Module 4.2 - Biodiversity Flashcards
What is CITES
Convention on International Trade in Endangered Species of Wild Fauna and Flora
International agreement by most of the world’s governments
Overall aim is to ensure that international trade in wildlife doesn’t threaten their survival
Aims of CITES
Conserve biodiversity
Regulate, monitor and prevent trade in endangered species
Ensure trade doesn’t endanger wild populations
Prohibit commercial trade in wild plants
Allow some trade in led endangered plants and animals
Allow trade in artificially propagated plants
How CITES helps conservation
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
What is the Rio Convention?
Recognises human needs for food, land, medicine, clean environment as well as the need for maintaining biodiversity
International agreement by 150 governments
Overall aim is to promote sustainable development
Aims of Rio Convention
Conserve biodiversity
Sustainable use of organism/habitats/ecosystems
Share genetic resources
Share access to scientific knowledge
Promote ex situ conservation methods
Raise profile of biodiversity with governments/general public
International cooperation on biodiversity issues
Aims of the Countryside Stewardship Scheme
Improve natural beauty
Enhance landscapes for their wildlife and historical features
Improve opportunities for public access
Conserve traditional livestock and crops
Define biodiversity
The range of habitats, the number of different species and their relative abundance, and the genetic diversity within a species within an area
Define habitat
The place where an organism lives
Define species
A group of organisms similar in appearance, physiology and genetics where members are able to interbreed to produce fertile offspring
Define habitat biodiversity
The range of habitats in which different species live within an area
Define species biodiversity
The number of different species living in a habitat (species richness) and their relative abundance (species evenness)
Define genetic biodiversity
Variation between individuals of the same species
Types of non-random sampling
Opportunistic
Stratified
Systematic
Explain opportunistic sampling
Prior knowledge of a site determines sample site
May deliberately sample an area where an organism is known to be present
Advantages of opportunistic sampling
Quicker and easier than random sampling
Guaranteed results
Disadvantages of opportunistic sampling
Biased - may overestimate/underestimate abundance of particular species (e.g. researcher may be drawn to areas with larger or colourful species, overestimating its importance)
Explain stratified sampling
Divide a habitat into areas which seem different and sample each separately
Advantages of stratified sampling
Ensures all different areas of a habitat are sampled so no under representation (random sampling may miss certain areas)
Disadvantages of stratified sampling
If too many samples are taken in proportionally smaller areas, it could lead to over representation of these areas
Explain systematic sampling
Samples taken at regular, predetermined intervals (e.g. line/belt transects)
Advantages of systematic sampling
Shows gradual change in environmental factors
Disadvantages of systematic sampling
Some species may not be within the line or belt so will be missed, leading to an underestimate in biodiversity
Method of random sampling
Use a computer to randomly generate numbers for coordinates (the number of coordinates required depends on the size of the area being sampled)
Go to the coordinates and place a quadrat there
Count the presence of species and the different types of species within the quadrats
Use this data to calculate the species richness and evenness
Methods of measuring abundance
Abundance scale (e.g. ACFOR scale) Estimate % cover Measure % cover using point frame (frame with 10 needles, put down 10 times in quadrat- each plant touching a needle has a 1% cover)
Model answer to sample plants
Set area to be sampled
Use a belt transect to sample
Use 0.5m x 0.5m quadrats at regular 5m intervals
Identify plant species using a key
Record the presence and absence of species in each quadrat
Measure the % cover of each species
Repeat this using several different transects for reliability
Calculate biodiversity using Simpson’s diversity index
Model answer to sample animals
Set area to be sampled
Use random numbers generated by a computer to make coordinates to locate the areas to randomly sample
Pick an appropriate capture method (e.g. sweep nets, pooters, pitfalls)
Identify each species using a key
Count the numbers of each species
Repeat this several times in each habitat using the same technique for reliability
Calculate biodiversity using Simpson’s diversity index
Explain pond/sweep nets
Use in water or low vegetation to catch small animals or insects
