BIOMES
Pre & Mains
AKSHAY VRAT
Environment, Ecology and Biodiversity
BIOMES
• AKA Ecoregions
• Biomes are very large ecological areas on the earth’s surface, with fauna
and flora (animals and plants) adapting to their environment. Biomes are
often defined by abiotic factors such as climate, relief, geology, soils and
vegetation.
• Biomes are large regions of the world with similar plants, animals, and
other living things that are adapted to the climate and other conditions.
BIOMES
• A biome is NOT an ecosystem, although in a way it can look like a massive
ecosystem. If you take a closer look, you will notice that plants or animals in
any of the biomes have special adaptations that make it possible for them to
exist in that area. You may find many units of ecosystems within one biome.
• Earth's biomes are areas with similar climate, geography, and other conditions
as well as similar plants, animals, and other living things.
BIOMES
• They were chosen based on the following parameters:
• species richness.
• Endemism.
• higher taxonomic uniqueness (e.g., unique genera or families, communities,
primitive lineages).
BIOMES
• There are five major categories of biomes: Aquatic, Grassland, Forest, Desert,
and Tundra.
• In these five, there are many sub-biomes, under which are many more well
defined ecosystems.
BIOMES
THE DESERT BIOMES
• They are the Hot and Dry Deserts, Semi Arid Deserts, Coastal Deserts and Cold
Deserts.
• Deserts makeup about 20% of total land cover on earth and are characterized
by little(less than 50cm/yr.) or no rainfall.
• Desert biomes come in four major kinds— each of these having their unique
features but have similarities in their biotic and abiotic makeup.
THE DESERT BIOMES
• They are the Hot and Dry Deserts, Semi Arid Deserts, Coastal Deserts and Cold
Deserts, and within these are many deserts located in many places of the
world.
• Desert biomes have very high temperatures because of the little vegetative
cover, less cloud cover, low atmospheric moisture and the land’s exposure to
the sun. Humidity is very low, with a few events of very little rain in a year.
DESERT BIOME
• Soil cover is shallow and rocky, as a result of very little weathering
(breakdown) and supports only a few plant types. Soils have very little or no
organic matter, and very low in salt content.
• Plants that survive here are short shrubs and cacti, which have the ability to
conserve water.
• Plants are also less leafy, using their stems for photosynthesis. Examples of
plants are the yuccas and the sotol.
DESERT BIOME
• Animals here tend to burrow, or stay in hideaways till dusk to avoid the heat.
They are mainly small carnivores, birds, insects, snakes and lizards, and are
adapted to survive with very little water. Examples of the Hot and Dry Desert
biomes include the Sahara of North Africa and the Chihuahuan of Southern
USA and parts of Mexico.
• Desert Biome
• Annual precipitation is less than 25 cm of annual rainfall
• Evaporation losses are higher than precipitation.
DESERT BIOME
• Desert Biomes are of two types: Hot and Cold
• Hot desert – mostly found in sub-tropical area, lie between 20-30 degrees N
and S, they are found in western side of continent, large range of temperature,
days are hot and nights are cool, low humidity, high temperature, absence of
rain
• Cold desert – mostly found beyond sub-tropical areas towards the poles,
annual precipitation is low but overall temperature is cold.
DESERT BIOME
• Vegetation in desert biomes are mostly xerophytes which have modified roots
to penetrate deepening soil modified stem into fleshy and spongy structure to
store water, leaves are hard and waxy to evapo-transpiratory losses,
reproductive cycle extends for just few days when the moisture is high.
DESERT BIOME
• Evapotranspiratory losses are higher.
• Precipitation in Desert; True desert rainfall is less than 12cm.
• Extreme desert rainfall is less than 7cm (Atacama, Peruvian)
• Adaptations in Desert vegetation:
• Roots: modified into tap root and hair like rootlets to penetrate deep (deep
root system)
• Stem: sometimes fleshy to store water, plants with fleshy stem are called
succulents.
