Ecosystems Flashcards
Individual
A single organism
Population
All the organisms of one species in a habitat
Community
All the organisms of different species living in a habitat
Ecosystem
A community of organisms along with the abiotic factors and their interactions
What is interdependence?
When organisms depend on each other for things like food and shelter in order to survive and reproduce
-change in pop can have huge knock on impacts for others in community
What is mutualism?
A relationship between two organisms for which both benefit
E.g. bees visit flowers for nectar and pollen is transferred to them, they then spread this with others plants they land on
-best get food, plants can reproduce
What is a parasitic relationship?
- parasites live on or within a host organism
- the parasite benefits, the host does not and may be harmed
- e.g. fleas eat dogs blood but dogs get nothing in return
What are abiotic factors?
Temperature
Amount of water
Light intensity
Levels of pollutants
What biotic factors are there?
Competition for the same resources, if there isn’t enough population size decreases as can be supported
Predation
What do plants do with sun energy?
- convert a small % into glucose of which some is used immediately in respiration and the rest stored in biomass
- organism that east this uses so,e of the energy the rest is stored in its biomass
- this process continues
What happens if the energy isn’t stored as biomass?
- some energy is used by organisms to survive e.g. respiration
- this energy isn’t stored as biomass so isn’t transferred to the organism at the next tropic level
Does all biomass energy get transferred?
No as not all of the organism gets eaten
- undigested material is lost from the food chain as faeces
- this is why most food chains don’t go beyond 5 food chain levels so energy is lost at each level so there isn’t enough to support organisms
Biomass
The mass of loving material that makes up an organism
What does a pyramid of biomass show?
- how much creatures at each level of a food chain would weight if put together
- since biomass is a store of energy this measure show much energy is at each stage
Equation for efficiency of energy transfer?
-energy transferred to next level/energy available at previous level x100
What is biodiversity?
The variety of living organisms in an ecosystem
-human interaction within ecosystems can effect this both positively and negatively
What is eutrophication
- fertilisers enter water adding excess nitrates
- this excess causes algae to grow fast and block out sunlight
- plants can’t photosynthesis due to lack of light and start to decompose
- which more food available, micro organisms that feed on decomposing,ants increase and use up oxygen in water
- organisms that need oxygen to survive due as water become anoxic
How can eutrophication occur?
-if too much fertiliser is applied and it rains afterwards that can run off
How does fish farming reduce biodiversity?
- food is added to nets for fish producing huge levels of waste that can leak into the open water causing eutrophication
- this can act as a breeding ground for parasites which can kill wild animals
- predators becomes attracted to the net, get trapped and die
- sometime fish escape =problems for indigenous species
Solution for fish farming?
- fish are farmed in large tanks rather than in one water nets
- low in biodiversity as only one species is farmed
- these are kept free from plants and predators and parasites are usual,y killed
How can introducing non-indigenous species reduce biodiversity?
- can be unintentionally or intentionally introduced
- non indigenous species can outcompete indigenous species for resources like food and shelter so they decrease in number and die out
- they can also bring new diseases infecting and killing indigenous species
What is reforestation?
- replanting forested areas
- frets have high biodiversity due to wide variety of biotic factors that provide food and shelter for other organisms
- can be carefully planned to maximise impacts e.g. deliberately plainly a variety of tree species
What are conservation schemes?
- protecting a species natural habitat
- protecting species in safe areas outside of their habitat including captive breeding programmes to increase numbers
- seed banks to store and distribute rate endangered plants
Benefits of conserving biodiversity?
- Protection of human food supply for now and future generations
- minimal damages to food chains as if one species become extinct others will too be effected due to interdependence
- medicines in undiscovered plants
- providing jobs like in ecotourism that bring money in
- cultural aspect e.g. world heritage sites
How does increasing human population effect food security?
- as people become wealthier their diets change e.g. a wider variety of food and eating more fish and meat
- less energy/biomass every time you more up a tropic level e.g. can produce more food through crops than grazing animals
- risk of overfishing so not enough for future
How can human activity cause less food security?
- burning fossil fuels releases harmful gases causing temps to rise through global warming
- This can effect growth patterns of crops hence reducing yields
- also soil/water pollution through things like acid rain can effect ability to grow food
How has sustainability effected food security?
- crude oil is running out so currently an increase in the growth of crops for biofuels which takes up land that otherwise might be used for food crops
- need to balance land use
- high input cost of farming (fertilisers and machinery) may make it too expensive for farmer’s to maintain food producing in certain areas
How do new pests and pathogens effect food security?
