Module 4.2 Biodiverity Flashcards
What does the term species evenness mean
It is the measure of relative abundance of each species in an area
What does the term species richness mean
Number of different species in an area
What are the three types of diversity and their meanings
Habitat: number of different habitats
Species: number of different species
Genetic: variation of alleles
How would you carry out random sampling
Divide field into a grid
Use a random number generator to select coordinates
Then count the number of organisms in the area
What is Simpson’s index of Diversity?
It takes into account species evenness and richness
What is a pro of random sampling
Not biased
why?
it ensures that each sample has the same probability of being chosen.
Why do we sometimes use non-random sampling
In the case, there is a wide range of species in an area
Name some techniques of sampling animals
Pooter sweep net kick sampling pitfall traps capture mark release Tullgren funnel
Name some techniques of sampling plants
Quadrat
Line quadrat
Point quadrat
What is an opportunistic sample and is it biased
An opportunistic sample is when the researcher chooses where the sample is carried out
Yes it is biased
What is systematic sampling
When you take samples at fixed intervals for example a line transect
What is stratified sampling
Is when you identify different areas of habitat and sample each area in proportion to the habitat as a whole
For example, there may be more daisies than lilies in a field, so you would sample the lilies in proportion to how much there are in the field
Genetic diversity
Why is genetic diversity important
having more genetic diversity means that you are more able to withstand changes in your environment as you can adapt and survive better
Genetic diversity
What is the locus of a gene?
alleles of the same gene are found at the same point on a chromosome
Genetic diversity
How do you work out polymorphism?
the proportion of polymorphic loci= number of polymorphic loci / total number of loci
Factors that affect biodiversity
How does human population growth affect biodiversity?
- Habitat loss: through deforestation, we cut down trees to provide land for agriculture and grazing.
- Overexploitation: We use more resources than we can replenish. An example of this is overfishing, which can lead to the extinction of fish.
- Urbanisation: Cities tend to isolate certain species this means they can’t interbreed which lowers genetic biodiversity,
- Pollution: High levels of pollution can destroy habitats
- high amounts of fertiliser can flow in water and kill the animals present
- Acid rain can lower the pH of rivers, lakes and soil. Some animals can’t live in these conditions
Factors that affect biodiversity
How does monoculture affect biodiversity?
Monoculture: land used to grow one type of crop
- Habitat loss: Trees in mangrove forests might be cleared out for shrimp farms reducing the biodiversity
- Use of herbicides and pesticides means that plants like weeds and insects reduce biodiversity
- some crops are not planted anymore because they don’t make enough money, this reduces species biodiversity (loss of heritage varieties)
Factors that affect biodiversity
How does climate change affect biodiversity
- Climate change can cause areas that were once habitable for species to become inhabitable, this may increase biodiversity or decrease biodiversity
- Climate change can cause some species to migrate like birds, this can decrease biodiversity where they were from but increase biodiversity where they go
- Plants can’t migrate like animals can and a change in temperature may cause them to go extinct. An example can be one type of coral reef in Panama
- global warming: melting ice caps, sea level rising
Maintaining biodiversity
What are the reasons to maintain biodiversity
- Ecological:
- Keystone species have a large effect on the environment, for example, wolves can ensure the numbers of prey are regulated.
Interdependence- disrupting food chains can have an effect on feeding., Disruption of nutrient cycles can affect the growth of plants - Aesthetic: inspiring, good for health, also it can have economic benefit as the more beautiful a landscape the more likely it will attract tourists
- Economic: reducing soil depletion means less money would be spent on fertilisers (happens due to monoculture)
- Maintaining genetic resources means we can have a variety of food, clothes, medicine, fuels etc, this also can help species adapt to climate change
conservation
What does conservation mean
protection or management of organisms/habiats
What are the types of conservation?
in situ
In situ
- creating wildlife parks, (restricts urban and industrial development) marine conservation zones
- control and prevent the introduction of new species like grey squirrels who compete with red squirrels
- control water levels, cutting down of trees
- restore damaged areas like a sea that has an oil spill
- provide legal protection
- promote some species by protecting a food source
What are the advantages and disadvantages of in-situ
Advantage
- habitat and species are conserved
- less disruptive
- chances of population recovering greater than ex-situ
Disadvantages
- hard to control disease
- climate
- poaching
- predators