Lesson 1 - The importance of biodiversity Flashcards
meaning species richness
the number of different species in an area
meaning biodiversity hotspot
an area with a particularly high level of biodiversity
meaning relative species abundance
the relative numbers of species in an area
meaning biodiveristy
the variety of plant and animal life in the world or in a particular habitat
what are 5 benefits of biodiversity
- Maintain natural balance between regions
- Some bacteria and fungi decompose waste which are toxic
- Plant roots reduce risk of flooding by holding soil together
- helps genetic variation that has allowed us to develop the production of crops, livestock, forests, and has allowed us to improve by cross-breeding and genetic engineering
- Some plants produce chemicals that are useful in medicine
what are the 2 main factors considered when measuring biodiversity
- species richness
- the evenness of the distribution of the different species
where is the area of highest biodiversity
the wet tropics
why do you find more mutations in species which reproduce rapidly
because of the speed of their reproduction, there is a higher chance of mutations occuring, so adaptations allow organisms to exploit more niches
formula for diversity index
D = N(N-1) // Sn(n-1)
meaning ‘D’ in formula
diversity index
meaning ‘N’ in foruma
total number of organisms of all species
meaning ‘n’ in formula
the abundance of different species
meaning ‘S’ in formula
the sum of all values that follow
where is the highest biodiversity seen
- very stable ecosystems as this allows many complex relationships to develop between species
- area where there are high levels of productivity as this can support more niches
- area where organisms can grow and reproduce rapidly, so more mutations are more likely to occur, so adaptations allow organisms to exploit more niches
why is biodiversity low in areas with extreme environmental conditions
as extreme environmental conditions are unstable, a change e.g. frost or flood could wipe out populations. So, there are many unfilled niches, so new organisms are accepted rapidly and may overpower existing species if they are competing for food or territory
why are less hostile environments more stable ecosystems
biodiversity is higher in less hostile environments. So, when a species moves in or out, it will have little effect on the ecosystem
why is the risk of biodiversity not evenly spread across the world
- biodiversity can be due to natural events e.g. volcanic eruptions or floodings
- certain habitats are more vulnerable to damage and loss than others
- if a biodiversity hotspots are damaged, many species will be lost
why is biodiversity not constant
- biodiversity in an area may vary between day and night e.g. bats
- biodiversity in an area may vary between seasons
