3. 3. 1 - importance of biodiversity

Question 1

what is biodiversity?

Answer 1

• variety of life on earth
• includes genetic diversity between individuals within a species and between different species
• variety of different ecosystems

Question 2

why is biodiversity important?

Answer 2

• if biodiversity is reduced in one area, the natural balance may be destroyed elsewhere
• air/water are purified by the action of a wide range of organisms
• waste is decomposed and rendered non-toxic by many organisms
• plants help to determine where rain will fall
• these all depend on rich biodiversity
• it has provided genetic variation -> that will also help us cope with problems arising from climate change
• also for the possibility of new medicines

Question 3

what are the 2 main factors that need to be considered when measuring biodiversity?

Answer 3

• species richness

- species evenness

Question 4

what is species richness?

Answer 4

refers to the number of different species in an area

Question 5

what is species evenness?

Answer 5

the relative abundance of the different types of organisms that make up the species richness
( the evenness of distributions of the different species)

Question 6

where are the areas that generally have the highest biodiversity?

Answer 6

wet tropics

for marine biodiversity:
coral reefs are the ‘biodiversity hotspots’

Question 7

what are biodiversity hotspots?

Answer 7

an area with a particularly high level of biodiversity

Question 8

what is endemism?

Answer 8

species that are found nowhere else

Question 9

why is it so difficult to prioritise areas for conservation?

Answer 9

because the areas of greatest biodiversity are not always the same as the areas with the biggest number of endemic species

Question 10

why do some areas have a particularly rich biodiversity?

Answer 10

• a very stable ecosystem allows many complex relationships to develop between species
• high levels of productivity (when photosynthesis rates are very high) can support more niches
• in areas where organisms can reproduce and grow rapidly –> more likely for mutations to occur –> leading to adaptations –> allow organisms to exploit more niches

Question 11

what is relative species abundance?

Answer 11

refers to the relative numbers of species in an area

Question 12

If you were looking at Plot A and Plot B of grass, which one would be more biodiverse?

Answer 12

the area showing an even abundance of different species compared to the other one containing the same number of different species but dominated by one or two in particular

Question 13

how can you measure biodiversity?

Answer 13

use the biodiversity index

D = N(N -1) / Σn(n-1)

(make sure you know how to calculate it –> memorise the table)

Question 14

what does a high biodiversity index mean?

Answer 14

the higher the value, the greater the variety of living organisms found in the area

Question 15

what is biodiversity like in an environment with extreme environmental conditions?

Answer 15

• it will be low
• change in environment –> big impact on population
• this type of ecosystem –> unstable + very susceptible to change
• this type of environment –> tends to have unfilled niches –> incoming organisms can become established and overpower an existing species

Question 16

what is biodiversity like in less hostile environments?

Answer 16

• can be very high
• results in a very stable ecosystem
• due to a new species moving in or out not having a lot of effect

Question 17

how can biodiversity be lost?

Answer 17

• natural events
• human activity

(small isolated ecosystems are much more vulnerable to damage and loss)

Question 18

will biodiversity remain constant throughout the year?

Answer 18

NO

• picture of biodiversity will change considerably throughout the year
• the number of plant species in the same area of UK woodland will differ from in the summer and winter