Paper 3: People And The Biosphere Flashcards
What does indigenous people mean?
Original people of the region that lead traditional lifestyles and use the area to survive
In tribes, what is shelter like?
Small circular houses are built from wood + leaves
In tribes, what are their strengths?
Use plants + wild honey to make traditional medicines
Whip men before hunting to strengthen them and for growth too
Whip women too
In tribes, what is the food like?
Gather wild yams, nuts, mushrooms + berries from the forest
Efe monkey + antelope for bushmeat + fish in the rivers
Hunt giant forest hog + sell its meat to others - buy + trade
What are the causes of deforestation?
Farming Cattle ranching Palm oil plantation Logging Mining Slash and burning
Why is there an increasing demand for resources?
Rising population - greater demand for resources e.g food - destruction of forests for farmland
Increasing wealth of people - means people use more energy and fossil fuels
Increasing urbanisation - more people living in towns and cities which have sprawled over biomes
What is carbon sink?
Natural stores of carbon containing chemical compounds like carbon dioxide and methane
How does a forest biome store the carbon which is found on this planet?
Stores carbon as biomass
When plants and animals die the dead biomass ends up in the soil
What 2 can humans destroy biomes and affect carbon stores?
Deforestation - so biomes absorb less and biomass such as tress are burned, and soil destroyed, releasing their stored carbon
What ways can humans affect the nutrient cycle?
By removing biomass e,g logging timber which takes away a large nutrient store
Through deforestation, once areas are deforested, they are at risk of soil erosion
How will removal of trees affect the water cycle?
Increased risk of flooding because the ground will get more saturated quickly as there are no trees to protect the large quantity of water causing flooding
What is Malthus’ theory?
There will not be enough resources to meet the demands of the growing population
What is Boserup’s theory?
Technology will provide resources for the growing population
What is exponential growth?
When a quantity increases constantly over to,e
What does the Malthusian view say about how food production differs?
It differs by only increasing arithmetically
What does the Malthusian view say about the outcome of population/resource growth?
Population will increase geometrically but food supply will increase only arithemtically
It can lead to a lack of food supply leading to a ‘population vs resources crisis’
Which two ways does the Malthusian view say the population falls to, to create a balance between food and population?
Positive checks - war starvation and famine would reduce population
Preventative checks - people marrying later and having fewer children
What is a biome?
A large area characterised by certain types of plants and animals
What factors affect biome location?
Sunlight Rainfall Temperature Altitude Rock type Drainage
Name all 8 biomes
Tropical savanna Tropical rainforest Arctic and alpine tundra Desert Temperature Boreal forest Temperature Deciduous forest Chaparral Grassland
How does rock and soil type affect biomes?
When rocks undergo chemical weathering, they release nutrients and chemicals into soils
Soils can be neutral, acidic or alkaline
The acidity/alkalinity of soil influences the plants that will grow there
How does water availability and drainage affect biomes?
Some plants can grow with their roots in waterlogged soil or boggy areas
How wet the soil is depends on factors:
Amount of precipitation
Amount of evaporation from soil
How permeable the soil is, sandy soils are dry and clay soils are wet
How does altitude affect biomes?
Height affects biome in 3 ways:
Temperature drops by 6.5 degrees for every 1000m increase in height
At high altitudes, below freezing temperatures are common, which limits the types of plants that can grow
Rainfall usually increases within height
What does biotic mean?
Part is made up of plant and animal life
What does abiotic mean?
Part includes the atmosphere, water, rock and soil
Where are tundra ecosystems found?
found at high latitudes in northern Europe and Canada, and Alaska
A hot and dry grassland with shrubs and isolated trees, which can be found between a tropical rainforest and desert biome
Tropical savanna
A very hot and wet biome located on or near the equator and with the greatest biodiversity found anywhere on earth
Tropical rainforest
It is below freezing at night all year round ; this biome covers one-fifth of the land on earth - there is little precipitation, a short growing season ; and poor nutrients
Arctic and Alpine Tundra
This area is very hot and also very, very dry. Because of this little grows - only very hardy plants such as cactus which can survive drought
Desert
This biome is called a Taiga and is a northern coniferous forest. It is a cold woodland located north of temperature deciduous forests. It is the largest biome covering 50 million acres of land
Temperate Boreal Forest
Can be found in the eastern half of North America, and the middle of Europe. No extremes of climate. In the autumn the leaves change colour. During the winter months the trees lose their leaves
Temperature Deciduous Forest
Found in a little bit of most of the continents
This biome has flat plains, rocky hills and mountain slopes.
