What is a biome?
Rajasthan shows sand and thorny shrubs, while Kerala shows thick green forest. When the climate differs, the living world differs too.
A biome is a large natural region of the world where particular plants and animals live under similar climate. A biome is the big region, while an ecosystem is a small 'neighbourhood' inside it. Biomes are either terrestrial (land) or aquatic (water), decided by temperature, rainfall and the main plants.
In the figure : Climate decides the biome.
Rule 1: Tell a biome from an ecosystem
- Easy : The whole desert region is a biome.
- Medium : One oasis inside the desert is a small ecosystem.
- Exam-type : One biome can contain many ecosystems.
Rule 2: Read the biome from the climate
- Easy : Hot and wet all year means rainforest.
- Medium : Very little rain means desert.
- Exam-type : Taiga has conifers such as pine, spruce and larch; deciduous forests have broad-leaved trees that shed leaves with the season.
Biomes are the big patches on Earth's quilt, each with its own climate and life.
Treating biome and ecosystem as the same; the biome is large and the ecosystem is small.
Memory clue: Biome = big region, Ecosystem = neighbourhood; Climate → Biome.
Spot the difference
| Idea | Size | Example |
|---|---|---|
| Biome | Very large region | Desert region |
| Ecosystem | Small part inside | One pond |
| Aquatic biome | In water | River, lake, ocean |
Practice questions
- 1What is a biome?
- 2Name the two main groups of biomes.
- 3Name any two factors that decide a biome.
- 4How is a biome different from an ecosystem?
- 5Which trees grow in the taiga?
- 6What is a deciduous forest?
- 7Which biome has very little rain and fierce heat all year?
- 8There are 6 biome types and a school has shown 4 on a map. How many are left?
Show answers (try them yourself first)
- 1A large natural region with particular plants and animals under similar climate.
- 2Terrestrial and aquatic.
- 3Temperature and rainfall (or the main plants).
- 4A biome is a large region; an ecosystem is a small part within it.
- 5Pine, spruce and larch.
- 6A forest of broad-leaved trees that shed leaves seasonally.
- 7Desert.
- 86 − 4 = 2.
Land biomes: forest, grassland, desert, tundra
The thick Andaman forest, the white salt flats of Kutch and the cold desert of Ladakh — India alone shows many biomes.
The rainforest lies near the Equator (23.5° N to 23.5° S), is hot and wet, and is called a 'gene bank' of biodiversity. Grasslands get moderate rain and are covered with grass. Deserts are the driest. Tundra is the coldest, with frozen ground (permafrost) and only mosses, lichens and small shrubs.
In the figure : Four land biomes and what marks them.
Rule 1: Read the rainforest layers from top to bottom
- Easy : Emergent layer at the top, then the upper canopy.
- Medium : Below come the understory and, at the bottom, the forest floor.
- Exam-type : In India rainforests are found in the Andaman & Nicobar Islands and the North-East.
Rule 2: Living things adapt to their biome
- Easy : Camels and cacti store water, so they survive in the desert.
- Medium : Reindeer and polar bears bear bitter cold, so they live in the tundra.
- Exam-type : African savannas have scattered trees with lions, elephants and giraffes; the Rann of Kutch is marshy in the monsoon and a white salt desert in the dry season.
Rainforests help keep oxygen levels up and shelter a huge store of biodiversity.
Thinking all deserts are hot; deserts like the Gobi are cold.
Memory clue: F-G-D-T — Forest (wet), Grassland (middle), Desert (dry), Tundra (cold).
Spot the difference
| Biome | Climate | Life |
|---|---|---|
| Rainforest | Hot and wet | Countless species |
| Desert | Very little rain | Camel, cactus, lizards |
| Tundra | Bitter cold, frozen ground | Moss, reindeer, polar bear |
Practice questions
- 1Where are rainforests found?
- 2Why is the rainforest called a 'gene bank'?
- 3What is a savanna?
- 4How does the Rann of Kutch look in the monsoon?
- 5What is permafrost and why do trees not grow there?
- 6How do desert animals live with little water?
- 7Name the four rainforest layers from top to bottom.
- 8A forest layer study finds 25 species in each of its 4 layers. How many species in all?
Show answers (try them yourself first)
- 1Near the Equator between 23.5° N and 23.5° S, as in the Amazon, Congo and Southeast Asia.
- 2It safeguards the genetic material of countless species.
- 3A tropical grassland with scattered trees and large animals.
- 4A marshy wetland.
- 5Ground frozen almost all year; roots cannot go deep.
- 6They store water and tolerate heat and dryness.
- 7Emergent layer, upper canopy, understory, forest floor.
- 825 × 4 = 100 species.
Aquatic biomes and the biome pyramid
A pond has frogs, fish and insects, and the sea has whales and corals. Both are water biomes, yet the life differs.
