1. Biomes Taiga (coniferous forest) Distribution of taiga
It covers great parts of North America and Eurasia.   

2. Biomes Characteristics of taiga
Winters are long and cold (-54 to -1 C˚) and summers are short and warm (-1 to 21 C˚).
Precipitation is fairly low throughout the year (30-85 centimeters), but snow is frequent during the winter.
Most of the precipitation in the taiga falls as rain in the summer.
The trees of the taiga are almost evergreen conifers with waxy needle leaves.

3. Biomes
Taiga biome   
Taiga (coniferous forest) biome with conifers

4. Biomes
Taiga biome   
Taiga (coniferous forest) biome in winter

5. Biomes
Taiga biome animals   
Bear
Tiger
Lynx
Moose

6. Biomes
Taiga biome animals   
Rabbit
Owl
Wolf
Wolverine

7. Biomes Tundra Distribution of tundra
It borders the Arctic Ocean (the North pole).   

8. Biomes Characteristics of tundra
The Arctic tundra is the world's youngest biome.
It is a treeless region bordering the Arctic Ocean.
Conditions in the tundra are severe, Winter temperature often reach -55 ˚C or below, winds can blow between 50 to100 kilometers an hour. Night can last for weeks in winter.
During summers, the temperature can drop to freezing, and the growing season may last only a few weeks before a hard frost occurs.
Precipitation averages 25 centimeters or less each year.
Nevertheless, the tundra support a variety of life; it is carpeted by grasses, small perennial flowers, mosses and lichens.
The tundra vegetation supports lemmings, which are eaten by wolves, snowy owls, arctic foxes and grizzly bears.
Insects provide food for migratory birds which reach tundra to nest and raise their young during the short summer.

9. Biomes
Tundra biome   
Tundra biome: The ground is permanently frozen 25 to 100 cm
down so that trees can't grow. 

10. Biomes
Tundra biome   
Tundra biome: During the short summers the top layer of soil may
thaw (melt) to let small perennial plants grow and reproduce.

11. Biomes
Tundra biome   
During summer, the ground of tundra biome is carpeted
with small perennial flowers

12. Biomes Tundra biome animals Arctic owl Polar bear Arctic hare  
Arctic owl
Polar bear
Arctic hare
Arctic fox

13. Biomes
Tundra biome animals   
Penguin
Caribou
Lemming
Arctic wolf

14. Biomes Deserts Distribution of deserts
The desert biome is found mostly around 20˚ to 30˚ north and south of the equator.   

15. Biomes Characteristics of deserts
Deserts are hot and have very little rainfall.
Precipitation averages 15 centimeters or less per year.
Deserts have widely spaced vegetation and large areas of bare ground.
Vegetation includes shrubs, cacti and short woody trees.
Plants are adapted to survive hot weather, for example the ability to store and conserve water.
Desert animals include lizards, snakes, insects, arachnids, birds, rat and camel.
Most desert animals are nocturnal (only active at night) to avoid the sun and heat.

16. Biomes
Desert biome   
Desert biome contains widely spaced vegetations. 

17. Biomes
Desert biome   
Desert biome contains vegetations which are adapted to stand
hot and dry weather.

18. Biomes
Desert biome animals   
Gray fox
Camel
Antelope
Kangaroo rat

19. Biomes Desert biome animals Rattlesnake Burrowing owl Scorpion  
Rattlesnake
Burrowing owl
Scorpion
Tortoise
Iguana

20. Aquatic Biomes Characteristics of aquatic biomes or ecosystems
Saltwater oceans and seas are the largest ecosystem on Earth.
Among the unique properties of water are:
water is slower to heat and cool than air. Therefore, temperature in aquatic ecosystems is more moderate than in terrestrial ecosystem.
It absorbs a considerable amount of the light energy that powers life.

21. Aquatic Biomes Types of aquatic ecosystems
There are many different kinds of aquatic ecosystems:
Freshwater ecosystems include:
rivers
streams
ponds
lakes
marshes
Marine (saltwater) ecosystems include:
coral reefs
the open ocean
estuaries

22. Aquatic Biomes Freshwater lakes
Freshwater lakes vary tremendously in size, depth and nutrient content.
Plants and animals live mainly in the shallow zone of the lake; they find abundant light and adequate nutrients.

23. Aquatic Biomes Rivers and streams
Freshwater ecosystems that have flowing or moving water.
Streams have flow of water faster than rivers.
Rivers are larger and deeper than streams.
River
Stream

24. Aquatic Biomes Marine ecosystems
Marine waters cover two-thirds of the surface of the Earth.
The ocean is divided into zones according to the amount of sunlight they get. The zones are:
photic zone (the upper layer of water to a depth of about 200 meters, receives sufficient light to support photosynthesis).
aphotic zone (the bottommost zone below the photic zone)

25. Aquatic Biomes Costal waters
The greatest concentration of life in the oceans is found in the shallow costal water where abundant light and nutrients.
Costal waters include:
the intertidal zone: the area that is alternatively covered and uncovered by water with the rising and falling of the tides.
near-shore zone: relatively shallow, but submerged areas.
The abundance of nutrients and sunlight in this zone promotes the growth of a large variety of organisms.

26. Aquatic Biomes Coral reefs
Coral reefs are most abundant in warm tropical waters (the temperatures range between 22 ˚C and 28 ˚C).
Reef-building corals thrive within the photic zone at depth of less than 40 meters, where light penetrates clear water and provide energy for photosynthesis.
The corals require light because they harbor photosynthetic unicellular algae called dinoflagellates within their tissues in a mutualistic relationship.
The algae give the corals their diverse brilliant color.
The skeletons of the corals accumulate over thousands of years, providing shelter and food for the most diverse collection of invertebrates and fish.

27. Aquatic Biomes Coral reefs
Coral reefs, composed of corals and algae, provide habitat for diverse communities of fish and invertebrates, such as sponges.

28. Aquatic Biomes Open ocean
Beyond the costal regions lies the open ocean.
Most life in the open ocean is limited to the photic zone, where organisms are pelagic (free swimming or floating organisms).
with deeper parts of open ocean, the aphotic zone, the pressure increases, the temperature drops and there is less light, or there is no light at all.
The food web of the open ocean is dependent on phytoplankton (floating microscopic photosynthetic organisms).
Phytoplankton is consumed by zooplankton (floating microscopic animals).
Zooplankton serve as food for larger invertebrates and small fish, which are in turn eaten by larger fish and marine mammals.

29. Aquatic Biomes Open ocean Phytoplankton Small fish Zooplankton Shark
The open ocean supports abundant life in the photic zone, where light is available. Phytoplankton are the producers. Phytoplankton are eaten by zooplankton, represented here by this microscopic copepod (a crustacean).