geo 3 for mokeys

Define a biome

A large-scale ecosystem where living and non-living things are located eg. tropical rainforest

7 biomes to be aware of

Tropical rainforest, tundra, hot desert, temperate forest, tropical grassland, temperate grassland, boreal forest / taiga

Location of a tropical rainforest

Close to equator, between tropics of cancer and capricorn

Temperature and rainfall of a tropical rainforest

Hot all year round (27-30C)

Wet all year round (2000-3000mm)

Vegetation of a tropical rainforest

Large variety of broadleaves plants

Trees dominate for space and light

Location of tundra

Close to north pole, with high latitude

Temperature and rainfall of a tundra

Temperatures remain around 0C, reaching 10C in summer

Low precipitation (often below 250mm)

Vegetation of a tundra

Very few plants live here, mostly lichens and mosses

Trees are rare and stunted

Location of a hot desert

Located close to the tropics of cancer and capricorn

Temperature and rainfall of a hot desert

Very hot all year round (above 30C)

Very low rainfall (less than 250mm)

Vegetation of a hot desert

Plants have water storing features, spines instead of leaves and a large root system

Location of a temperate forest

40-60° north and south of the equator, but as far north as the arctic circle

Temperature and rainfall of a temperate forest

Warm summers (18C) and cool winters (5)

Precipitation all year round (1000mm)

Vegetation of a temperate forest

Trees shed their leaves – deciduous trees

Location of a tropical grassland

Close to the equator, between tropics of cancer and capricorn

Temperature and rainfall of a tropical grassland

Hot all year round (25-30C)

500-1000mm of rain a year with a dry season

Vegetation of a tropical grassland

Tall grasses with some drought adapted plants and shrubs

Location of a temperate grassland

North and south of the tropics of cancer and capricorn

Temperature and rainfall of a temperate grassland

Hot in summer (25C) and very cold in winter (below 0C)

500-900mm per year, mostly occurs in late spring and summer

Vegetation of a temperate grassland

Grasslands with very few trees or shrubs

Location of a boreal forest / taiga

A continuous band across north america and russia

Temperature and rainfall of a boreal forest / taiga

Warm summers (16-30C) and very cold winters (below 0C)

Low precipitation (less than 500mm per year), mainly in summer

Vegetation of a boreal forest / taiga

Coniferous trees which have needles not leaves to survive cold weather and reduce water loss

Climate is a key factor which influences the distribution of biomes. Give 5 aspects of climate that can affect the distribution of biomes

Temperature, wind, diurnal temperature variation, seasonal temperature variation, precipitation

How can temperature affect the distribution of biomes

Affects the types of land formed

How can wind affect the distribution of biomes

Affects moisture levels and seed dispersal

How can diurnal temperature variation the distribution of biomes

Affects which plants and animals survive

How can seasonal temperature variation affect the distribution of biomes

Affects growing seasons

How can precipitation affect the distribution of biomes

Rain = vegetation // less rain = less vegetation

Explain how aspects of climate affect the distribution of desert (2)

Located near equator and high air pressure

Sinking air causes it to be warmer and hold more moisture

Little cloud coverage leads to hot days and cold nights

Explain how different aspects of climate affect the distribution of temperate grasslands (3)

Due to interior location of continents, extremes are seen between summer and winters (continentiality)

As oceans regulatory presence is absent

Warm moist summer vs cold dry winter

Explain how different aspects of climate affect the distribution of tropical rainforests (2)

High temperatures cause air to rise (low pressure)

Leading to year round rainfall

Explain how different aspects of climate affect the distribution of tropical grasslands (2)

A close proximity to equator causes high temperatures

But due to movement of ITCZ a dry season is produced

Explain how different aspects of climate affect the distribution of tundras (2)

High latitude causes low temperatures and little sunlight in winter months

High air pressure causes little precipitation

Explain how different aspects of climate affect the distribution of boreal forests / taigas (2)

High air pressure leads to little precipitation, mainly snow

Due to cold temperatures and high latitude

Explain how different aspects of climate affect the distribution of temperate forests (2)

Low air pressure leads to high rainfall all year

Due to higher latitude, winters and cool and summers are warm

4 local factors which affect the distribution of biomes

Altitude, rock type, drainage, soils

Explain how altitude affects distribution of biomes (3)

Temperatures fall with increasing altitude

Mountains more exposed to wind and usually have more precipitation, along with thinner soils and steeper slopes

Forests become stunted and are replaced with species eg. grasses

Explain how rock type affects distribution of biomes (3)

Some rocks are harder than others

Some rocks let water soak through them (permeable) so infiltration occurs

Some rocks are impermeable so surface runoff occurs

Explain how drainage affects distribution of biomes (2)

Poor drainage caused by impermeable surfaces causes water logging

Leading to peat bogs / marshland farmingExplain how soils affects distribution of biomes (4)

Explain how soils affects distribution of biomes (4)

Sandy = good infiltration leading to dryness

Clay = poor infiltration causing waterlogging

Chalky = good infiltration supporting grasses

Peat = rich in nutrients required for forest growth

Define biotic and abiotic components

Biotic = living parts

Abiotic = non-living parts

Define weathering

The breakdown of rock / material on land / in situ

Define biological weathering

Where rock is broken down by living organisms

Define bio-phsyical weathering

When the roots of plants and trees force their way into the joints of rock, physically forcing them apart

Define bio-chemical weathering

When flora or fauna secrete acids which dissolve the rock

Living organisms interact with the atmosphere in different ways eg. producing methane via digestion / decomposition. The main ways are through..