Aquatic biomes cover about three-fourths of the Earth's surface. There are two kinds: freshwater (rivers, lakes, ponds, wetlands) and marine (oceans, seas, coral reefs). A biome pyramid shows in a picture how energy passes from producers to herbivores, carnivores and top consumers; energy is lost as heat at every level.
In the figure : The layers of a biome pyramid.
Rule 1: Know the two kinds of aquatic biome
- Easy : Rivers and lakes are freshwater biomes.
- Medium : Oceans and coral reefs are marine biomes.
- Exam-type : Marine biomes influence Earth's climate by storing and sharing heat.
Rule 2: Going up the pyramid, energy and numbers fall
- Easy : Plants sit at the base and animals such as tigers at the top.
- Medium : A rough rule of thumb says about one-tenth passes on at each level.
- Exam-type : If producers hold 1000 energy units, herbivores get about 100 and carnivores about 10.
Producers capture sunlight; higher levels get less energy, so there are fewer animals at the top.
Thinking the animal at the top is the most numerous; it is the least numerous.
Memory clue: P-H-C-T — Producer, Herbivore, Carnivore, Top. Many below, few above.
Spot the difference
| Level | Who | Example |
|---|---|---|
| Producers | Make their own food | Plants, algae |
| Herbivores | Primary consumers | Deer, snail |
| Carnivores | Secondary consumers | Tiger, snake |
Practice questions
- 1How much of the Earth do aquatic biomes cover?
- 2Name two freshwater biomes.
- 3Give two examples of marine biomes.
- 4Who sits at the base of a biome pyramid?
- 5Why does energy fall as we go up the pyramid?
- 6Why are there fewer animals at the top?
- 7How do marine biomes affect climate?
- 8Producers hold 2000 energy units. By the one-tenth rule, how much do herbivores get?
Show answers (try them yourself first)
- 1About three-fourths.
- 2River and lake (or pond, wetland).
- 3Ocean and coral reef.
- 4Producers (plants and algae).
- 5Part of the energy escapes as heat during metabolism.
- 6The energy reaching them is small.
- 7They store and distribute heat.
- 82000 ÷ 10 = 200 units.
Aquatic biomes and the biome pyramid
In the app you can move this figure with your finger.
Open in the appBiodiversity and its conservation
A small frog of the Western Ghats may be found nowhere else on Earth. If such a species is lost, it is lost for ever.
Biodiversity is the variety of life on Earth: species, the genetic differences within them and their habitats. The Himalaya, Western Ghats, North-East India and the Andaman & Nicobar Islands are biodiversity hotspots. Conservation uses protected areas (national parks, sanctuaries, biosphere reserves), wildlife corridors and ecotourism.
In the figure : Four ways to conserve.
Rule 1: Match the conservation method to the geography
- Easy : On the coast, mangrove forests are protected.
- Medium : On hills, planting trees and terrace farming help.
- Exam-type : Rivers, mountains and valleys can act as barriers or corridors, so planners study the geography before marking a corridor.
Rule 2: Ecotourism is responsible tourism
- Easy : Tourists enjoy nature without harming it.
- Medium : Local people earn as guides or eco-guards.
- Exam-type : Thenmala in Keralam is India's first planned ecotourism destination; its name means 'Honey Hill'.
Biodiversity is not only the number of species; it also covers genetic differences and the variety of habitats.
Believing tourism and conservation always clash; good planning can serve both.
Memory clue: H-P-C-E — Hotspots, Protected areas, Corridors, Ecotourism.
Spot the difference
| Tool | What it does | Example |
|---|---|---|
| National park and sanctuary | Keeps habitats safe | Protected wildlife areas |
| Wildlife corridor | Joins broken habitats | Safe path for animals |
| Ecotourism | Earns income while protecting nature | Thenmala, Keralam |
Practice questions
- 1What is biodiversity?
- 2Name two biodiversity hotspots of India.
- 3Name the kinds of protected areas.
- 4Why is a wildlife corridor needed?
- 5Define ecotourism.
- 6Which forest is protected along coasts?
- 7How do local people gain from the Thenmala project?
- 8A park has 3 herds of 18 deer each. How many deer in all?
Show answers (try them yourself first)
- 1The variety of species, genetic differences and habitats on Earth.
- 2Western Ghats and Himalaya (or North-East, Andaman & Nicobar).
- 3National parks, sanctuaries, biosphere reserves, World Heritage Sites.
- 4To join broken habitats and let genes flow between groups.
- 5Responsible travel to nature with little harm and with support for local people.
- 6Mangrove forests.
- 7They get jobs as guides, eco-guards and service providers.
- 818 × 3 = 54 deer.
Forests and livelihoods
A woman selling tendu leaves, mahua flowers or wild honey in a market depends on the forest. For her the forest is income, not just trees.
Forests give food, fuel, fodder, medicine, timber and bamboo. Non-timber forest products are honey, fruits, resins, lac and medicinal plants. Sacred groves are small forest patches that communities protect for religious reasons. A GI (Geographical Indication) tag is a label showing that a product comes from a particular place and owes its quality to it.
