Geography Paper 3 Flashcards
Where is the biosphere located?
The biosphere is the layer of the earth’s surface between the lithosphere and the atmosphere
What are biomes?
Biomes are large scale ecosystems
What factors alter biome distribution?
Factors that alter biome distribution:
- Rock and soil type = acidity and nutrients affect plant growth
- Water availability and drainage = some plants prefer wet soil, others dry soil
- Altitude = temperature decreases with height, rainfall increases with height
What do biomes consist of?
Biomes consist of biotic parts (living) and abiotic parts (non-living)
What are the importance of ecosystems to people?
- Biomes provide people with goods (food, fuelwood, timber, chemical materials etc
- Supporting services (nutrient cycling, photosynthesis, soil formation)
- Regulating services (carbon storage and hydrological cycle)
- Cultural services - tourism, education, science and well-being
What are large biomes exploited for?
Biomes are being cleared for commercial farming, mining metal ores, timber, construction of dams for HEP and water supply
How does destroying biomes affect the atmosphere?
- Biomes remove co2 from the atmosphere, destroying them releases the co2
- Biomes maintains healthy soil by the nutrient cycle - by removing biomass, nutrient stores are removed
- Flood risks and water supply reduced (more surface run off due to deforestation leading to less interception of water)
- Burning forests turns them into carbo sources
What has led to an increase in demand for natural resources?
Industrialisation, urbanisation, population growth and risin wealth has led to an increase in demand for natural resources
What was Malthus’ viewpoint?
Malthus - pessimistic - population will grow, planet will run out of resources, leading to war famine and fewer children
What was Boserups’ viewpoint?
Boserup - humans will invent new ways to allow more resources to be supplied eg gm crops and farm machinery
Why is biodiversity high in tropical rainforests?
Biodiversity is high in rainforests because of the hot and wet climate all year round, species have evolved over millions of years, contains multiple layers of vegetation
How are hardwood trees adapted to the climate?
Hardwood trees are adapted to the climate as they have large buttress roots that support the weight of trees and leaves and branches are only found at the top
How are lianas adapted to the climate?
Lianas are adapted to the climate as they use the tree to climb up to the sunlight in the canopy
How are birds adapted to the climate?
Birds such as macaws have strong beaks to break open nuts
How are primates adapted to the climate?
Primates such as monkeys use their tails for balance and live in the canopy where most food is found
Why is the nutrient cycle in the tropical rainforest so rapid?
The tropical rainforest nutrient cycle is so rapid because:
- It has a 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 has organisms in the taiga adapted to the cold climate?
Organisms in the taiga has adapted to the cold region by:
- Mammals have thick oily fur to retain heat
- Some animals hibernate in winter
- Some birds and animals migrate
- Trees are coniferous (evergreen), the trees are cone shape to allow snow to slip off and the waxy needles reduce water loss
How does the nutrient cycle in the taiga compare to the nutrient cycle in the rainforest?
The nutrient cycle in the taiga is slower than the rainforest, because the stores are smaller wil smaller flows of nutrients between. Most nutrients are found in the litter because decay happens much slower in cold temperatures. The biomass store is small because trees can only grow for a few months of the year. Precipitation is also lower.
What are the consequences of growing deforestation in the tropical rainforest?
The consequences of growing deforestation rates in the tropical rainforest:
- Cattle ranching (an increasing global demand for beef and the need to grow soya to feed cattle)
- Poverty
- Loss of habitats and indigenous communities
- Increased development of urbanisation, HEP stations and palm oil plantations
- Increased demand for timber, oil, gas, iron core and gold
What is the main indirect threat to the tropical rainforests?
The main indirect threat to tropical rainforests is climate change. Common droughts, dry leaf litter reduces decomposition and dying leaves in canopy reduces food supply, affecting food webs. During droughts rainforests can switch from absorbing co2 to emmiting co2.
What are the causes of taiga deforestation?
The causes of taiga deforestation include:
- Paper - comes from softwood trees eg fir and pine
- Construction - from softwood
- Mining - clearing forest for minerals eg gold and iron ore
- Extraction of fossil fuels eg oil and gas
- Building HEP dams
What factors lead to a loss of biodiversity in taiga forests?
Factors that lead to a loss of biodiversity in taiga forests include:
- Forest fires (hot and dry summers)
- Pests and disease (Warm temperatures increase infection and diseases in coniferous trees)
- Acid rain (sulfur dioxide from burning fossil fuels
What are the pros and cons of CITES? (the convention of international trade in endangered species)
CITES are adopted by 180 coutnries to protect species. However, protecting species does not prevent deforesatation and global warming, and illegal trade is still common
What are the pros and cons of REDD? (reducing emissions from deforestation and forest degredation)
REDD helps to decrease deforestation, but is difficult to police so illegal logging often takes place