Photosynthesis and respiration

Explain how oxygen and carbon dioxide are used in photosynthesis and respiration

1. Oxygen produced by plants

2. Oxygen breathed in by animals

3. Sugar molecules broken down by animals

4. Oxygen produced by plants

5. Carbon dioxide taken up by plants

6. Carbon used by plants to make sugar molecules

And the process repeats

What is the nutrient cycle also known as?

The Gersmehl cycle

What does the nutrient cycle show

How nutrients are transferred within an ecosystem

The nutrient cycle proposes the idea that each ecosystem has 3 nutrient stores. Name them

Litter store, biomass store, soil store

In the nutrient cycle, what is meant by the litter store

Demand plant material eg. leaves that have fallen to the ground. Nutrients are stored here

In the nutrient cycle, what is meant by the biomass store

The living things found in the ecosystem, they all contain nutrients

In the nutrient cycle, what is meant by the soil store

Nutrients stored in the upper layers of earth, in the soil

Explain the nutrient cycle

1. Nutrients in rainfall enter the litter store

2. Some nutrients are lost from the litter store through leaching

3. Nutrients in the litter store are transferred to the soil store through decomposition 

4. Nutrients enter the soil store through weathered rock

5. Nutrients are transferred from the soil store to the biomass store when they are uptaken by plants

6. Nutrients are transferred from the biomass store to the litter store when they die and fall out

Explain how trees regulate the hydrological cycle (3)

Trees intercept and absorb rainfall

Which slows the passage of rainfall to the ground, reducing surface runoff

Which reduces flood risk and regulates groundwater and surface water

Explain how the hydrological cycle is regulated in tropical rainforests (3)

The transpiration by plants returns moisture to the atmosphere during the day

When temperatures cool in the evening, condensation takes place

And there is heavy precipitation

Explain how the hydrological cycle is regulated in the desert (2)

Succulent plants eg. cacti store water

Slowing its evaporation

Diagram of all of the hydrological cycle regulations taking place

Define biosphere

Layer of planet where life exists, made of many different ecosystems

3 examples of how humans use the biosphere for food

Natural vegetation can be replaced with crops like wheat and rice

Sustainable harvesting of fruits, berries and nuts

Fish and meat are part of biosphere

3 examples of how humans use the biosphere for medicine

The periwinkle plant is used to treat Leukaemia and Hogdkin’s disease

Poppies are a source of the painkiller morphine

The Aloe plant has soothing properties and is used in many cosmetic products

3 examples of how humans use the biosphere for building materials

Timber, essential for construction, comes from trees

Animal dung can be mixed with clay and straw to make bricks

Straw and stalks of cereal plants are used for roofing and insulation

3 examples of how humans use the biosphere for fuel

Animal dung is dried and burned

Biofuels convert to plant products to fuel through a range of processes

Wood from trees and shrubs are burned

Explain how an increase in the demand for water has lead to exploitation of the biosphere (2)

Due to high water demand, parts of biosphere are deprived of water

Eg. wetlands have dried up in Hamoun, Iran due to dams in Afghanistan and poor irrigation practices

Explain how an increase in the demand for biofuels has lead to exploitation of the biosphere (3)

Biofuels are valuable as they provides alternative to fossil fuels and are renewable

Commercial production means huge areas of land dedicated to biofuels crops not fuel crops

So vital resources from biosphere eg. food + fuel are more expensive for locals and have negative impacts on biodiversity

Explain how an increase in the demand for minerals has lead to exploitation of the biosphere (2)

Increased demand for minerals has major impact on biosphere

Eg. mountain-top removal mining where tops of mountains are removed to access coal seams

The biosphere plays an important role globally, in terms of regulating the atmosphere, soil health and managing water. 

Give 2 examples of how it regulates the atmosphere

Photosynthesis removes carbon dioxide and increases oxygen levels

Respiration releases carbon dioxide and this leads to natural greenhouse effect which keeps us warm

The biosphere plays an important role globally, in terms of regulating the atmosphere, soil health and managing water. 

Give an example of how it regulates soil health

Decomposition adds nutrients to soil eg. rich humus soil

The biosphere plays an important role globally, in terms of regulating the atmosphere, soil health and managing water. 

