4.2.1 - Biodiversity Flashcards
Biodiversity
Measure of how varied life on earth is
3 types of biodiversity
Habitat
Species
Genetic
Genetic diversity
Measure of how many variations that are in the genetic code between individuals in spp. or diff spp
Species diversity
Measure of how many diff species are present
Species
Share common physiological, anatomical and behavioural characteristics
Can interbreed to produce fertile offspring
Hybrid
Produced by diff species but are infertile
Community
Several populations of diff spp living in a habitat at a certain time
Habitat
Place where organisms live at a certain time
Population
The amount of spp living in a habitat at a certain time
Endemism
Group of organisms unique to one particular habitat (geographically discrete)
Things to consider when sampling
Size of samples
No. of samples
Sampling technique used
Ways to not disturb the habitat
Random sampling
Uses a calculator to generate random numbers which can be used as coordinates on an imaginary grid
Opportunistic sampling
Involves using prior knowledge to select sample sites or changing the sampling strategy on site
Stratified sampling
Involves carrying out samples in each recognisable sub-habitat
Systematic sampling
Involves carrying out sampling at fixed intervals in each distance
Methods of using quadrats
Point sampling - counting species touching quadrat
Grid sampling - estimating how many smaller squares are occupied by each species
Methods to sample animals
Longworth trap (mark, release, recapture)
Observation
Pitfall trap
Tullgreen funnel (invertebrates living in leaf litter)
Sweep net and kick sampling
Pooters
Tree beating
Measures of species diversity
Species richness
Species evenness
Species richness
No. of diff types of species in a particular area. The greater the number of spp, the ‘richer’ the area
Species evenness
How evenly each species is represented throughout a habitat
What does a high Simpson’s index indicate
Habitat with high diversity
High species evenness and richness
May survive disruption (introduction of new disease or competition)
Should be conserved
When is genetic diversity increased
When there is more than one gene variant (allele) for a particular locus
Factors affecting biodiversity
Human population growth
Increasing use of agriculture (monoculture)
Climate change
Reasons for maintaining biodiversity
Ecological
Economic
Aesthetic
Ecological reasons for maintaining biodiversity
Regulation of O2 and CO2 in the atmosphere
Soil formation and retention
Protecting keystone species
Maintaining genetic resource
Economic reasons for maintaining biodiversity
Pollination of crops depends on bees
Unknown species may be effective medicines
Growth of food and timber relies on correct functioning of ecosystem
To avoid soil depletion (continuous monoculture)
Natural predators to pests reduce the need for pesticides
Aesthetic reasons for maintaining biodiversity
Maintaining the landscape
Being around nature relives stress and helps recovery from injury
A healthy, well-balanced ecosystem is complex and beautiful
Types of conservation
In situ
Ex situ
In situ conservation
Conserving a species in its natural habitat by creating marine conservation zones and wildlife reserves
Advantages of in situ conservation
Tourism generates money
Generates jobs for locals
Both habitats and species are conserved
Organisms will behave normally
Disadvantages of in situ conservation
Can be difficult to monitor organisms and ensure they’re healthy
Poachers/hunters
The environmental factors that caused the decline may still be present
Difficult to treat diseases
Ex situ conservation
Conserving a species using controlled habitats away from its normal environment e.g. seed banks, botanic gardens and zoos
Advantages of ex situ conservation
Easy research
Diseases can be controlled
Controlled breeding
Once populations have been increased, some can be reintroduced to the wild
Seed banks can store seeds of millions of rare/extinct plants using a smaller area
Disadvantages of ex situ conservation
Organisms living in unnatural habitat (effects on behaviour)
May not breed
Little point in conserving individuals if their natural habitat is lost and there nowhere to return to
Conservation agreements
CITES
CBD
CSS
Keystone species
Is one that has a disproportionate effect on the ecosystem - loss of these species affects many others
CITES
Conservation on International Trade in Endangered Species
International countries voluntarily agree to ensure their trade of wild animals and plants doesn’t affect their survival
Prohibit commercial trade on wild plants
CBD
Rio Convention on Biological Diversity
Promotes development of sustainable resources of food, water and medicine
Promotes ex situ conservation measures with shared resources
CSS
Countryside Stewardship Scheme
Aims to enhance natural beauty of UK country side and improve public access
How does human population growth lead to a decline in biodiversity
Deforestation to build houses, habitats destroyed (lower habitat diversity)
How does agriculture lead to decline in biodiversity
Monoculture; only growing one type of crop
Excessive use of pesticides - lower genetic diversity
How does the excessive use of farmland cause a reduction in biodiversity
Only promotes growth of one species
Others are outcompeted and die out
Why will a reduction in biodiversity present problems for agriculture
Loss of genetic diversity
Lost genes may have been useful e.g. gene for drought resistance
Fewer pollinators
Advantages of seed banks
Not susceptible to diseases
Remain viable for longer
Requires less space so more can be kept
Why are seeds in seed banks collected from several sites
Maintain gene pool
Reduce chance of inbrrrding
In case there are environmental factors affecting one of the sites
Why is it bad for endangered species to be isolated
Small gene pool
More vulnerable to predators and poachers
Natural disaster could wipe out part of population
How can zoos help endangered animals if captive breeding doesn’t work
Raise awareness
Promote conservation projects
Niche
Organisms role in the habitat its living in
How will having smaller fields increase biodiversity
More hedges in between the fields, species can live there
Why might deforestation increase biodiversity in the short term
Many species are forced to live in a small area
After a while however, the woodland will reach its carrying capacity and organisms either migrate or die
Requirements to use Spearmans rank
Paired data
More than 5 data points
Independent of each other
Ordinal/interval data
Advantages of standard deviation vs range
Less affected by outlier
Takes into account every value