DESERT BIOME
• Leaf: hard and waxy, to reflect sunlight and deep sunken stomata for lowering
transpiration. Also leaves modify into spines and thorns. E.g. Cactus, Babool,
Acacia, Date palm, Khijdi/Khejri.
• Reproductive cycle: plants reproduce quickly when favorable conditions arrive.
• CAM Pathway: Photosynthesis at Night (Skotoactive stomata).
• Xeromorphic Animals: Adaptations like no sweat gland, padded feet, Store fat
in Hump.
HOT DESERT
• Great sandy desert Australia
• Great Victorian desert Australia
• Gibson desert Australia
• Simpson desert Australia
• Great Salt Desert : Iran
• Dasht-e-lut : Iran
• Sonoran : USA and Mexico
• Mojave : USA and Mexico
• Kalahari : Namibia
• India:
• Western Part of Rajasthan, adjoining
part of Haryana, Punjab and Gujarat.
• Bundelkhand region UP/MP, Some
part of CG
• Deccan Plateau : MH/ TG/ KA
COLD DESERT
• Gobi Desert : China, Mongolia
• Patagonia Desert : Argentina, Chile
• Taklamakan Desert : China
• Kyzyl-Kum Desert : Central Asia
• Karakum Desert : Turkmenistan
• Colorado Plateau, Great Basin Desert : USA
• Namib Desert : Angola Namibian (cooling effect of cold ocean current)
THE FOREST BIOMES
• There are three main biomes that make up Forest Biomes. These are the
Tropical Rainforest, Temperate and Boreal Forests (also called the Taiga)
Examples of animals found in marine biomes include star fishes, sharks and
tuna and sea birds. Examples of animals in freshwater biomes include salmon,
tilapia worms, water-surface insects and crabs.
FOREST BIOME
• Small mammals, birds, insects and bats are common in the tropical
rainforests, as they either can fly up for sunlight or do not need sunlight.
However all the forest biomes have lots of skunks, deer, squirrels, foxes,
birds and reptiles.
• An example of the Tropical Rainforest is the Amazon. Other examples are
the Scandinavian forest (boreal) and those in the North East of America.
TROPICAL RAIN FOREST
• Also known as Tropical Moist Equatorial Evergreen Forest.
• Considered as Optimum Biome for favorable climatic conditions.
• Distribution is between 28 degrees N to 28 degrees S
• Temperature is from 25 degrees Celsius to 30 degrees Celsius, it has to be
above 18 degrees Celsius throughout the year
• Seasonal range of temperature is very small
• Cloudy weather condition specially after noon
• Relative humidity is high with high rainfall
TROPICAL RAIN FOREST
• Seasons remains constant throughout the year
• Vegetation of rain forest in multi-layered with canopy layer at top understory
layer between canopy and forest floor
• Occupy roughly 13% of global land area but responsible for 40% of Global
NPP.
• Very high biodiversity rich in epiphytes, orchids, mosses and lichens
• Great species diversity but bigger animals are not found
• Economic exploitation of this area is difficult because of hard wood trees
TROPICAL RAIN FOREST
• Space and Sunlight are limiting factors.
• Forest floor receives just 3% to 15% sunlight thus only few adapted plants can
grow.
• Nutrition source are mainly Fallen leaf, Bacterial and fungal decay is high.
• Soil is unfit for agriculture due to high rainfall and leaching of nutrients.
• They maintain high specie richness especially rich flora of epiphytes like
orchids, bromeliads, mosses, Lichens, Climbers and poorly developed herbs.
• Trees : Rubber, Rosewood, Mahogany, Cocoa in Africa, Ebony and cinchona.
TROPICAL RAIN FOREST
• Fauna: Nocturnal (active at Night), crepuscular (active at morning and
evening) Bison and African elephant, Arboreal (live on tress) Chimpanzee,
Gorilla.
