P1 SB The Living World πΏ Flashcards
What are ecosystems?
Natural systems made up of plants, animals and the environment. Complex interrelationships between living + non-living components
Biotic = ?
Living factors eg plants / animals
Abiotic = ?
Non-living factors eg climate / soil
Large scale / global ecosystems are defined by what?
The dominating vegetation
KEY EXAMPLE: Avington Park lake. Where is it?
A country estate near Winchester, Hampshire
Avington Park lake is of ______ and _____ importance
Historical
Ecological
What was the issue at Avington Park lake?
Lack of maintenance = accumulation of silt + vegetation growth
What was a positive of what had happened at Avington Park lake?
It created excellent habitats for birds
What was a negative of what had happened at Avington Park lake?
The view of the lake from the house had been lost
When was the restoration carried out at Avington Park lake?
2014
What were the outcomes of the Avington Park lake restoration?
The view was restored, and new habitats were created to attract birds and water fowl
What is a producer?
An organism that converts energy from their environment into sugar
Eg plants
What is a primary consumer?
Something that gets its energy from producers
Eg herbivores
What is a secondary consumer?
Something that gets its energy by eating a primary consumer
Eg a carnivore
What do decomposers do?
Return nutrients to the soil
Eg bacteria / fungi
_____ one component of an ecosystem ____ all other ____
Changing
Impacts
Components
Example of changing a component:
If perch were added to a pond, they would eat more of theβ¦
Smaller fish and animals such as frogs
The Mediterranean biome is found where?
40-45 degrees N of equator
Some other locations with similar climate, eg California, South Africa, western Australia
What are summer and winter like in the Mediterranean climate?
Hot, dry summers and mild winters
What kinds of plants can be found in Mediterranean climate?
Olive + fruit trees
Why is the polar climate so cold?
Cold air sinks at the north and south poles β> low temps and dry conditions
Where is temperate grassland found?
30-40 degrees N + S of equator
Eg prairies in N America, steppes in E Europe
Temperate grasslands are mainly used for what?
Grazing animals
Tropical rainforest is foundβ¦
Near the equator
Temperatures and rainfall are both high in what biome?
Tropical rainforest
What proportion of the worldβs plant / animal species are found in TRFs?
Over half
What proportion of all medicines come from TRF plants?
One quarter
Desert biomes are found ___ degrees N and S of equator
30
Deserts cover what proportion of the worldβs land surface?
One fifth
Hot deserts are associated with __-_____ high pressure belts
Sub-tropical
Tropical grassland (savanna) is found where?
15-30 degrees N and S
What large scale ecosystem is found 50-60 degrees N of equator?
Deciduous + coniferous forests
Why do deciduous trees shed their leaves?
To retain moisture
Why do coniferous trees keep their leaves?
To maximise photosynthesis in the summer months
Tundra is found ___ - ___ degrees north of the equator
60 - 70
In the tundra there are ___ growing plants adapted to retain ___ and ____
Low
Heat
Moisture
What is the climate like in TRFs?
Warm and wet
How much rainfall do TRFs receive each year?
Over 2000mm
What is the average temp in TRFs?
27 degrees C
Why is rainfall high in TRFs?
Due to low pressure over the equator
Rising air = clouds = heavy rain
How long is the wet season in TRFs?
6 months
The soil in TRFs is _____ and most nutrients are foundβ¦
Infertile
On the surface
Trees have ___ roots to absorb nutrients
Shallow
____ transfer nutrients directly from air (_____ _____)
Fungi
Nutrient cycling
Heavy ____ washes away nutrients, leaving behind ____, ___-rich soil
Rainfall
Infertile
Iron
Where do the majority of animals live in the TRF, and why?
In the canopy - most light
What adaptation do many leaves have that allows rain to run off?
A drip tip
Why to TRF trees have thin, smooth bark?
To allow water to flow down easily
Why do many leaves have flexible bases?
So they can turn to face the sun
What are epiphytes?
Plants that live on branches high in the canopy and get their nutrients from water and air rather than soil
What are lianas?
Woody creepers rooted to ground and carried into canopy by trees
What do buttress roots do?
Support base of tree, help transport water, may also help oxygen / carbon dioxide exchange by increasing surface area
How have sloths adapted to TRF conditions? Name 4 ways
Coat is camouflaged
Green algae grows on fur
Slow movements = concealed from predators who rely on vision
Sharp claws to grip branches and defend themselves
Turn head 270 degrees
Thick coats = dry during rainy season
Slow metabolism = stay in trees for days
How have strangler figs adapted?
Seed dropped in nook and uses debris as nourishment
Sends aerial roots down trunk
Gradually surrounds host
Branches grow taller to reach sunlight + roots rob host of nutrients
Host eventually dies and decomposes
A desert isβ¦
An area that receives less than 250mm of rainfall / year
What are desert soils like?
Dry soil
Little or no organic matter due to lack of leafy vegetation
Evaporation draws salts to the surface leaving a white powder
Infertile
Hot deserts are found in ___ ____ ___ away from coasts
Dry continental interiors
Hot deserts are found in belts at approximately __ degrees N and S
These generally follow the lines of the Tropic of ___ and ____
30
Cancer
Capricorn
During what months are desert temperatures at their highest?
June to September
In winter there is some rainfall with around __mm per month
5
In winter temps drop by about __ degrees C
30
Around the tropics there is __ pressure due to the warm air ____
High
Sinking
How have cacti adapted to desert conditions?
No leaves so water loss is reduced
Store water in stems
Spikes to defend from being eaten by animals
How have animals adapted to desert conditions?
Fennec foxes have large ears to radiate heat away from their body, which cools them down
Camels store fat in humps instead of in their body so they donβt overheat
CASE STUDY: THAR DESERT
Where is the Thar?
NW India and into Pakistan
200,000 km squared
Most of it is in the Indian state of Rajasthan
The Thar is the mostβ¦
Densely populated desert in the world
In the Thar, soil and sand isβ¦
And there is littleβ¦
Not fertile
Surface water
How much rainfall does the Thar desert receive each year?
Between 100mm and 240mm
What temperature does the Thar reach in summer?
53 degrees C
Jaisalmer is found on the ___ ___ β> opportunity for ___
Silk Road
Trade
Jaisalmer has grown by over ___ in a ___ and has over _____ inhabitants
1/3
Decade
600,000