Sweep net in arcs to catch animals
Identify and count on a white background
Explain pooters
Use for small animals or insects once caught with a pond/sweep net or from trees
Suck up animals into a clear container to stop them flying off
Explain trapping from trees
Use for small animals or insects in trees
Hit tree branches with a stick to knock off animals into a white tray or white paper to identify and count
Explain pitfall traps
Use for small animals or insects on the ground
Container buried in soil so insect fall into it
Water or a chemical to stun them can be used to stop them crawling out
Should be sheltered in rain
Explain tullgren funnels
Use for small animals or insects from leaf litter
Leaf litter placed on mesh
A light dries out the leaf litter
Animals fall through mesh into a collecting jar
Explain light traps
Use for insects attracted to light at night
UV light attracts insects which fall into alcohol in the trap
Explain longworth traps
Use for small animals (e.g. mice)
Bait put in trap, it snaps shut behind animals, leaving them unharmed
They can be marked, released and recaptured to estimate population sizes
Method of mark, release and recapture
Allows estimate to be made of population size of a species
Capture sample of animals
Mark them
Number captured = C1
Release animals
Retrap/recapture another sample using the same method for validity
Number captured = C2
Number recaptured (marked) = C3
Calculate total population using C1 x C2 / C3
Define species richness
Number of different species in the habitat
Define species evenness
Relative numbers of how many individuals in each species
What is Simpson’s Index of Diversity?
A measure of biodiversity of a habitat as it takes into account species richness and species evenness
Why would we need to assess genetic biodiversity of a small/isolated population?
Genetic biodiversity can be very low
Calculations to assess genetic biodiversity indicates how useful that population will be in providing a wide range of genes to support the species’ conservation
What causes genetic biodiversity?
Different/more than one allele on a locus
How to calculate genetic diversity
Number of polymorphic gene loci / total number of loci
Define polymorphic gene locus
Locus that has more than two alleles
What has reduced biodiversity?
Human population growth
Agriculture
Climate change
How has human population growth reduced biodiversity?
Use the environment or our own advantage
Alter ecosystems to provide ourselves with food
Destroy habitats
Use Earth’s resources
Pollute the atmosphere
Our activities result in harming other species either directly or indirectly, which can lead to extinction
How has agriculture reduced biodiversity?
Clearing vegetation reduces the size of habitats and populations, so reduces the genetic diversity and the species has less capacity to adapt to changing conditions
May leave isolated and fragmented populations that are too small to survive
Monoculture has very limited genetic diversity
Selective breeding also reduces genetic diversity and can cause genetic erosion (process where an already limited gene pool of an endangered species diminishes even more when individuals from the surviving population die off without getting a chance to meet or breed with others in their endangered population)
How has climate change reduced biodiversity?
As climate changes, species are less able to adapt to changes in temperature and rainfall
Only alternative is to migrate and follow the climate patterns they are most suited to
Obstructions to migration: major human developments; agricultural land; large bodies of water; mountain ranges
Define keystone species
Species that has a disproportionate effect upon its environment relative to its abundance
Ecological reasons to maintain biodiversity
Interdependence of organisms (higher species diversity means more stable habitat, decline of keystone species will have dramatic effect on habitat e.g. beavers create large areas of still water where other species can live)
Genetic resource (for genetic engineering or selective breeding to produce new species which can cope with new effects of climate change)
Natural medicines/vaccines
Economic reasons to maintain biodiversity
Regulation of atmosphere and climate Purification and retention of fresh water Formation and fertilisation of soil Recycling of nutrients Detoxification and recycling of wastes Crop pollination Growth of timber, food and fuel Discovery of molecules with potential as medicines Food production - avoid soil depletion
Aesthetic reasons to maintain biodiversity
Patients recover more quickly from stress and injury when exposed to pleasant natural environment conditions
Deforestation causes flooding
Soil protection reduced when trees are removed so run-off and drainage increase
