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A biome is a large biological community or ecosystem in which various types of living organisms such as plants, animals, birds, insects, and humans are accustomed to living in a specific type of climate. The world contains a huge diversity of environments, which are divided and grouped into different types of biomes based on adaptations, temperature range, weather, and climatic conditions. In 1916, ecologist Frederic Edward Clements proposed the term “biome,” which referred to the term biotic community.
Biogeographers have divided the earth into large, climatically distinct areas with similar flora and fauna. These areas are known as biomes. The tropical evergreen forests of Congo Basin, Africa, have tall, lush green trees, colourful birds, and butterflies. Thousands of kilometres away, evergreen forests in South America look the same. Upon close observation, the plant and animal species might differ from the Congo Basin. However, the essential characteristics of plant and animal life remain the same. These areas fall under the same biome. Therefore, a biome may be defined as a large area where the biota has minimum common characteristics and have more or less uniform environmental conditions.
Read More: Climatology
Biomes of the World
Biomes are large ecosystems characterized by distinct climates, flora and fauna. Some of the main Biomes of the World include:
Biomes Factors Affecting
Below are the factors affecting biomes.
Temperature and Precipitation
Temperature and precipitation are important factors that influence biome characteristics and distribution. Temperature and precipitation variations affect various aspects of biomes, such as plants. Biomes with low precipitation and extreme temperatures have short growing seasons and poor soil. Thus, fewer types or quantities of plants and animals will grow under these conditions.
Differences in biomes can also be caused by latitude. This depends on their position in relation to the Equator. The temperature will vary depending on which angle receives sunlight. For example, biomes in high latitudes farthest from the Equator, such as taiga and tundra, receive the least sunlight and have lower temperatures. However, biomes in the middle latitudes between the poles and the Equator, such as temperate deciduous forests, receive more sunlight and have moderate temperatures.
Elevation refers to the height of land above sea level, and it has a significant impact on biomes. The change occurs as the atmosphere thins at higher elevations, retaining less heat. Elevation influences precipitation because moist clouds rise and release rain or snow.
Read More: Equatorial Climate Region
There is a close relationship between climate types and the world’s distribution of biomes. The biomes are divided into three major types based on climate type. These are Tundra Biome, Temperate Biome, and Tropical Biomes. Further, these three biomes are divided into sub-types based on dominant vegetation. Below are the important biomes of the world.
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Tropical biomes are discussed below:
- Tropical Evergreen Forest
- Monsoon Deciduous Forests
- Savanna Biome
- Desert Biome
- Mediterranean Biome
Tropical Evergreen Forest
Tropical evergreen forests are dense and multi-layered, and they are home to a diverse range of plants and animals. These forests can be found in areas that receive a lot of rain (more than 200 cm annual rainfall). They are extremely dense. Even sunlight cannot reach the ground. These forests are home to numerous tree species.
The tropical evergreen forests are found between 5° and 10° north and south of the equator. Its greatest range is located in the Amazon Basin (South America), Congo Basin (Africa), and Indo-Malaysian region (Java, Sumatra, Borneo, Malaysia, and Guinea).
Tropical evergreen forests thrive in a climate that is consistently warm, frost-free, and mostly wet throughout the year. The monthly average temperature is always around 27°C. The daily temperature is moderated by cloudiness and heavy precipitation. Plants grow abundantly in such situations.
Plant and Animal Species
The tropical evergreen rainforest biome contains the most plant species. For example, 6000 to 7000 species of flowering plants have been identified in western Africa (Congo Basin); 20,000 species of flowering plants in Malaysia, 40,000 species of flowering plants in Brazil; and 2000 species of flowering plants in the Panama Canal Zone. In tropical evergreen forests, tall, tightly spaced evergreen trees, woody vines, and climbers are major plant species. The floor of the tropical evergreen forest is usually densely shaded by a canopy of tree crowns.
Major animal species include herbivores such as sloths and tapirs; carnivores such as jaguars; anteaters; monkeys; birds such as toucans, and parrots, etc. Numerous colourful butterfly species are also found.
The productivity of the tropical evergreen forest biome is the highest of all biome types in the world. It accounts for 40 per cent of the total biological productivity of the world.
