Geography paper 1 The Living World

what is an ecosystem

a system in which organisms interact with each other and their environment

ecosystem components

abiotic- non living factors such as air, rocks, heat and water

biotic- factors that are living such as plants, animals and insects

flora- plant life occurring in a particular region or time

fauna- animal life of any particular region or time

food webs and chains, producers and consumers

food chains- a sequence of events in an ecosystem, where organisms eat each other. it starts with a producer (plant) then a primary consumer then secondary etc

food webs- a network of many food chains connected together

producer- plants that use photosynthesis and nutrients to create energy

consumers- animals that eat plants or other animals e.g. herbivores or carnivores

nutrient cycle

plants take in nutrients to build into new organic matter.

animals take in nutrients when they eat plants and the nutrients are retuned to the soil when the animal dies and the body is broken down by decomposers.

litter, biomass and soil

litter- the surface layer of vegetation which over time breaks down to become humus.

biomass- the total mass of living organisms per unit area

  

biomes

biome- large geographical area of distinctive plant and animal groups, which are adapted to that particular environment. the climate and geography of an area determines what biome can exist there

-more productive biomes= biomes that are the greatest in biomass= grow in climates that are hot and wet (humid)

tropical rainforest biome

location- along the equator

temperature- hot all year (25-50 degrees)

rainfall- very high (over 2000 a year)

flora- tall trees form a canopy

fauna- greatest range of animal species, most live in canopy layer

tropical grassland biome

location- between latitudes 5-30 north and south of the equator

temperature- warm all year (20-30)

rainfall- wet and dry season (500-1500mm)

flora- grasslands with widely spaced trees

fauna- large hooved herbivores and carnivores dominate

hot desert biome

location- found along the tropics

temperature- hot by day cold by night

rainfall- very low (below 300mm a year)

flora- lack of plant and few species adapted to drought

fauna- small nocturnal animals except the camel

temperate forest biome

location- between latitude 40-60 north of the equator

temperature- warm summers and mild winters

rainfall- variable rainfall

flora- deciduous trees and a variety of species

fauna- animals adapt to colder and warmer climates. some migrate

tundra biome

location- latitudes of 65 degrees north and south of the equator

temperature- cold winter and cool summers

rainfall- low (below 500mm)

flora- small plants grow close to the ground and only in summer

fauna- low number of species, most found at the coast

coral reef biome

location- found within 30 degrees north and south of equator in tropical waters

temperature- warm water all year round with temps of 18 degrees

rainfall- wet and dry seasons, rainfall varies greatly due to location

flora- small range of plant life including algae and sea grass

fauna- dominated by polyps and fish

tropical rainforest biome

covers 2% of the earths surface yet accounts for over 50% of the worlds plant and animals

interdependence in the rainforest

interdependence- where plants and animals depend on each other for survival.

if one component changes, there can be serious knock-up effects for the entire ecosystem. e.g. removal of the python can lead to more rodents which would eat more bird eggs.

rainforest nutrient cycle

-hot damp conditions on the forest floor lead to high levels of decomposition of dead plant material

-this leads to many nutrients being absorbed by plant roots

-however, as these nutrients are in high demand, they don’t remain in the soil for long and stay close to the surface

-this means soils are thin and poor as most nutrients are locked away in biomasses.

-leaching removes minerals but not iron= the soil is a red colour.

distribution of tropical rainforests

-centred along the equator

-found in south America, central Africa and south east Asia

-the amazon is the largest

layers of the rainforest

emergent- highest layer with trees reaching 50m. most light here

canopy- more life is found here as it receives 70% of the sunlight and 80% of life

under canopy- trees that reach 20m high

shrub layer- lowest layer with small trees that have adapted to being in the shade

climate of TRFs

clouds= temp doesn’t get higher than about 32 degrees= plants don’t scorch

heavy afternoon rainfall

the Hadley cell and convectional rainfall cause the climate

case study- Epping forest- small UK ecosystem- London/Essex

-English lowland deciduous woodland

-70% of the area is designated as a site of special scientific interest (SSI)

-60% is designated as a special area of conservation (SAC)

components and interdependence of Epping forest

spring- flowering plants (producers) such as bluebells store nutrients to be eaten by consumers later

summer- broad tree leaves to maximise photosynthesis

autumn- trees shed leaves to conserve energy due to sunlight hours decreasing

winter- bacteria decompose the leaf litter, releasing nutrients into the soil

ecosystem/ food web disturbance

-grey squirrels introduced= more disease and territorial= red squirrels die out

example of a food chain: shrubs, insects, mice, foxes

TRF Malaysia case study

Malaysia is made up of peninsular Malaysia and east Malaysia which is a part of the island Borneo.

