biodiversity

Question 1

3 levels of biodiversity

Answer 1

1. genetic
   - allelic variation within a species
2. habitat
   - no. of different habitats in an area
3. species
   - no. of species in an area

Question 2

population

Answer 2

total number of individuals

Question 3

species

Answer 3

group of organisms that can interbreed and produce fertile offspring

Question 4

habitat

Answer 4

an environment in which a particular species lives

Question 5

biodiversity

Answer 5

the variety of life within an area, including both biotic and abiotic factors

Question 6

sampling general

Answer 6

• taking measurements of a limited number of individual organisms present in a particular area
• carried out when it’s difficult to count every single individual
• produces a representative estimate of a whole area

Question 7

random vs non-random sampling

Answer 7

random

• every element has an equal chance of being picked
• sampling frame required
• elements selected randomly

non-random

• elements are picked according to a system
• elements have different chances of being picked

3 types

1. opportunistic
2. stratified
3. systematic

Question 8

random sampling

Answer 8

• allocate a number to each element
• use a random number generator to generate numbers

/
avoids bias
easy
fast

X
difficult for large populations
less representative

Question 9

systematic

Answer 9

• population grouped within itself
• different areas identified
• each area sampled separately based on a system i.e. every 3rd element

/
simple
suitable for large samples

X
can introduce bias

Question 10

stratified

Answer 10

• population divided into groups
• random sample taken from each stratum proportional to the size of the group

/
reflects population structure
proportional representation of groups within the population

X
introduces bias 
more resources required 
the population must be divided into groups 
difficult with larger populations

Question 11

opportunistic

Answer 11

• sample picked based on availability/accessibility as long as they fit specific criteria

/
easy
fast
suitable for large populations

X
bias
not representative

Question 12

PLANT sampling techniques

Answer 12

• quadrat
  grid using a tape measure, place quadrat at coordinations calculate the number of plants or percentage cover (use a key to help identify plants)
• transect
  belt or line (shows change in areas well)
  use a tape measure as a transect, count the number of organisms touching the line
• point quadrat
  sampling frame
  holds vertical pins, record the number of times the pin “hits” the organism being investigated

Question 13

ANIMAL/INSECT sampling techniques

Answer 13

• sweep net
  in tall vegetation
  hold sweep net and move side to side in an arc
  count no. of organisms collected
• pooter
  insects
  the jar used to collect insects, apply suction on one side and insect drawn in on other
• pitfall trap
  ground surface organisms
  a device, such as buried beaker, traps insects and small animals which are then counted
• tullgren funnel
  extraction on invertebrates from the soil/ litter
  the sample is placed in the funnel above disc, placed under light, heat dries the sample, animals fall into the beaker

Question 14

why measure biodiversity?

Answer 14

measuring biodiversity gives a baseline to test the effects of human activity, climate change and disease

Question 15

Simpson’s index

Answer 15

D = 1 - (sum of (n/N)2^)

D = biodiversity 
n = number of organisms of specific species 
N = total number of organisms of all species 

LOW = dominated by 1/ few species, low species richness and evenness, an unstable ecosystem which is less likely to cope with change

HIGH = many species, not dominated, high species richness and evenness, a more stable ecosystem

Question 16

species richness

Answer 16

no. of different species in an area/ habitat

Question 17

species evenness

Answer 17

the relative abundance of individual species in an area

Question 18

agriculture

Answer 18

monoculture
- reduced variation, affects soil richness
- increased dependence on herbicides + fertilisers
/
crop rotation
legumes - secrete nutrients into soil

pesticides/herbicides

• kills pest species
• reduces dependant species

deforestation
- reduces habitat diversity
- vegetation/ food source loss
= species diversity decrease

Question 19

population growth

Answer 19

land is lost to accommodate growing population and provide sufficient services, facilities and transport, e.g. road building = decrease in habitat and species diversity

more people, more fossil fuels burnt = global warming, climate change = migration of species, flooding/damage to habitats

Question 20

climate change

Answer 20

global warming 
- melting ice caps, flooding
- extinction of species that live in extreme conditions 
- migration of species 
- habitat damage/loss 
- land loss 
- food resource decrease 
- extreme weather/ rainfall = nutrients washed from soil, poor soil richness which limits the growth of vegetation
= decrease in biodiversity

Question 21

benefits of plant diversity

Answer 21

• medicine
• increases genetic variation
• potential genetic resourcce
• selective breeding/ genetic engineering
• agents for biological control

Question 22

benefits of animal diversity

Answer 22

• vital for life

- evolution

Question 23

aesthetic reasons for maintaining biodiversity

Answer 23

• tourism
• enriches lives
• potential medical cure
• protect landscapes

Question 24

economic reasons for maintaining biodiversity

Answer 24

• tourism
• plant-derived products i.e. rubber, coffee
• protection against abiotic stresses
• plants are source of food, drink, clothes, fuel, materials
• medicine
• scientific research

Question 25

ecological reasons for maintaining biodiversity

Answer 25

- disruption - interdependence - conserve keystone species (in proportional affects on the environment, maintain and support ecological community)

Question 26

in-situ conservation

Answer 26

inside organism's natural habitat maintains genetic diversity preserves interdependent relationships 1. marine zones; protect species-rich areas e.g. coral reef 2. wildlife reserves; controlled grazing, restrict human access, remove invasive species, feed animals, controlled poaching, reintroduce species

Question 27

ex-situ conservation

Answer 27

outside organism's natural habitat protection from predators, poaching, herbivores controlled health 1. botanic gardens; provides plants with best growth conditions 2. seed banks; stores genetic material 3. captive breeding; produce offspring in human-controlled environment/ reduce/ prevent extinction

Question 28

CBD/ RC

Answer 28

convention biological diversity/ Rio convention - countries develop national strategies for sustainable management - maintain biodiversity sustainably

Question 29

CSS

Answer 29

countryside stewardship scheme - government grants landowners money to improve and extend wildlife habitats and conserve wildlife and biodiversity - promote land management techniques to landowners

Question 30

CITES

Answer 30

convention international trade endangered species - ban the trade of wildlife plants - allows the trade of less endangered species - regulates/monitors trade of endangered species - allows the trade of artificially propagated plants

Question 31

seed banks

Answer 31

seeds dried, stored in low humidity and in temperatures below 20 degrees = maintain viability seeds checked at regular intervals why? genetic resource potential medical uses provide back up in case of extinction ``` / little space large numbers stored viable for long time less susceptible to disease/ pests ```

Question 32

EIA's

Answer 32

environmental impact assessments - predicts positive/ negative effects of project on biodiversity of an area