Section 9- Ecosystem And Material Cycles Flashcards
how are ecosystems organised
- individual
- population
- community
- ecosystem
individual
a single organism
population
all the organism of one species living in a habitat
community
all the organisms of different species living in a habitat
ecosystem
a community of organisms along with all non living conditions
abiotic
non living
interdependence
-organisms depend on eachother for things like: food, shelter in order to survive and reproduce
what happens if theres a change in the population
if theres a change in the population of one species, it can have a knock on effect for other species in the same community.
mutualism
the relationship between 2 organisms in which both of the organisms benefit from
how do bees and flowering plants have mutualistic benefits
- when bees visit flowers to get nectar, the pollen is transferred into the bees body
- bees then spread the pollen to other plants when they land on their flowers
- the bees get food and the other plants get help reproducing
parasites
parasites live very closely with a host species (in or on them).
the parasite takes what it needs to survive, however the host doesnt benefit.
how are flees parasites
flees are parasites to mammals such as dogs.
fleas feed on their hosts blood, benefiting the flea, but don’t offer anything in return
abiotic conditions
- mutualism
-interdependence
-parasites
abiotic factors which affect communities
- temperatures
- amount of water
- light intensity
- level of pollutants
biotic factors
- predation
- competition
competition
organisms compete with other species and members of their own for the same resources.
if 2 organisms compete for the same resources, that means 1 organism dont have enough resouces, making their species decrease as they dont have enough resources to reproduce
predation
if a number of predators decrease, the number of preys may increase as fewer of them are being eaten by the predators
equipment used to study the distribution of small organisms
quadrats
quadrats
a square frame enclosing a known area in order to compare how common an organism is in 2 samples
how to study the distribution of small organisms
- place a 1m^2 quadrat on the ground at a random point within the first sample area
- count all of the organisms that youre interested in within the quadrat
- repeat step 1 and 2 multiple times
- work out the mean number of organisms per quadrat within the first sample area.
- repeat step 1 to 4 in the second sample area
- compare the 2 means
how to get a representative data
divide the sample area into a grid and use a random number generator to pick the coordinates to place the quadrat
how to estimate the population size
you need to work out the mean number of organisms per m^2, then multiply the mean by the total area of the habitat
what do you use to study the distribution along a gradient
a belt transect
gradient
some abiotic factors will change across a habitat, this change is known as a gradient.
belt transect
the quadrats are laid out along a line forming a belt transect
how to measure the distribution along a gradient
- mark out a line in the area you want to study
- collect data along the line using quadrats placed next to eachother. collect the data by counting all of the organisms of the species youre interested in OR by estimating a percentage cover
- you could also record other date: mean height, abiotic factors in each quadrat
- repeat step 1 and 2 several times, then find the mean number of organisms
- plot a graph to see if the changing abiotic factor is correlated with a change in the distribution of the species.
what happens of the transect is long
you could place your quadrats at regular intervals
equipment to use to measure the light intensity
light meter
human activities which affect biodiversity
- fertilisers
- fish farming
- introduction to non-indigenous species
biodiversity
the variety of living organisms in an ecosystem.
fertlisers
- fertilisers are put onto fields, if too much fertiliser is added and it rains afterwards, the fertiliser can easily make their way into rivers and lakes adding nitrates, more than plants can take in
- the excess nitrates can cause algae to grow fast and block out light
- plants cant photosynthesise due to the lack of light making them decrease in the population and decompose
- with more food available, microorganisms that feed on decomposing plants increase in number and use up oxygen in the water.
- organisms that need oxygen for aerobic respiration decrease in the population
- this causes a decrease in biodiversity
eutrophication
when too much nutrients is added which leads to death of many species.
fish farms
- food is added to the nets to feed the fish, which produce huge amounts of waste. both food and waste can leak into the open water, causing eutrophication and the death of wild species.
- fish farms in open water often act as a breeding ground for large numbers of parasites. these parasites can get out of the farm and infect wild animals, sometimes killing them.
- predators are attracted to the nets and can become trapped causing them to die.
- sometimes farmed fish can escape into the wild which can cause problems for wild populations of indigenous species.
what happens if fish are farmed in large tanks
these farms are low in biodiversity as often only 1 species are being farmed, the tanks are often kept free of plants and predators and any parasites and microorganisms are usually killed.
introducing non-indigenous species
- when non-indigenous species are introduced, they can be introduced intentionally and non-intentionally. they can cause problems to indigenous species.
- non-indigenous species compete with indigenous species for resources like food and shelter. sometimes, the non-indigenous species are better at getting these resources and out-compete the indigenous species, causing a decrease in number of the indigenous species and eventually dying out.
- non-indigenous species sometimes also bring new diseases to habitats. these can often infect and kill lots of indigenous species, reducing the habitats biodiversity
intentional ways for the introduction of biodiversity
- food
- hunting
unintentional ways for the introduction of biodiversity
-as a stowaway international cargo
indigenous species
native species
What does the water cycle mean
When water is endlessly recycled
The water cycle
- Energy from the sun makes water evaporate from the land, plants and sea, turning it into water vapour into the air (water from pants= transpiration)
- The water vapour is carried upwards as warm air rises. When it gets hugged up, it cools and condenses to form clouds, known as precipitation
- Water falls from the clouds as precipitation onto land, where it provides fresh water for plants and animals.