- can cause damage to livestock reduce yield
- stead new diseases that organisms might not be resistant to
How are materials constantly cycled in an ecosystem?
- living organisms are made from elements taken from the environment
- these are turned into complex compounds which are passed along food chains
- waste products and dead organism are decomposed so the elements within return to the soil or air to be taken in again by other plants
Why is the carbon cycle important?
- there’s only a fixed amount in the world, this ensures its recycled
- decomposition of materials means habitats can be maintained for the organisms that live there e.g, nutrients to the soil
Why is water cycle important?
- droughts can can cause big problems and the water cycle means that it is constantly recycled to reduce this
- sea, clouds, rains, transpiration/interception,drains into sea
- all organisms need water to survive
What is desalination?
- Removes salts and mineral ions from sea water
- thermal desalination means the water is boiled in am enclosed vessel so the water evaporates
- steam rises whilst a salts stay at the bottom
- steam ravels down a pore and is condensed back into pure water
- expensive as requires large amounts of thermal energy and releases harmful gases through burning
What is reverse osmosis?
- reverses osmosis to get rid of impurities
- salt water is treated to remove solids and then is fed at high pressure into a vessel with a partially permeable membrane
- pressure causes the water molecules to move in the opposite direction to osmosis (higher salt concentration to lower)
- as the water is forced through the salts are left behind
What is the nitrogen cycle?
Nitrogen in the atmosphere is very uncreative so can’t be used by plants but nitrogen is needed for making proteins for growth
-plants absorb these from the soil and pass them on through food chain
What is decomposer (type of bacteria in nitrogen cycle)?
Decomposes proteins and urea and turns them into ammonia
Ammonia forms ammonium ions in solution that plants can use
What is nitrifying bacteria?
Turns ammonia in decaying matter Into nitrites and then into nitrates
-these can be taken up by plants in their roots
What is nitrogen fixing bacteria?
Turns atmospheric into ammonia which forms ammonium ions
-some live in the soil, some live in the nodules of legume plants (peas and beans)
Some can leak out during growth, they have a mutualistic relationship, bacteria get food from the plant and plants get nitrogen ions
What is denitrifying bacteria?
Turns nitrates back into nitrogen gas
No benefit to living organisms, these are often found in waterlogged soils
What can lightening do in the nitrogen cycle?
Due to the huge amounts of energy they can make nitrogen react with oxygen in the air to give nitrates
How do farmer’s increase nitrates in the soil?
Crop rotation= different crops are grown each year in a cycle, it usually includes nitrogen fixing crops helping to put nitrates back into the soil for following years
-fertilisers =(manure/compost) recycled the nutrients left in plant and animal waste retuning them to soil through decomposition, can be artificial ones as well but these are expensive
What raw indicator species?
Organisms very sensitive to environmental change can can indicate the surrounding conditions their in
What indicator species show water pollution?
- if raw sewage containing nitrogen are released into a river, microorganisms in the water increase using up oxygen
- freshwater shrimp are sensitive to oxygen concentration so them and stonefly indicate clean water
- bloodworms and sludge works indicate very high levels of water pollution
What indicative species show air pollution?
- lichen are sensitive to sulphur dioxide, the more lichen in an area the cleaner the air is
- black spot fungus will also indicate clean air
- some lichens of a certain colour indicate dirty air
What are other ethos’s to indicator species?
Dissolved oxygen meters and chemical tests are used accurately to measure the concentration of dissolved oxygen in water
-electronic meters show concentration of sulphur dioxide in the air
Pros and cons of indicator species?
- cost effective and simple
- given long term pollution levels
- don’t give accurate readings with figures and also can be confusing or misinterpreted (e.g. some lichens in both clean and dirty air)
What conditions speed is decomposition?
- temperature speeds up the reaction so decay happens waster until the enzymes denature
- water content as decay happens faster in moist conditions as they need water to survive and process
- oxygen availability is faster with more as it is needed for aerobic respiration, those who don’t need oxygen work slower anyway
How do you preserve food?
- in fridges or freezes lowers the temp slowing down rate
- storing food in airtight cans stops microorganisms getting in and also reduce the amount of O2 e.g. can be stored in oil
- drying food removes water needed to survive so can be salted meaning they loose water by osmosis
What are ideal conditions to make compost?
=decomposed organic matter that is used as fertilise
-produces quickest in warm, moist, oxygen rich conditions e.g. compost bins that can have mesh sides for more oxygen, and most/heat is generated by decomposed themselves yet insulators might be used
