Biomes of the World

What is a biome? A BIOME is the largest geographic biotic unit, a major community of plants and animals with similar life forms and environmental conditions.

How are biomes formed? Biomes are distributed across the Earth based primarily on climate. Therefore, in areas that are far apart, you will sometimes find similar plants and animals because the climate is similar. One factor affecting climate is latitude. Typically, the farther you move north or south of the equator, the colder the temperature gets. Another factor affecting climate is elevation. The higher you go in elevation, the colder the temperature gets. Biomes usually found at cold latitudes far from the equator are sometimes also found on high mountains at low latitudes. Typically, a climb of 100 feet in elevation is equivalent to traveling 600 miles northward.

How many biomes are there?

Tropical Rainforest Desert Freshwater Saltwater Grassland Temperate Deciduous Forest Temperate Coniferous Forest Tundra Although there is some disagreement among scientists on how to divide up the Earth’s biomes, most can agree on the following eight:

Tropical Rainforest Typically found near the equator Receives more than 200 cm of rain annually Temperatures typically fall between 20 o C and 25 o C for the entire year As many as 50% of all the world’s animal species may be found here

The largest tropical rainforest is in South America. It is called the Amazon rain forest. They are also found in central Africa, Central America, Southeast Asia, Hawaii, and a small area of Australia.

Freshwater Freshwater is contained in lakes, ponds, rivers and streams It usually originates from snow melting off mountains and melting ice When fresh and salt water meet it is called an estuaries.

* Many of the plants that live in freshwater have strong roots to keep them in one place. * Some plants grow around the edge of the lake or float on the top of the water cattailwater lily

bass carp mallards trout bull frog

Desert Typically found between 25 o and 40 o latitude Receives less than 25 cm of rain each year Temperatures typically range between 20 o C and 25 o C but some extreme deserts can reach temperatures higher than 38 o C and lower than –15 o C

In Africa, western North America, western Asia, central Australia, and western South America.

* can live there because the roots are close to the top of the ground and can get the water quickly. CactusAloe Barrel Cactus Prickly Pear Cactus

Black-collared lizard snakes camel desert iguana roadrunner jackrabbit

Saltwater Cover 70% of earth’s surface Ocean floor is made up of shelves, plains and mountains All oceans are connected and water moves between them through currents Waves and tides have a great impact on the earth Oceans can have depths of up to 7 miles

Many of the plants live near the top of the water they need the sunlight to help them grow and make food

Most marine organisms live near the top of the water or close to land Many animals dig down into the sand or hang on to rocks, so they do not get lost in the sea Other larger animals live where the water is deep barracuda star fishclown fishcrab flashlight fishgreen sea turtlekiller whaleshrimp

Grassland Because of the dry climate, trees are found only near water sources such as streams Usually receives between 50 and 90 cm of rainfall each year Summer temperatures can reach up to 38 o C, and winter temperatures can fall to –40 o C

The largest grassland is in Africa. There are also grasslands in North America, South America, central Asia, and northern Australia.

Grass Can live without a lot of rain Acacia tree Baobab tree

African elephant Black RhinocerosCheetah Giraffe HippopotamusHyena Lions Ostrich Warthog Wild Dog Zebra

Temperate Deciduous Forest Moderate climate Most trees will lose their leaves in the winter Temperatures range between – 30 o C and 30 o C Averages from 75 to 150 cm of precipitation Well developed understory

Deciduous forests are between northeastern United States and Canada. Some are in the eastern United States. Others grow in Europe and eastern Asia.

* Trees * Oak* Hickory * Maple* Beech * Flowers * Lily of the valley * Star Flower

EagleBrown BearBlack BearChipmunk RaccoonPorcupineRed Fox White-tailed Deer MouseCoyote

Temperate Coniferous Forest Also known as Taiga Typically found between 45 o and 60 o North latitude Cold climate with summer rains Very few reptiles Limited understory Snow is primary form of precipitation (40 – 100 cm annually)

In Canada, Alaska, northern Asia, and northern Europe EuropeAsia Canad a Alaska

Conifer trees (have cones) Have needles covered with wax Wax protects the needles from freezing cone needles Kinds of conifer trees pin e fir spruc e

MooseBeaverWolfBlack bear Hawk OwlLynx Wolverine Red Squirrel Snowshoe Rabbit

Tundra Means treeless or marshy plain Characterized by permafrost – permanently frozen soil starting as high as a few centimeters below the surface – which severely limits plant growth Winter temperatures average – 34 o C while summer temperatures usually average below 10 o C Low precipitation (15–25 cm per year) but ground is usually wet because of low evaporation

Plants Fungi and algae They cover the rocks and ground Animals wolf caribouduck lemming marmot musk ox polar bear sandy hill crane snowy owl