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YEAR 2 BIO > human impact on environment > Flashcards

human impact on environment Flashcards

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Biology 101 flashcards
1
Q

what is the 6th mass extinction

A

the holocene extinction mainly due to human activity

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2
Q

what happened to the dodo

A 
most famous extinct species 
no reason to be scared 
were eaten 
couldn't fly 
humans destroyed habitats
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3
Q

what happened to the quagga

A

heavily hunted

extinct in the wild by 1878

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4
Q

EX

A

extinct

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5
Q

EW

A

extinct in the wild

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6
Q

CR

A

critically endangered

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7
Q

EN

A

endangered

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8
Q

VU

A

vulnerable

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9
Q

NT

A

near threatened

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10
Q

LC

A

least concern

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11
Q

DD

A

data deficient

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12
Q

NE

A

not evaluated

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13
Q

what are the main reasons that species are threatened

A
  • natural selection
  • non contiguous population
  • loss of habitat
  • overhunting by humans
  • competition from introduced species and accidental introduction
  • pollution
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14
Q

what is conservation

A

sensible management of the biosphere to maintain habitats and enhance biodiversity allowing human activity

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15
Q

what is charismatic mega fauna

A

gets people interested conserving animals

using ‘prettier’ animals

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16
Q

what are the different conservation animals

A

seed banks = to conserve plants (used for medicine)
zoos = to conserve animals (educates people and scientific research)
captive breeding programmes

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17
Q

what are captive breeding programmes

A

need to maintain or increase genetic diversity
increase pop. numbers
stud books (record of animals mating)
sperm banks/AI/IVF/surrogacy

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18
Q

what are reintroduction programmes

A

reintroducing captive animals into the wild

  • is the habitat still intact
  • protected sites/wildlife reserves
  • ‘hacking out’ - released into a fenced area as similar as possible to natural habitat. will gradually reduce food and increase living space
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19
Q

what is intensive farming

A

open system, net loss of nutrients as large yields are being exported from the farms which then has to be related by fertilisers
animals farmed at high densities which increase the chance of catching diseases due to dress and overcrowding, this leads to antibiotics being added to their food

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20
Q

what is monoculture

A

the growth of large numbers of genetically identical crops plants in a defined area for economic efficiency

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21
Q

what are the effects of monoculture

A

soil condition
field size
shelter
habitats
environment impact of increased use of pesticides and chemical fertilisers in relation to species diversity and loss of stability
loss of biodiversity
unstable ecosystem at risk from interspecific competition
machinery compacts soil
(squeezes air pockets - nitrogen fixing bacteria prefer aerobic conditions)

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22
Q

what is soil erosion

A

removal of topsoil which contains valuable nutrients

invasions of pests

23
Q

what is toxic pollution

A

-eutrophication = loss of biodiversity

species present in large numbers due to lack of interspecific competition in polluted habitats

24
Q

what do pesticides do

A

kill non target species
target species evolve resistance to insecticide
some insecticides become concentrated up food chains

25
Q

what do PCBs and heavy metals do

A

egg shell thinning
interference with mammalian reproduction
damage to immune system
carcinogenic

26
Q

what are hedgerows

A

narrow belt of vegetation dominated by shrubs and occasional trees

27
Q

what are hedgerows used for

A

barrier to movement of livestock

marking property boundaries

28
Q

why do hedgerows have a high landscape and conservation value

A

provide foraging and nesting sites for birds
rich in plants and animals
source of beneficial insects
wildlife corridors through hostile landscapes

29
Q

advantages of hedgerow removal

A

acts as refuge for weeds
reduces loss of yield
decreases land needed for turning machinery

30
Q

disadvantages of hedgerow removal

A

increases soil erosion
reduce crop yield through loss of beneficial insects species
predators for pest control
pollinators

31
Q

what is deforestation

A

removal of forests for
timber
agricultural use of land
increasing housing development

32
Q

what is caused by deforestation

A

loss of vegetation and roots lead to soil erosion
water floods from higher to lower levels
water runs off soil instead of being retained
water evaporates more easily from soil leading to desertification

33
Q

how can we solve deforestation

A

coppicing - tree trunk is cut , leaving a stool a few cm high. new shoots emerge from buds and from into poles which thicken they are cut on rotation to produce timbers. a long rotation increases sustainability which favours diversing wildlife
selective cutting - steep slopes where total removal of trees would leave soil very vulnerable to erosion. also maintains nutrients in soil and minimises amount of soil washed away

34
Q

how does overfishing happen

A

nets with small mesh catch young fish that are sexually mature overtime there are fewer individuals left to reproduce so population size decreases

35
Q

what is drift netting

A

pelagic fish live in surface water. swim into a net suspended between two boats. but non target species are caught e.g. turtles and dolphins

