Geography A edexcel GSCE - ecosystems

Factors that affect distribution?

• climate

• altitude

• soil type

How does altitude affect distribution?

high altitudes are colder so less plants grow... also limits no. of animal species

How does soil type affect distribution?

- nutrient rich soil supports more plants

- acidity, drainage and thickness of soils affects the type of plants grown

How does climate affect distribution?

- sunshine hours

- rainfall..

- temperature

Tropical Forest climate?

• always hot and rainy

Tropical forests characteristics? (plants)

- mostly trees evergreen

- grow quickly

- adapted to take in maximum light

Tropical forests characteristics? (animals)

-dense vegetation = lots of food and different habitats for animals = lots of species of animals

- e.g. sloths , pythons , beetles

Tropical forests characteristics? (soils)

plants shed leaves all year round

- decompose quickly = constant supply of nutrients in soil

Temperate forest climate?

• 4 distinct seasons..

• rainfall is high - rain all year round

• days shorter in winter, longer in summer

• sunshine varies through year

Temperate forests characteristics? (plants)

- broad leaves tree - drop leaves in autumn

- contains shrubs and undergrowth (e.g. ferns)

Temperate forests characteristics? (animals)

- mild climate + range of plants = food and habitat for mammals, birds and insects

Temperate forests characteristics? (soils)

- plants loose leaves in autumn

- leaf litter decomposes quickly = soils thick and nutrient rich

Boreal forests climate?

• short summers and long winters

• winter temp - below -20C , summer temp - around 10C

• precipitation low - less than 500mm (most is snow)

• loads of daylight during summer, none during winter

• skies clear, so plenty of sunshine

Boreal forests characteristics? (plants)

- mostly evergreen

- coniferous trees such as pine, fir are common

- low growing mosses and lichen are common

Boreal forests characteristics? (animals)

- few species due to less food available

- e.g. black bears, wolves, eagles

Boreal forests characteristics? (soils)

- needles from trees decompose slowly = soils thin and acidic

- some areas ground is frozen for most of the year

Desserts climate?

• low rainfall - might rain once every 2 years...

• temperature - hot in day (45C) , cold at night (below 0)

• clear skies - lots of sunshine every day

Dessert characteristics (plants)

- growth sparse due to lack of rainfall

- plants there - cactus, thornbushes

- short life cycle ,only appearing when it rains

Dessert characteristics (animals)

- few species due to lack of vegetation

- species adapted to cope with harsh climate

- snakes , lizards , scorpions

Dessert characteristics (soils)

- sparse vegetation = little leaf litter

- dry climate = organic matter slow to decompose

- soils thin and nutrient poor

tropical grasslands climate

• low rainfall

• fires quite common during dry season

• temperatures highest right before wet season

• temperatures lowest right after wet season

• near equator so there's plenty of sunshine all year round

Tropical grasslands characteristics (plants)

- mostly grass, scrub and small plants

- few scattered trees e.g. acacia

- plants adapted to recover quickly after fire

Tropical grasslands characteristics (animals)

- lots of insects e.g. grasshoppers , beetles

- larger animals are zebras, lions, elephants

Tropical grasslands characteristics (soils)

- grass burned during dry season forming a thin nutrient rich soil

- but nutrients washed out in wet season

Temperate grasslands climate

• hot summers and cold winters

• 250mm-500mm rainfall each year

Temperate grasslands characteristics (plants)

- dominated by grasses and small plants

- rainfall too low to support large plants, so few trees

Temperate grasslands characteristics (animals)

- less animal species

- e.g. mammals (bison and wild horses) and rodents (mole rats)

Temperate grasslands characteristics (soils)

- high temperatures in summer = decomposition quick =

soils are relatively thick and nutrient rich

Tundra climate

• temperature is low

• precipitation - less than 250mm per year (most is snow)

• tundra found at high latitudes

• summer - mostly daylight ,winter- little to no daylight

Tundra characteristics (plants)

- lack of light = hard for plants to grow = hardly any trees

- vegetation - mosses, grasses and low shrubs

Tundra characteristics (animals)

- lack of vegetation = few animals

- e.g. arctic hares and artic foxes

Tundra characteristics (soils)

- sparse vegetation = little leaf litter

- organic matter decomposes slowly = thin soil

- layer of permafrost below soil - water cant drain away

What resources does the biosphere provide?

• food

• medicine

• building materials

• fuel

What is the biosphere exploited for?

• energy

• water

• minerals

How is the biosphere exploited for energy?

Demand for energy is increasing as the population increases and becomes wealthier..

• large area of forest cut - grow biofuels /mining /power station

• drilling for oil and gas - permafrost melted in tundra

• some areas of forests flooded from HEP dams

• fracking can pollute air and contaminate groundwater

How is biosphere exploited for water?

• sources of water e.g. lakes, rivers are overexploited to meet needs of the growing population

• this causes damage to the biosphere as plants and animals don't have enough water to survive

How is the biosphere exploited for minerals?

