Biodiversity Flashcards
Define species
Organisms similar in appearance, anatomy, physiology, biochemistry and genetics whose members are able to interbreed freely to produce fertile offspring
Define habitat
The place where an organism lives
Define population
Group of organisms of the same species living in the same area at a particular time
Define community
all the populations of living organisms in a habitat
Define biodiversity
1) range of habitats
2) range of living organisms
3) number of different species
4) genetic diversity
Define species richness
The number of different species living in a particular area
Define species evenness
A comparison of the numbers of individuals of each species in a living area
Why is it that we do not know the exact number of species
We cannot be sure that we have found all species on earth
New species are being found all the time
Evolution and speciation are continuing
Endangered species and extinctions
What does genetic biodiversity mean
The variety of different genes that make up a species
Why is it that a species with greater genetic biodiversity will survive long term
There is a greater range of genes
Greater chance that an organism will survive a change in habitat
Better adapted to catch pray/ avoid new predators
Why is sampling random
To avoid any bias
To make sample representative of an area
Explain the process of sampling species of plant on a field
1) lay out two long tape measures along the sides of study area
2) obtain 2 coordinates using random number generator
3) place quadrant 0.5m^2 at coordinates
4) record % cover
5) repeat many times
6) calculate mean and species diversity
Describe the three non random sampling techniques
1) opportunistic - uses organisms that are conveniently available
2) stratified- sub groups , based on a particular characteristic
3) systematic- often uses a line or belt transects
What is a belt transects
Two parallel lines are marked and samples taken of the area between the two lines
What is a line transect
Place a tape/ rope along the study site
At regular intervals record species touching the line
What is different in a interrupted belt transect
Take numbers at regular intervals
What is a quadrat
What can a quadrat be used to work out
A frame that forms a known area (m^2)
Density, frequency and percentage cover
What is a point quadrat
The apparatus consists of a free standing drama with a row of ten sliding pins
What 3 things can a quadratic be used to work out
Density
Percentage cover
Frequency
What is a point quadrat
A free standing frame with a row of ten sliding pins
These are lowered onto the vegetation
A record is kept of the PIN number and each species of plant that is touching the pin
What scale is used for measuring species abundance
ACFOR
What does ACFOR stand for
A=abundant ( greater or equal to 30%) C=common (20-29%) F=Frequent (10-19%) O=occasional (5-9%) R=rare (1-4%)
Describe a pit fall trap
Used to catch small crawling invertebrates
Like a hole in the ground which has a roof structure so that it does not fill with water
What us sweep netting used to catch
Insects in areas of long grass
What can be used to sample birds and bats
Nets
Describe tree beating
A large white cloth is placed under the tree
The animals fall onto the sheet and can be collected and studied
Basically smacking a tree with a big stick
What is a pooter
Used to catch small insects
Person sucks on mouthpiece
Insects are drawn into the holding chamber via an inlet tube
What is kick sampling
Used to study organisms that live in rivers
River bank is kicked for a period of time
A net is held downstream and captures organisms released from the substrate into the flowing water
What is a tullgren funnel
Soil is placed into a funnel
A light above it dries out the soil, organisms move away from the heat/light and fall through the sieve
What will a light trap catch
Small mammals
How can you improve sampling methods
Randomly select a sample area with random coordinates
Sample many times to collect a mean
Use a standardised technique ( same size pitfall trap etc)
Sample area at different times of the day/year
What is used to estimate population sizes
Mark-release recapture
What is the issue with mark-release-recapture
Assumes samples are representative of the whole population
Assumes organisms mix evenly
Assumes there has been no immigration
Assumes there has not been many births or deaths
What needs to be done before sampling living organisms
An environmental impact assessment
What is used to measure: A) wind speed B) light C) humidity D) pH E) temperature F) conc of O2 in water
A) anemometer B) light meter C) humidity sensor D) ph probe E) temperature probe F) dissolved oxygen probe
What is used to find species diversity
Simpsons diversity index
What the formula for species diversity index
1-(sum of(number of each species/ number of organisms in total)^2)
Why is a high diversity better than a low one
If a change in environment affects one species, and that one species dominates the habitat, and this species dies, the whole habitat will be affected and may not recover.