36
Q

what is trawling

A

fish living in deeper water. caught by a large net dragged through water. equipment damages the ocean bed which destroys habitats

37
Q

what are the effects of overfishing on other wildlife

A

trawlers catch capelin but important prey for cod fish (contributes to decline of cod stocks)
harvesting antarctic krill - primary consumers main food of whales and seals, heavily fishing affects the food web

38
Q

methods to regulates fishing and allow stock to recover

A
  • mesh size but allow young fish to swim through
  • quotas to only allow a certain mass of fish
  • prohibit fishing in areas at certain times to allow reproduction
  • legislation controlling size of fishing nets
  • legislation controlling number of days at sea
39
Q

what is fish farming

A

bred and grown to maturity in ponds and lakes
sometimes farmed in a pod (large steerable device)
fish convert their food into protein more efficiently
greater proportion of fish are edible
lower carbon footprint

40
Q

what can fish farming cause

A
  • diseased fish = densely stocked huge doses of antibiotics
  • pollution = ecological balance of waterways may be upset, eutrophication, fish excreta carried into water around pens
  • escaped fish = rapid growth of farm fish which out competes wild fish for food transmits parasites
  • resource use = farmed salmon are carnivorous and eat 3x their body weight in fish food
  • environmental toxins = more concentrated toxins than wild salmon although concentration so small that doesnt outweigh health benefits of eating fish
41
Q

what are the 9 planetary boundaries

A

1) biosphere integrity boundary
2) land system change
3) biogeochemical flow
4) stratospheric ozone
5) ocean acidification
6) fresh water use
7) aerosols
8) introduction of novel entities
9) climate change

42
Q

which boundaries have been crossed

A

climate change
biosphere integrity
land system change
biogeochemical flow

43
Q

which boundaries have been avoided

A

stratospheric ozone

44
Q

which boundaries are avoidable

A

ocean acidification

fresh water use

45
Q

which boundaries are not quantified

A

aerosols

novel entities

46
Q

what is the climate change boundary

A

higher atmospheric c02 linked to higher global temp
increases sea level by 7m
combatting climate change –>
- kyoto protocol signed by 84 countries
- COP21 signed by 174 countries
keep global temp well below 2 degree above pre industrial temp
limit greenhouse gases to human activity to what can be naturally absorbed
help poorer nations to adapt

47
Q

what is the biosphere integrity boundary

A 
habitat destruction 
leads to species becoming extinct 
1 species lost per year in a million to natural selection 
boundary - 10 per million per year 
current rate - 100 per million per year 
must increase public awareness
48
Q

what is the land system change boundary

A

problems - natural ecosystems used for urban development, raising livestock
pollutants derived from agriculture and other human activity
production of biofuel crops and crops grown for export means not enough food for local use
solutions - no more than 15% ice free land should be used for crop growing and human habitation
eat less meat

49
Q

what is the biogeochemical boundary

A

fertilisers use - atmospheric nitrogen is fixed in the haber process
combustion of fossil fuels
led to -
- eutrophication
- acidification (co2 forming carbonic acid in rivers)
current - 150 million tonnes
boundary - no more than 62 million

50
Q

what is the stratospheric ozone boundary

A

hole in ozone layer in 1970
measures taken - use of chlorinated hydrocarbons was banned
boundary - 276 dobson units
current - 300 dobson units

51
Q

what is the ocean acidification boundary

A

was pH 8.16 –> now pH 8.03 h+ ions are 30 times more complicated
decreases internal pH of phytoplankton
less o2 produced less co2 removed
gas exchange in fish is less efficient
calcium leaches out of the calcium carbonate skeletons od corals out of the shells of molluscs and arthropods current 2.9:1
boundary 2.7:1

52
Q

what is the freshwater boundary

A 
2.5% fresh water on earth 61% is frozen 
not all fresh water is drinkable 
human activity reduces water - 
 - irrigation systems 
- polluting water 
- increased human population 
leads to - 
- desertification 
- rivers fail to reach seas 
- fisheries are destroyed 
boundary = 4000 km y-1 
current = 2600 km y-1 
solutions = 
stop irrigating non food crops 
drip irrigation for food crops 
reduce reuse recycle
53
Q

what is the atmospheric aerosol boundary

A 
atmosphere contains minute particles. some are natural 
consequences = 800,000 premature deaths
soot absorbs heat 
sulphate reflects heat 
no boundary
54
Q

what is the introduction of novel entities boundary

A 
synthetic organic pollutants
radioactive materials 
genetically modified organisms 
nano materials no bigger than 100nm 
boundary = 
- ddt is banned 
- pcb controlled as its toxic and reports of it being carcinogenic 
few have been properly assessed

YEAR 2 BIO (11 decks)

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