4.2 - Biodiversity Flashcards
Explain the importance of sampling in measuring the biodiversity of a habitat(model answer - 2 marks)
- It is impossible to count every individual in a species’ population
- So sampling provides an estimate of the population that is representative of the whole area/habitat
What is the significance of a low Simpson’s Biodiversity Index?
- The habitat is dominated by one species
- So the habitat is less likely to be able to cope with change
Sampling in ANIMALS model answer mechanisms
• set grid/area to be sampled
• use random numbers generated by a computer to locate the areas you will
randomly sample
• pick appropriate capture method CHOSE ONE e.g. sweep nets, pooters,
pitfalls etc
• identify each sp. using a key and count the numbers of each sp.
• repeat this several times in each habitat, using the same technique each
time to show repeatability and identify anomalies
- extrapolate the data to estimate biodiversity in the entire habitat
Sampling in plants model answer
- set grid/area to be sampled
- use belt transect to sample
- use 50cmx50cm quadrats
- at regular 5m intervals ‐ systematic sampling
- identify plant species using keys
- record the presence/absence of sp. in each quadrat
- estimate the % cover of each species in your quadrat
- repeat this using several different transects to show repeatability and identify anomalies
- extrapolate the data to estimate biodiversity in the entire habitat
Reasons for maintaining biodiversity
- Ecological reasons
- plants form habitats for other organisms
- protect keystone species
- genetic diversity for genetic resources, e.g. medicine, selective breeding, genetic engineering
- Economic reasons
- tourism
- source of medicines or resources
- Aesthetic reasons
- e.g. different breeds of dog
Ethical reasons:
- we should protect animals as it is our duty to protect and preserve biodiversity of other organisms
Three biodiversity agreements and conferences
- CITES - Convention on International Trade in Endangered Species of Wild Flora
- Rio Convention on Biological Diversity
- Countryside Stewardship Scheme
Aim of CITES
- conservation of biodiversity
- regulate, monitor and prevent trade in endangered species
- ensure trade does not endanger wild populations
- prohibit commercial trade in wild plants
- allow some trade in less endangered plants and animals
- allow trade in artificially propagated plants
How does CITES help save endangered species?
- countries in agreement make it illegal to poach species
- place ban on trade of endangered species
- increase cooperation between countries
- increase awareness of impact of illegal trade
Aims for Rio Convention on Biological Diversity
- conservation of biodiversity
- sustainable use of organisms / habitats / ecosystems
- share genetic resources
- share access to scientific knowledge
- promoting ex situ conservation methods (to complement in situ measures)
- raising profile of biodiversity with governments / general public
- international cooperation on biodiversity issues
Biodiversity def
-The range of habitats, the number of different species and their relative abundance, and the genetic diversity within a species within an area.
Species biodiversity def
- The number of different species living in a habitat (species richness) and their relative abundance (species evenness).
Factors affecting biodiversity
- Human Population Growth:
- more food and land needed = alter ecosystems and destroy habitats
- Using up more natural resources, e.g. crude oil is finite
- More energy sources and materials needed = more pollution
- Over hunting/fishing decreases biodiversity
- Agriculture and monoculture:
- monoculture will have reduced genetic diversity
- More land and natural habitats are cleared for land monoculture - reduces size of habitats and of wild species populations
- reducing population sizes reduces genetic diversity - less able to survive changes in conditions and leads to extinction
- Climate Change:
- Species with low genetic diversity are unable to adapt to the climate changes
- So species may have to migrate, which is risky as it is not always possible and could lead to extinction of a species
Habitat def
The place where an organisms lives
Habitat biodiversity def
-The range of habitats in which different species live within an area
Species def
-A group of organisms similar in appearance, physiology and genetics whose members are able to interbreed to produce fertile offspring
Genetic biodiversity def
-Variation between individuals of the same species e.g. breeds of dog.
2 types of sampling
- Random
- Non-random