deciduous forest and grassland Model of global air circulation and biomes. The direction of air flow and the ascent and descent of air masses in convection cells determine the earth’s climatic zones.

Uneven Solar Heating and Latitude Earth as a whole is in thermal equilibrium, but different latitudes are not. Moving masses of air and ocean currents transport energy from locations with a surplus to those with a deficit.

2.4.2 Explain the distribution, structure, and relative productivity of tropical rainforests, deserts, tundra, and any other biome Tropical Rainforest Temperature: 26 C Rainfall: Over 2500 mm/yr Insolation (Light Level): High Distribution: Between the tropics of cancer and capricorn Structure: Highly stratified (Emergent, Canopy, Understory, Immature, and Herb layers) Productivity: High

2.4.2 Explain the distribution, structure, and relative productivity of tropical rainforests, deserts, tundra, and any other biome Desert Temperature: 45 C Rainfall: Under 250 mm/yr Insolation (Light Level): High Distribution: 30 o N and S Structure: Little vegetation, organisms highly adapted to low water and fluctuating temperatures Productivity: Very low

2.4.2 Explain the distribution, structure, and relative productivity of tropical rainforests, deserts, tundra, and any other biome Tundra Temperature: Low down to -50 C Rainfall: Low Insolation (Light Level): Low Distribution: High Latitudes Structure: Plants with leathery leaves or underground storage organs, larger animals with fur Productivity: Low

2.4.2 Explain the distribution, structure, and relative productivity of tropical rainforests, deserts, tundra, and any other biome Temperate forest Temperature: cold winters, hot summers Rainfall: mm/yr Insolation (Light Level): varies through year Distribution: 40 to 60 o N Structure: Dominated by one species of tree (evergreen or deciduous) bigger shrub layer due to less dense canopy Productivity: Relatively high

2.4.2 Explain the distribution, structure, and relative productivity of tropical rainforests, deserts, tundra, and any other biome Grasslands Temperature: cold winters, hot summers, fluctuate wildly if removed from the sea Rainfall: mm/yr Insolation (Light Level): varies through year Distribution: Almost every continent 16% of the earth’s surface Structure: Diverse grasses, with a mat of slowly decomposing vegetation Productivity: Relatively low

AQUATIC BIOMES Coral reefs Rivers LakesMangroves Ocean

High tide Low tide Coastal Zone Estuarine Zone Continental shelf Open Sea Sea level Sun Euphotic Zone Bathyal Zone Abyssal Zone Depth in meters Photosynthesis 500 1,000 1,500 2,000 3,000 4,000 5,000 10,000 Darkness Twilight

Aquatic Ecosystems Environmental Factors Temperature

Aquatic Ecosystems Environmental Factors Light

Aquatic Ecosystems Environmental Factors Salinity Lake Michigan 0.5 PPT Baltic Sea 5-15 PPT The Dead Sea 332 PPT The Black Sea 16 PPT The Red Sea & The Persian Gulf 40 PPT Pacific Ocean 36 PPT

Aquatic Ecosystems Environmental Factors Currents

Aquatic Ecosystems Environmental Factors Dissolved Oxygen Dissolved Oxygen (mg/L) Depth (m) Temperature (ºC) Dissolved Oxygen Temperature

Aquatic Ecosystems Zonation

Aquatic Ecosystems Human Impacts Waterways across the United States are contaminated by a medicine chest of antibiotics, hormones, caffeine, painkillers and other drugs Agricultural runoff can carry fertilizers, including traces of antibiotics and hormones, into waterways