67% of Malaysia is TRF

between 2000- 2013, the area of forest lost was larger than the area of Denmark

over 600 species and 25% of all plant species in Malaysia are found in the TRF

orangutans and tribes who practise slash and burn live in the TRF

issues related to biodiversity in Malaysia

high biodiversity rates due to:

humid climates= vegetation growth

rapid nutrient recycling rates

most of the TRF is untouched

value of rainforest in Malaysia to people and the environment

people- HEP crops, meat and fish, wafer, medicines and employment

environment- air purification, wildlife habitats, biodiversity and carbon sink

causes of deforestation in Malaysia

logging- largest exporter of tropical wood in the 1980

commercial and subsistence farming- largest exporter of palm oil. subsistence farmers such as tribes using slash and burn.

mineral extraction- mining for tin common in Peninsular Malaysia. oil and gas drilling has begun in Borneo

population growth- poor people encouraged by government to move from urban Malaysia to the countryside (transmigration) forest is then cleared for the settlers.

energy development- Bakun dam supplies energy for Peninsular Malaysia. 700km squared has been flooded.

road building- roads are needed to transport supplies and provide access to settlements and mining areas.

impacts of deforestation

economic development:

mining, farming and logging creates employment and tax income for the government

cattle ranching and soya bean production

loss of biodiversity reduces tourism.

soil erosion

once the land is exposed by deforestation, it is more vulnerable to rain

with no roots binding soil together, it can easily wash away

climate change

when rainforests are cut down, the climate becomes drier

trees are carbon sinks. loss of carbon sinks= less GHGs absorbed, so more greenhouse emissions in the atmosphere leads to global warming

trees are burnt, releasing carbon into the atmosphere and enhancing the greenhouse effect.

sustainability for the rainforest: ways to increase sustainability

uncontrolled exploitation= irreversible damage such as biodiversity loss, soil erosion and climate change. strategies include:

conservation- creating national parks/ areas of protected land

selective logging- trees are only felled when they reach a particular height, conserving other species

debt swap- when governments swap debt to conserve rainforests e.g. USA reducing debt for Brazilian rainforest

Hot desert: Thar desert India

found in the state of Rajasthan NW India and into Pakistan.

most densely populated desert in the world, slightly smaller than the whole of Uk

200,000km squared

characteristics of hot deserts

aridity- hot deserts are extremely dry with average rainfall below 250mm

heat- hot deserts get over 40 degrees

landscapes- some places have dunes, but most are rocky

distribution of the world’s hot deserts

found in the subtropics between 20 degrees and 30 degrees north and south of the equator.

usually run through the tropics.

climate of hot deserts

-less than 250mm rainfall per year

-only rains once every 2-3 years

-hot day temps (45) cold night temps (5) due to little clouds

-some winters may have frost or snow

interdependence in hot deserts

vegetation stops wind blowing sand and soil away, allowing plants to grow

cactus survival adaptations

widespread, shallow roots to absorb water soon after rainfall

needles instead of leaves to reduce surface area and so transpiration

thick waxy cuticle to reduce water loss through evaporation

camel adaptations

hum stores fat which can be metabolised for energy

large, flat feet to spread on the sand for balance and to prevent sinking

tough tongue to eat cacti

thick eyelashes to keep sand out eyes

large surface area to volume ratio to increase heat loss

opportunities of hot deserts

-valuable minerals for extraction= job opportunities

-rich in energy. oil found in Barmer district could be transformative. Jaisalmer wind farm is India’s largest wind farm. solar energy ideal due to the sun.