- It then drains into the sea and the whole process starts again as the water has gone back to earth and it can seep into soil and flow into rivers
Reverse osmosis
- This is widely used as a modern method for desalination
- the higher the salt concentration, the lower the water concentration
1. Salt water is first treated to remove solids before being sent at higher pressure into a vessel containing a partially permeable membrane
2. The pressure causes the water molecules to move in the opposite direction to osmosis, from a higher salt concentration to a lower salt concentration.
3. As the water is forced through the membrane, the salts are left behind removing them from the water.
5 places where carbon is stored
- In the air where- oxygen
- In plants- where it is locked up in biological molecules
- In the soil- contains a lot of bacteria and other microorganisms
- Fossil fuels
- Animals- where carbon is locked up in biological molecules
How are materials recycled through biotic and abiotic components of the ecosystem
- Living things are made of elements to take from the environment, for example, plants, take in carbon and oxygen from the air and nitrogen from the soil.
- They turn these elements into the complex compounds (carbohydrates, proteins and fats) that make up living organisms. I’ll pass along the food chain, what animals eat the plants, and also each other.
- The elements are recycled, waste products and dead. Organisms are broken down by decomposers which are usually microorganisms and the elements in then will return to the soil or are ready to be taken in my new plants and put back into the food chain.
Stages of the carbon cycle
- There is CO2 in the air and the carbon compounds in plants. Take in CO2 by photosynthesis green plants use the carbon from CO2 to make carbohydrates, fats and proteins.
- These carbon compounds can be passed on to animals that eat the plants which will be passed along to the animals in a food chain both plants and animals respiration, while the organisms alive release CO2 back into the air
- When these plants and animals die, they are decayed by microorganisms such as bacteria and fungi. they can be killed and turned into useful products, these live in the warm, moist aerobic conditions of the soil. This would break them into small pieces until all the carbon has been released as CO2 during microbial respiration.
- However if these organisms avoid this and be decayed anaerobically they will slowly be converted into fossil fuels
- These fossil fuels are then burned by humans to produce CO2 which will be passed into the atmosphere
- CO2 can also be passed from the plants by respiration which passes carbon back into the atmosphere or by burning plants.
- Decomposition of materials mean the habitats can be maintained for the organisms that live there.
How much nitrogen does the atmosphere contain
The atmosphere contains 78% of nitrogen gas, however this is very unreactive and so it can’t be used directly by plants or animals
What is nitrogen needed for
For making proteins for growth
Decomposers
Decompose PROTEINS and UREA and turn them into AMMONIA. AMMONIA forms AMMONIUM IONS I’m solutions that plants can use
Nitrifying bacteria
Turn AMMONIA into NITRITES and then into NITRATES
Nitrogen fixing bacteria
Turns ATMOSPHERIC NITROGEN into AMMONIA which forms AMMONIUM IONS
Denitrifying bacteria
Turn NITRATES back into NITROGEN GAS. This has no benefit to living organisms. These are often found in WATERLOGGED SOILS
Stages of the nitrogen cycle
- There are 78% of nitrogen gas in the air. When lightning strikes, the nitrogen in the atmosphere can convert it to nitrates. This is because there’s so much energy in the bolt of lightning that it’s enough to make nice gin react with oxygen in the air to give nitrates.
- Lightning fixes the nitrogen to nitrates.
- These nitrates absorbed into plants by the roots to either make protein or DNA.
- Legumes is a protein which has bacteria to break down nitrogen to nitrates. Legumes have nitrogen fixing bacteria in the soil. These have nodules on the roots and inside is nodules are bacteria which contain nitrogen fixing bacteria. However, not only are these found in the nodules they are also found in the soil freely.
- Nitrogen in the atmosphere is used by nitrogen fixing bacteria which is converted into ammonia
- They use ammonia produced by nitric, fixing bacteria and converts ammonia into nitrites
- These nitrates are then converted by nitrifying bacteria into nitrates, which are then absorbed into organisms by the roots to be used for either protein or to make DNA.
- Animals that eat plants build proteins in DNA in its body.
- Animals excretes these through urea which is a waste product, when an animal urinates It is returning nitrogen base products to the soil.
- However, when the animal dies, bacteria is known as decomposers (decays, dead material) will break down you, where in the soil and also the proteins in the sheep into AMMONIA. The animal will undergo decay.
- The nitric, fixing bacteria would then converts ammonia into nitrates, then the nitrifying bacteria, converts the nitrites into nitrates, which will then be absorbed into organisms by the roots into making protein or DNA
- denitrifying bacteria is found in waterlogged soil. These convert nitrates in the soil back to nitrogen in the air however this isn’t beneficial for living plants as they produced a nitrate concentration in the soil by converting nitrates back into nitrogen gas
What is the relationship of legumes
It is a MUTUALISTIC RELATIONSHIP as nitrogen-containing ions can also leak out of the nodules in them and in their nodules during plant growth.
The bacteria get food (sugars) from the plant and the plant gets nitrogen-containing ions from the bacteria to make into proteins.
How can farmers increase the amount of nitrates in the soil
- crop rotations
- fertilisers
Crop rotation
Where instead of growing the same crop in a field year after year, different crops are grown each year in a cycle. The cycle usually includes a nitrogen fixing crop, for example, peas or beans. These help to put the nitrates back into soil for another crop to use the following year.
Fertilisers
Spreading animal manure compost on fields recycles the nutrients left in plant and animal waste and returns them to sort through decomposition.
Artificial fertilisers containing nitrates and other middle ions needed by plants can also be used, but these are very expensive
