Ecology P2 Flashcards
what equipment is used for assessing ecosystems?
quadrats - square frames used for estimating population sizes.
transects -lengths of tape stretched across a habitat to investigate the effect of a factor on a species’ distribution.
total population size equation
total area/total sampled x number of organisms counted
apex predator
The predator at the top of a food chain.
primary/secondary/tertiary consumers
Feed on other organisms for their energy.
P- 1st
S- 2nd
T- 3rd
producer
Converts the sun’s energy into useful compounds through photosynthesis (grass).
stable community
Where all abiotic and biotic factors are balanced
what may species depend on each other for?
- food
- shelter
- pollination
- seed dispersal
interdependence
The interaction between two or more organisms where it is mutually beneficial.
ecosystem
An area made up of living (biotic) organisms and nonliving (abiotic) parts.
individuals
a single member of a species
what do animals compete for + why?
- food = provides energy for animals for growth and reproduction
- mates = to reproduce and pass on their genes
- territory = an area of habitat which provides animals with factors like water, shelter, food and mates
what do plants compete for + why?
- water = essential for photosynthesis and plant growth
- space = space above soil (so leaves can absorb maximum sunlight) and below soil ( so roots can absorb minerals and ions)
- light = needed for photosynthesis to make glucose which provides energy for growth
- minerals and ions = such as magnesium ions to make chlorophyll and nitrate ions to make proteins
populations
Groups of individuals that make up a single species.
community
multiple populations (different species) living and interacting in the same area
extremophiles
Any organism that likes living in extreme environments.
what does the arrow mean in a food chain/web.
Indicates where the energy is going.
Interspecific vs Intraspecific
Inter—> competition between different species (internet is world wide)
Intra—> competition within the same species
Respiration chemical/word equation
glucose + oxygen —> carbon dioxide + water
C6H12O6 + 6O2 —> 6CO2 + 6H2O
2 Resources humans are using up?
- finite reserves of metal ores
- non-renewable energy resources (crude oil/ natural gases)
Food security
Having enough food to feed a population
How do humans pollute the land?
- human waste in soil causes parasites and chemicals
- farming increases CO2 emissions
- household waste in landfills means chemicals are spread into soil
How do humans pollute the sea?
- minerals and fertilisers are washed from soil into local streams, ponds and rivers.
- untreated sewage that is washed into waterways/pumped into seas —> causes high levels of NITRATE in water
Pros + Cons of breeding programmes for endangered species
Pros-
- increase in numbers
- prevents extinction
Cons-
- inbreeding
- can’t always be re interduced (to wild)
Eutrophication
Fertilisers which run off into lakes in surface water runoffs, causing a dense plant growth
Negative consequences of increasing farming?
- genetic modification
- pollution
- greenhouse gases
- increase in pests and pathogens
- increase in fertilisers
- deforestation
- extinctions of overfishing
Bioaccumualtion
Accumulation of chemicals in an organism that takes place if the rate of intake exceeds the rate of excretion.
The Carbon Cycle key points
Carbon dioxide in atmosphere, enters via photosynthesis
Carbon dioxide returns to atmosphere by aerobic respiration
The Carbon Cycle
1) Carbon dioxide in atmosphere through respiration of plants, algae, animals, decomposing microorganisms and combustion of fossil fuels.
2) Carbon dioxide taken from atmosphere via photosynthesis of plants and algae.
3) This carbon transferred through feeding of animals, then more animals (they respire, back into atmosphere).
4) When they die, decomposing microorganisms feed and then respire (carbon back into atmosphere).
5) Through a lack of oxygen, decomposers cannot work effectively meaning carbon in remains turns into fossil fuels, which humans burn (combustion of fossil fuels from dead remains brings carbon back into atmosphere)
Why are decomposing microorganisms important (TCC)
- They cycle materials through an ecosystem
- Return carbon to atmosphere as carbon dioxide
- Release mineral ions to the soil
What happens if there is a lack of oxygen for decomposers (TCC)
decomposers cannot work effectively, leading to the carbon in dead remains to convert into fossil fuels
Decomposing microorganisms carry out anaerobic decay.
