ECOSYSTEMS - BIOMES

Biomes

• Biomes are groups of smaller ecosystems with:

• Similar climates (temperature and precipitation)

• Inhabitants with similar adaptions

Tundra

• Found at latitudes around the North Pole

• Less than 25 cm precipitation yearly

• Very cold year round (-40ºC in winter)

• Cold, dry, treeless region

• Winter lasts 6 to 9 months with no daylight

• Summer is short and cold with 24 hours of sunlight a day

• Soil is poor

• Permafrost

• Layer of permanently frozen soil

Plants and animals:

• Tundra plants are resistant to drought and cold

• Examples: Lichens, True mosses, Grasses, Small shrubs and flowers

• Many animals of the tundra migrate there during the short summer

• Examples: Biting insects, Snowy owls, Arctic hares, Caribou, Musk

oxen, Lemmings

Taiga

• Warmer and wetter than the Tundra

• Winters are long and cold

• 35 to 40 cm of precipitation yearly (mostly snow)

• Warmer and wetter than the Tundra

• Winters are long and cold

• 35 to 40 cm of precipitation yearly (mostly snow)

Plants and animals

• There is no permafrost, so trees can grow. Mosses and lichens grow on the

forest floor.

• Examples: Cone-bearing Evergreen trees (Firs, Spruces, Pines,

Hemlocks, Cedars)

• Many animals live in the Taiga.

• Examples: Moose, Black Bear, Lynx, Wolves, Badgers, Wolverines, Ermines, Deer

Temperate Forest

• Found below 50ºN latitude

• 75 to 150 cm precipitation yearly

• Wide range of temperatures with 4 seasons

• Below freezing in winter to 30ºC in summer

• Soil is rich in nutrients from layers of decomposing leaves

• Layers of vegetation

• Canopy

• Understory

• Forest floor

Plants and animals

The mild climate and rich soil of the temperate deciduous forest supports a wide

variety of plant and animal life.

• Plant life is abundant.

• Examples: Oak trees, Hickory trees, Maple trees, Shrubs , Wildflowers, Ferns

• Animal life is diverse.

• Examples: Deer, Foxes, Snakes, Bears, Birds, Raccoons, Amphibians, Small

mammals

Temperate Grassland

• Grasslands are known by many names.

• U.S.A. – Prairie or Plains

• Asia – Steppe

• South America – Pampas

• Africa –Veldt or Savanna

• Australia - Savanna

• Wet seasons followed by a season of drought

• 25 to 75 cm precipitation yearly

• The soil is rich and fertile.

• The grass has extensive root systems, called sod.

Plants and animals

Grassland regions of the world are important farming areas. Cereal and

grains grow here.

• Examples: Wheat, Rye, Barley, Corn

• The most noticeable animals in grassland ecosystems are

usually grazing mammals.

• Examples: Bison, prairie dog, pronghorn, coyote

Savanna

• Tropical, rolling grassland scattered with shrubs and isolated trees

• Not enough rainfall to support forests

• Long dry winter with 4” rainfall and rainy summer with 15 – 50

inches of rainfall annually

• 90oF in dry season; 70oF in summer

• Clay and sand mixed soils

Plants and animals

• Plants:

• Tall, wild grasses

• Acacia trees

• Small shrubs

• Animals:

• Large herbivores such as antelope, gazelles, giraffes,

elephants, zebras, wildebeests

• Large carnivores such as lions, hyenas, and leopards

Chaparral

• Cross between a grassland and a forest

• May contain mountain slopes and plains

• Hot, dry summers and mild winters

• Average winter temperature ~ 46oF

• Average summer temperature ~ 72oF

• Annual rainfall 15 - 40 inches

• Nutrient poor soil with low moisture

Plants and animals

• Plants:

• Trees such as oak

• Shrubs with thick waxy coverings to conserve water

• Animals

• Aardvark

• Coyotes

• Lynx

• Chipmunks

Tropical Forest

Found near the equator in Africa, South America, Australia, and the

Pacific Islands

• Found near the equator

• 200 to 225 cm precipitation yearly

• Hot and humid all year

• Temperatures are fairly constant

around 25ºC

• Soil is nutrient poor and acidic

• Most plants have shallow roots

Plants and animals

• A rain forest may contain more than 700 species of trees and over 1000

species of flowering plants.