TROPICAL RAIN FOREST
• Areas: Amazon basin of South America, Orinoco Basin (South America),
Central American isthmus, Central America Islands like belize, Honduras, El
Salvador, Congo Basin (Democratic Republic of Congo of Africa), Western
Africa, Some parts of Madagascar, South East Asian countries, Pacific and
Indian ocean islands.
• India: Lakshadweep, western Ghats, North east, Andaman and Nicobar Is.
• Semi Evergreen: Coastal Part of West Bengal and Odisha, Some parts of Tamil
Nadu, Chhattisgarh and Madhya Pradesh.
TEMPERATE DECIDUOUS FOREST
• Also called Temperate Broad Leaf forest biome
• It is found between 40 degrees-60 degrees N and S
• Good for economic exploitation as single species dominates throughout the
region
• Average temperature is between 18-25 degrees Celsius during summers and
can go as low as zero degrees Celsius in winters
• Thus, summers are warm and moist whereas winters are mild
TEMPERATE DECIDUOUS FOREST
• Rainfall is between 50-120 cm and the autumn season is the driest (shedding)
• Thus, the trees shed their leaves in the autumn season.
• Flora: Oak, Elms, Beech, Maple, Red wood, Birch and Fir, Kauri (Kauri gum),
spring ephemerals (Grow and flower in short favorable period)
• Eastern North America, Eastern Asia, NW Europe, Some parts of Tasmania,
New Zealand, and Southern S. America.
• Great Smoky Mountain National Park (Tennessee N Carolina, USA): Best
Temperate deciduous forest (Also UNESCO World Heritage site).
TROPICAL DECIDUOUS FOREST / MONSOON BIOME
• It is also called Sub Tropical and Tropical Dry Broad Leaf forest
• It sheds its leaves at the same time during the dry season under influence of
Abscisic Acid (ABA).
• It is found between 10 degrees-20 degrees N and S, in South Asia it is found
in 30 degree N
• Three seasons are seen: Hot, Rainy and Winter
• Rainfall is between 75-200 cm
• 60% of forest in India is Tropical Deciduous Forest.
TROPICAL DECIDUOUS FOREST / MONSOON BIOME
• Vegetation is broad leaf deciduous with important trees of Teak, Tendu, Bamboo
(in Rainy season), Saal, sheesham, kusum, Arjun, Eucalyptus, Mulburry, Mountain
Ebony, Baobab etc.
• Found in Indo-China (Myanmar, Cambodia, Vietnam), Mexico, South Asia, Bolivia,
Madagascar.
• Moist Deciduous: Some parts of leeward side of western ghats, inner part of North
east and Islands, terai region of Himalayas, western odisha with adjoining parts of
Jharkhand and Chhaitisgarh, Most forest of MP except Bundelkhand.
TROPICAL DECIDUOUS FOREST / MONSOON BIOME
• Dry Deciduous: Maximum forest in India, All areas except Himalayas, North
East, Islands, Goa and Kerela.
• Economic exploitation is comparatively easier. Over 95% of original biome is
destroyed.
• Fauna : Wild Dogs, Dhole (mammal), Sloth bear, Horse, Rhino, Buffalo, Largest
human population and domestic animals are found here.
THE GRASSLAND BIOMES
• There are two main types of grassland biomes: the Savanna Grasslands and
the Temperate Grasslands.
• As the name suggests, these are massive areas dominated by one or a few
species of grass, with a few sparsely distributed trees. There are two main
types of grassland biomes: the Savanna Grasslands and the Temperate
Grasslands. One major savanna is located in Africa and takes up more than a
third of the continent's land area. Others can be found in India, South
America and Australia.
• Temperate grasslands can be found in South Africa, Argentina, and some
GRASSLAND BIOME
• If the grassland is prevented from developing into a forest by climatic conditions
such as rainfall, it is termed as ‘climatic savannas’. If their characteristics are kept by
soils, they are termed as ‘edaphic savannas’.
• Sometimes, large animals such as elephants can constantly disturb young trees
from taking over grasslands. Human activities such as farming or bush fires can
also prevent grasslands from developing into forests. Such grasslands are termed
‘derived savannas’.