• gold + iron are used a lot for many things , demand increasing

• minerals extracted by mining

• mines in tropical forests are responsible for deforestation

• toxic chemicals are washed into water sources, killing wildlife

• mining removes large areas of land - reducing habitats for plants and animals

What does terrestrial ecosystems mean?

land based ecosystems

What are the 4 terrestrial ecosystems that the UK has?

• Heath

• Moorland

• Wetlands

• Woodlands

Where are heaths found?

• found in lowland areas (below 1000)

• there are large areas of heaths in south of England

Where are moorlands found?

• found in upland areas

• e.g Scotland, north of England

Where are wetlands found?

• found on floodplains - near rivers and lakes

• can also be found in upland areas

Where are woodlands found?

• cover most of the UK

• example - Forest of Dean in southern England

Similarities between heath and moorlands

• acidic and poor

• high rainfalls

• open landscapes

• few trees

Wetlands Characteristics

• soil are waterlogged for most or all of the year

• anaerobic soils (water stops oxygen form getting into the soil)

• vegetation in bogs decomposes slowly - peat bogs

• acidic soils and marshes - alkaline/neutral soils

• habitats for mammals - e.g. otters and birds

• ideal breeding conditions for flying insects - e.g. dragonflies

Coniferous Woodlands characteristics

• most trees are evergreen

• most CW are commercial plantations - grown for timber

Decidouos Woodlands characteristics

• trees lose their leaves in autumn

• fertile soils

• fallen leaves decompose and mix with soil to form thick soil called brown earth

• shelter + fertile soils = right condition for small plants

What resources do marine ecosystems provide?

• recreation - leisure activities = income generated from tourism

• energy - drilling for oil, used as fuel for transport + industry.

• energy - renewable energy - tidal ,waves, wind farms

• fishing - source of food and also provides jobs

How are human activities (pollution) are degrading marine ecosystems?

• plastic waste eaten by sea creatures - kills or suffocate them

• eutrophication - excess fertiliser run into estuaries , algae grows rapidly - reduces oxygen supply and light to seabed - killing organisms under seabed fast

How are human activities damaging the seabed?

• dredging - removes important nutrients + damages seabed

- reduces supply of food to marine organisms

• fishing ( with trawl nets) - damages habitat e.g. coral reef

• building marine infrastructure - e.g. offshore farms can physically damage seabed + harm organisms living there

How is fishing degrading the marine ecosystems?

• overfishing - fish are caught faster than they can be replaced through breeding, causes fish to decline

• overfishing can have a knock off impact on population of birds, seals as there are fewer fish for them to eat

Tropical RAINforests climate

• climate same all year round

• hot because its near equator

• rainfall high

Tropical RAINforests soils

• soil isn't fertile - rain washes away nutrients

• decaying fallen leaves provides layer of nutrients but layer is thin as decaying happens fast in moist conditions

Tropical RAINforests water

• rain intercepted by tree canopy

• some water absorbed by plants and stored inside them

• runs off into streams which feed large rivers (amazon)

Tropical RAINforests plants

• most trees evergreen

• trees really tall and vegetation cover is dense - little light reaches forest floor

• lots of epiphytes e.g. orchids

What are epiphytes?

plants that grow on other plants and take nutrients and moisture from air

Tropical RAINforests animals

• e.g. gorillas, jaguars , tree frogs

• lots of species of insects and birds

• many animals brightly coloured and make a lot of noise

Tropical RAINforests humans (indigenious people)

• people adapted to live there over many generation

• make a living by hunting, fishing and gathering nuts, berries and growing vegetables to survive

What are the 4 layers of the tropical rainforest

• Emergent layer

• Main canopy

• Under canopy

• Shrub layer

Emergent layer characteristics

• tallest trees

• branches and leaves at top to reach the light

• tall trees have buttress roots, keeping them stable as they grow taller

• roots are above ground so they can get nutrients from rich layer on soil surface

Main canopy layer characteristics

• continuous layer of trees

• only have leaves on top

• dense layer of leaves shades rest of forest

Under canopy layer characteristics

• younger trees that haven't reached their full height

• only survive where little breaks in canopy are - to have light

Shrub layer characteristics

• nearest to ground where its quite dark

• large and broad leaves to absorb as much light as possible

How are animals adapted to tropical rainforests?

• strong limbs (climbing)

• camouflage (hiding)

• modified beaks (opening nuts)

• modified wings (Flying)

What do food chains show?

shows what is eaten by what

What is a food web?

shows a lot of food chains an how they overlap

Parts of a food chain

• producer - uses sunlight energy to produce food

• consumer - energy by eating other organisms

What model shows the nutrient cycle?

Gersmehl model

What 3 stores are in an ecosystem (according to Gersmehl model)

• biomass - living organisms

• litter - dead organic material

• soil

What does the size of the circle and arrow show?

amount of nutrients

What is leaching?

nutrients are washed away from plants roots and soil

Gersmehl model....

