People and the biosphere Flashcards
What is the biosphere
Contains all living organisms and the layer of the Earth’s surface between lithosphere and the atmosphere
Split into nine major biomes
What are biomes
Large scale ecosystems, consisting of the biotic and abiotic factors.
Usually carbon sinks
What are the location and characteristics of biomes influenced by
- Precipitation
- Temperature
- Sunshine
All controlled by an area’s latitude
Local factors that can alter the biome distribution
- Rock and soil type - acidity and nutrients affect plant growth
- Water availability and drainage - some plants benefit from dry, some from wet soil
- Altitude - Temp decreases with height, rainfall increases
Different services that biomes provide:
- Provisional services (goods) - Food, timber, fuelwood, chemical materials
- Supporting services - Nutrient cycling, photosynthesis and soil formation
- Regulating services - Carbon storage and the hydrological cycle
- Cultural services - Tourism, education, science
How are some ecosystems being exploited commercially?
- Commercial mining
- Mining metal ores
- Timber
- Construction of dams for HEP and water supply
What is a carbon sink
Where carbon is stored
They maintain healthy air, soils and the hydrological cycle
How do biomes provide healthy air
Remove carbon dioxide from the atmosphere through carbon sequestration and photosynthesis.
How do biomes provide healthy soils
Soil health is maintained by the nutrient cycle
How does destroying forests cause flood risk
Reduces interception and infiltration affecting groundwater supplies
Surface run-off and erosion increases and flooding becomes more frequent
What has lead to an increase in demand for natural resources
- Industrialisation
- Urbanisation
- Rising wealth
What is Malthus’ view
Pessimistic view on population growth
- That the planet will run out of resources, leading to ‘positive checks’ (war, famine) or preventative checks (fewer children)
What is Boserup’s view
Optimistic view on population growth
- That humans will invent new ways to allow more resources to be supplied (GM crops, irrigation, farm machinery)