What can scientists do to determine long term survival of the species
Calculate the genetic biodiversity
What increases genetic diversity
Differences in alleles
Mutations in DNA
Gene flow ( interbreeding between different populations)
Name factors that decrease genetic biodiversity
1) selective breeding
2) captive breeding programmes in zoos
3) rare breeds
4) artificial cloning
5) natural selection
6) genetic bottlenecks
7) founder effect (when a new colony is created the gene pool is very small)
8) genetic drift ( certain alleles disappearing)
How can scientists quantify genetic diversity
Polymorphism
What is a polymorphic genes
Genes that have more than one alleles
What is the name where a single allele exists for a gene
Monomorphic
What does the locus of a gene refer to
The position of the gene on the chromosome
Define endangered species
Population critically low due to humans, species close to being extinct
Define critically endangered
Likely to go extinct, numbers are not sustainable and too low for the survival of the species
What are the main problems humans are causing in regard to biodiversity
Deforestation
Agriculture
Climate change
How does deforestation reduce biodiversity
It directly reduces the number of trees present in an area
If only a specific type of tree is felled that species is reduced
Destroys habitat and food source
Animals forced to migrate
How does agriculture reduce biodiversity
Removal of hedgerows (destroys habitat)
Use of chemical pesticides and herbicides, reduces species diversity
Use of monoculture- only planting one species
Why are hedgerows good
Food and shelter to important species
Control water levels and run off
Pest control as predators live in them
Pollination of crops by insects
What is the greenhouse effect
Where the short wavelength hits the earth, is reflected back but with a longer wavelength so some of it gets reflected again by the atmosphere
What is contributing to the greenhouse effect
Burning fossil fuels
Deforestation (removing trees which remove CO2)
Cattle and rice fields (produces methane)
What are the consequences of climate change
- melting ice caps- removing a habitat- forcing extinction on the inhabitants
- rising sea levels= flooding, destruction of habitat
- higher temperatures and less rainfall results in some species failing to survive
- insect life cycles will change and so will pollination patterns
- disease being able to survive the winter
Name a plant species that flooding will cause to go extinct
Mangrove swamps which depend on their roots being out of water to obtain oxygen
How may fish go extinct by climate change
Some species stop growing once a certain temperature is reached
If this is before reproductive age or before they weigh enough to survive winter- could go extinct
What are the three groups as to why we should maintain biodiversity
- aesthetic
- economic reasons
- ecological
What are the aesthetic reasons for maintaining biodiversity
Enrichment of lives- relaxing on a beach/ walking in woodland
- provides inspiration for people
- people recover more quickly when supported by plant and natural environment
What are the economic reasons for maintaining biodiversity
- soil erosion and desertification affect the countries ability to produce crops- become dependent on other countries
- non sustainable removal of resources will reduce in collapse of industry
- species which may have medical or chemical value will go extinct
- ecotourism
What are the ecological reasons for maintaining biodiversity
Organisms are part of a food chain and are interdependent , if one goes extinct, could trigger a chain reaction
Keystone species, play a key role in , maintaining structure of an ecological community, when removed habitat alters
Give 2 examples of a keystone species, what makes them special
-Prairie dogs
Provide food source and burrows for other animals
Tunnelling aerated the soil
Faeces adds nutrients to soil
-star fish
Eat mussels and sea urchins
Creates a balanced ecosystem
What does in situ mean
Give an example
Conservation of a species in its natural habitat
Marine conservation zones
Wildlife reserves
What are the advantages of in situ
- habitat conserved along with all organisms within the habitat
- biodiversity of the whole area is maintained
- cheaper just needs managing
- allows evolution to continue
What are the disadvantages of in situ
- large amounts of land needed
- local people may still hunt
- animals may leave reserve
- hard to control disease, fire etc
What do in situ conservation charities do
Purchase of land
National campaigns
Lobby government
Educate and make public aware
What does a wildlife reserve do
Control grazing
Restrict human access
Control poaching
Culling removing invasive
What do marine conservation zones do
Preserve species rich areas such as coral reefs
They create areas of refuge within which populations can build up
How many national parks in the UK
14
Define Ex situ reserves
Conservation of a species by removal of the organism from its natural habitat
Give three examples of ex situ
Botanic gardens
Seed banks
Captive breeding programmes
Describe botanic gardens
Plant species are actively managed
Provided with the best resources to grow
What is the problem of botanic garden
Many wild relatives of selectively bred species are still under represented
Describe seed banks
A gene bank- storage of genetic material
Used to store temperate and tropical seeds
Seeds will remain viable for centuries
Used as a back up against the extinction of wild plants
What does viability mean
Keeping seeds healthy
What is the problem of seed banks
Could be wiped out by power failure or natural disaster
What are the main advantages of seed banks
Plants can be researched on site
Easy and cheap to transport
Can be collected without disturbing the habitat
What are the disadvantages of seed banks
Collection of wild seeds will cause some disturbance
Asexual breeding means clones (genetically identical)
Seeds stored of ra long time might not grow
What is the aim of captive breeding programmes
Once a stable healthy population of a species and then gradually reintroduce them back into the wild
What is a problem of captive breeding
They do not evolve within their environment
How are individuals selected
They must be not related, health and of reproductive age and from several different backgrounds to increase genetic variation
What must happen before the animals are released
They are quarantined
Where are animals released to
A protected reserve with a method of monitoring the population
Major threats have been removed
What will the zoos and aquariums do before releasing animals
Store there eggs and sperm so if species number falls, they can repopulate
Why may some organisms born in captivity not be suitable for release in the wild
Might not be resistant to local disease
Some behaviour must be learnt
Stress on habitat. Individuals may fight for territory
What are some of the pros of ex situ rather than in situ
Protection from hunting
Breeding can be manipulated
Species can be treated for disease
Reduced competition
What are some disadvantages of ex situ with animals
Small gene pool for breeding
Have to raise money through funding
Capturing the species for conservation is difficult
Affect on wild population size
Give an example of an international agreement made to protect species and habitats
The Rio convention, 172 nations
Three agreements were reached:
-convention of biological diversity (develop national strategies)
-United Nations framework convention on climate change (stabilising greenhouse gas concentrations within atmosphere)
-United Nations convention to combat desertification (reduce the affects of drought)
Give an example of local agreements
Countryside stewardship scheme
Describe the countryside stewardship scheme
Farmers were given government payments to enhance and conserve English landscape
Aims: to restore neglected land, sustain diversity of landscape
