Impact of Climate on Biome Distribution
- There are 9 biomes in Earth's biosphere
Biome distribution
- The main factor affecting biome distribution is climate
- Each biome has its own distinct characteristics which are determined by its climate, this affects:
- Length of the growing season
- Temperature and precipitation levels, which in turn, impact on the amount of plant growth
- This impacts on each biome's biodiversity
- The hotter and wetter a place is, the more plant species there tends to be
- These provide food and habitats for animals; so the greater the number of animal species
Worked example
Define the term biodiversity
(1 mark)
Answer:
- The number of species / how many species there are (1)
OR
- The diversity/variety/types/kinds /number of life/organisms/animals & plants (must have both) (1)
Distribution of the world biomes
Tropical Biomes
| Characteristics | Tropical Rain Forest | Tropical Monsoon Forest |
| Location |
Low latitudes Within the Tropics 23.5° north and south of the equator Amazon in South America, New Guinea, Southeast Asia, Zaire Basin |
5° to 30° north and south of the equator India, Central America, Southeast Asia |
| Annual Precipitation |
Over 2000mm |
Between 700 - 2000mm |
| Temperature Range |
26-28°C |
30-45°C in summer and 15-30°C in winter |
| Seasons |
No seasons: hot and wet all year round |
Three seasons Cool, dry Hot, dry Rainy season |
| Growing Season |
All year round |
During the rainy season and cool, dry season |
| Soils |
Infertile due to leaching and rapid uptake of nutrients by plants |
|
| Biodiversity |
Approx. 50% of the world's plant and animal species live within the rainforest biome Four layers of vegetation: mahogany, teak trees, lianas, orchids Toucans, jaguars, frogs, snakes |
High levels of biodiversity Hardwood, deciduous trees, teak, mahogany, lianas and orchids Monkeys, parrots, jaguars, panthers, snakes, frogs |
Temperate and Boreal (Taiga) Forest Biomes
| Characteristics | Temperate Forest | Boreal (Taiga) Forest |
| Location |
Between 40°- 60° north and south of the equator Western Europe, northeast USA, Eastern Asia |
Between 50°- 60° north and south of the equator Canada, Russia, Scandinavia |
| Annual Precipitation |
750-1500mm (all year round) |
300-900mm (all year round) |
| Temperature Range |
Over 0° C in winter and summer between 20°C-25° C |
-30°C in winter and up to 20°C in summer |
| Seasons |
Four seasons of equal length |
Two main seasons: winter and summer |
| Growing Season |
6-8 months |
2-3 months |
| Soils |
Fertile soils Nutrient rich due to decomposition of organic matter over autumn and winter |
Not very fertile often acidic with permafrost Shallow soil with a thick litter layer due to slow decomposition |
| Biodiversity |
Wide range of animals and plants higher biodiversity than boreal forests Deciduous trees: beech, oak, birch Deer, rabbits, squirrels, bears |
Less biodiverse than temperate forests Coniferous trees Squirrels, bears, reindeer, wolves |
Hot Deserts
| Characteristics | Hot Desert |
| Location |
15° - 30° north and south of the equator North Africa - Sahara, Southern Africa - Kalahari and Namib, Australia, Middle East |
| Annual Precipitation |
Below 250mm |
| Temperature Range |
Daytime temperatures can reach 50°C but average around 25°C Night time temperatures below 0°C |
| Seasons |
Summer and winter |
| Growing Season |
All year round |
| Soils |
Infertile |
| Biodiversity |
Low diversity Cacti, yucca Spiders, scorpions, camels, meerkats |
Grassland Biomes
| Characteristics | Savanna | Temperate Grasslands |
| Location |
North and south of the tropical and monsoon forest biomes 5° - 30° north and south of the equator Central Africa - Tanzania, Kenya |
The 'veldts' of South Africa, the 'pampas' of Argentina, and 'steppes' of Russia and the 'plains' of the USA 40°- 60° north and south of the equator |
| Annual Precipitation |
800-900mm |
250-750mm |
| Temperature Range |
15°C to 35°C |
-40°C to 40°C |
| Seasons |
Wet and dry season |
Four seasons |
| Growing Season |
During the wet season (4-5 months) |
During the summer (dependent on temperature) |
| Soils |
Free draining with a thin layer of humus Not very fertile most nutrients near the surface |
Fertile soil |
| Biodiversity |
Wide range of plant and animal species Grasses, baobab and acacia trees Zebras, elephants, giraffes Greatest diversity of hoofed animals |
Large numbers of plant and animal species Grasses, sunflowers Bison, antelopes, rabbits Grasses and trees |
Tundra Biomes
| Characteristics | Tundra |
| Location |
North of the Arctic Circle and Antarctica |
| Annual Precipitation |
Less than 250mm |
| Temperature Range |
Below 0°C for 6-10 months |
| Seasons |
Winter and summer |
| Growing Season |
6-10 weeks |
| Soils |
Thin infertile soil Permafrost |
| Biodiversity |
Low biodiversity Snowy owls, snow bunting and tundra swan Arctic foxes, hares and wolves Polar bears, musk ox and caribou Small grasses, mosses, lichen |
Worked example
State two characteristics of the temperate forest biome
(2 marks)
Answer:
- Deciduous / seasonal trees (1)
- Seasonal climate / four seasons / idea of seasons (‘warmer summer but colder winter’) (1)
- Hotter/wetter than another named biome (‘cooler than rainforest’) (1)
- May rain throughout year (1) or all year round (1)
- Northern limit of approximately 40 to 60 degrees (1)
- Southern limit approximately 30 to 40 degrees (1)
- Covers UK / much of Europe / valid named countries (1)
- Structure of forest e.g. mentions multiple layers (1)
- Broad leaves (1)
- High Biodiversity – relative to other named biome (1)
- Detail of food chain e.g. ‘top predator is brown bear’ (1)
- Nutrient rich soils (1) or ground litter (1)
Exam Tip
You may be asked to describe and explain the distribution of biomes or climate patterns. Consider the following;
- Biome distribution
-
- Latitude
- Country and continent names
- Factors which affect the distribution: latitude, altitude, ocean currents, continentality
- Climate patterns
- Temperature: maximum and minimum
- Seasonal variations
- Rainfall totals, maximum and minimum