Human and Tropical Evergreen Forests
The forests are sparsely populated in terms of life and economy. The majority of primitive people in the forests are hunter-gatherers. The more advanced people practice shifting cultivation. Many tropical rainforests have been cleared for felling or shifting cultivation.
Read about: Continental Drift Theory
Monsoon Deciduous Forests
The biome of any open woodland in tropical areas has a long dry season followed by a season of heavy rainfall, also known as monsoon forest or tropical deciduous forest.
It is found in latitudes ranging from 5° to 30° latitude on either side of the equator. They are most developed in India, Burma, Thailand, Laos, Cambodia, parts of Vietnam, south China, and northern Australia.
The climate is characterized by tropical rainy seasons and dry seasons. The average temperature in summer ranges from 27°C to 30°C. The average annual rainfall is 1500mm.
Plant and Animal Species
The natural vegetation of tropical monsoon lands is determined by the rainfall received during the summer. Trees are deciduous due to the prolonged dry period. They shed their leaves to survive the drought period. There are fewer plant species than evergreen forest biome. Sal, teak, and bamboo are major plant species.
Major animals found in these forests include rhinos, elephants, tigers, wild buffalo, etc. Several bird species are also found.
Human and Tropical Monsoon Deciduous Forests
The biome has the largest human population in the world. Agriculture is the people’s primary economic activity. Rice, cane sugar, jute, and other major crops are grown.
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The savanna biome is frequently described as grassland with scattered trees or clusters of trees. The savanna’s lack of water makes it difficult for tall plants like trees to grow. Savanna grasses and trees have adapted to life with little water and high temperatures.
The Savanna or Sudan Climate is a transitional climate between the equatorial forest and the hot deserts. It is restricted to the tropics and thrives best in Sudan, where the dry and wet seasons are most distinct. The belt extends from West African Sudan to East Africa and southern Africa north of the Tropic of Capricorn. In South America, there are two different savannah regions located north and south of the equator, namely the llanos of the Orinoco basin and the Campos of the Brazilian Highlands. They are also found in northern Australia.
Savanna’s climate is distinguished by distinct wet and dry seasons. There is also no distinct rainy season, as there is in the monsoon climate. The average annual temperature is higher than 18° C. The days are hot, and the nights are cold.
Plant and Animal Species
The trees are spaced widely apart because of insufficient soil moisture. A dense lower layer develops in the open spacing, usually consisting of grasses. They have an open park-like appearance. Baobab, palm, and eucalyptus are some plant species found in the savanna biome.
The African savanna has the largest number of grazing animals. Some important species are African buffalo, zebra, giraffes, and elephants. The Australian Savanna is dominated by kangaroos.
Human and Savanna Biome: The economy of many tribes is based on the savanna lands. The Masai tribes are pastoralists, while the Hausa of northern Nigeria is settled farmers. However, agriculture is still underdeveloped.
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A desert biome is a collection of habitats that develop in arid (dry) environments as a result of little or no rainfall (50 cm per year).
The major hot deserts of the world are located on the western coasts of continents between latitudes 15º and 30º N and S. They include the Sahara Desert (3.5 million square miles), the Great Australian Desert, the Arabian Desert, the Iranian Desert, the Thar Desert, the Kalahari Desert, and the Namib Desert. The desert in North America stretches from Mexico into the United States. It is known by various names such as the Mohave, Sonoran, Californian, and Mexican Deserts. The Atacama or Peruvian Desert is the driest desert in South America. It receives less than 2 cm of rain per year.
The deserts are some of the hottest places on Earth, with high temperatures all year. In the hot deserts, the average summer temperature is around 30°C. In the Sahara, the highest shade temperature recorded is 58°C at Al Azizia, Libya. The diurnal temperature range in the deserts is large. Rainfall is scanty- below 30 cm.
Plant and Animal Species
Plants in desserts are well adapted to conserve water. They are called xerophytes and have thick, fleshy stems and spines, for example, cacti. The main animals are arthropods, reptiles, birds and mammals. Large animals are generally not found. Small rodents are the most common animal followed by foxes and rabbits. These animals are also well adapted to extreme climatic conditions. For example, black-tailed jackrabbits are also adapted to have extra-long ears to help transfer excess heat from their body into the air.