GRASSLAND BIOME
• Soils in savanna are thin-layered and do not hold water. The soils contain some
organic matter from dead grass, which is the main source of nutrients for
plants.
• Rainfall is moderate, and not enough to cause major floods. Animals in the
savannas include large mammals such as lions, hyenas, snakes, giraffes and
buffaloes with lots of insects.
• Temperatures in the Temperate grasslands are extreme, with high summer and
freezing winter temperatures.
GRASSLAND BIOME
• Animals here include hawks, owls, deer, mice, foxes, rabbits and spiders.
Temperate grasslands with short grasses are called ‘steppes’ and those with tall
grasses are called ‘prairies’
TROPICAL GRASSLAND BIOME
• Found in Semi Arid and Semi humid climate variation.
• Forms continuous belt in Africa and Australia.
• Africa : South of Sahel region.
• S. America: Campos (Brazil), Llanos (Venezuela, Colombia and Bolivia).
• Australia: Northern region, Queensland (Rangeland).
• India: Banni Grassland (Gujarat), Shola grassland (Low lying)
• Terai Duar Savannah : UP, Bihar, Assam, Also in Bhutan and Nepal.
• Indian Savannah in Karnataka, AP, Telangana, MP, Chhattisgarh, Rajasthan,
Gujarat, Maharashtra.
TROPICAL GRASSLAND / SAVANNAH BIOME
• Flora: trees are scattered, seasonal rains allows grass to grow taller. Eg. Elephant
grass, Baobab, Acacia. Dominated mostly by grass, scrubs and shrubs although
trees are scattered.
• Indian Savanna also has Teak, Saal and Bamboo.
• Fauna is rich in grazing Animals
TEMPERATE GRASSLAND/ PRAIRIES BIOME
• Soil is fertile, In fact it is considered as one of the most fertile soil due to
ambient nutrients and minerals. Ideal for extensive agriculture , some of the
most productive grain growing regions.
• Biome is largely Treeless because moisture is limiting factor.
• Areas: Prairies : Southern Canada, Central USA
• Steppe: Mongolia and Central Asia
• Downs: Murray Darling Basin in Australia
• Pampas: Parts of South America
• Welds: Southern
TEMPERATE GRASSLAND/ PRAIRIES BIOME
• Canterbury: New Zealand
• Pusztas: Hungary
• India: Bughyal : Uttarakhand; Margs: Kashmir; Khajjiar: Himachal Pradesh;
Shola: Nilgiri (due to high altitude)
• Flora: Grass are short but Nutritious, Alfa-Alfa Grass, Indus Grass, Buffalo Grass,
Wheat Grass, low Shrublands and pastures popular for commercial activities.
Trees like Willows, Poplar, and Alder.
• Forbs: Herbaceous plants other than grass, Gramineae(Grain family),
Leguminosae (Pulses like)
TEMPERATE GRASSLAND/ PRAIRIES BIOME
• Canterbury: New Zealand
• Pusztas: Hungary
• India: Bughyal : Uttarakhand; Margs: Kashmir; Khajjiar: Himachal Pradesh;
Shola: Nilgiri (due to high altitude)
• Flora: Grass are short but Nutritious, Alfa-Alfa Grass, Indus Grass, Buffalo Grass,
Wheat Grass, low Shrublands and pastures popular for commercial activities.
Trees like Willows, Poplar, and Alder.
• Forbs: Herbaceous plants other than grass, Gramineae(Grain family),
Leguminosae (Pulses like)
TEMPERATE GRASSLAND/ PRAIRIES BIOME
• Fauna: Large in Size, Herbivore like Bison, Antelopes, Ostrich, Emu, Saiga, Pampa
Deer, Marsupials etc.
• Also infested with Invasive species like European Rabbit in Australian Downs,
African Paddy in South America, Mongolian Gazelle in Prairies.
