P1. Sec B Flashcards
What is an ecosystem?
A natural system made up of plants, animals and the environment. It is made up of links between living and non-living component of an ecosystem.
What is biotic?
Living
What is abiotic?
Non-living
What are producers?
Convert energy from the environment (mainly sunlight) into sugars (glucose)
e.g plants
Where do consumers get food/energy from?
They get energy from the sugars produced by producers.
What do decomposers do? E.g?
They breakdown plant and animal material and return the nutrients to the soil.
e.g bacteria and fungi
What does a food web show?
What does the arrows show?
Shows all the connections between organisms in an ecosystem?
- the arrows shows transfer of energy
What does a food chain show?
Shows the direct link between organisms in an ecosystem, in the form of a line.
What does a food chain pyramid show?
The number of organisms or biomass, who consumes (eats) who, through trophic levels
- it shows a loss of energy and biomass.
What is the difference between a food chain pyramid and a food chain.
A food chain pyramid shows the amount of organisms whereas a food chain does not
Explain why the amount of organisms decrease from each trophic level?
Because energy is lost through:
1. Excretion (using the toilet)
2. Movement —> this burns energy
3. Not everything of the animal is eaten - bones —> energy is trapped
4. Coldness to generate heat
What are fertilsers?
Chemical nutrients to speed growth of crops.
Explain the steps of Eutrophication (8)
- fertilizers are washed into ponds
- algae starts to grow as a result of increased nutrients –> produces algal bloom
- algae blocks sunlight which causes plants to die
- plants dying, decreases oxygen in the pond
- algae stops growing due to using up the nutrients
- bacteria decomposes (breaks up) the dead algae and plants
- eventually bacteria uses up all the oxygen
- water becomes anoxic –> ceases all life in the water
What is anoxic?
What without oxygen
What are biomes?
Global scale ecosystems
what are 7 major global ecosystems?
- Tundra
- Grassland
- Temperate deciduous forest
- Polar
- Hot dessert
- Tropical rainforests
- Boreal Forests
tundra (6)
Found in high latitudes (above 60 degrees north) in northern europe canada and alaska
- Winters are cold
- Summers are brief with little rainfall
- hardly any trees
- Vegetation: mosses, grasses and low shrubs
- There’s a layer of permanentley frozen ground called permafrost
Where are tropical rainforests found?
- ## Found around equator near the tropics
Hot dessert (5)
-Found between 15 and 35 degrees north and south of the equator
- Little rainfall
- very hot during day
- cold at night
- Shrubs and cacti are sparsely distributed in the sandy soil
Polar (4)
- Found around north and south poles
- Very cold, icy and dry
- not much grows at all
- Remain dark dark for several months so growing season very short (about 2 months)
temperate deciduous forest (5)
- found mainly in mid-latitudes where there are 4 distinct seasons
- Summers are warm
- Winters relatively mild
- Rainfall year round
- Deciduous trees lose their leaves in winter to cope with cold weather
what are the 2 types of grassland?
Savannah and temperate
Savannah grassland
- found between the tropics
- there are distinct dry and wet seasons although rainfall is relatively low
- most of the vegetation is grasses with a few scattered trees
Temperate grasslands
- found at higher latitudes where there is more variation in temperature and less rainfall
- there no trees here just grasses
what are Boreal forests also known as?
Taiga
What is latitude?
How far north and south you are from the equator
What is altitude?
The height above sea level (meters)
Why is the equator warmer than the poles?
2 reasons
At the poles the earth is more curved so has a larger surface area so solar radiation is less concentrated as it spreads over a larger surface area.
The second reason is because solar radiation travels a longer distance through the atmosphere so is absorbed or reflected back into space before reaching the earth
What is relief?
The shape pf the land
How do mountains produce ranifall
What are the 5 layers of the tropical rainforest? (Starting from top layer)
- Emergents
- Main canopy
- Under canopy
- Shrubs
- Soil
What are emergents?
The tallest trees in the rainforest (up to 70 metres)
- there isn’t as many of them as trees in other layers
Main canopy (2)
- these trees from the thickest layer of the rainforest
- the canopy layer absorbs 80% of the sunlight, meaning only 20 % goes below the trees
What are under canopy?
are shorter trees than thee canopy layer as they are younger, they will grow and take place of canopy trees that die
What do shrubs have?
Have large leaves to try and get as much sunlight as possible as it is very dark ther
Describe the rainforest soil quality?