-tourism: many visit from Pakistan. safaris are popular

-farming: grazing in grassy areas cultivating for fruit and veg. commercial farming of wheat and cotton= job opportunities

challenges in hot deserts

-heat= difficult to work outside for too long

-water shortages are common= people need to adapt to low water

-aquifers are salty and poor quality

-accessibility is poor due to rough roads and tarmac melting. buses are overloaded.

causes and definition of desertification

desertification- the turning of semi-arid areas (drylands) into deserts

population growth- high fertility rates= growth. poverty= economic migration so higher water demands

fuel wood (pop growth)- people rely on wood for fuel. deforestation= soil exposure which dries up.

over cultivating/ over grazing (pop growth)- if crops are grown in the same areas too often, nutrients are used up causing soil erosion. too many cattle= overgrazing= soil erosion

strategies to reduce desertification

water management- growing crops that don’t need much water. collecting water on roofs.

tree planting- trees protect the soil from wind and soil erosion e.g. Africa’s great green wall.

soil management- leaving areas of land to rest and recover lost nutrients. building low walls to stop soil erosion.

natural hazard definition

a natural process which could cause death, disruption or injury to humans, properties and possessions.

types of natural hazard

tectonic- caused by land and tectonic processes (earthquakes, volcanos)

geomorphic- events that happened on earths surface (flooding, landslides)

atmospheric- caused by weather and climate

biological- hazards involving living things (forest fires)

factors affecting the risk of hazards

location- plate margins, volcanos, equator

poverty- LICs, island nations

population density- rural/urban

GACM rules

hot rising air= low pressure, stormy wet cloudy weather at equator= rainforests

cold sinking air= high pressure, dry clear weather, at tropics= deserts

wind is the movement of air. surface winds always moves from areas of high to low pressure.

Coriolis effect- the earth’s rotation deflects the winds as they blow from areas of high to low pressure and earth rotates from west to east

tropical storm conditions

low pressure systems

between 5-20 degrees N

sea must be above 26 degrees for several days (usually during autumn)

trade winds

sea needs to be 70m deep

250-300 mm rainfall

formation of tropical storms

-in summer and autumn, sun heats ocean causing warm moist, air to rise

-once 27 degrees, rising warm air causes low pressure which turns into a thunderstorm.

-this causes air to be sucked in from trade winds.

-the thunderstorm spins due to Coriolis effect.

when storm spins faster than 74mps, a tropical storm forms.

-cool air sinks in the centre of the storm, creating the eye.

-when it hits land, the storm loses energy and dies.

effect of climate change on tropical storms

increased climate change= increased tropical storms as oceans reach 26+ degrees more often

warmer atmosphere holds more moisture holds more moisture= heavier rainfall.

primary effects of tropical storms

-death, destruction of buildings, communities and communication

-shortage of clean water and sanitation

-winds cause high waves= storm surges which account for 90% of deaths

secondary effects of tropical storms

-disease

-homelessness= poverty, distress, illness due to lack of shelter

-damaged businesses= unemployment

-damaged crops= food shortage

short term responses to tropical storms

rescue, search, helping the injures

long term responses to tropical storms

rebuilding schools building homes, kickstarting the local economy

Nepal earthquake 2015 LIC

7.8 magnitude

primary effects- 8600 dies, 21,000 injured, 3.5 million made homeless, Dharahara tower destroyed (popular tourist spot)

secondary effects- 10,000 landslides, one destroyed the village of Langtang, human trafficking levels raised, area received 10x the usual amount of landslides

short term responses- simple tools used by locals to recover people, 4.3 million given food rations for months, countries sent rescue teams

long term responses- government sent $3000 to affected families to rebuild their homes (some didn’t spend the money accordingly) cash for work scheme meant locals were paid to rebuild parts of the city, Oxfam provided sustainable living spaces, food, sanitation and jobs. UK provided waterproof shelters.

Chile earthquake 2010- HIC

8.8 magnitude Earthquake 500x more powerful than Nepal earthquake

primary effects- 500 died, 12000 injured, buildings destroyed and communications cut

secondary effects- tsunamis in coastal areas, 70k left the city, cost $30 bn to repair schools + hospitals

short term responses- emergency services supplied, field hospitals, communications restored, temporary repairs to infrastructure, power and water restored to 90% of homes within the first ten days

long term responses- national appeal raised $60bn, 300 shelters built, strong economy meant little international aid was required.

