Biodiversity Flashcards
what is biodiversity
variety of organisms living in an area
what are species
a group of similar organisms able to reproduce and give fertile offspring
what is a habitat
- the area inhabited by a species
- influenced by physical and living dactors
what is habitat diversity
the number of different habitats in area
what is species diversity
- the number of different species in an area
- the abundance of each species in an area
what is genetic diversity
the variation of alleles within a species
what is random sampling
- sample should be random
- random number generator to select coordinates
- avoid bias but may not be representative
what are the types of non-random sampling
- systematic
- opportunistic
- stratified
what is systematic sampling
- samples taken at fixed intervals
what is opportunistic sampling
- samples chosen by an investigator
- biased data
what is stratified sampling
- different areas in a habitat are identified and sampled separately in proportion to their part of a habitat as a whole
what is species richness
- number of different species in an area
what is species evenness
- measure of the relative abundance of each species in an area
- more similar the population size of each species the greater the species evenness
what is quadrating
- percentage of ground cover for smaller species
- square frame
- random sampling generates random numbers/coordinates
- divided quadrat makes estimating easier
types of transects
- belt transect
- line transect
what is Tullgren funnel
- collecting small animals from leaf litter
- light drives them down
- animals fall into the collecting jar
why do we sample
- to see how human activities may be affecting an area
- environmental impact assessment prior to planning developments
- importance of maintaining habitats and reducing the damage we do to them.
what is Simpsons index of diversity
- closer to 1 = more diverse the habitat
- greater species richness and evenness
D= diversity index
n = total number of individuals of one species
N = total number of organisms of all species
how can genetic diversity be assessed
- low genetic diversity the population may not be well adapted to a change in the environment and the whole population could be wiped out
- isolated populations - bred in captivity
- efforts can be made to increase the genetic diversity if needed - breeding programmes
what is polymorphism
- a gene has more than one allele
- hair colour, eye colour
what is monomorphism
- when a gene has more than one allele
what is the calculation to measure genetic diversity
proportion of polymorphic gene loci =
number of polymorphic gene loci / total number of loci
how does human population growth affect biodiversity
Habitat loss = deforestation to make way for grazing and agriculture - decreases habitat diversity
Over-Exploitation = greater demand for resources , used up faster than can be produced
Urbanisation = cities and road developments can isolate species, populations cannot interbreed
Pollution = high amounts of pollutants can kill species or destroy habitats
how can the use of monoculture in agriculture affect biodiversity
- habitats are lost and land is cleared to make way for large fields
- local plants and animals seen as weeds and pests and destroyed with pesticides and herbicides
how does climate change affect biodiversity
- most species need a particular climate to survive
- cause an increase or decrease in the range of some species
- some species forced to migrate
ecological reasons to maintain biodiversity : protecting keystone species
loss of a keystone species
- disrupt food chains
- disrupt nutrient cycle
ecological reasons to maintain biodiversity: maintaining genetic resources
Food = from animals
Clothing = cotton and leather
Drugs = from plant compounds
economic reasons to maintain biodiversity : reducing soil depletion
- monoculture is growing one crop
- continuous monoculture = planting the same crop in the same field
- continuous causes soil depletion as nutrients required by the crop are used up
- economic costs = increased spending on fertilisers
economic reasons to maintain biodiversity : aesthetic reasons
- areas rich in biodiversity provide pleasant, attractive landscapes
- increase tourism
what is in-situ conservation
- establishing protected areas such as national parks as restricted areas
- controlling or preventing the introduction of species that threaten local biodiversity
- protecting habitats
- promoting species
- legal protection to endangered species
what is ex-situ conservation
- relocating an organism to a safer area
- breeding organisms in captivity and releasing them into the wild when they are strong enough
- botanic gardens to grow rare plants
- seed banks
what is the rio convention on biological diversity
- develop international strategies on how to use plant and animal resources in a sustainable way
- provides guidance to governments on how to conserve biodiversity
what is the CITES agreement
- illegal to kill endangered species
- conserve species by limiting trade
- illegal to trade products from endangered animals
what is the countryside stewardship scheme
- conserve wildlife and biodiversity
- improve and extend wildlife habitats by promoting management techniques
- pay landowners who followed techniques
