Flashcards in Paper 3 Deck (72)
What is a biome?
A large-scale ecosystem
What are the 7 types of biome?
Boreal forest (taiga)
How are tropical rainforests distributed?
-Either side of the equator
-Between 15°N and 15°S
-South East Asia
How are Boreal forests/ taiga biomes distributed?
-Found in the Northern hemisphere
Which biomes have hot climates all year?
Which biomes have cold climates all year?
Which biomes have changing climates?
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?
Give an example of an indigenous tribe in the rainforest and what they do:
Efe tribe: Congo Basin, Africa
-Use wood and leaves for temporary houses
-Wood for cooking fires
-Hunt monkey and antelope
-Gather wild yams, nuts and mushrooms
-Use plants and honey for medicine
How are biospheres commercially exploited?
-Biofuels (e.g. palm oil): energy
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?
-Destruction of biomes (and therefore carbon stores)
-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?
-Precipitation adds nutrients
-Runoff washes away litter, removing nutrients
-Leaching washes nutrients out of soil
-Weathering adds nutrients from rocks to soil
How can humans negatively impact the nutrient cycle?
Deforestation (leading to soil erosion)
Why is there a lower productivity rate in the Taiga biome?
-The nutrient cycle is less active (cold temperatures)
-Lower levels of biodiversity (smaller flows and stores)
Describe a broken nutrient cycle due to deforestation:
Less nutrients entering the soil
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.
Why does industrialisation increase the demand for resources?
More secondary activity such as manufacturing requires more energy and uses more materials.
What was Malthus’ theory?
He thought that the population was increasing faster than the number of resources available.
He believed that eventually catastrophes would occur to return the population to a level which could be supported by the environment.
The point of catastrophe would be when there are more people than resources.
What was Boserup’s theory?
People would always produce sufficient resources to meet their needs however big the population got.
She believed that people would come up with new technology whenever resources were limited.
Population increases with resources.
How are TRF plants adapted to their warm climate?
Emergent trees have tall trunks and thick buttress roots
Shrub layer has trees with large, broad leaves
Top 3 layers only have leaves at the top of their tree
Thick, waxy leaves with pointed tips for water run-off
Smooth thin bark
Climbing plants get sunlight
How are TRF animals adapted to their warm climate?
Strong limbs to live in the canopy
Flaps of skin for gliding and suction cups for climbing
Adapted to low light levels