A group of distinct plants and animals who have adapted to the climate living in a large geographical area is known as a biome. There are various biomes in the world, which are often divided into tundra, grasslands, desert, forests and aquatic biomes.
The natural world has been organized into biomes because they have specific characteristics that divide them naturally. The characteristic traits of a biome are its climate, plants and animals, which exist in a harmonious relationship to each other. Alterations in any of the characteristic elements of a biome can change the nature of the biome.
WWF: An informative guide about biomes from WWF
Kids DO Ecology: A great resource for kids to learn about biomes and many other ecology topics
Wild Class Room: Detailed information on biomes

Types of Biomes

Scientists don’t agree on the exact number of biomes but the following are the major biomes of the world.
Tundra
Tundra is a bleak and stark place which covers about 20 percent of the earth. The northern hemisphere is the land of tundra. The ground here is continuously covered with ice and snow. The word tundra is derived from the Finnish word "tunturia" meaning barren land. The land here is frozen all the time; there is up to 3 feet of snow under the ground which does not let anything grow here. There is hardly any vegetation in these areas but surprisingly a large number of insects and birds dwell here.

• Plants: Arctic willow, caribou moss, arctic moss, diamond-leaf willow, bearberry, pasque flower, tufted saxifrage
• Animals: Grizzly bear, arctic fox, ermine, caribou, polar bear, snowy owl
• Climate: It is probably one of the coldest places on earth with average temperatures of -56 ° C. It remains cold throughout the year except for a brief summer when the sun shines continuously. Cold winds blow all the time.

Major Biomes of the World: Professional level information about major biomes from the department of Geography at Radford University
University of California Museum of Paleontology: Great information about the six major biomes from the University of California
Classroom of the Future: A useful resource for information about biomes

Taiga
The taiga is a large biome which covers parts of North America, Asia and Europe. The southern part of taiga has a human population while the northern part does not have much of a population. Unlike tundra, fairly wide temperature differences exist between winter and summer. A large part of taiga in North America used to be covered with glaciers and the depressions in the ground left by these glaciers often fill with water due to high precipitation.

• Plants: Jack Pine, Douglas-fir, paper birch, balsam fir, white spruce, eastern red cedar, Siberian spruce, white poplar, etc.
• Animals: Grizzly bear, gray wolf, bald eagle, wolverine, bobcat, Canadian lynx, red fox, river otter,
• Climate: It is also very cold like the tundra due to bitter cold air from the Arctic. During the winter months, taiga turns away from the sun. The average temperature during winter ranges from -54 ° C to -1° C; even summers are nothing like summer with temperature ranging from 21° C to -7° C. The only seasons here are winter and summer.

Blue Planet Biomes: World biomes described in an easy to understand manner
World Biomes: Information about five major biomes of the world
World biomes : University of Puget Sound: This site explains the concepts of Biomes and gives definitions of the characteristics by which they are defined: climate, soils, vegetation, diversity, plant and animal adaptations, human effects

Grasslands
Grasslands are very different from tundra and taiga as they have lands with lots of grass, flowers and other vegetation. Growth of the grass and other vegetation is dependent upon precipitation. This biome does not have many trees because the dry and thin soil does not support the growth of trees. There are two types of grasslands: grasslands with tall grass and grasslands with short grass. The tall-grasslands are generally quite humid with plenty of rain but the short-grasslands have less rain. There are three main grassland areas: Asian Steppes, North American Prairies and the Mexican Pampas.

• Plants:
• Steppes: Sweet vernal, tumbleweed, fringed sagebrush and rhubarb
• North American Prairie: Buffalo grass, purple coneflower, big bluestem grass, stinging nettle, fleabane, Indian grass
• The Pampas: Pampas grass
• Animals:
• Steppes: Northern lynx, Mongolian gerbil, saker falcon, saiga antelope
• North American Prairie: Coyote, badger, bobcat, American bald eagle and bumble bee.
• The Pampas: Geoffroy's Cat, greater rhea.
• Climate:
• Steppes: There is a lot of variation in temperatures between summer and winter. The temperature in summer can go as high as 104° F; winter is also extreme with cold winds and temperature as low as -40° F.
• The Pampas: The climate in the Pampas is relatively milder with summer temperature from 40° F to 77° F, but the weather can be very humid and uncomfortable

New World Encyclopedia: Very detailed information about different classifications of biomes
Think Quest: Useful information about five major types of biomes together with some interesting activities and games
Biome Basics: A University of Richmond project about biomes

Deciduous Forest
This biome has a diverse climate because of its location between the tropics and the Polar Regions so it gets the best and worst of both the regions. Most of the people on earth live in this biome. The precipitation in deciduous forests is about 30 to 60 inches. The soil in these regions is very fertile because when the trees shed leaves in these areas, the leaves decompose to make the land very fertile.

