Earth Science - Habitats/Biomes

Biomes are very large ecological areas or habitats on the earth’s surface. In each biome, both plants and animals learn to adapt in order to exist and survive in that biome.

There are five major biomes and each of those biomes has sub-biomes.

THE BIOMES:

1. The Desert Biome: Deserts make up about 20% of the Earth’s landmass. The desert biome is an area that is dry and can either be hot or cold. There is very little vegetation and even less cloud cover. Plants that do survive in the desert include short shrubs and cacti. Any animals that live in the desert tend to burrow under the ground or stay in little rock holes. Among the animals that can be found in the desert are snakes, birds, insects, lizards and small carnivores (meat eaters). There are four sub-desert biomes as follows:

(A) The Hot and Dry Deserts – These would include places like the Sahara in North Africa and the Chihuahuan of the southern U.S. and parts of Mexico.

(B) The Semi-Arid Deserts – These would include sagebrush areas found in Utah, Montana and the Great Basin.

(C) The Coastal Deserts – These would include the Atacama Desert of Chile and Peru.

(D) The Cold Deserts – Cold deserts are found in higher elevations. Antarctica is considered a cold desert.

2. The Aquatic Biomes: The aquatic biomes include all bodies of water found on the Earth’s surface. Living things in these biomes depend upon abiotic factors such as sunlight, temperature, pressure and salt. In water biomes, the amount and variety of plants is directly related to the amount of sunlight that can penetrate the water. The sunlight also affects the amount of algae and plankton (both food sources for aquatic life). Aquatic biomes in colder areas tend to have fewer plants and, hence, aquatic life. The aquatic biomes are divided into two sub-biomes.

(A) The Freshwater Biomes - This includes streams, rivers, lakes, ponds and wetlands. The Amazon River in Brazil is an example of a freshwater biome. A few examples of animals that live in the freshwater biomes include salmon, tilapia worms, water-surface insects and crabs.

(B) The Marine Biomes – This includes oceans, coral reefs and estuaries. The marine biomes make up around 73% of the Earth’s surface. A few examples of animals that live in the marine biomes include fish, starfish, sharks, whales, otters and sea birds.

3. The Forest Biomes: The forest biomes make up about 30% of the Earth’s landmass. Forest biomes are a warehouse of carbons and they play a huge role in climate control for the entire planet. Even a very small portion of the Rainforest, for example, is home to literally millions of insects, birds, animals and plants. For the most part, temperatures in forest biomes are high all year round but are cooler at the surface or floor of the forest. It is cooler at the floor because very little sunlight can penetrate through. All forest biomes have skunks, deer, squirrels, foxes, birds, bats, insects and reptiles. There are three main forest biomes. These three are:

(A) The Tropical Rainforest – Plants found in the tropical rainforest include unusually huge trees with buttress roots, lots of large green leaves, ferns and palms.

(B) The Temperate Forest – In the temperate forest plants are less dense allowing for more sunlight to penetrate through. Trees found in this biome include willows, elms and basswood.

(C) The Boreal Forest - The boreal forest is also known as the Taiga. It contains trees that have more needle-like leaves such as the fir and the spruce trees.

4.The Grassland Biomes: The grassland biomes are large areas that are dominated by one or a few specific species of grass and have very few trees. There are two grassland biomes as follows:

(A) The Savanna Grasslands - Soils in savanna are thin layered. They also do not hold water. The soils do contain some organic matter from dead grass which then becomes the main source of nutrients for plants. A major savanna grassland is found in Africa. It takes up more than a third of the African continent. Other large savanna grasslands can be found in India, South America and Australia. Savanna grasslands have a good to moderate amount of rainfall. Some animals that live in this biome include lions, hyenas, snakes, giraffes, buffaloes and lots of insects.

(B) The Temperate Grasslands – Temperate grasslands are found in South Africa, Argentina, and in some plains in both Central and North America. The temperatures in the temperate grasslands go from one extreme to another with high temperatures in the summer and freezing, cold temperatures in the winter. Animals that can be found in these biomes include hawks, owls, deer, mice, foxes, rabbits and spiders.

5. The Tundra Biomes: The tundra biomes are the coldest of all the land biomes. “Tundra” comes from a Finnish word, Tunturia, which means “barren land.” There is very little rain in the tundra biomes but they have extremely freezing temperatures. In addition, tundra biomes cover approximately 20% of the Earth’s landmass. There are two major tundra biomes. They are:

(A) The Arctic Tundra – The arctic tundra is located in the northern hemisphere near and around the north-pole. The arctic tundra has temperatures of about 2-3° C in the summer and about -35° C in the winter. Plants that can be found in the arctic tundra are short and grow closely to each other. These include mosses, heaths and lichen. Animals include herbivores like hares and squirrels, as well as carnivores such as polar bears and artic foxes. In addition, there are several types of birds, insects and fish like cod and salmon.

(B) The Alpine Tundra - The alpine tundra is very cold. These biomes are located on top of very high mountains. Very few trees and vegetative is able to grow as the land is covered with ice for most of the year. Animals in the alpine tundra include birds, mountains goats and marmots, as well as some insects such as beetles and butterflies.

And there you have the major habitats found on the Earth. Now let’s see how well you can remember each habitat or biome. Look at the following questions and locate the correct answers.