Paper 3 Flashcards
What is the biosphere and local factors that determine biomes
The biosphere contains all living organisms and is the layer of the Earth’s surface between the lithosphere and the atmosphere.
Rock and soil type – acidity and nutrients affect plant growth.
• Water availability and drainage – some pants prefer wet soil, others dry soil.
• Altitude – temperature decreases with height, rainfall increases.
What do biomes supply people with
Provisioning services (goods) – food, fuelwood, timber, and chemical materials
• Supporting services – nutrient cycling, photosynthesis, and soil formation
• Regulating services – carbon storage and the hydrological cycle
What are ecosystem being exploited for
Commercial farming
Mining metal ores
Timber
Construction of HEP dams
Problems with destroying biomes
Healthy air – Biomes remove carbon dioxide from the atmosphere through carbon sequestration and photosynthesis. Destruction of biomes releases additional carbon dioxide into the atmosphere, contributing to global warming.
• Healthy soils – Soil health is maintained by the nutrient cycle. Removing biomass takes away nutrient stores.
• Water supply and flood risk – Destroying forest biomes reduces interception and infiltration affecting groundwater supplies. Surface run-off and erosion increases, and flooding becomes more frequent.
• Burning forests turns them into carbon sources.
Malthus and bosserup
Pessimistic view (Malthus) – The population will grow, and the planet will run out of resources, leading to ‘positive checks’ (war, famine) or preventative checks (fewer children).
Optimistic view (Boserup) – Humans will invent new ways to allow more resources to be supplied (for example, technology such as farm machinery,
Why is biodiversity in rainforests high and what adapatations do the plants have
• of the equatorial climate (hot and wet all year around)
• species have evolved over millions of years
• multiple layers of vegetation.
Hardwood trees, such as mahogany which have large buttress roots to support the weight of trees and leaves and branches are only found at the top
• Lianas that use the tree to climb up to the sunlight in the canopy
• Birds such as macaws that have strong beaks to break open nuts
• Primates such as monkeys that use their tails for balance
Why is nutrient cycling rapid in rainforest
large biomass store (dense vegetation)
• a small litter store (rapid decay)
• a large take-up of nutrients (rapid plant growth)
• a larger supply of nutrients (weathering)
• a larger loss of nutrient (throughflow).
How are plants and animals adapted for taiga and why is the nutrient cycle slower
Mammals have thick, oily fur to retain heat.
• Some animals hibernate in the winter.
• Some birds and animals migrate.
• Trees are coniferous (evergreen). The trees are cone
shape to allow snow to slip off
The nutrient cycle in the taiga occurs more slowly than in rainforests. The stores are smaller, with smaller flows of nutrients between.
Deforestation reasons
Cattle ranching – There is an increasing global demand for beef (and the need to grow soya to feed cattle).
• Poverty – Local people cut down trees for subsistence farming and fuelwood.
• Debt – Countries export timber and grow cash crops to pay off debts.
• Development – urbanisation, HEP stations and palm oil plantations
• Demand – The need for timber, oil,
Why so taiga under attack
Forest fires – hot and dry summers make the forest prone to fires from lightning strikes.
• Pests and diseases – warmer temperatures increase insect infection and diseases in coniferous trees.
• Acid rain – burning of fossils releases sulphur dioxide into the air – the acid rain weakens trees by reducing photosynthesis
Companies helping rainforests
CITES is an international treaty adopted by 180 countries that protects species However, protecting species does not prevent deforestation and global warming
REDD is a UN project that aims to stop deforestation with governments and TNCs funding projects to conserve forests in development countries
Ecotourism and agroforestry
Ecotourism provides jobs for local people and educates tourists, whilst agroforestry maintains biodiversity allowing crops to grow between trees
Accses to fuels
Malawi, have mainly primary economies, using only a small amount of energy, mostly in the home. Many developing countries suffer from energy poverty, lacking electricity, or money to pay for it, collecting fuelwood or dung as an alternative.
Newly industrialising or emerging economies use large amounts of energy for manufacturing
People in developed countries consume more products increasing the demand for energy (gas and oil). However, with these products made elsewhere
Why has oil cost changed
Demand – high demand causes prices to rise.
• Supply – too much oil and the price falls.
• Political decisions – countries can increase supply to
increase income and gain control of markets.
• New supplies – fracking in the USA has caused oversupply
and prices have fallen.
Exploitation and mining of oil
High profits and new technology (drilling, seismic imaging have enabled oil and gas companies to drill in regions previously difficult to access. The Arctic has up 25% of the world’s remaining oil and is at risk from exploitation.
Using tar sands to produce oil and gas is unconventional Shale gas and tar sands oil extraction is only possible because of technological improvements, and high energy prices.
