3. 3. 1 - importance of biodiversity Flashcards
what is biodiversity?
- variety of life on earth
- includes genetic diversity between individuals within a species and between different species
- variety of different ecosystems
why is biodiversity important?
- 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
what are the 2 main factors that need to be considered when measuring biodiversity?
- species richness
- species evenness
what is species richness?
refers to the number of different species in an area
what is species evenness?
the relative abundance of the different types of organisms that make up the species richness
( the evenness of distributions of the different species)
where are the areas that generally have the highest biodiversity?
wet tropics
for marine biodiversity:
coral reefs are the ‘biodiversity hotspots’
what are biodiversity hotspots?
an area with a particularly high level of biodiversity
what is endemism?
species that are found nowhere else
why is it so difficult to prioritise areas for conservation?
because the areas of greatest biodiversity are not always the same as the areas with the biggest number of endemic species
why do some areas have a particularly rich biodiversity?
- 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
what is relative species abundance?
refers to the relative numbers of species in an area
If you were looking at Plot A and Plot B of grass, which one would be more biodiverse?
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
how can you measure biodiversity?
use the biodiversity index
D = N(N -1) / Σn(n-1)
(make sure you know how to calculate it –> memorise the table)
what does a high biodiversity index mean?
the higher the value, the greater the variety of living organisms found in the area
what is biodiversity like in an environment with extreme environmental conditions?
- 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