B2.1 distribution & niche partitioning, population growth & carrying capacity Flashcards
distribution
where an organism is found. could be a whole biome or a very small set of conditions for highly specialised organisms.
6 abiotic factors thats may affect distribution
- temperature
-water/precipitation
light - Nutrients/mineral ions/salinity
- pH
- Wind speed
how to measure abiotic factors
digital meter/data logger or indicator species
what indicator species would show oxygen levels in water and why? what device can be used in their place?
mayfly = clean (can only live in water)
sludge worm = polluted (lots of haemoglobin so are good at absorbing O2 in low O2 environments)
Or you could use a digital oxygen meter.
what can lichen be used to monitor? what device can be used in their place?
acid deposition - the amount of sulphur dioxide in the air from combustion. Or you could use a digital pH meter or air monitoring station.
what is eutrophication? (5 steps)
- fertiliser runs off into water bodies
- this causes algae bloom, covering surface
- aquatic plants die - cant photosynthesise
- they decompose, using up available oxygen in the pond
- fish die
give 4 digital devices that measure weather
- light meter
- rain meter
- wind meter
- thermometer
give 4 digital devices that you might use to monitor water
- oxygen meter
- nitrate meter
- pH probe
- turbidity meter
what is turbidity?
how many particles (sediment, plankton, organic by-products) there are in the water
what is a niche
“The specific set of resources required and the role by a population for it to survive, thrive and reproduce successfully.”
- fundamental = where it could live, general (eg: land)
- realised = where it does live due to environmental presure (bees can only live where flowers are)
=**unique set of conditions **–> exactly where it is in the habitat
population’s distribution will be concentrated…
…within the part of the habitat that has these niche
resources that is is adapted to use.
what type of diagram is useful for representing changing abiotic factors in a habitat?
kite diagram
communities rely on ___________ to maintain an ecosystem
population interactions
PLANTS ARE THE MOST IMPORTANT ORGANISMS in an ECOSYSTEM because…….
They are producers. Through photosynthesis they make all the biological molecules (biomass) for all
organisms on the ecosystem to use. Particularly glucose.
DECOMPOSERS ARE THE MOST IMPORTANT ORGANISMS in an ECOSYSTEM because…….
They break down detritus and release nutrients so that they can be recycled. This provides nutrients for plants to use to produce biomass. Decomposition also removes toxic waste from the ecosystem.
competition
Similar Niche - similar limited resources required.
issue with any model
oversimplified
two types of growth curves
J and S
J-curve
what would happen if there were no biotic or abiotic limiting factors.
density dependent factors
larger populations = more competition. negative feedback interactions. disease and predation increases as population increases.
true or false: an s curve is a less realistic model of population growth
false
what does a transition phase show
when population growth has started to slow because of density dependent biotic factors
when the graph plateaus, it has reached…
carrying capacity
carrying capacity
maximum population an ecosystem can sustain. natality rates = mortality rates.
carrying capacity is reached because…
Competition for limited resources and biotic interactions all start to limit survival.
negative feedback interactions cause fluctuations over time, leading to
boom or bust
