Ecology Flashcards
This is a measure of the different species in a living area
Biodiversity
This is the number of organisms of the same species living in the same area
Population
This is where a population lives
Habitat
These are the conditions which surround and effect an organism and their habitat
Environment
This is the total number of different populations living in one area
Community
This is an area where a community of organisms live
Ecosystem
What is an abiotic factor?
A non living factor that can affect the environment
How is wind speed measured?
Using an anemometer
How is the pH of the soil measured?
pH probe
How is light intensisty measured?
Using a light meter
How is the temperature of the soil measured?
Using a soil thermometer
Give 2 examples of biotic factors
Competition and predation
Give 2 examples of what animal may complete for
food, mates and territory
Give 2 examples of what plants may compete for
light, minerals and water
What square piece of equipment is used for sampling organisms?
A quadrat
How do you improve reliability during an experiment?
Repeat it multiple times and then calculate an average
When would you use random sampling?
This method is used for a FIELD or GRASSLAND (where the environment looks the same)
What is the method for random sampling?
- Place 2 tapes at right angles (to represent an X and Y axis)
- Use random numbers to generate co-ordinates (the random number generator on a calculator can be used for this) this makes sure we are not being bias
- Place the quadrat at the first co-ordinate and identify the species present
- Estimate percentage cover (to the nearest 5%)
- Repeat for all other co-ordinates
- Calculate an average
When is systematic sampling used?
This method is used along a ROCKY SHORE / SAND DUNNE SYSTEM/ PATHWAY TO GRASSLAND / CONIFER TO DECIDIOUS WOODLAND/ STREAM TO FIELD (there is an environmental gradient –> gradual change in environment)
Describe how to carry out systematic sampling
- Place a belt transect (tape) perpendicular (at right angles) to the shore
- Place the quadrat continuously (every metre for shorter sampling areas) or at intervals (every 5mfor longer sampling areas)
- Estimate percentage coverage in each
- Calculate an average for each species present
What is the source of energy of all food chains?
The Sun
Give an example of a producer
Any plant
What is a trophic level?
The level an animal feeds at (feeding level)
How do producers create energy for the rest of the food chain?
Trap light energy for photosynthesis
What do the arrows represent in a food chain?
They represent the transfer of energy from one organism to the next
Why are food chains short?
- Most food chains are short because energy is lost at each stage of transfer (most will have no more than 4 organisms) so much is energy lost through the food chain that there is not enough energy to support another trophic level
How is energy lost between the Sun and the producer?
Less than 1% of the Sun’s energy is used by the leaf as:
* Light is reflected off the leaf
* Light passes through the leaves and misses chloroplasts
How is energy lost between the producer and consumer?
- Not all of the plant is eaten e.g. roots
- Cellulose is indigestible and passes through the animal and is egested as faeces
- Dead plants enter the decomposer food chain
How is energy lost between the consumers?
- Not all of the animal is eaten e.g. fur and bones
- Not all the animal is digested and passes through the animal and is egested as faeces
- Energy is lost as heat in respiration
- Dead animals enter the decomposer food chain
How do you calculate energy efficiency between tropic levels?
Energy efficiency = (energy in primary consumer)/(energy in producer ) x 100
What is an advantage of using a pyramid of number?
It is easy to count calculate the data
What is disadvantage of using a pyramid of number?
- They can be misleading as they do not consider the size of the organism
- This means the pyramid can end up inverted
What is biomass?
mass of living tissue
What is an advantage of using a pyramid of biomass?
- It considers the size of the organism
What is a disadvantage of using a pyramid of biomass?
- Biomass is the dry mass of the organism this means the organism must be heated to remove water
- By doing this it can kill the organism
- This data is more difficult to obtain
What is a detritivore?
- These are small organisms like woodlice and earthworms
- They break down dead/decaying material into smaller pieces
Explain how decomposers break down dead organisms
- These include saprophytic bacteria and fungi
- They secrete enzymes onto the dead organism or soil
- The enzymes break down the dead organism
- The products are then absorbed back into the bacteria or fungi
- This is called extracellular digestion as it occurs outside the bacteria/fungi
What is humus?
