If you travel around the world, you can visit dry deserts with lots of cacti, the cold arctic with little plant life, or humid tropical rainforests. These different regions on Earth are all called biomes. Continue reading to learn about different types of biomes.
Definition of a Biome
Biomes are large areas on Earth with similar conditions, such as similar climates and similar living organisms. There are two main categories of biomes. Terrestrial biomes are usually defined by the type of vegetation that is present. The major climatic factors contributing to the vegetation types in these biomes are temperature and precipitation.
Aquatic biomes are defined by the type of water they contain.There are many different classification systems used to determine biomes, each resulting in different numbers of biomes. Here we will just be covering some of the major biomes (9 terrestrial and 4 aquatic).
Let’s take a look at the terrestrial biomes.The coldest biome is called the tundra. It is located at the North (Arctic) and South (Antarctic) Poles. An alpine tundra is also found on top of mountains at very high elevations. The vegetation is very low to the ground and includes short shrubs, grasses, and lichens. A layer of permafrost, or permanently frozen soil, is usually present.
The taiga or boreal forest, is found south of the Arctic tundra. Here, it is cold and snowy. The vegetation consists mostly of coniferous evergreen trees. Coniferous trees are those that have needle-like leaves.
This biome is also sometimes called the northern coniferous forest.The temperate deciduous forests have hot summers and cold winters. Vegetation includes shrubs, mosses, and broadleaf trees. Broadleaf trees, such as oaks and maples, are deciduous (lose their leaves during the winter). This is the natural biome for much of the eastern United States.
Temperate rainforests have mild temperatures and rain all year long. They receive over 60 inches of rain a year and are home to many trees, mosses, and ferns. They occupy very small areas on all continents except Antarctica. In the United States, temperate rainforests can be found in Washington and Oregon.
The prairies in the Midwestern United States are considered temperate grasslands. These areas consist mostly of grasses and can be found on all continents except Antarctica. There are usually no large shrubs or trees in temperate grasslands. While temperatures are similar to those in temperate deciduous forests, there is usually less precipitation.
The chaparral, or shrubland, biome is found in only a few small areas, including part of Australia, around the Mediterranean Sea, and in most of California. This biome contains mostly shrubs and is hot and dry in the summer. In winter, it is cool and moist.
Fires occur frequently in chaparral areas, so many plants have thick waxy coatings to resist fire damage. Additionally, many plants rely on fires for proper germination of their seeds.Deserts are very dry areas with generally less than 10 inches of rain a year.
Deserts can be either hot, like those in Africa, or cold, such as in Antarctica. Temperatures usually change dramatically between night and day. The only plants that live in deserts are those that are adapted to conserve water. These include cacti and some shrubs and grasses.Savannas are also sometimes called tropical grasslands because they are found in the warm tropics and consist mostly of grasses. Savannas have both a rainy season and a dry season. During droughts, fires commonly kill any trees that may have started growing.
You are probably most familiar with African savannas that are home to elephants, giraffes, and zebras.Tropical rainforests are found near the equator. Temperatures are warm all year long. Tropical rainforests are very humid, and anywhere from 60 to almost 400 inches of rain can fall in a single year. Plant life is very abundant and includes tall broadleaf trees, vines, ferns, palms, and small plants. This biome is home to more than half of all terrestrial species!
Now let’s take a look at some aquatic biomes.
Only a very small portion of Earth’s water is freshwater (mostly free of salt). Most of it can be found in rivers, lakes, and wetlands. Rivers and smaller streams have water that flows in one direction. The water is usually cooler near the source, or beginning, of a river. Water tends to warm as it gets closer to the river’s end, or mouth.
Lakes or ponds are still bodies of water. Wetlands have permanent water and lots of aquatic plants; some wetland plants include cattails and water lilies.Oceans are large marine bodies of water containing saltwater. The intertidal zone is the area between land and ocean. Parts of it are exposed during low tide, while it is covered with water at high tide.
The pelagic zone is open water away from the shore. It is usually much colder than the intertidal zone.In warm, shallow waters around the world, coral reefs can be found near the coasts. The water here tends to be clear and lacking in nutrients.
Coral reefs provide protection and food for other animals, including fish, sea turtles, sea stars, and various invertebrates.Estuaries are places where freshwater and saltwater mix. This happens where a river meets up with the ocean. The water in an estuary has more salt than freshwater but less salt than the ocean, and it is termed brackish water. Animals that live in estuaries, such as shore birds and crabs, must be able to tolerate this mixed water.
The earth has many different climatic regions or biomes. There are both terrestrial biomes and aquatic biomes.
The most important factors defining terrestrial biomes are temperature and precipitation. Some of the major biomes on land include: tundra, taiga, temperate deciduous forest, temperate rainforest, temperate grassland, chaparral, desert, savanna, and tropical rainforest. Freshwater aquatic biomes include lakes, rivers, and wetlands. Marine biomes include coral reefs and the oceans.
Estuaries are where freshwater mixes with saltwater.
Types of Biomes
|*Tundra*Taiga *Temperate deciduous forest *Temperate rainforest *Temperate grassland *Chaparral *Desert *Savanna *Tropical Rainforest||Fresh Water: *Lakes*Rivers *Wetlands Marine: *Coral reefs *Oceans Mixed: *Estuaries|
When you are finished, you should be able to:
- Recall the definition of a biome
- Distinguish between the two main types of biomes
- Identify the characteristics of the terrestrial and aquatic biomes