Very hot and dry - winter is very mild
Chaparral
A large biome with rolling terrains of grasses, flowers and herbs.
It is a region where the annual precipitation is great enough to support grasses, and in some areas a few trees
Very unpredictable precipitation that the drought and fire prevent large forests from growing
Grassland
What resources are provided by the biosphere?
Building materials and fuel Food Fuel resources Medicine Water
How do we obtain medicine from the biosphere?
Lots of plants that are used in medicines can only be found in tropical rainforests.
The Wasai plant is good for your kidneys.
The Lapacho plant is used as part of anti-cancer treatments
Name examples of commercially exploited resources caused by humans
Mineral extraction
Water
Energy
What are the causes of rising demand?
A larger global population and economic development
Why are minerals a commercially exploited resource?
Mineral extraction is often achieved by mining.
Surface mines lead to deforestation.
Infrastructure and roads also need to be built around mines and this leads to even more deforestation
Why is water a commercially exploited resource?
The course of rivers can be changed by hydroelectric power plants and their dams.
Water can be polluted by surface run-off, with pesticides and fertilisers flowing into water sources.
Climate change is causing global temperatures to rise and this could cause desertification in some parts of the world
How is energy a commercially exploited resource?
Large-scale deforestation is being carried out to make space for cattle farming, to clear land for biofuel crops, and to allow surface mining to extract coal and minerals from the ground.
Hydroelectric power stations need large dams to create energy and huge areas of forest are often flooded in the creation of these dams
What does the biosphere do?
Regulates the composition of the atmosphere
Maintains soil health
Regulates the hydrological cycle
How does the biosphere regulate the composition of the atmosphere?
When plants photosynthesise, they take in carbon dioxide and give out oxygen.
When animals breathe, they take in oxygen and give out carbon dioxide
How does the biosphere maintain soil health?
Soil structure and fertility is maintained thanks to plant roots and certain animals spreading nutrients throughout the soil.
Soil is held together by the roots of vegetation.
By intercepting rainfall, plants help to minimise leaching, which is the washing away of nutrients so that plants can no longer reach them
How does the biosphere regulate the hydrological cycle?
The hydrological cycle (also called water cycle) describes how water moves between land, water bodies and the atmosphere.
By taking up water, plants reduce the amount of water in rivers, which reduces the amount of flooding and soil erosion caused by the rivers
What process do plants minimise by intercepting rainfall?
Leaching
Why is soil fertility low in tropical rainforests?
The heavy and frequent rain washes away nutrients
Why is soil fertility low in tropical rainforests?
because the heavy and frequent rain washes away nutrients
What is the soil like in boreal forest and why?
Nutrients poor, acidic and thin
This is because needles from the coniferous trees take a long time to decompose when they fall because of the cold, dry climate
Describe the climate of tropical rainforests
2,000 mm of rainfall annually
21-30 degrees Celsius
Describe the climate of temperate forests
Rain all year round Up to 1,500 mm annual rainfall Mild winters Shorter days in winter Warm summers
Describe the climate of boreal forests
Average summer temperatures are about 10 degrees Celsius
Most precipitation fall as snow
Short summers
Usually less than 500mm annual precipitation
What are the main reasons for increasing energy demands?
Economic development
Increasing global population
Technological advances
Urbanisation
How does economic development cause global demand for energy?
More countries becoming more economically developed will increase the demand for energy and electricity.
Manufacturing new products normally uses lots of energy and lots of water
How does advances in technology cause global demand for energy?
Technology has increased people’s quality of life however they need energy or electricity to run
How does urbanisation cause global demand for energy?
Lots of people living in the same place means that public transport works better. Public transport is more energy efficient.
However, incomes are generally higher in cities, so people consume more and use more energy
How does increasing global population size cause global demand for energy?
More people are consuming more energy so there is a greater demand
What did Thomas Malthus call the point at which resource supply became insufficient to support the population?
Point of catastrophe
Explain how latitude affects temperature
Locations near the Equator, where sunlight is more intense, are warmer than those near the poles
As latitude increases (towards the Poles) winter becomes longer and colder, and the climate more seasonal
How does latitude affect precipitation?
North and south of the equator, there are the 3 main convection cells in the atmosphere
Precipitation is high at the rising parts of these cells due to low air pressure
What are large areas of biomes cleared for?
Commercial farming Commercial crops e.g palm oil Mining metal ores e.g copper Timer - used for furniture Construction of dams and reservoirs for HEP to supply water to cities
Define biodiversity
Biodiversity is the range of different organisms in a biome
