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11T5 - Ecosystems & Human Impact - Coggle Diagram
11T5 - Ecosystems & Human Impact
Organisms in the environment
Population - the number of organisms of a single species
Community - a group of organisms of different species
Habitat - the place where an organism lives
Ecosystem - distinct self-supporting system of organisms interacting with each other and with a physical environment
Biodiversity - a measure of the range of species living within an ecosystem
Biotic factors
Disease
Prey/food availability
Predators
Competition between individuals of the same species, or of different species
Abiotic factors
Temperature - affects the rate of enzyme controlled reactions
Light - affects rate of photosynthesis in plants
Water availability - required for growth in plants
Mineral ion availability
pH - affects rate of enzyme controlled reactions
Carbon dioxide or oxygen concentration
Feeding relationships
Producers - organisms that make their own food by photosynthesis e.g. plants and algae
Primary consumers - herbivores that only eat pants (producers)
Secondary consumers - carnivores that eat primary consumers
Tertiary consumers - carnivores that eat secondary consumers. They have no predators and so are called apex predators
Decomposers - Bacteria and fungi that break down dead animal's body and waste for energy, using enzymes
Food chains - the feeding relationships between organisms. They are organised by trophic levels
Food webs - a collection of different food chains to show hoe the organisms in the habitat interact with each other
Pyramid of numbers - shows the population of each organism at each tropic level in the food chain. Producers are at the bottom and the bars usually get smaller as you go up. However is the producer is a large plant like a tree the size of the bar will be very small as 1 tree can feed many insects
Pyramids of biomass - show the relative biomass at each tropic level. There is less biomass as you move up the tropic levels. This is because not all of the food consumes by an animal is converted to biomass
Pyramids of energy - show the amount of energy contained within the biomass of individuals within different tropic levels. The area of the box represents the quantity of energy present. As you move up the pyramid the quantity of energy decreases as not all energy so transferred to biomass
Transfer of energy
Producers convert light energy into chemical energy through photosynthesis
Primary sonsumers consume the prioducers and they break down the biomass of the producer.
Secondary consumers consume primary consumers and break down the biomass of primary consumers
As chemical energy is transferred from one tropic level to another the biomass is also transferred
Losses of energy
Only 10% of energy is transferred from one tropic level to the next
Organisms rarely eat every part of the organism they are consuming
Not all the ingested material is digested
Energy is used for movement, to generate heat and metabolic processes
Some material is lost as waste - carbon dioxide, water and urea
Calculating efficiency of biomass transfer
Percentage efficiency transfer = Biomass in higher tropic level / biomass in lower tropic level x100
Carbon cycle
Respiration - plants and animals aerobically respire, which releases CO2 into the air - decomposers also respire while they break down compounds
Photosynthesis - Plants remove CO2 form the air through photosynthesis
Decomposition - Dead plants and animals are broken down by decomposers - the carbon is then returned into the atmosphere
Combustion - when plants and fossil fuels are burnt, the carbon dioxide is released into the atmosphere
Human influences on the environment
Sulfur dioxide - released when fossil fuels are burnt - dissolves in water droplets on clouds to form dilute sulfuric acid which creates acid rain - acid rain makes rivers to acidic which leas to aquatic organisms dying - it corrodes metals and limestone buildings and leeches minerals out of the soil so plants and trees cannot survive
Carbon monoxide - released when fossil fuels are burnt through incomplete combustion - binds irreversibly to haemoglobin which then reduces the oxygen carrying capacity of red blood cells - this can lead to tiredness, unconsciousness or even death in severe cases.
Greenhouse gases -
water vapour
from rivers and lakes -
carbon dioxide
from deforestation and fossil fuels -
nitrous oxides
from fertilisers and engines of vehicles -
methane
from cattle and rice paddy fields -
CFCs
- from refrigerators and aerosol sprays
Greenhouse gases absorb infrared radiation from the Sun, trapping it above the Earth's surface which leas to the increase of the Earth's temperature
Pollution of water by sewage - sewage is rich in minerals and nutrients that will allow decomposers and algae to thrive - the algae bloom tops light from reaching aquatic plants causing them to die - this leads to oxygen depletion meaning other aquatic organisms will die.
Eutrophication - when fertilisers are washed off from the land into nearby rivers and lakes by rain - the excess nutrients that are washed into lakes and rivers can lead to an increase in the growth of algae - this algae blocks sunlight reaching plants below so they cannot photosynthesise leading oxygen deprivation.
Effects of deforestation
Leeching - trees normally take up nutrients and minerals form soil to use for growth so without trees these run into rivers and lakes
Soil erosion - tree roots help to stabilise the soil so without trees the soil will be washed away by rain
Disturbance to cycles - transpiration from trees releases water vapour which contributes to the water cycle and the carbon cycle
Imbalance in oxygen and carbon dioxide - remova and burning of trees will result in more atmospheric carbon dioxide levels and lower oxygen levels