Biomes

By Drew Buzzell, Rebecca Forman and Nina Sevilla

Objective Question:What defines a biome?• A biome is a terrestrial ecosystem that covers a large region

of the earth• Characterized by communities of plants, animals and other

organisms that are adapted to its climate and other abiotic factors

Tropical Forest• Tropical forests occur near the equator where

temperatures are warm year-round      • One type of tropical forests--tropical rain forests--can

receive as much as 350 centimeters of rainfall yearly• Tall broad-leaved trees create a canopy and little light

actually reaches the forest floor• Tropical rain forests have the greatest diversity of life

o 50% of all species on Earth• Clearing forests affects global weather patterns

Savanna

• Savannas are grasslands with scattered trees• Found in tropical regions of Africa, Australia and South

America• Grasses grow rapidly and are food for grazing animals• Warm climate with alternating wet and dry seasons

o Organisms in the savanna must be able to cope with drought

Desert

• Deserts are land areas that receive less than 30 cm of rain per year

• Some have soil temperatures of over 60 degrees C, while others are relatively cold

• Some have little to no plant life and others are populated by scattered shrubs and cacti

Chaparral

• Temperate coastal biome dominated by dense evergreen shrubs are known as chaparrals

• Climate consists of mild, rainy winters and hot, dry summers

Temperate Grassland

• Temperate grasslands are characterized by deep, nutrient-rich soil that supports a varity of species and other plants

• Seasonal drought and occasional fires prevent woody shrubs and trees from growing

• Drier areas have shorter grass species, but wetter areas support plants that grow over 2 meters in height.

Temperate Deciduous Forest

• Temperate deciduous forests are characterized by dense stands of deciduous trees (trees that drop their leaves each year)

• Winters tend to be cold, and summers tend to be quite hot.• New England falls into this category.

Coniferous Forest

• Coniferous forests are characterized by cone-bearing evergreen trees (pine, spruce, fir, and hemlock)

• These regions are also called the taiga• Winters are long, cold, and have heavy snowfall• Typical animals are hares, moose, elk, wolves, and bears

Tundra

• Tundras are characterized by extremely cold temperatures and high winds

•  Found within the Arctic Circle and on high mountaintops at all latitudes

• Permafrost is the permanently frozen subsoil, during the summer only the first few inches melt

Aquatic Ecosystems

Background

• Nearly 3/4ths of the Earth's surface is covered with water• Aquatic (water) ecosystems provide homes to many of the

Earth's organisms• Major abiotic factors affecting aquatic ecosystems include

the amount of dissolved salt, the water temperature and the availability of sunlight

Ponds and Lakes

• Standing (not flowing) bodies of water• Photic zone is made up by the shallow water close to shore

and the upper zone of water away from shoreo Water plants and Phytoplankton--microscopic algae and

cyanobacteria that carry out photosynthesis--live in this zone

• The aphotic zone is the deep, murky areas of a lake where light levels are too low to support photosynthesis

• The benthic zone is what the bottom of any aquatic ecosystem is calledo consists of rock, sand, and sediment

Streams and Rivers• Bodies of flowing freshwater

o Streams are smaller, rivers are larger• Near the source, river water is usually cold, low in nutrients,

and clearo Few phytoplankton inhibit this part, instead the major

producer is algae on rockso Many species of anthropds live in the benethic zone and

the most common fish are trout• Downstream the river becomes warmer, murkier, wider and

deepero Marshes and other wetlands are commono More phytoplankton, as well as many other species,

inhabit this parto Worms and insect larvae are more abundant in the

benethic zone

Estuaries

• An estuary is the area where a stream or river merges with the ocean

• There are changes in slat concentration and temperature• Nutrient rich soil supports a rich diversity of life, it is one of

Earth's most productive ecosystems• Along the east coast of the United State, the major

ecosystems found in estuaries are salt marshes• In tropical areas, the typical estuary ecosystems are

mangrove swamps

Objective Question:

Freshwater Flowing

Standing Salt and Fresh Water

Aquatic Ecosystems

Ocean Zones

• The ocean can be divided into zones based on deptho Pelagic Zone (open water above the ocean floor)

Photic, Aphotic o Benethic Zone

 • The ocean can also be divided into zones based on the

distance from shoreo Intertidal Zoneo Nertic Zoneo Oceanic Zone

Intertidal Zone

• Intertidal zone is the area of shore between high-tide and low-tide

• Benethic organisms in this zone must be well-adapted to the harsh conditions of the sun and wind during low tide and pounding waves during high tideo Ex. Barnicles

cement themselves to rocks trap-door holds moisture during low-tide

Neritic Zone

• Neritic zone is the area of the ocean from the low-tide line out to the edge of the continental shelf

         • Sunlight allows for seaweeds and phytoplankton• Other animals include mollusks, crustatians, sponges, sea

turtles, fish and marine mammals

Oceanic Zone

• Oceanic zone is the vast, open ocean from the edge of the continental shelf outward

• The photic zone is inhabited by phytoplankton and zooplankton (microscopic animals that serve as food)

• Swimming animals include dolphin, whales, squid and numerous species of fish that are adapted to life at different depths

Coral Reefs

• Visually spectacular and biologically diverse ecosystemo Equivalent to tropical rain forests on earth

• Contain one out of every four marine species• Usually in the neritic zone • Most coral reefs are formed by colonies of coral polyps

Deep-Sea Vents

• Hydrothermal vents are spots on the ocean floor where hot gasses and minerals escape from the Earth's interior

• No sunlight reaches this deep zone• Vent communities use chemical energy from the Earth

o The producers in this ecosystem are prokaryotes that can extract energy from sulfur compounds and use it to make carbohydrates