IAS NOVA Interactive Atlas
Biomes of the World
Explore how heat, moisture, latitude, altitude, soils and disturbance create Earth’s great ecological regions.
Definition
A biome is a very large ecological region defined mainly by climate and its characteristic vegetation, with animals and soils adapted to the same conditions. The world pattern is controlled chiefly by temperature, rainfall, seasonality, latitude and altitude. This atlas uses the 14-terrestrial-biome framework associated with the RESOLVE 2017 ecoregions map.
Learn with the map: Open it in FULL SCREEN, select a biome family or legend colour, and hover, tap or use the Index to explore each region.
What is a biome?
A biome is a broad ecological zone whose climate supports a characteristic structure of vegetation and associated animal life. It is larger than an ecosystem and usually contains many ecosystems and ecoregions. The same biome may occur on different continents: tropical moist forest appears in the Amazon, Congo Basin and Southeast Asia, even though their species are not identical.
The five controls that build the world biome pattern
The 14 terrestrial biomes
The atlas follows the major habitat types used in the RESOLVE 2017 ecoregions dataset. Climate values below are broad learning ranges, not rigid boundaries. Mountain exposure, ocean currents, continentality, soils and disturbance create local exceptions.
Tropical and subtropical moist broadleaf forests
Climate: warm throughout the year; usually more than 1,500 mm rainfall, with a short or absent dry season. Structure: layered evergreen canopy, lianas and epiphytes. Examples: Amazon, Congo Basin, Southeast Asia, Western Ghats. Adaptations: drip-tip leaves, buttress roots and intense nutrient recycling. Biodiversity is exceptionally high, while many soils are strongly leached.
Tropical and subtropical dry broadleaf forests
Climate: warm with a pronounced dry season. Structure: deciduous or semi-deciduous canopy, thorny understorey and open woodland. Examples: central India, Madagascar, Indochina and Mexico. Adaptations: leaf fall reduces water loss; thick bark and deep roots help plants survive drought and fire.
Tropical and subtropical coniferous forests
Climate: warm to mild, often seasonal, mainly on mountains or nutrient-poor soils. Structure: pine and other conifer formations mixed with broadleaf species. Examples: Mexican pine-oak highlands, Caribbean pine forests and Himalayan subtropical pine. Fire and elevation are important controls.
Temperate broadleaf and mixed forests
Climate: moderate rainfall and marked warm-cold seasons. Structure: deciduous broadleaf trees or mixtures of broadleaf and conifers. Examples: eastern North America, Europe and East Asia. Adaptations: winter dormancy and leaf fall. Soils are often relatively fertile, encouraging dense settlement and farming.
Temperate coniferous forests
Climate: cool to mild; moisture ranges from humid coastal to seasonally dry montane. Structure: tall evergreen conifers or open pine forest. Examples: Pacific Northwest, Rockies, Himalaya and southern Chile. Needle leaves conserve water and resist cold; many species depend on periodic fire.
Boreal forests or taiga
Climate: long severe winters, short cool summers and low to moderate precipitation, much of it snow. Structure: spruce, fir, pine and larch, with bogs and lakes. Distribution: Alaska, Canada, Scandinavia and Siberia. Conical form, waxy needles and dark foliage are classic cold adaptations.
Tropical and subtropical grasslands, savannas and shrublands
Climate: warm year-round with alternating wet and dry seasons. Structure: grasses with scattered drought- and fire-resistant trees. Examples: African savannas, Cerrado, Llanos, India and northern Australia. Fire, herbivory and seasonal water stress prevent a closed forest canopy.
Temperate grasslands, savannas and shrublands
Climate: hot summers, cold winters and moderate but insufficient or unreliable rainfall for forest. Examples: prairie, steppe, pampas, veld and downs. Deep, dark, humus-rich soils made many regions major grain belts. Fire, drought and grazing maintain grass dominance.
Flooded grasslands and savannas
Control: seasonal or permanent shallow flooding rather than climate alone. Examples: Pantanal, Sudd, Okavango, Everglades and Terai-Duar. Sedges, reeds and flood-tolerant grasses dominate. These wetlands support waterbirds, large herbivores, fisheries and flood regulation.
Montane grasslands and shrublands
Climate: cool, windy and strongly affected by altitude, slope and aspect. Examples: Tibetan Plateau, puna, paramo, East African highlands and New Guinea highlands. Plants are low, cushion-shaped or tussock-forming. High endemism results from geographic isolation.
