What is a Biome?

WHAT IS A BIOME?

A biome is a large geographic region characterized by the type of climate, animals, and plants found in that area. The organisms in a biome often have similar characteristics that allow them to survive and thrive in a given region. Biomes are also called major life zones.

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CATEGORIES OF BIOMES

There are two main categories of biomes: terrestrial and aquatic biomes. These are further divided into the major types of biomes found in different parts of the earth.

TERRESTRIAL BIOMES

Terrestrial biomes are land-based and can be defined by the type of plants in an area. These biomes have different types of trees, grasses, and shrubs.

Types of Terrestrial Biomes

Terrestrial biomes are divided into five major types:

(a) Forest Biome

• Forests cover up to 30% of the earth’s surface. They are complex ecosystems that create specific conditions which determine the species of animals that can exist in a region.

Examples of Forest Biomes:

Tropical Rainforest Biome

• These rainforests are found close to the equator. Tropical rainforests create hot and wet biomes that allow prolific plant growth. The Amazon forest is a good example of a tropical rainforest.
• Tropical rainforests contain several trees that provide shelter to different species of animals.
• The trees in tropical rainforests absorb a large percentage of the carbon dioxide in the earth’s atmosphere.

Temperate Forest Biome

• Temperate forest biomes experience all four seasons throughout the year.
• The temperature conditions may vary depending on whether it is winter, summer, spring, or autumn. They also experience varied precipitation.
• These forests mainly consist of broadleaf trees such as maples, hickories, oaks, etc. The trees in temperate forest biomes shed their leaves during certain seasons.

Boreal Forest (Taiga) Biome

• Boreal forest biomes are characterized by long dry winters and are found at higher latitudes. These regions are mainly made up of coniferous trees with needle-like leaves.
• The animals in taiga biomes have thick fur that keeps their bodies warm even in sub-zero temperatures.
• Precipitation mainly occurs in the form of snow in boreal biomes.

(b) Tundra Biome

• Tundras are the coldest terrestrial biomes. This biome is split into alpine and arctic biomes.
• Arctic biomes are found in the nethermost region of the earth and are defined by extremely low-temperature conditions. They also experience poor drainage.
• Alpine biomes are located in mountainous regions and have better drainage than arctic biomes.
• Tundra biomes have few or no plants. Lichens, grasses, shrubs, mosses, and sedges are some of the common plants found in the tundra biome.
• Polar bears, arctic foxes, reindeers, and arctic hares are good examples of tundra biome animals.

(c) Grassland Biome

• Grasslands often have warm and dry climates. These areas are mostly dominated by grass.
• There are two types of grassland biomes—temperate grasslands and tropical grasslands/ savannas.
• Tropical grasslands or savannas are found around the equatorial regions of the earth. They receive a substantial amount of rain at specific times of the year, followed by severe drought. Savannas have few trees due to insufficient rainfall.
• Temperate grasslands are found further away from the tropics. They are characterized by extremely cold winters and hot summers. These regions receive moderate precipitation in the form of rain or snow.
• Gazelles, elephants, ground squirrels, and giraffes are well adapted to grassland biomes.

(d) Desert Biome

• Deserts are the driest terrestrial biomes. They receive less than 20 inches of rain per year and are defined by high temperatures. Subtropical deserts are extremely hot during the day and cold during the night.
• There is no biodiversity of species in the desert due to the harsh climatic conditions.
• Desert plants and animals have unique adaptations that allow them to survive. For example, cacti have thick stems that can store a lot of water, while animals burrow to escape the heat.
• Camels, scorpions, and lizards are some of the animals that thrive in desert biomes.

(e) Chaparral Biome

• Chaparral biomes are found in a few regions around the world. They have hot, dry summers and rainy winters.
• Since chaparral areas receive minimal rainfall (less than 30 inches) in a year, they are characterized by shrubs and scattered trees.
• A chaparral biome is vulnerable to fires during hot summers. The southern parts of California and central Australia are perfect examples of chaparral biomes.
• Jackrabbits, mule deer, and coyotes are chaparral animals.

AQUATIC BIOMES

Aquatic biomes can be classified based on the type of water found in the region. These biomes can be divided into two main categories: marine and freshwater biomes.

Types of Aquatic Biomes

(a) Marine Biome

• This is the largest biome on the planet. The marine biome consists of all the oceans in the world and is defined by saltwater conditions.
• The ocean biome covers 70% of the earth.
• Coral reef and estuary biomes are also part of the marine biome.
• Estuary biomes are found in areas where freshwater bodies meet the ocean.
• Coral reef biomes are located in the shallow parts of the ocean, especially near the tropics. Corals provide shelter to different species of marine animals. The sea turtle biome is mainly found around the corals.

(b) Freshwater Biome

• Freshwater biomes consist of both small and large water bodies that are surrounded by land. This includes lakes, rivers, ponds, and streams.
• These biomes contain less than 1% of salt content. Freshwater biomes host a wide range of fish species, algae, and other microorganisms that are not adapted to saltwater.

WHAT ARE THE THREE MAJOR THREATS TO TROPICAL RAINFOREST BIOME?

Deforestation

Deforestation is the cutting down of trees without planting new ones. Tropical rainforests are cut down to make room for new settlements and farms.

Climate Change

Adverse changes in climatic conditions around the tropics cause a rapid increase in temperature. When temperatures rise, there will be a reduction in rainfall, leading to a decrease in the number of trees.

Over-exploitation

Trees are a source of fuel and timber. When tropical rainforests are logged at a faster rate than reforestation, they can easily be overexploited.

BIOMES ARE ESSENTIAL FOR THE STUDY OF ECOLOGY

Biomes can help us have a better understanding of the existing ecosystems. Through them, we can learn how plants and animals adapt to their environment. Scientists can achieve this by studying how members of a particular biome interact in their natural habitat.

Some biomes are, however, under threat. The tropical rainforest and coral reef biomes need to be protected to prevent the extinction of certain species.

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