MEDITERRANEAN BIOME
• Dry and Hot Summers , Wet winters (rainfall, Moist and Cold)
• Areas: Countries along Mediterranean Sea, California, Cape Province of South
Africa, Central Chile, Southern Australia (Adelaide) and SW Australia (Perth).
• Sclerophyllous plants (type of vegetation that is adapted to long periods of dryness
and heat) Broad Leaves, and Drought resistant.
• Tree: Olive, Myrtle, Cork, Oak, Juniper, Cedar.
• Fruits: Figs, Citrus, Walnuts, Grapes, Chestnut. Region is also called World Orchards.
• Wheat and barley in Winters
MEDITERRANEAN BIOME
• Vegetation is prone to fire, Pyrophytes (fire loving) needs fire to reproduce,
recycle nutrients, removal of senescent (aged/old) vegetation.
• Tall trees are rare.
THE TUNDRA BIOMES
• There are two major tundra biomes—The Arctic Tundra and the Alpine Tundra.
• Biomes play a crucial role in sustaining life on earth. For example, the Aquatic
biome is home to millions of fish species and the source of the water cycle. It
also plays a very important role in climate formation. The terrestrial biomes
provide foods, enrich the air with oxygen and absorb carbon dioxide and
other bad gases from the air. They also help regulate climate and so on.
• This is known to be the coldest of all the terrestrial (land) biomes, with the
least bio-diversity capacity.
TUNDRA BIOMES
• Tundra got its name from ‘Tunturia’ a Finnish word that means ‘ barren land’.
This biome has very little rain with freezing temperatures, and covers about
a fifth of the earth’s land surface.
• There are two major tundra biomes: The Arctic Tundra and the Alpine
Tundra. The Arctic tundra is located around the north-pole in the northern
hemisphere. This biome has temperatures of about 2-3degrees in the
summer and about -35degrees in the winter. Bogs and ponds are common
as a result of constantly frozen surface moisture and melted permafrost.
TUNDRA BIOME
• Plants in the Arctic Tundra are short and grow closely to each other.
• Examples include mosses, heaths and lichen. They are adapted to perform
photosynthesis even in the freezing conditions. Animals here include herbivores
like hares and squirrels. Carnivores include polar bears and artic foxes. It also has
lots of birds, insets and fish like cod and salmon.
• The Alpine Tundra is very cold, located on top of high mountains, often with very
few trees and very little vegetative cover. They are icy for a larger part of the year.
Animals in this biome include some birds, mountains goats and marmots. There
are also beetles and butterflies.
THE AQUATIC BIOMES:
• Aquatic biomes are grouped into two, Freshwater Biomes (lakes and ponds,
rivers and streams, wetlands) and Marine Biomes (oceans, coral reefs and
estuaries).
• This includes all water bodies on the earth’s surface. Aquatic biomes are
grouped into two, Freshwater Biomes (lakes and ponds, rivers and streams,
wetlands) and Marine Biomes (oceans, coral reefs and estuaries). These
biomes make up about 73% of the total earth’s surface.
AQUATIC BIOMES
• Life forms in these waters depend on the abiotic factors such as sunlight
entering the waters, temperature, pressure, salt content and so on.
• Water biomes with lots of light tend to have more flora (plant) diversity, and
the growth of algae and plankton is more.
• Small water bodies that freeze during the cold seasons, or dry out in the dry
and hot seasons tend to have less diversity.
• There are mainly two types of Aquatic Biome: Fresh water and Marine water.
AQUATIC BIOMES
• One example of a marine biome is the Great Barrier Reef (a coral reef
system) of Australia.
• Examples of animals found in marine biomes include star fishes, sharks
and tuna and sea birds. Examples of animals in freshwater biomes include
salmon, tilapia worms, water-surface insects and crabs.
• Aquatic biomes are very important because apart from being home to
millions of water animals, they also form the basis of the water cycle and
help with atmospheric moisture, cloud formation and precipitation.
BIOMES
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BIOMES
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