Tundra
Climate: very cold, low precipitation, short growing season and widespread permafrost in Arctic areas. Structure: mosses, lichens, sedges, dwarf shrubs; trees are absent. Distribution: Arctic margins and ice-free Antarctic areas. Shallow roots, low growth and rapid life cycles conserve heat and use the brief summer.
Mediterranean forests, woodlands and scrub
Climate: cool wet winters and hot dry summers. Examples: Mediterranean Basin, California chaparral, Chilean matorral, South African fynbos and southwest Australia. Small hard leaves, deep roots, resprouting and fire-triggered germination are common.
Deserts and xeric shrublands
Climate: water deficit dominates; many deserts receive less than 250 mm annually, but some xeric regions receive more with extreme evaporation. Examples: Sahara, Arabian, Gobi, Atacama, Namib, Sonoran and Australian deserts. Succulence, reduced leaves, CAM photosynthesis, nocturnality and water conservation are key adaptations.
Mangroves
Setting: sheltered tropical and subtropical coasts, deltas, estuaries and tidal flats. Examples: Sundarbans, Niger Delta, Southeast Asia, northern Australia and tropical American coasts. Salt filtration or excretion, aerial roots and floating propagules allow survival in saline, oxygen-poor mud.
Why biomes form belts, mosaics and mountain steps
Latitude creates broad belts
- Equatorial convergence favours humid tropical forests.
- Subtropical high pressure favours many major deserts near 20 to 30 degrees.
- Mid-latitude westerlies support temperate forests and grasslands.
- Low polar energy produces tundra and ice environments.
Altitude repeats latitude
- Temperature normally falls with height.
- Lowland forest can grade into montane forest, alpine grassland and nival conditions.
- Windward slopes are wetter; rain-shadow slopes are drier.
- Compressed altitudinal zones make mountains biodiversity hotspots.
Biome climate comparison
| Biome group | Temperature pattern | Moisture pattern | Dominant physiognomy | Frequent constraint |
|---|---|---|---|---|
| Tropical moist forest | Warm all year | High, reliable rainfall | Multi-layer evergreen forest | Leached soils; rapid nutrient cycling |
| Tropical dry forest and savanna | Warm all year | Strong wet-dry season | Deciduous woodland or grass-tree mosaic | Seasonal drought and fire |
| Temperate forest | Warm summer, cold winter | Moderate rainfall | Deciduous, mixed or conifer forest | Winter cold and seasonality |
| Boreal forest | Long cold winter | Low to moderate; snow important | Needleleaf conifer forest | Short growing season |
| Temperate grassland | Large annual range | Moderate or unreliable | Continuous grass cover | Drought, fire and grazing |
| Desert | Hot or cold extremes | Persistent water deficit | Sparse xerophytes | Water scarcity |
| Tundra and alpine | Cold; brief summer | Low, but evaporation also low | Low herbs, moss, lichen and shrub | Permafrost, wind and frost |
| Mangrove and flooded grassland | Mainly warm for mangroves; variable for wetlands | Waterlogged or tidally flooded | Flood-tolerant trees, reeds or grasses | Low soil oxygen, salinity or inundation |
Where do aquatic biomes fit?
The RESOLVE map used above is a terrestrial classification. School geography often adds two broad aquatic groups. Freshwater biomes include rivers and streams, lakes and ponds, and inland wetlands; their salinity is low and flow or water depth is a major control. Marine biomes include coasts and estuaries, coral reefs, continental shelves, open-ocean zones and the deep sea; salinity, light, depth, temperature, nutrients and currents structure them.
Freshwater
Running water is lotic; standing water is lentic. Wetlands are waterlogged transition systems with exceptional value for flood control, nutrient cycling and biodiversity.
Marine
Coastal waters are generally more productive because light and nutrients are available. Open oceans cover immense areas but often have low productivity per unit area away from upwelling zones.
India within the world biome pattern
India’s position across tropical latitudes, the monsoon, the Himalaya, the Thar Desert, a long coastline and large river floodplains create exceptional biome diversity. Tropical moist forests occur in the Western Ghats, Northeast and islands; tropical dry forests cover extensive monsoonal interiors; savanna-like grasslands and scrub occur across semi-arid and seasonal regions; temperate and conifer forests rise through the Himalaya; alpine and montane grasslands occupy high elevations; deserts and xeric shrublands occur in the west; flooded grasslands line parts of the Terai and Brahmaputra valley; and mangroves occupy deltas and sheltered coasts, especially the Sundarbans.
