Biodiversity, 4.2 Flashcards
Define species
A group of organisms that interbreed to produce fertile offspring
Define habitat
Where an organism lives
Define biodiversity
Variations in the living world eg gene, species and habitats
Define genetic biodiversity?
Measure of genetic variation between individuals belonging to the same species
What is the risk of low genetic biodiversity?
Extinction
Define species biodiversity
How many different species in an area and how many individuals of each species there are
Define habitat biodiversity
Different habitats present in an area
What do we need to do to find biodiversity?
Compare different sites. Compare same areas at different times
What is random sampling?
Divide habitat into coordinates and use random number generator. Quadrats placed at random. Minimum of 10 samples
What are the advantages of random sampling?
Ensure data isn’t biased
What are the disadvantages of random sampling?
May not cover all of the habitat equally. Species may be missed.
What are different types of non-random sampling?
Opportunistic. Stratified. Systematic.
What are the advantages of Opportunistic sampling?
Easier and quicker than random sampling
What are the disadvantages of Opportunistic sampling?
Data may be biased leading to an overestimation in biodiversity
What is Opportunistic sampling?
Use prior knowledge
What is stratified sampling?
Divide a habitat into areas that appear to differ
What are the advantages of stratified sampling?
Ensures that all types of an area are studied and represented.
What are the disadvantages of stratified sampling?
Lead to an over representation of some areas
What is systematic sampling?
Samples are taken at fixed intervals across a habitat using a transect
What are the advantages of systematic sampling?
Useful when the habitat shows a gradient
What are the disadvantages of systematic sampling?
Only species along transect line so may be an underestimation of biodiversity
What are quadrats?
Square frames used to define a set area for sampling
What is a line transect?
A line drawn through an area to be examined. Move along line and record species at intervals
What is a belt transect?
Quadrats at regular intervals along the line. Shows density of species as well as what is there.
How do you sample animals by observation?
Can look for things such as footprints or droppings.
How do you sample animals by a sweep net?
Sweep net in wide arcs so insects become trapped. Empty onto a white sheet and use a pooter
How do you sample animals from trees?
Lay a white sheet and shake the branches
How do you sample animals with a pitfall trap?
Put in soil. Animals fall in into a container with a little water at the bottom
How do you sample animals with a Tullgren funnel?
Collecting from leaf litter. Shine a light driving the animals down so they fall through the mesh
How do you sample animals with a light trap?
Light attracts flying insects
How do you sample animals with a longworth trap?
Traps small animals - can then tag/mark them
What is a pooter?
Can trap small invertebrates in a jar
Define species richness
Number of different types of species in a habitat
Define species eveness
Number of individuals of each species
What do we use to measure biodiversity using both species richness and species eveness?
Simpsons index of diversity
What is the equation for Simpsons index of diversity?
D= 1-(sum (n/N)^2)
What does a high index of biodiversity indicate?
A diverse habitat. Tends to be stable
What does a low index of biodiversity indicate?
Suggests it is dominated by few species. Less stable
Define genetic diversity
More than one allele for a particular locus
How do we measure the genetic diversity?
Measure by the % of loci that have more than one allele as this gives an indication of possible variation
What are the advantages of a highly diverse habitat?
Provides a place to live for many organisms. Small changes to the environment may affect one species but not all the organisms will be affected.
How does human population growth affect biodiversity?
Habitat destruction - eg forests. Pollute the atmosphere. Alter ecosystems. Use earths resources
How does agriculture/monoculture growth affect biodiversity?
Clearing natural vegetation - reducing habitat size. Reduces biodiversity, crop of one species - monoculture. Reduces genetic diverstiy - population decreases. Creates pollution and deforestation.
How does selective breeding growth affect biodiversity?
Reduces genetic diversity - genetic erosion
How does climate change affect biodiversity?
Species will no longer be adapted to the habitats. Organisms could move - migration of populations. There will be obstructions to migrations.
Define keystone species
Disproportionate effect upon its environment relative to its abundance
Why is it ecologically important to maintain biodiversity?
Loss of a keystone species can destabilize an ecosystem. Loss of biodiversity results in a loss of genetic diversity.
Why is it economically important to maintain biodiversity?
Ecosystems are beneficial to the economy. Detoxification and recycling of waste. Growth of timber, food and fuels. Pollination of crops. Purification of fresh water. Fertilization of soil. Protects soil erosion
Why is it aesthetically important to maintain biodiversity?
Natural landscapes are beautiful and good for our well being. Help to recover from stress and injury faster. Looks nice
Define conservation
Enable endangered species to survive and to maintain biodiversity
What is conservation in situ?
Conserving species in their natural environment.
What are some examples of conservation in situ?
Wildlife reserves. National Parks. Laws against hunting. Restricting industrial development.
What are the advantages of conservation in situ?
Conserved in their natural habitats. Permanently protects biodiversity. Management of areas to make sure ecosystems are maintained.
What are the disadvantages of conservation in situ?
Habitats may be fragmented. Endangered species may be in too small groups with little genetic diversity - won’t survive. Will still be in the conditions that they became endangered in. Honey pot for poachers.
What is conservation ex situ?
Conservation outside the normal habitat of the species
What are some examples of conservation ex situ?
Zoo’s and botanic gardens
What is the purpose of a zoo?
Increase numbers. Ensure genetic diversity. Reintroduce species.
What are the advantages of a zoo?
Protected from poachers and predation. Health of animals can be monitored. Genetic diversity measured
What are the disadvantages of a zoo?
Organisms living outside of their natural habitat. Hard for them to be reintroduced into the wild.
What are botanic gardens?
Plants conserved ex situ. Protect endangered species of plants.
What are seed banks?
Collection of seed samples. Cleaned, check and packaged for storage at sub zero temperatures. Periodically germinated
What are the advantages of seed banks?
Seeds can be stored compactly and in huge numbers. Seeds remain viable for a long time. Easier to transport. Less susceptible to disease.
What are the disadvantages of seed banks?
Funding is difficult. Seeds collected from one area may not be genetically varied.
What does CITES stand for?
Convention on International Trade in Endangered Species.
What does CITES do?
Ensure international trade does no threaten a species survival. Regulate and monitor trade of plants/animals. Ensure it doesn’t endanger survival of populations in the wild. Ensure trade of wild plants is prohibited.
What is the Countryside Stewardship Scheme?
Enhance and conserve British landscapes. Improve natural and beauty and diversity. Encourages farmers and landowners to manage land in a way that benefits the environment.
What is the Rio Convention of Biological Diversity?
Promotes sustainable development. Conservation of biological diversity. Sustainable use of its components. Shared access to genetic resources