Poor quality and has lots of plant litter
- this is due to leaching which drains the nutrients from the soil
- there are high levels of rainfall which washes away the nutrients ( except the top layer because decomposers bring the nutrients back to them)
Why are the emergents so tall?
Because they are the tallest therefore they absorb the most sunlgiht
What are 2 conditions of the rainforest floor?
Moist and dark
What are the 4 vegetation with adaptations in the tropical rainforests?
- A fan palm
- Buttress roots
- Lianas
- Drip tips
What is an adaptation of a fan palm? Why?
Has large leaves that are segmented
- need large leaves to capture sunlight to photosynthesise
Buttress roots adaptations (3)
1.Root found above ground (2m) around the tree
2. Roots below ground are shallow because he nutrients are on the top layer of the soil
3. Stabilise the tree as they grow tall
What are 2 adaptations of Lianas
- Grow tall to reach the sunlight
- Has woody vines which use other trees for support so they can grow tall
What are drip tips? Adaptation?
Leaves which come to a point at the end
- allows water to drop of leaf —> if water stays on leaf bacteria and fungi grow —> can’t photosynthesise
What do vegetation need to adapt to in TRFs? (3)
- Lack of sunlight
- Nutrient poor soil (apart from the top layer)
- High levels of precipitation
What are 4 adaptations of spider monkeys? How does it help them?
- Long tail with no hair at the end
- so can grip branches
- rely on long tail for balance so they can use their hands when needed to get fruits
- Live in trees
- to avoid being eaten by predators
- Tails has skin grooves on tip
- to act a a fifth hand as they spend most time in the canopy
- Flexible strong arms
- to move around the canopy.
What are nutrients?
occur naturally in the cycle and are constantly recycled
What are the 2 inputs of the nutrient cycle
- rainfall
- weathering of parent rock
what are the 3 transfers of the nutrient cycle?
- littering (leaves and branches)
- plant uptake
- decomposition
what are the 2 outputs of the nutrient cycle?
(how are nutrients lost?)
1.Nutrients can be lost by surface run-off as the nutrients are washed away
- Nutrients can be lost by leaching as the nutrients are drained from the soil
why rainfall important in the nutrient cycle?
it is needed for decomposition
what is biomass?
trees and plants
what happens if we remove trees by deforestation?
the amount of biomass decreases –> less nutrients and littering of leaves and branches —> less decomposition
What is interdependence?
The mutual reliance of different things/ parts of the ecosystem on each other
(When 2 parts of the ecosystem depend on each other to survive/function)
Why are tropical rainforests important? (7)
- rich in natural resources such as food (tropical climate ideal for growing fruit, nuts, coffee)
- 25 % of all medicines come from rainforest plants - provide clean water to millions of people
- 20% of the world’s fresh water comes from the Amazon Basin - produce 28% of world’s oxygen and also provide moisture to areas around the world via atmospheric circulation, stopping many areas from becoming arid
- Act as a carbon sink
- they absorb and store CO2 within soil and trees –> they slow global warming
- Amazon rainforests absorb 5% world’s carbon emissions each year - Communities
- indigenous communities lived in rainforests for generations –> displacing these communities would force them to live very different lifestyles - Wildlife
- huge biodiversity
- estimated within 4 square miles of a rainforest there are up to 1,500 flowering plants, 750 species of trees, 400 species of birds
and 150 species of butterflies - Research
- a lot of tropical rainforests are relatively untouched by humans which makes it a good environment for scientists to research
What are 6 causes of deforestion in the amazon rainforest?
- Commercial logging (2%)
- Commercial farming (70%)
- Hydroelectric power (2%)
- Population pressure (1%)
- Mining/ mineral extraction (3%)
- Subsistence farming (20%)
What is commercial logging and its % of deforestation?
Fell (cut) trees in order to sell the wood for income
(2%)
Commercial farming
70%
Split into:
1. Cattle farming (65%)
The main cause of catte farming is cattle grazing( when you deforest to put cattle e.g cows on
- Crops e.g palm oil (5%)
Hydroelectrc power
2%
Dams and reservoirs forms behind. Water is released to generate electricity.
Population pressure
1%
Land needed to build houses and infrastructure
Mining/ mineral extraction
3%
Land cleared for minerals to be extracted (taken out of ground) e.g gold —> to make profit
Subsistence farming
20%
Grow crops/ animals in order to survive and feed their families.
