What is a biome?
A large-scale ecosystem
What are the 7 types of biome?
Tropical rainforest Boreal forest (taiga) Temperate grassland Tundra Temperate forest Tropical grassland Desert
How are tropical rainforests distributed?
How are Boreal forests/ taiga biomes distributed?
Which biomes have hot climates all year?
Which biomes have cold climates all year?
- Tundra
Which biomes have changing climates?
- Temperate forests
What are the key climate characteristics of a Tropical Rainforest?
Hot all year: 25-30°C
Wet all year: 200-3000mm precipitation/year
Same day length all year (12 hours)
What are the key climate characteristics of a Boreal Forest?
Mild summers: 10-20°C
Very cold winters: below 0°C
Low precipitation: less than 500mm precipitation/year
Lots of daylight in summer but little to none in winter
What are abiotic factors?
Non living parts of a biome
What are biotic factors?
Living parts of a biome
How do indigenous people use resources from the biosphere?
Food
Medicine
Fuel
Building material
Give an example of an indigenous tribe in the rainforest and what they do:
Efe tribe: Congo Basin, Africa
How are biospheres commercially exploited?
What is carbon sequestration?
The storage of carbon dioxide in ‘carbon sinks’ via photosynthesis. Carbon sinks are biotic material.
What negative impact can humans have on the atmosphere through deforestation?
- Release of carbon stores when trees are burnt/ destroyed
Outline the nutrient cycle:
Soil stores nutrients
Nutrients move into biomass via growth/ uptake
Fallout from dead plants and animals leaves litter on soil surface
Litter decays and returns to the soil
Which 4 things can affect things can affect the nutrient level in the nutrient cycle?
How can humans negatively impact the nutrient cycle?
Removing biomass
Deforestation (leading to soil erosion)
Why is there a lower productivity rate in the Taiga biome?
- Lower levels of biodiversity (smaller flows and stores)
Describe a broken nutrient cycle due to deforestation:
Deforestation Less vegetation Less litter Less decomposition Less nutrients entering the soil Infertile soil Leaching
How do biomes impact the hydrological cycle?
Trees intercept the water, reducing soil erosion
Trees increase levels of infiltration, increasing groundwater supplies
Trees decrease surface runoff so water gets into channels more slowly
There is less flooding and cleaner water
Forests prevent the soil from drying out via evaporation
Why does rising affluence (increasing wealth) increase demand for resources?
More disposable income so goods can be bought in excess and fridges, flushing toilets, etc. can be installed.
Why does urbanisation lead to an increased demand for resources?
More energy is needed for transportation and streetlights, etc.