Topic 3.3 Biodiversity Flashcards
not in summer exams L6
What is biodiversity?
The variety of organisms in an ecosystem
variety of life
( short is bd )
How to measure biodiversity?
- species richness
- relative species abundance/species evenness
What is species richness?
number of species in an area
what is relative species abundance?
relative number of species in an area
how to use the Simpson’s diversity index (D) to measure biodiversity?
D= N×(N - 1) / Σn×(n - 1)
N=total num of organisms of all species in a community
n=total num of organisms of each individual species
What does the Simpson diversity index mean?
Higher index = greater diversity
what is a disad of diversity index?
- can only be used wen comparing 2 environments
- No limit so hard to comment on diversity with 1 value
How can ecosystems be more diverse?
if each species in ecosystem is genetically diverse
why is a larger gene pool better for the species?
increased variation allows greater chance of survival if selection pressure changes
how can a species be more genetically diverse?
- increase gene pool
- mutations increase gene pool, if advantageous, gene is passed on and increases population freq
what is the biodiversity within a habitat vs within a species?
within a habitat: species richness and evenness
within a species: genetic variation
what are the acts of agriculture on biodiversity?
- destroy species habitat (reduction of hedgerows from soil erosion)
- use of pesticides
- monocultures grown
- increase land used for growing crops
what is the result / impact of biodiversity from agriculture?
fewer habitats and niches
reducing stability of food chain
3 reasons why biodiversity is important? (3 Es)
- ecological
- ethical
- economic
why is it good to have rich biodiversity?
- allow ecosystems to function and self-regulate
they are interlinked on a global scale - cope with selective pressures
what is an ecosystem service?
service provided by natural environment that benefits people
what is the role of cultural ecosystem services in maintaining biodiversity?
important for health and wellbeing, education and tourism
what are some ethical reasons to support biodiversity?
- it is our duty, doing it for future gens
- protect lives of animals and humans
- maintain homes of organisms. we’ve only got 1 planet
how does supporting ecosystem services contribute to maintaining biodiversity?
help promote the maintenance of the environment
examples of human activities causing loss of biodiversity
- deforestation
- forest fires
- non-sustainable resources used and not replaced
- urbanisation
what is the significance of provisioning ecosystem services in biodiversity?
involve products gained from ecosystems eg food from cereal plants
how do regulating ecosystem services help maintain biodiversity? + examples?
regulate environment
e.g. disease control, plant trees to reduce carbon footprint
conservation vs preservation?
c: actively managing and interfering
p: not interfering, keeping it exactly the same
what are the 2 main types of conservation?
ex-situ
in-situ
where does ex-situ take place?
outside their natural habitat
where does in-situ take place?
within their natural habitat
disad of ex-situ conservation (animals)/zoos
- animals domesticated. Reliant on humans
- loss of natural behaviours
- hard to reintroduce species back into wild
- too much focus on ‘attractive’ species
what are some advantages of ex-situ conservation for animals
- education about endangered animals
- more research
- protect endangered species
- less inbreeding
- money can be raised for conservation
disadvantages of in-situ conservation?
- take up land of local people
- lots of restoration of habitat needed
- eradication of pests
advantages of in-situ conservation?
- species have access to natural resources and breeding sites
- conserve natural behaviour
- less expensive
- can protect larger breeding populations
why are seeds important?
- produces in food chain, essential for animal survival
- medicines and fibres
- p/s removes CO2 from atmosphere
what are seed banks?
store seeds from plants that are endangered to help conserve bd
if extinct in the wild, store seeds can be used to grow new plants
what conditions are required for seed banks?
- low temp
- keep v dry
why must seeds be kept at low temps?
reduce growth of microorganisms, slow rate of decomposition
why must seeds be kept very dry?
reduce metabolic processes, seeds less likely to germinate (grow)
why do viability of seed banks need to be checked regularly?
to ensure highest quality + quantity
adv of seed banks?
- takes less space, more stored
- can be stored for long periods of time
- cheaper
- doesn’t require as much maintenance as growing plants
- different species can be stored tgt
disadvs of seed banks?
- testing seeds for viability can be time consuming and expensive
- expensive to store and test regularly
- difficult to collect exotic plant seeds
- some don’t store well
What are importantly procedures at seed banks? 2 marks
Low temp low humidity
Check viability regularly
What are some uses of in-situ conservation in comparison to ex-situ? (2 marks)
- no change in behaviour, natural
- less inbreeding
- other species in ecosystem also conserved
Why is using an index better than counting the number of species?
It considers population of each species
Explain why glass containers are used to store seed banks. (4 marks)
- see through, no need to remove lid
- keeps seed viability high
- can keep air and moisture out
Explain how seed viability tests will be different around the world. (3 marks)
- viability test requires similar conditions as the country
- germination affected by temp / pH / humidity
- if not correct conditions, seed wouldn’t germinate even if viable
Suggest how the effects of habitat loss on the biodiversity of a tropical forest could be measured. (2 marks)
- measure species richness / count number of species
- comparing before and after habitat loss