Prediction, protection, planning

prediction- constant monitoring gives advanced warning of tropical storms (seismometers)

protection- building construction projects to reduce the risk of buildings collapsing

planning- involves getting people and services ready to deal with impacts. emergency storm shelters can be built and drills take place in public buildings.

UK Heatwave, July 2022

UKs hottest ever temp of 40.3 C

34 locations exceeded the previous hottest temp of 38.7 in 2019

5 died due to drowning

London fire brigade declared a major incident after several fires broke out in the capital = busiest day since ww2

250+ firefighters tackled 3 fires in london

operating theatres were too hot so surgeries cancelled.

Natural causes of climate change

Sun spots (solar outputs) small dark patches of suns surface. more sun spots= more solar output= solar flares. less sun spots= less solar output

the structure of the Earth

the crust- varies in thickness (5-10km) made up of several large plates. oceanic crust is denser but thinner. continental is thicker but less dense

the mantle- widest layer (2900km) the heat and pressure means the rock is in a state of convection

the inner and outer core- hottest section (5k degrees) mostly made of iron and nickel and is 4x denser than the crust. inner section is solid, outer section is liquid

convection currents

the crust is divided into tectonic plates which move sue to convection currents in the mantle

-radioactive decay of some of the elements of the mantle and core generate lots of heat

-as molten magma towards the bottom of the mantle heat up, they become less dense and begin to rise

-as they rise to the top, they begin to cool down, become denser and so sink

-this circular movement is convection current

-the convection currents create drag on the bottom of the tectonic plates, causing them to move

why continue to live in tectonic areas?

confidence in technology

benefits- water and fertility

family ties

poverty

destructive plate margins

denser oceanic plate subducts under the less dense continental plate, resulting in the release of pressure due to friction. this friction causes the oceanic plate to melt and become molten magma. this forces it’s way up the continental plate and forms a volcano.

the release of energy also causes earthquakes

how are ocean trenches formed

they are formed in a destructive plate margin, where the two plates meet and the continental plate crumples into fold mountains

constructive plate margin

two plates moving apart causing new magma to reach the surface through the gap

volcanoes formed across this crack cause a submarine mountain range

conservative plate margin

where two plate margins slide past each other in opposite directions or in the same direction at different speeds. this causes earthquakes.

causes of earthquakes

caused when two plates become locked, causing friction to build up. from this stress, the pressure will eventually be released triggering the plates to move into position, this movement causes energy in the form of seismic waves to travel from the focus to the epicentre. as a result, the crust vibrates triggering an earthquake

epicentre, seismic waves, focus

epicentre- the point directly above the focus, where the seismic waves reach first

seismic waves- energy waves that travel out from the focus

focus- the point where pressure is released

atmospheric circulation

the large scale movement of air by which heat is distributed on the surface of Earth

global pattern of air circulation

Hadley cell- largest cell which extends from the equator between 30 to 40 degrees north and south

Ferrel cell- middle cell where air flows poleward between 60 and 70 degrees

Polar cell- smallest and weakest cell that occurs from the poles to the Ferrel cell

management and monitoring storms

protection- construction projects that improve protection

development- the scale of the development depends on whether the country has the resources to cope with the storm. LICS tend to struggle with technology

prediction- constant monitoring and installing warning systems gives advanced warning for storms

aid- involves assisting after the storm, usually in LICs

planning- emergency storm shelters can be built and communicated to vulnerable populations

education- reduces panic

Typhoon Haiyan 2013 causes

started as a tropical depression on 2nd November 2013 and gained strength. became a category 5 super typhoon and made landfall on the Pacific islands of the Philippines. 5 storm surges hit the coastline. 341mph winds

typhoon Haiyan primary and secondary effects

6,500 deaths

130,000 homes destroyed

emotional grief

water and sewage destroyed= disease

30k boats destroyed

water shortages

typhoon Haiyan short and long term effects

the UN raised £190 million in aid

UK and USA sent carrier ships

education on typhoon preparedness

cash for work programme

Oxfam assisted new fishing boats

1,200 evacuation centres set up