Human and the Desert Biome
The desert has always been inhabited by various groups of people. The desert inhabitants are classified as follows: primitive hunters and collectors (Bushmen and Bindibu), nomadic herdsmen (Tuaregs of the Sahara, Gobi Mongols, and Bedouin of Arabia), caravan traders, settled cultivators, and mining settlers. Temperate Biome
Temperate biomes are found between the tropics and the poles. The differences between summer and winter in these regions are generally moderate, rather than extreme. This enables a wide range of habitats, including forests and grasslands.
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Mediterranean vegetation, is any dense scrubland composed of broad-leaved evergreen shrubs, bushes, and small trees growing in regions between 30° and 40° north and south latitudes.
It is found between 30°-40° latitudes in both hemispheres. They are found in western parts of the continents. It includes the European lands bordering the Mediterranean Sea, central and southern California in the USA, central Chile in South America, north-western coastal lands of Africa bordering the Mediterranean Sea, coastal zones of Western and Southern Australia, western Turkey, Syria, western Israel and Lebanon.
It is characterized by a Mediterranean type of climate. The summers are warm and dry and the winters are cool. Most of the rainfall occurs during the winter. The average temperature in winter ranges from 5-10C, while the average summer temperature ranges from 20-27C. Average rainfall range from 370mm to 650mm.
Plant and Animal Species
It is dominated by trees and shrubs. Shrubs and trees are equipped with small, hard, or thick leaves that resist water loss through transpiration during the dry summers. These plants are called sclerophylls. Some important plant species include holm oaks, olive trees, laurels, carob trees, junipers, and cypresses. Herbs like rosemary, thyme, sage, and oregano are also found.
The biome is home to animals like wild goats, sheep, cattle, mouflon, lynx, wild boar etc.
Human and Mediterranean biome: The region is significant for fruit cultivation, cereal production, winemaking, agricultural industries, engineering and mining.
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Temperate Grassland Biome
Temperate grasslands have cold winters and warm, rainy summers. Annually, the grasses die back to their roots, and the soil and sod protect the roots and new buds from the cold of winter and dry conditions. Because of the lack of rainfall, this biome may have a few trees along the streams.
The temperate grasslands are located in the interiors of the continents in the northern hemisphere. In the southern hemisphere, they are located on the southeastern margins of the continents. The grasslands are known by different names in different parts of the world.
- The temperate grasslands are known as steppes in Eurasia. They stretch from the shores of the Black Sea to the plains of Manchuria in China.
- In North America, grasslands are known as Prairies. They lie between the foothills of the Rockies and the Great Lakes.
- The temperate grasslands are known as Pampas in Argentina and Uruguay. In South Africa, they are known as Velds and are located between the Drakensberg mountains and the Kalahari desert.
- They are known as Downs in Australia and are found in the Murrary – Darling basins of South Australia.
The temperate grasslands of the northern hemisphere are characterized by a continental climate. Extreme summer and winter temperatures are recorded. In the southern hemisphere, temperate grasslands have a moderate climate as they are located closer to the sea. In the grasslands of both hemispheres, rainfall is received mostly in summer.
Plant and animal species: The natural vegetation of these regions comprises treeless grasslands. These grasses are perennial and belong to the family Gramineae. Major animals species of the grasslands include antelopes, wild asses, horses, wolves, kangaroos, emus, and dingo
Human and Temperate Grasslands: The grasslands have been ploughed up for extensive, mechanized wheat cultivation. They have become the world’s granaries. Maize is increasingly being grown in warmer and wetter climates. The grasslands also provide grazing grounds for a wild range of animals.
The taiga is a cold-weather subarctic forest. The subarctic region of the Northern Hemisphere is located just south of the Arctic Circle. The taiga is located between the tundra and temperate forests to the north and south, respectively. Taigas can be found in Alaska, Canada, Scandinavia, and Siberia.
In the northern hemisphere, it is located in the sub-arctic region, south of the Arctic Circle. It is found in Alaska of USA, Canada, Scandinavia, and Siberia. They are also known as the Boreal forest Biome.