Give 4 examples of how it manages water

Decreases surface runoff

Decreases flood risk

Surface water regulation

Groundwater regulation'

Explain how population growth has lead to an increase in resource consumption (3)

Increase in population means more people need food

And more require water for drinking, sanitation and leisure

So the demand for water and food increases

Explain how affluence has lead to an increase in resource consumption (3)

Increase in GDP / capita means people spend more on luxuries

Which often require electricity to power and use more energy resources to manufacture

Therefore demand is greater

Groups expected to develop soon

BRICs, MINTs, Africa

5 resources which are being used more due to urbanisation and industrialisation

Food, water, raw materials, waste, energy

Explain how use of food has increased due to urbanisation (4)

Urban areas are characterised by fast food consumption 

Which increases the amount of meat eaten in a diet

Greater livestock is needed for food eg. burgers

Increasing demand for it and pressure on the land to produce it

Explain how use of water has increased due to urbanisation (2)

More demand for water

For drying clothes, sanitation, drinking

Explain how the use of raw materials has increased due to urbanisation (2)

Raw materials are used for refining, plastics, mining lithium for batteries

Due to a rise in demand for electronic goods in urban areas

Explain how urbanisation has increased the amount of waste (2)

Urbanisation has meant there are more people in a smaller area

Putting pressure on waste disposal which is often in rural areas / settlements

Explain how industrialisation has increased the amount of waste (2)

Industrialisation means there are more factories which produce more waste

Which can have knock on effects eg. polluted rivers

Explain how industrialisation has increased energy consumption (2)

Industrial processes that involve heat eg. refining oil

Require large amounts of energy

Explain how urbanisation has increased energy consumption (3)

Urban areas are characterised by tertiary sector work

Which is mostly online work

Therefore there is a greater demand to produce electricity for this

Consumption of food, water and energy is leading to biosphere damage. Give 4 examples

Cattle farming, palm oil plantations, hydroelectric power plants, mining

4 negative effects of cattle farming on the biosphere

Deforestation occurs to provide the food to feed the cattle

Cattle need water for irrigation, drinking and processing the meat

Cattle produce methane, a GHG 23x as polluting as carbon dioxide

Desertification occurs due to deforestation and trampling by cattle

2 negative effects of palm oil plantations on the biosphere

Palm oil plantations are used for cosmetics + food

Deforestation leads to reduced biodiversity and the formation of a monoculture

Additionally less carbon dioxide is intaken

2 negative effects of hydroelectric power plants on the biosphere

Eg. 3 gorges dam

Dam creation requires cement which is a carbon dioxide intensive industry

Reservoir flooding behind the dam leads to anaerobic respiration of vegetation = methane

3 negative effects of mining on the biosphere

Open-cast mining = removal of ecosystem to dig and extract natural resources

Mountain-top mining = blowing top off mountains to extract natural resources

Deforestation = removal of trees to extract raw materials below

How “happy” are the malthusian and boserupian theories

Malthusian theory is more pessimistic, while boserupian is more optimistic

Describe the malthus theory of population growth and food production

As population growth meets food supply

A catastrophe occurs eg. famine

Which causes a population decline

1 advantage of the malthus theory

Wars, civil wars, famine, droughts, disease have taken place due to food shortages

3 disadvantages of the malthus theory

Human innovation eg. agricultural revolution ensured food supply remains higher than population growth

Birth rates and population growth decline as a country develops economically – not shown on this model

Outdated model with limited view of future population growth

Describe the boserup theory of population growth and food production

Advances in technology eg.:

• Agricultural revolution

• Genetically modified crops (increase yields, increase disease and drought resistance, hydroponics, vertical farming, lab grown meat)

Allows supply to meet growing population

3 advantages of the boserup theory

The fact that the agricultural revolution took place

Fertilisers / pesticides as evidence

Irrigation practices as evidence

2 disadvantages of the boserup theory

Doesn’t consider population crashes due to malnutrition or famine

Limited understanding of population growth

TRFs: (t8)

• Located

• Temperature

• Rainfall

• Therefore ideal for

20 degrees N  / S

Hot temp of 27 to 30C

Wet with 2k to 3k mm rainfall / yr all yr round

Therefore ideal for plant growth

Give 2 examples of biotic and abiotic components in a TRF

Biotic = tree, frog

Abiotic = rain, wind

What is the biggest store in the TRF nutrient cycle?

Biomass, made up of biotic components

Why do leaves and branches decompose very quickly in the litter store?

Moist, humid, warm temperature, oxygen rich which is ideal for decomposition

Describe leaching and the impact this has on soil nutrients

Leaching is the loss of nutrients from the soil store via rainfall

So less nutrients

Give/explain 3 reasons why the TRF has high levels of biodiversity (high range of plants and animals living)

Stable ecosystem: TRF characteristics haven’t changed for a long time therefore there is varied evolution

Limited competition: vast amount of food available to all plants + animals 

Conditions for growth are ideal = warm, wet, sunny, oxygen rich

Explain 2 ways trees are adapted to their environment in a TRF

The emergent layer of trees gains the maximum sunlight for photosynthesis, therefore they outcompete smaller trees and plants

The driptip leaf (waxy layer) reduces mass growth and increases photosynthesis. Also the pointy tip allows rainwater to flow off