Anaerobic decay produces methane (greenhouse gas) = this is called biogas
The Water Cycle
1) Energy from sun causes water to evaporate from the surface of the sea. The water vapour travels into the air and cools down.
2) When it cools, the water vapour condenses to form clouds.
3) Water in clouds falls to ground as precipitation (rain, snow, sleet and hail) = all forms of precipitation contain fresh water/ NO SALT
4) Once water hits the ground, some of it evaporates back into out atmosphere as water vapour.
5) Some of the water passes through rocks and forms aquifers.
6) A lot of the water forms rivers/streams which eventually drain back into our sea.
Aquifers
A body of permeable rock which contains/transmits groundwater (the water cycle)
Is water abiotic/biotic factor?
water is an abiotic factor (non-living) which effects communities
Living organisms contribution to the water cycle
- plants take up water in roots ( moves up the plain in the xylem, passing out through leaves in the stomata as water vapour) = aka transpiration
- animals take in water through drinking and in foods (animals release water through urine, faeces and exhalation)
Transpiration
(of a plant or leaf) the exhalation of water vapour through the stomata.
examples of decomposing microorganisms
bacteria
fungi
Conditions needed for decomposition
- temperature
- amount of water
- amount of oxygen
decomposition (temperature)
Faster at warmer temperatures as decomposers use enzymes to breakdown the plant materials as these enzymes work faster in warm conditions.
Compost heaps of warm as the decomposers release energy through aerobic respiration.
You do not want to get too hot as enzymes and decomposers can denature and die
decomposition (amount of water)
Faster if compost is moist as chemical reactions in decay require water.
DO NOT let compost dry out.
decomposition (amount of oxygen) - what is done in farming to help?
Decomposers carry out aerobic respiration (requires a good supply of oxygen).
- Compost bins have holes in for oxygen to enter
- Gardening forks to mix = more oxygen to pass through centre, breaks up large clumps increasing surface area for decomposers to act on.
What happens if there is no oxygen (decomposition)
Decomposing microorganisms carry out anaerobic decay.
Anaerobic decay produces methane (greenhouse gas) = this is called biogas
Biogas
Anaerobic decay producing methane from fermentation of organic matter.
biotic and abiotic meaning
biotic - living factors
abiotic - non-living factors = effecting an environment
RP 9 - sampling organisms
Estimate the total population of daisies in a field
1) First place two tape measures at right angles. These should be 20m in length.
2) Get two bags containing the numbers 1 to 20 , should be in groups of three.
3) Student 1 picks a number at random and stands at the number in meters on the tape measure (student 2 does the same along other tape measure).
4) Student 2 places a quadrat where the two points meet (like a graph, along x up y).
5) Students record the number of daisies in first quadrat.
6) Return number to bag and repeat 9 more times (10 in total).
7) Estimate the total population size of daisies using this equation total area/area sampled x number counted of daisies
- if you think 10 is not representative of population, increase number of quadrats to cover a greater percentage of area -> increases validity
RP 9 - sampling organisms
Measure the effect of light intensity on the distribution of daisies
1) Place a tape measure at the tree.
2) Then use a quadrat to count the number of daisies at the start of the transect.
3) Using a light meter record the light intensity at the same point.
4) Move the quadrat by 1m down the tape measure and repeat measurements all the way down transect.
5) Most likely to see a greater number of daisies as we move further from tree as plants need light for photosynthesis. Also, tree will absorb a lot of water + minerals from soil so it might be that light intensity is not the only abiotic factor affected the distribution of daisies.
algal bloom
a rapid increase in the number of plants
In eutrophication, what directly causes the death of fish?
bacteria use up oxygen in respiration