Biodiversity Flashcards
What is biodiversity?
The variety of living organisms present in an area
What different levels can biodiversity be studied at?
- Habitat biodiversity
- Species biodiversity
- Genetic biodiversity
What is habitat biodiversity?
Refers to the number of different habitats found within an area
What are the 2 components of species biodiversity?
- Species richness
- Species evenness
What is species richness?
The number of different species living in a particular area
What is species evenness?
A comparison of the numbers of individuals of each species living in a community
What is genetic biodiversity?
Refers to the variety of genes that make up a species
How is species richness measured?
- Sample organism
- A list should be compiled of each speices identified
- Total number of species can be calculated
How is species evenness measured?
- Can be even or uneven based on the number of populations of each species
- Use frame quadrats
- Samples taken at a number of different points
- Calculate mean of individual qudrat
- Multiply mean value per m2 by the total area
How can an animal population size be estimated?
- Capture-mark-release-recapture
- Capture as many individuals of a species in an area as possible
- Organisms are marked and released back into community
- Time is allowed for organisms to redistribute themselves throughout the habitat before another sample of animals is collected
- The greater the number of marked individuals recaptured, the smaller the population
What are abiotic factors?
Non-living conditions in a habitat
Give 2 factors that increase genetic biodiversity
1- Mutations
2- Interbreeding
What is gene flow?
When an individual migrates from one population to another and breeds with a member of another population, alleles are transferred between the 2 populations
Give 8 factors that decrease genetic biodiversity
1- Selective breeding 2- Captive breeding programmes 3- Rare breeds 4- Artificial cloning 5- Natural selection 6- Genetic bottlenecks 7- Founder effect 8- Genetic drift
What is a genetic bottlenecks?
- A sharp reduction in the size of a population
- Could be due to a natural event, such as a flood
- Reduces gene pool
What is the founder effect?
Where a small number of individuals create a new colony, geographically isolated from the original
What is genetic drift?
Due to the random nature of alleles being passed on from parents to their offspring, the frequency of occurence of an allele will vary
What 3 human factors affect biodiversity?
- Human population growth
- Agriculture
- Climate change
How does human population growth affects biodiversity?
- Destruction of habitat, e.g. deforestation
- Separating populations, e.g. roads
- Unsustainable hunting/fishing, e.g. overfishing of cod
- Pollution
- Decreases habitat/species/genetic biodiversity
How does agriculture (monoculture) affect biodiversity?
- More land is needed to feed growing population
- Increased habitat destruction, e.g. deforestation
- Use of herbicides kills weeds
- Continuous monoculture causes soil depletion, reducing other plant species ability to survive
- Decreases habitat/species/genetic biodiversity
How does climate change affect biodiversity?
- Humans burn CO2, a greenhouse gas
- Weather patterns change
- Changes the abundance and distribution of species
- Some species will become extinct
- Decreases habitat/species/genetic biodiversity
Give 3 reasons why biodiversity should be maintained
1- Aesthetic reasons
2- Economic reasons
3- Ecological reasons
Describe the aesthetic reasons for why biodiversity should be maintained
- Enrich people’s lives
- Provides inspiration
- Recovery from stress and injury
Describe the economic reasons for why biodiversity should be maintained
- Resources for non-medical reasons (e.g. building materials)
- Ecotourism
- Continuous monoculture causes soil depletion, decreasing yields and requires more fertiliser
Describe the ecological reasons for why biodiversity should be maintained
- All species are part of the ecosystem
- Provides habitat for other organisms
- Part of food change
- Species are a genetic resource
- Possible source of medicine
- If keystone species are removed, the ecosystems collapses (they maintain structure of an ecological community)
What is conservation?
Preservation and careful management of the environment and of natural resources
What is in situ conservation?
Within the natural habitat
What is ex situ conservation
Out of the natural habitat
What 2 ways can in situ conservation occur?
- Wildlife reserves
- Marine conservation zones
Describe in situ conservation
- Habitat and species are conserved at the same time
- Removal of invasive species
- Supplementary feeding
- Legal protection (e.g. poaching, trade)
- Restricting human access
What are the limitations of in situ conservation?
- Hunting/predations is hard to control
- Unavoidable if habitat cannot be saved, e.g. climate change
What is succession?
A natural process in which early colonising species are replaced over time until a stable mature population is achieved
What 3 ways can ex situ conservation occur?
- Botanic gardens
- Seed banks
- Captive breeding programmes
Describe what happens at a seed bank
- Stores genetic material
- Seeds are stored so that new plants may be grown in the future
- They are dried and stored at -20 degrees
Describe ex situ conservation
- Health of individuals can be monitored
- Reduced mortality of young (e.g. eggs can be artificially incubated)
- Protection fro hunting/predation
- Reduced interspecific and intraspecific competition
- Mates can be selected to maintain genetic biodiversity
What are the limitations of ex situ conservation?
- Few breeding individuals, genetic diversity decreased
- Some species don’t breed well in captivity, e.g. panda
- Expensive and long term
Why are some organisms born in captivity not suitable for release into the wild?
- Diseases (loss of resistance)
- Behaviour (e.g. looking for food not taught)
- Genetic races (populations cannot interbreed)
- Habitat (stress/tension as fighting for limited resources)
What does CITES stand for?
Convention on International Trade in Endangered Species
What is CITES and what does it do?
- It’s an international agreement to stop the trade in endangered species (live or dead)
- Ensure that trade doesn’t endanger wild populations
- Prohibits trade in wild plants
- Allows trade in artificially propagated plants
- Allows some trade in less endangered species
What was the Rio Convention on Biological Diversity?
An international agreement to use habitats/ecosystems/organisms sustainably
Give 4 aims of the Rio Convention
1- Share genetic resources
2- Share access to scientific knowledge
3- Raise profile of biodiversity with governments and public
4- Cooperate on biodiversity issues
What is the countryside stewardship scheme?
A conservation scheme set up at a local level (England) from 1991-2014
What did the countryside stewardship scheme aim to do?
- Give financial incentives to land managers to look after the environment
- Restoring wildlife habitats
- Reducing agricultural pollution
- Preservation/restoration of habitats important in the conservation of rare species