• Plants: Lady fern, guelder rose, white birch, white oak, American beech, common lime, northern arrowwood, pecan, carpet moss.
• Animals: White-tailed deer, American black bear, eastern chipmunk, American bald eagle, coyote, European red squirrel, fat least weasel
• Climate: Since the weather is not very extreme, this biome has all four seasons. One of the characteristics of deciduous forests is that they are almost always near an ocean which is a big contributing factor to the versatility of the climate. Summers here are mild and winters also not as cold as other biomes.

Exploring Nature Educational Resource: Science and environmental knowledge in an interesting and engaging format
Geography for Kids: An interesting and easy to understand collection of information about biomes
Internet Geography: This site provides a range of information targeted primarily at GCSE and A level students about a wide range of 'Geo Topics' covering key areas in physical and human geography
Desert
Although most people associate deserts with sand and extreme heat, there are cold deserts as well. Examples of these extremes are the Australian desert and the Gobi desert respectively. The climate in deserts depends upon a number of factors such as atmospheric pressure, location and presence of mountains, etc. Deserts can be found along coastal areas as well as deep inside the continents.

• Plants: Jumping cholla, Mojave aster, barrel cactus, Palo Verde, brittle bush, ocotillo, chainfruit cholla, creosote bush, crimson hedgehog cactus, desert ironwood, prickly pear cactus, Joshua tree, pancake saguaro cactus
• Animals: Desert tortoise, bobcat, armadillo lizard, coyote, banded gila monster, desert kangaroo rat, cactus wren, desert bighorn sheep, javelina, Sonoran desert toad, Sonoran pronghorn antelope.
• Climate: Deserts are known to be extremely hot because the sun shines directly overhead. When the cold air comes down and becomes warm, it is evaporated by the intense heat from the ground before it can rain. The average temperature here is more than 64° F.

Tropical Rainforest
Southeast Asia, Africa and South America are home to the largest tropical rainforests. This is a hot and humid biome with up to 160 inches of precipitation. Due to the moisture and temperature, it is an ideal place for several types of plants and a variety of animals to exist. There is an amazing biodiversity in tropical rainforests with over 15 million species of plants and animals. In addition to the plants and animals, the climate here is also conducive for microorganisms. The soil here, as opposed to deciduous forest, is not fertile because rapidly growing plants quickly consume all of the nutrients.

• Plants: Strangler figs, bougainvillea, Bengal bamboo, curare, mangrove forests, coconut tree, durian, jambu, kapok tree and tualang.
• Animals: King cobra, proboscis monkey, dawn bat, forest elephant, Bengal tiger, chimpanzee, harpy eagle, jambu fruit dove, common palm civet or musang, golden lion tamarin, kinkajou, Linn’s sloth, orangutan, silvery gibbon, slender Loris, Sumatran rhinoceros, toco toucan, wagler's pit viper
• Climate: The climate here is very humid with lots of rain which can reach up to 250 cm per year. There is not much variability in the temperature and it remains around 77° F.

Research Guide: This site provides several links to information about biomes
About.com: Lots of useful information about various aspects of land biomes
Ecosystems : Geotopics : internet geography: It provides information on a range of topics surrounding ecosystems including tropical rainforests, Savanna, Taiga, deserts and tundra. The web pages use diagrams and photographs to explain the main points
Slater Museum biodiversity resources: It provides a variety of resources on biodiversity topics including biomes, plants and animals

Environmental Links at StartLocal

Environmental Consultants
Conservation & Environment Organisations
Environmental Products & Supplies
Environmental Law Solicitors
Waste Reduction & Disposal Equipment
Solar Energy Equipment