Biomes are dynamic, not frozen lines
Biome maps show potential or characteristic natural patterns at a broad scale. Agriculture, cities, logging, grazing, invasive species, dams and altered fire regimes have transformed large areas. Climate change can shift suitable climate zones poleward or upslope, but soils, dispersal barriers, land fragmentation and slow tree migration mean vegetation does not instantly follow climate.
Major pressures
- Conversion to cropland and pasture
- Fragmentation and infrastructure
- Unsustainable fire or fire suppression
- Overgrazing, logging and mining
- Hydrological change and coastal development
Why transitions matter
- Biome boundaries are ecotones, not sharp walls.
- Ecotones combine species from adjacent systems.
- They may respond quickly to climate and land-use change.
- Fine-scale ecoregion maps are required for conservation planning.
World biomes quiz
1. Which factor combination most directly defines a terrestrial biome?
A biome is chiefly recognized by large-scale climate and the vegetation structure adapted to it.
2. Tropical savannas usually persist because of which combined controls?
Wet-dry seasonality, recurring fire and grazing help prevent formation of a continuous tree canopy.
3. Which sequence best represents rising altitude in many tropical mountains?
Falling temperature with elevation creates vertical zonation comparable in part to moving poleward.
4. Aerial roots and salt-management mechanisms are most characteristic of:
Mangroves tolerate saline, waterlogged and oxygen-poor tidal mud through specialized roots and salt regulation.
5. Why are temperate grassland soils often highly fertile?
A large mass of fine roots dies and renews in the soil, building humus-rich topsoil.
6. Which biome has cool wet winters and hot dry summers?
Winter rain and summer drought define the Mediterranean climate and its sclerophyll vegetation.
7. Which statement about a biome boundary is most accurate?
Biome edges usually grade into one another and are generalized differently by different classification systems.
8. The extensive conifer belt across Canada and Siberia is known as:
Taiga is the boreal conifer forest south of much of the Arctic tundra.
Frequently asked questions
How many major terrestrial biomes are there?
There is no single universal count because classifications use different purposes and scales. This atlas uses the 14 major habitat types in the RESOLVE-WWF terrestrial ecoregion framework.
What is the difference between a biome and an ecoregion?
A biome groups large areas with similar climate and vegetation structure across continents. An ecoregion is a more geographically specific unit with a distinctive assemblage of natural communities and species. Many ecoregions belong to one biome.
What are the main factors controlling biomes?
Temperature, precipitation, seasonality, latitude, altitude, soils and disturbance are the principal controls. At global scale, available heat and moisture are dominant.
Which biome has the greatest biodiversity?
Tropical moist broadleaf forests generally have the highest terrestrial species richness because warm, wet and relatively stable conditions support high productivity, complex vertical structure and specialization.
Why are many deserts near 30 degrees latitude?
Descending air in the subtropical high-pressure belts warms and dries, suppressing clouds and rainfall. Cold ocean currents, continental interiors and rain shadows reinforce aridity in particular regions.
Are grasslands natural or human-made?
Both occur. Many major grasslands are natural products of climate, fire and herbivory. Human burning, clearing and grazing can expand or degrade grass-dominated landscapes.
Do biome boundaries stay fixed?
No. Boundaries are transitional and can shift with climate, disturbance, hydrology and land use. The map represents a broad educational generalization rather than a parcel-level boundary survey.
Are oceans included in the 14-biome map?
No. The 14 categories shown on the map are terrestrial. Freshwater and marine systems use separate aquatic classifications; this guide provides an overview of them without mixing the systems.
Sources and further reading
- Olson et al. (2001), Terrestrial Ecoregions of the World: A New Map of Life on Earth, BioScience.
- Dinerstein et al. (2017), An Ecoregion-Based Approach to Protecting Half the Terrestrial Realm, BioScience.
- Google Earth Engine Data Catalog: RESOLVE Ecoregions 2017.
- RESOLVE: Ecoregions of the World.
- University of California Museum of Paleontology: The World’s Biomes.
