4.2.1 Biodiversity Flashcards
What is biodiversity
- The variety of living organisms
- Can be measured in terms of species density, habitat diversity and genetic diversity
Define species diversity, habitat diversity and genetic diversity
Species diversity: number of species in a community
Habitat diversity: range of different habitats
Genetic diversity: variety of alleles within a species
What is the difference between species richness and species evenness
Species richness: the number of species in an area
Species evenness: whether species have similar numbers
Discuss different types of sampling
- Random: no particular system however aim is to still be representative
- Opportunistic: those that are encountered first are chosen
- Stratified: population divided into smaller groups based on characteristics, then sampled
- Systematic: follows a particular pattern
Why is sampling important
- Studying the whole population is impractical
- Using a representative sample allows us to investigate the population easily
Describe how Simpsons index of diversity is used
- A measurement of the total number of organisms compared to the total number of organisms of each species
- A high index of diversity means several different species are equally abundant, whereas a low index means one or two species dominate over others
Give factors that affect biodiversity
- Population growth
- Deforestation for agriculture
- Climate change affecting habitats
Give reasons to maintain biodiversity
- Protecting species
- Maintaining resources
- Protection landscapes
Define conservation
- The protection and management of species and habitats, in order to maintain biodiversity
- Can in in situ or ex situ
What is in situ conservation with examples
- Conservation within an organisms habitat
- Marine conservation zones
- Wildlife reserves
What is ex situ conservation with examples
- Conservation outside of an organisms habitat
- Seed banks
- Botanic gardens
- Zoos
Give some agreements made with the aim of protecting species and habitats
- Conservation on international trade in endangered species (CITES)
- Rio convention on biological diversity (CBD)
- Countryside stewardship scheme (CSS)
Define species richness
the number of different species in an area
Define systematic sampling
different areas of a habitat are identified and sampled separately. Often carried out using a line or belt transect.
What are ways of catching organisms
kick sampling, pitfall traps, sweep nets, pooter
What is a point quadrat
a frame has a horizontal bar - set intervals aong the bar long pins can be pushed through the bar to reach ground, each plant that touches the pin is recorded
What is random sampling
sampling where each individual in the population has an equal likelihood of selection.
how does random sampling work
random number tables or computers are used - mark out a grid using two tape measures laid at right angles, use random numbers to generate the x and y coordinate on your grid, take a sample at each of the coordinate pairs measured
How is biodiversity measured
habitat biodiversity, species biodiversity, genetic biodiversity
What is habitat biodiversity
the number of different habitats found within an area (greater habitat biodiversity, greater species biodiversity)
What is species biodiversity
species richness and species evenness
What is non-random sampling
an alternative sampling method to random sampling, where the sample is not chosen at random. It can be opportunistic, stratified or systematic.
What is sampling
taking measurements of a limited number of individual organisms present in a particular area
What is abundance of organisms
number of individuals of a species present in an area