HUMUS – soil formed from decomposed plant or animal material
What factors affect decomposition?
- The temperature is warmer
- Sufficient moisture
- Large surface area in the decomposing organism
Why would waterlogged soils make decomposition happen slower?
Waterlogged soils cause decomposition to happen slower as there is less oxygen available for the bacteria to use in respiration
By what process do plants, animals and microorganisms release carbon dioxide back into the air
Respiration
What process releases carbon dioxide into the air when fossil fuels are burnt?
Combustion
If animals and plants die in conditions where decomposing microorganisms are not present the carbon in their bodies can be converted, over millions of years and significant pressure, into fossil fuels. What is this process called?
Fossilisation
What is a green house blanket?
- Carbon dioxide and other green house gases trap heat from the Sun forming a ‘green house blanket’
Why are carbon dioxide levels rising?
- Increased use of burning fossil fuels –> when burnt they release CO2 back into the air
- Increased deforestation –> this process removes trees –> less trees to photosynthesise –> less carbon dioxide is removed from the air
What are the effects of global warming?
- Increasing temperatures causing polar ice caps to melt sea levels rise causing flooding
- Extreme weather droughts and storms are occurring more often
- More land becoming desert loss of habitats
How can we reduce global warming?
- Plant more trees
- Reduce deforestation
- Reduce amount of fossil fuels burned / use alternative fuels
What form do plants absorb nitrogen?
Nitrates
What are nitrates used for in plants?
To make plant proteins for growth
During decay decomposers (bacteria and fungi) break down dead plant and animal proteins to release _________________
Ammonia
Which bacteria convert ammonium compounds into nitrates?
Nitrifying bacteria
What type of bacteria are found in the root nodules of legumes?
Nitrogen fixing bacteria
What type of conditions do Nitrogen fixing and nitrifying bacteria require?
Aerobic conditions
What is the role of nitrogen fixing bacteria?
They convert nitrogen gas into nitrates
What conditions do denitrifying bacteria require?
anaerobic conditions e.g. waterlogged soil
What do denitrifying bacteria convert nitrates into?
Nitrogen gas
Nitrogen compounds in waste products (e.g. urine and faeces) and dead organisms are converted into ammonia by ________________
saprophytic bacteria
Definition of active transport
The movement of molecules from an area of low concentration to an area of high concentration. This process requires oxygen for aerobic respiration to produce energy to move molecules against the concentration gradient.
Where do mineral enter the plant?
Root hair cell
Which mineral is needed for plant cell walls?
Calcium
Which mineral is needed to make chlorophyll?
Magnesium
Give and example of a natural fertiliser
manure, slurry or compost
Give advantages of using natural fertiliser
No cost
Nutrients are released slowly
Less likely to leach into waterways
Give advantages of using artificial fertiliser
Easily applied to field
More accurate way of knowing what minerals are being added to the soil
Give disadvantages of using artificial fertiliser
Expensive
Can leach into waterways causing eutrophication
What is the process of eutrophication?
- Excess nitrates in fertiliser or sewage runoff into waterways
- This causes the algae (and other plants) to grow rapidly
- The algae ‘bloom’ shades the plants below the surface and so blocks out their light
- The plants below die as they cannot photosynthesise
- Aerobic bacteria break down the dead plants using up the oxygen in the water
- Fish and other invertebrates die due to a lack of oxygen
Why does eutrophication occur?
- Too much fertiliser is used on the land, so the excess runs off into the water
- It is applied during heavy rainfall or on slopped ground
How is eutrophication prevented?
- Only apply the exact amount of fertiliser needed
- Apply during the ‘dry’ season
- Do not apply on slopped ground
- Correct storage of fertiliser
How can humans increase biodiversity?
Reforestation –> planting trees to replace trees that have been harvested
Sustainable woodland –> planting to meet the human needs so that native forests are left unharmed
* Only a small number of trees are harvested at one time
* Only harvest in one area every 30 years
What international treaties help to reduce carbon dioxide emissions?
- Kyoto Protocol 1997 many countries did not sign up to the agreement
- Paris Agreement 2015 195 countries of the world agreed to a legally binding global climate change deal (plan to limit global warming to 2oC compare with pre-industrial levels.