In the figure : How forests and people are linked.
Rule 1: Sort forest produce
- Easy : Timber and bamboo are forest produce.
- Medium : Honey, resin and mahua flowers are non-timber produce.
- Exam-type : The Gond and Bhil communities honour forest deities before collecting produce; this is a sustainable cultural practice.
Rule 2: Understand forest dwellers' roles and troubles
- Easy : Forest women collect fuelwood, fodder and medicinal plants.
- Medium : In the Bishnoi movement (Amrita Devi) and the Chipko movement, forest people saved trees.
- Exam-type : Challenges: poor health and education access, human–wildlife conflict, forest fires, landslides and low prices for produce.
With processing and marketing, forest dwellers can earn more from non-timber produce.
Thinking forests are only for timber; they also give food, medicine and culture.
Memory clue: GI = Geography Identity — the product carries its place's name.
Spot the difference
| GI product | State | Speciality |
|---|---|---|
| Tezpur litchi | Assam | Bright colour, juicy pulp |
| Kandhamal turmeric | Odisha | High curcumin, medicinal value |
| Channapatna toys | Karnataka | Made from a forest tree's wood |
Practice questions
- 1What is non-timber forest produce? Give two examples.
- 2What are sacred groves?
- 3Why are sacred groves important for biodiversity?
- 4Where and how did the Chipko Movement happen?
- 5What is a GI tag?
- 6State any three challenges faced by forest dwellers.
- 7How does the Ujjwala scheme help the health of forest women?
- 8A group gets 400 rupees per kg of honey. How much for 15 kg?
Show answers (try them yourself first)
- 1Produce from forests other than timber; honey and resin.
- 2Small forest patches protected by communities for religious reasons.
- 3Rare plants, medicinal species and animals survive there, and some groves keep water sources alive.
- 4In Uttarakhand village women hugged trees to stop them being cut.
- 5A label showing a product comes from a specific place and owes its quality to it.
- 6Poor health and education access, forest fires, crop damage by wild animals (or low prices).
- 7It reduces harm from cooking smoke.
- 8400 × 15 = 6000 rupees.
Forest rights, community management and shared resources
In Mendha (Lekha) village in Gadchiroli the Gram Sabha takes forest decisions together. Their motto is 'our village, our rule'.
The Forest Rights Act 2006 (FRA) recognises the rights of traditional forest dwellers over forest land and produce. In Joint Forest Management (JFM) local people guard the forest and share its benefits. Ecological commons are resources such as forests, rivers, lakes and grazing lands that a community uses together.
In the figure : Conservation through rights and participation.
Rule 1: Rights come with responsibility
- Easy : Under FRA forest dwellers may collect bamboo, honey and medicinal plants.
- Medium : The book says Mendha Lekha was the first village in India to gain community rights over its forest under the FRA.
- Exam-type : The Gram Sabha there controls tree cutting, prevents fires and spends forest income on education and facilities.
Rule 2: Commons survive through community rules
- Easy : A tank, grazing land or river belongs to the community, not one person.
- Medium : Between 800 and 1200 CE the Chandella and Bundela kings built about 8,000 tanks in Bundelkhand.
- Exam-type : Bihar's Fish Jalkar Management Act 2006 increases community involvement in water bodies; India today has over 15 lakh working tanks.
When people have rights and a say in decisions, they protect nature better.
Thinking a common resource means anyone may take any amount; commons are kept going by rules.
Memory clue: Rights + Gram Sabha + rules = a lasting forest. Mendha: 'our village, our rule'.
Spot the difference
| Scheme / example | What | Benefit |
|---|---|---|
| Forest Rights Act 2006 | Recognises dwellers' rights | Can collect forest produce |
| Joint Forest Management | People and government partner | Forest care and income |
| Mendha Lekha | Gram Sabha manages forest | Bamboo income, funds for education |
Practice questions
- 1What does the Forest Rights Act (FRA) do?
- 2What is Joint Forest Management?
- 3Where is Mendha Lekha and which community lives there?
- 4Explain the meaning of 'our village, our rule'.
- 5What are ecological commons?
- 6Who built the tanks of Bundelkhand?
- 7Give two reasons why commons are shrinking.
- 8A village has 1,800 ha of forest. If it is split into 6 equal parts, how many hectares in each?
Show answers (try them yourself first)
- 1It recognises traditional forest dwellers' rights over forest land and produce.
- 2A programme where local people guard the forest and share its benefits.
- 3Gadchiroli district, Maharashtra; the Gond community.
- 4The village makes its decisions together through the Gram Sabha.
- 5Shared resources like forests, rivers, lakes and grazing lands.
- 6The Chandella and Bundela kings.
- 7Population growth and industrial use or privatisation.
- 81800 ÷ 6 = 300 ha.