• trees evergreen - dead leaves and material fall all year round

• decomposition of dead organic matter quickly (warm climate)

• nutrients released are soluble and soaked up by soil

• dense vegetation and rapid plant growth = nutrients rapidly taken up by soil

What is biodiversity

variety of organisms living in a particular area -both plants and animals

Gersmehl model arrows

green arrows - inputs

red arrows - losses

blue arrows - transfers

How does climate change have a negative effect on rainforests?

• plants not adapted - can die

- droughts = fires - destroy large areas of forest

• plants respond to changes by producing fruit at different times than usual affecting food supply of animals.

- leaf litter decomposes slower = less nutrients for plants

• biodiversity reduction

- knock on effect..loss of species impact other species..

Why does deforestation happen? (economic)

- agricultural purposes - grow crops or commercial farms

- resource extraction - wood from trees , mining for minerals

Why does deforestation happen? (social)

- population pressures - trees cleared for new settlements

- trees used as fuel for cooking or burned to make charcoal

Management of the amazon - governance

Central Amazon Conservation Complex in Brazil protects a large amount of the rainforest - limits hunting ,logging, fishing

• NGO's - Natutima is an organisation in Colombia which works with the locals to protect river species and teach people about endangered animals.

• Local fisherman also report illegal hunting or fishing

Management of the Amazon - commodity value

•selective logging - felling certain trees allowing forest to regenerate - saves logging company money in the long run as they don't have to keep planting trees

•international agreements - reducing illegal lodging and promote wood from a sustainable source

• precious woods amazon - lodging company in Brazil - limits number of trees that are cut down,so rainforest can regenerate

What does commodity value mean?

how much goods and services from the rainforest are worth

What is ecotourism?

tourism that minimises damage to the environment and benefits the local people

Management of the Amazon rainforest - ecotourism

• tourists pay entrance fees - money for rainforest conservation - profit invested to promote conservation in local community

• tourists visit in small groups so damage minimised and partake in activities to raise awareness for conservations

• Yachana lodge - ecotourism project in Ecuador - people rely on subsistence farming for a living

• project employs local people - reliable income for them = better quality of life

• also encourages conservation of forest so visitor still come

Decidious woodlands climate

• 4 distinct seasons

• rainfall quite high - 1000mm

Decidious woodlands - soils

• fallen leaves decompose quickly = rich soils due to humus

• earthworms and other organism in soil mixed humus with minerals from weathered rock to form fertile soils called brown earth

What is humus?

organic matter

Decidious woodlands - water

• rains all year round ,supplying water to many water sources

• pools and lakes sometimes freeze in the winter

Deciduous woodlands - plants

dominated by tall, broad leaved trees

• plants stratified in 3 layers - canopy , shrub and herb

Decidious woodlands - animals

• birds, insects and small mammals live in trees

• larger mammals e.g fox make homes in ground by burrowing

Deciduous woodlands - humans

• people exploit deciduous woodlands for commercial purposes

• woodlands used as places for recreation

Are abiotic and biotic factors in woodlands interdependent?

yes!

How are abiotic and biotic factors interdependent?

• trees get water and nutrients from the soil ,photosynthesis releases oxygen which humans and animals need to breathe • when leaves fall and decompose , nutrients return to the soil

• woodlands mainly sheltered and cants rely on wind to disperse seeds instead they rely on animals

How do animals disperse seeds?

• eat the fruit and release seeds by excrement

• ants carry seeds to their nests to feed their young ,this makes seed go far from parent plant

3 layers of deciduous woodlands

• canopy layer

• shrub layer

• herb layer

canopy layer characteristics

• top layer

• trees have broad, flat leaves and spread their branches wide - forms dense canopy which captures sunlight

Shrub layer characteristics

• some plants get sunlight by climbing trees e.g. ivy

•plants adapted to lack of sunlight - e.g. hazel has wide leaves to absorb as much sunlight as possible

Herb layer characteristics

• plants are shade-tolerant

• some plants grow in the spring when canopy is still growing so more sunlight reaching woodland floor e.g. bluebells

Plant adaptations - decidious

• as weather cooler in autumn, trees conserve resources by drawing food and nutrients back from leaves into stems - leaves stop capturing sunlight and dry up then fall..

• helps trees to conserve water which is lost by surface of leaves - also means trees don't need to use energy to prevent leaves from freezing

•when temp warmer signal sent to the tree so it could produce new leaves - these capture sunlight and helps tree grows till cycle restarts

animal adaptations to changing seasons

• birds migrate in the autumn to avoid cold weather

•some mammals such as brown bears hibernate in the winter - reduce their need for food - heartbeat and breathing rate slow down so they can survive on fat stored in their body

• some animals store food in the autumn - e.g. squirrels store nuts in ground under bushes - this is used for them to survive when food is scarce

What model is used for deciduous woodland?

Gersmehl model

deciduous woodlands - model

• biomass biggest store due to lots of trees

• litter store quite large due to leaves falling in autumn

• soil is also big as leaves falling forms a layer of humus which is mixed with minerals from weathering - this store is large as loads of nutrients get transferred from litter store through decomposition