ecosystems - biomass - carbon/ nitrogen stores Flashcards

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1
Q

ecosystem

A

living and non-living parts of an environment and the interactionx that occur between them
eg african savannah, tropical rainforest, garden pond, farm

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2
Q

biotic

A

living organisms

eg fish, flower, plant

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3
Q

abiotic

A

non-living

eg rock, water, table, soil

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4
Q

population

A

total no. one species in an ecosystem

eg pop of humans - 7.8bill, pop of fish - 3.5 trill

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5
Q

community

A

all plants/ animals living in a single ecosystem

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6
Q

individual

A

a single organism

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7
Q

biodiversity

A

range of diff. species in an ecosystem

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8
Q

habitat

A

place where an organism lives in an ecosystem

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9
Q

interdependence

A

where organisms depend on each other for survival

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10
Q

effect of temp on rabbit populations

A

temp increase > snow melts > white rabbits no longer camoflagued > easier for predator to spot > white rabbits more likely to be eaten > if snow disappears white rabbits could become extinct > brown rabbits less competition > pop. could explode

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11
Q

CO2 (plants)

A

0.04% in air
rate of photosynthesis increases if CO2 increases
used for photosynthesis to make food which is used for energy/growth

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12
Q

temp (plants)

A

temp increases = faster metabolic reactions - enzymes work faster and catalyse reactions more

ectotherms - rely on sun/temp to warm them and temp increases metabolic reactions

endotherms - less affected by change in temp

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13
Q

moisture levels (plants + humans)

A

10-20% of water loss is life threatening to huamns
plants lacking water - wilts - cells become plasmolysed - plant cant keep upright
plants filled with water - turgid - stays upright

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14
Q

soil pH (plants)

A

impact of soil pH changes - affects biological activity + availability of minerals
acidic soil - ferns
alkali soil - cucumber
ph of soild in high rainfall areas - acidic (alkaline compounds drain away)
as soil pH increases - elements increase - Ca, Mg, N, S, K

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15
Q

light intensity decrease - effect on ecosystem

A

plants use photosynthesis to make food which needs light
they wont be able to grow if LI is low + will die
less plants means less food for herbivores and therefore less food for carnivores so organisms cant grow or make energy so die

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16
Q

food chain

A
diagram that shows what an organism eats
arrow direction (transfer of energy)
TROPHIC LEVELS - each step in a food change
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17
Q

how glucose stores energy

A

in chemical bonds

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18
Q

apex predators

A

carnivore with no predators

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19
Q

food web

A

series of interlinked food chains

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20
Q

producer

A

make their own food (using sunlight) - first level of all food chains
algae, plants

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21
Q

primary consumer

A

organisms that eat producers ( herbivores)

deer, turtles

22
Q

secondary consumer

A

eat primary consumers

23
Q

pyramid of numbers

A

shiws the pop. at each trophi level
bar width = no. organisms
do not take into acount size of orgnisms

24
Q

pyramid of biomass

A

amount of biomass at each trophic level
both NUMBER and SIZE of organisms present
bar = relative mass of living material

25
Q

biomass calc

A

average mass of organisms x no. organisms = total biomass of one trophic level

26
Q

challenges of measuring total biomass

A
  • organisms need to be collected + killed to measure biomass
  • difficult to catch + weight organisms
  • biomass varies ( tree increases in summer , tree decreases in winter)
  • some organisms feed on more than one tropic level
27
Q

why is dry mass used

A

water content can vary between individual but dry mass cant

28
Q

why is biomass lost in a food chain

A
  • used to make energy (respiration) - lost to environment as CO2+ H2O
  • lost in keeping warm (respiration)
  • organism is left uneaten
  • biomass is indigestible + passes out organism as faeces
    loss of biomass means pyramids are limited to max 4/5 tropic levels
29
Q

biomass transfer efficiency

A

= energy used to grow tissues/ energy eaten x 100

30
Q

predator / prey relationship

A

follow cyclical pattern
predators dependant on prey
cycle of predator is out of phase ( lags behind) cycle of prey

31
Q

mutualism

A

both organisms benefit from relationship

32
Q

parasitism

A

parasites live at the expense of the host organism - harm the host

33
Q

why do organisms compete

A
  • for resources they both need

- to get sufficient resources

34
Q

plants compete for

A
  • light
  • water
  • space
  • minerals
  • pollinators
35
Q

animals compete for

A
  • mates
  • teritory
  • shelter
  • food/water
36
Q

inter specific

A

between diff. species

37
Q

intra specific

A

within species

38
Q

intra specific is more significant

A
  • have same niche - compete for EXACT same resources

- can avoid other species competition cant avoid same species

39
Q

decay

A

break down organic matter to release nutrients

40
Q

saphrophytes

A

feed on dead matter and break it down

- releases enzymes which digest organic matter - bacteria/fungi absorb products of enzyme digestion

41
Q

detrivores

A

speed up decay (increase surface area)

worms , woodlice, maggots

42
Q

factors that speed decomposition

A
  • water - lack of water prevents decay
  • oxygen - lack of oxygen prevents decay
  • temp - high temp stops decay - low temp slows decay
43
Q

water cycle

A

evaporation
condensation
precipitation - when clouds are full water falls to ground
runoff/ percolation / transpiration - loss of water from plants

44
Q

roles of water

A
  • maintains habitat
  • maintains internal fluids/ transport system
  • needed for chemical reaction
  • reactant in photosynthesis
45
Q

nutrients cycled

A

carbon, water, nitrogen, oxygen

46
Q

nitrogen cycle

A

N2 (g) > (nitrogen fixation) > ammonium > (nitrification)> nitrite> (nitrification)> nitrate >(denitrification >N2 (g)) > absorb/assimilate > N2 in plants/animals > decay > ammonia

47
Q

nitrogen fixation

A

process of turning nitrogen in air into ammonium ions
- nitrogen fixing bacteria in soil/root nodules of legumes
- energy from lightning splits N2gas allowing it to react with oxygen and form nitrates
- haber process- artificial nitrogen fixation process
anaerobic conditions

48
Q

decomposition

A

decomposers break down protein and urea and turn them into ammonia

49
Q

nitrification

A

process of turning ammonium ions into nitrates
nitrification is performed by nitrifying bacteria
aerobic conditions

50
Q

denitrification

A

turning nitrates into nitrogen gas
anaerobic conditions
by denitrifying bacteria ( IN WATER LOGGES SOIL)

51
Q

carbon cycle

A

see diagrams of both carbon and nitrogen
the amount of C on earth is fixed
process by which carbon is cycled through the atmosphere earth plamts and animals

52
Q

carbon stores

A

shells of marine organisms on sea ed
these compress to form limestone
acid rain (= carbonic acid from CO2 reacting with rain) weathers limestone and releases carbon
CO2 can be absorbed by oceans (carbon sinks)
volcanic eruptions and forest fires release CO2