The taiga biome has the lowest annual average temperatures, with mean annual temperatures ranging from -5 to 5 °C. The winters are long and cold while the summers are short and warm. The rainfall is low.
Plant and animal species: The most dominant member of the Taiga Biome is coniferous trees. These trees form dense forest cover, which is one of the world’s richest sources of softwood. Coniferous trees have needles instead of leaves. They don’t shed their needles in winter and hence are called evergreen.
There are four major evergreen coniferous trees: pine (white pine, red pine, Scots pine, jack pine, lodgepole pine, etc.), fir (Douglas fir, balsam fir, etc.), spruce (Picea), and larch (Larix). A few species of temperate deciduous hardwood trees have developed in this climate. These species are primarily in areas cleared by man through the felling of original temperate coniferous trees. Temperate deciduous trees found in this biome include alder, birch, and poplar trees.
Animals are well adapted to the cold. Moose, lynx, bears, Siberian tigers etc are found in this biome. Birds of this biome are migratory. They migrate to the south during freezing, harsh winters.
Humans and the Taiga Biome
Forests are cleared for lumbering. There is little agriculture because few crops can survive in harsh climates. Siberian Samoyeds, Yakuts, and some Canadians engage in hunting, trapping, and fishing.
The Tundra ecosystem is devoid of trees and is blanketed in snow for the majority of the year. This type of ecosystem is most common in cold climates with little rainfall. Because of its harsh climate, this climate is found at lower altitudes and is very similar to deserts.
Tundra is a Finnish word that means “deserted land.” This means that the tundra region has the least amount of vegetation and the most extreme polar or arctic climate. It is further classified as (i) arctic tundra biome and (ii) alpine tundra climate (which is found over high mountains of tropical and temperate areas).
Polar climate and vegetation are found primarily in the northern hemisphere north of the Arctic Circle. The ice cap is limited to Greenland and the highlands of these high-latitude regions. The ground is permanently covered in snow in these areas. Tundra vegetation can be found in the lowlands during the few months when the ice is not present. They include Greenland’s coastal strip, the barren lands of northern Canada and Alaska, and the Arctic coastal region of Eurasia.
It has a very low mean annual temperature and its warmest month, June, rarely exceeds 10°C. Temperatures in mid-winter (January) can drop to -35°C and are much colder in the interior. Winters are long and harsh, while summers are cool and brief. Precipitation is primarily in the form of snow. It falls in winter and is blown around during snowstorms.
Plant and Animal Species
Plants grow during the brief summer of long days and short (or absent) nights. Plant species are dwarf. Major vegetation includes grasses, mosses, lichens, flowering herbs, and shrubs. They mainly grow in summers when marshy land develops. Air temperatures rise above freezing and a shallow surface layer of ground ice thaws during summers. However, the permafrost beneath remains frozen, keeping the meltwater at the surface. These conditions produce a marshy environment for a short time over wide areas.
Not much variety of animals is found because of the harsh climate. Major animal species include reindeer, wolves, foxes, musk-ox, arctic hares, seals and lemmings.
Human and the Tundra Biome: The economy of the tundra is primarily confined to the coast. The few people who live in the tundra are semi-nomadic and adapt to harsh environments. The discovery of minerals has prompted new settlements, aside from the efforts of governments to help the Eskimos, Lapps, and Samoyeds.
The terrestrial portion of the biosphere is divided into large sections known as biomes, which are defined by climate, flora, animal life, and general soil type. There are no two identical biomes. The climate determines the boundaries of each biome, as well as the abundance of plants and animals that inhabit it. The most important climatic elements are temperature and precipitation.
The terrestrial portion of the biosphere is divided into large sections known as biomes, which are defined by climate, flora, animal life, and general soil type. There are no two identical biomes. The climate determines the boundaries of each biome, as well as the abundance of plants and animals that inhabit it. The most important climatic elements are temperature and precipitation. This article will explain Biome, which will help you prepare for the UPSC Civil Service exam’s Environment syllabus. This article will explain Biome, which will help you prepare for the UPSC Civil Service exam’s Environment syllabus.