• Examples: Mahogany trees. Bromeliads and orchids. Giant ferns,

Many flowering plants

• The rain forest is home to a huge number of animals.

• Examples: Monkeys, Exotic birds, Snakes, Sloths, Bats, Insects,

Large cats, Exotic mammals

Desert

• Found on every continent.

• The driest biome on Earth

• Extreme temperatures- Very hot during the day and cool at night

• Very little rainfall

• Less than 25 cm precipitation yearly

• The soil ranges from gravel to sand.

• Soil is nutrient poor.

Plants and animals

Desert plants have evolved adaptations to help them survive in the

extreme temperatures and dryness of this biome.

• Examples: Cactus, Mesquite, Joshua trees, Wildflowers, Creosote

The animals of the desert are adapted to the hot temperatures.

• Examples: Lizards, Camels, Snakes, Scorpions, Kangaroo rat,

Gila Monster, Predatory birds, Tarantula

AQUATIC BIOMES

Ocean Zones

Ocean covers approximately 70% of the earth’s surface and is nearly 7 miles deep at its deepest.

Factors that affect life:

• Salinity of the water - 3% NaCl

• Availability of light (photic and aphotic zones)

• Distance from the coastline

• Intertidal zone

• Neritic Zone

• Oceanic Zone

The Intertidal Zone

• Area of the shoreline between low and high tides.

• The high tide repeatedly brings in coastal water with its rich load of

dissolved nutrients.

• Plenty of sunlight for photosynthesis. Organisms living in this zone must

be able to:

• Avoid being swept away or crushed by waves.

• Deal with being immersed during high tides and left high, dry

and hotter at low tides.

• Survive changing levels of salinity.

The Neritic Zone

• Neritic biomes occur in ocean water over the continental

shelf.

• The water here is shallow, so there is enough sunlight for

photosynthesis.

• The water is rich in nutrients.

• These favorable conditions allow large populations of

phytoplankton live in neritic biomes.

• They produce enough food to support many other

organisms, including both zooplankton and nekton. Neritic biomes have relatively great biomass and

biodiversity.

• They are occupied by many species of invertebrates and fish.

• Most of the world’s major saltwater fishing areas are in neritic biomes.

The Oceanic Zone

Oceanic biomes occur in the open ocean beyond the continental

shelf.

There are lower concentrations of dissolved nutrients away from

shore, so the oceanic zone has a lower density of organisms than

the neritic zone.

The oceanic zone is divided into additional zones based on water

depth due to light availability.

In the photic zone there are both producers (protists and bacteria)

and consumers (fish and large mammals).

In the aphotic zone animals feed mainly on dead organisms and

must have adaptations to deal with high pressures.

Estuaries

An estuary is a bay where a river empties into the ocean.

It is usually semi-enclosed, making it a protected environment.

The water is rich in dissolved nutrients from the river and shallow

enough for sunlight to penetrate for photosynthesis.

As a result, estuaries are full of marine life.

Examples of estuary communities include bays, mudflats mangrove

swamps and salt marshes.

Freshwater

Lakes and Ponds

Standing freshwater biomes include ponds and lakes.

Divided into two categories:

• Eutrophic – rich in organic matter and vegetation, plants, algae

and bacteria – cloudy

• Oligotrophic – little organic matter, water clear, sandy and rocky at

the bottom

Different Zones:

• The littoral zone is the water closest to shore

• The limnetic zone – top layer away from shore

• The profundal zone – deep-water, no sunlight

• The benthic – bottom of the lake

Rivers and Streams

Compared with standing water, running water is better able to

dissolve oxygen needed by producers and other aquatic organisms.

Flowing water also provides a continuous supply of nutrients,

providing a greater degree of biodiversity.

Algae are an important producer.

Consumers in running water include both invertebrate and

vertebrate animals.

Wetlands

A wetland is an area that is saturated or covered by water for at least one season of the year. Freshwater

wetlands are also called swamps, marshes, or bogs.

Wetland vegetation must be adapted to water-logged soil, which contains little oxygen.

Wetlands are extremely important biomes for several reasons.

•They store excess water from floods and runoff.

•They absorb some of the energy of running water and help prevent erosion.

•They remove excess nutrients from runoff before it empties into rivers or lakes.

•They provide a unique habitat that certain communities of plants need to survive.

•They provide a safe, lush habitat for many species of animals.