4.2 - C - Biodiversity Flashcards
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
What is a habitat?
The place where an organism lives
What is a species?
A group of organisms similar in appearance, physiology and genetics whose members are able to interbreed to produce fertile offspring
List and define the 3 types of biodiversity
Habitat biodiversity - the range of habitats in which different species live (within an area)
Species biodiversity - the number of different species living in a habitat (species richness) and their relative abundance (species evenness)
Genetic biodiversity - variation between individuals of the same species eg: breeds of dog
List the 4 types of sampling
Random Non-random: Opportunistic Stratified Systematic
Explain and evaluate opportunistic sampling
Prior knowledge of a site determines the sample site.
You may deliberately sample an area where you know an organism is present.
+ quicker than random sampling
- may introduce bias - could lead to overestimation of its abundance or biodiversity
Explain and evaluate stratified sampling
Separately sampling areas in a habitat which seems very different.
+ ensures all different areas in the habitat are sampled - ensures no under representation
- if too many samples are taken in small areas, it could lead to over-representation
Explain and evaluate systematic sampling
Samples are taken at regular, predetermined intervals across a habitat eg: belt or line transact
+ if there is a clear gradual change in an environmental factor across an environment, transects can show how species abundance changes and therefore the effect of the factor on the different plant species.
- species may be missed - not representative/underestimation
Define species evenness
The degree to which the species are represented
Define species richness
The number of species in the area
Explain how to use a quadrat
Place at your sample sites (random coordinates/points on transect)
Identify plants within the quadrat using a key
Measure the abundance of each species (and bare ground) by using the abundance scale or an estimate percentage cover
What is a quadrat?
A square frame used to define edges of a sample site
Define ACFOR and expand what it stands for
An anagram that measures abundance Abundant Common Frequent Obvious Rare
What is a negative of using ACFOR?
It isn’t based around quantitative data - subjective
Give an exam answer on sampling habitats regarding plants
Set grid/area to be sampled
Use belt transect to sample
Use 50cmx50cm quadrats
At regular 5m intervals ‐ systematic sampling
Identify plant species using keys
Record the presence/absence of sp. in each quadrat
Estimate the % cover of each species in your quadrat
Repeat this using several different transectsto show repeatability and identify anomalies
Extrapolate the data to estimate biodiversity in the entire habitat
List the 7 ways of trapping animals
Pond/sweep nets Poorer From trees Pitfall trap Tullgren funnel Light trap Longworth trap
Explain the type of animal/area pond/sweep nets trap and how they work
Water/low vegetation - catch small animals/insects
Sweep nets in arcs catch animals. They are identified and counted on a white background
Explain the type of animal/area pooters trap and how they work
Small animals/insects once caught with sweep nets/from trees
They suck up animals into a clear container to stop them flying off
Explain the type of animal/area from trees trap and how they work
Small animals/insects in trees
They hit tree branches with a stick to knock odd animals into a white tray/paper to identify and count
Explain the type of animal/area pitfall traps trap and how they work
Small animals/insects on the ground
The container is buried in soil - insects fall into it. Water or a chemical to stun them can be used to stop them crawling out. It should be sheltered in rain.
Explain the type of animal/area Tullgren funnels trap and how they work
Small insects/animals from leaf litter.
Leaf litter is placed on mesh, and a light dries it out - animals go down and fall through the mesh into a collecting jar
Explain the type of animal/area light traps trap and how they work
Insects attracted to light at night
UV light attracts insects which fall into alcohol in the trap
Explain the type of animal/area Longworth traps trap and how they work
For trapping small animals eg: mice
Bait is put in the trap and it snaps shut behind animals, leaving them unharmed. They can be marked, released and recaptured to estimate population size.
What is the purpose of the mark, release and recapture technique?
Allows you to estimate population size of a species.
Explain the method of the mark, release and recapture technique
Allows you to estimate population size of a species.
1. Capture sample of animals
2. mark them ‐ the total number captured = C1
3. Release animals
4. (re)trap/(re)capture another sample using the same method for
validity
Number captured = C2
Number recaptured = C3
5. Calculate total population = (C1 x C2)/C3
Suggest 3 species populations which could be estimated with mark, release, recapture
Mice, butterflies, birds
Suggest 2 considerations that are needed before carrying out mark,
release, recapture
Where and how the individuals will be marked ‐ this must not
cause harm
e.g. butterflies ‐ not on wings (flight), not on top of body (predation)
Suggest 1 limitation of mark, release, recapture
Some animals being trapped with Longworth traps may become ‘trap happy’ and learn that the trap gives them food and safety from predation and become more likely to return to traps ‐ gives overestimation of population size (data is not representative)
Give an exam answer on sampling habitats regarding animals
Set grid/area to be sampled
Use random numbers generated by a computer to locate the areas you will randomly sample
Pick appropriate capture method CHOSE ONE e.g. sweep nets, pooters, pitfalls etc
Identify each sp. using a key and count the numbers of each sp.
Repeat this several times in each habitat, using the same technique each time to show repeatability and identify anomalies
Extrapolate the data to estimate biodiversity in the entire habitat
Define allele/gene variant
A version of a gene
What is a locus?
The position of that gene in a chromosome
What is a polymorphic gene locus?
A locus that has more than 2 alleles
What is Simpson’s index of biodiversity and what is the equation?
A measure of diversity of a habitat
D = 1 (E(n/N)^2)
What does it mean if the answer D is closer to 1 or 0?
If D is closer to 1 - the area is more biodiverse
If D is closer to 0 - the area is less biodiverse
How do species richness and species evenness determine biodiversity?
Higher species richness + higher species evenness = higher biodiversity
Define climate change
Significant, long-lasting changes in weather patterns
What is a monoculture?
A crop consisting of one strain of one species
What are the 3 ways human activity affects biodiversity?
Human population growth
Agriculture (monoculture)
Climate change
How does human population growth decrease biodiversity?
More food and land needed -this is achieved by:
Altering ecosystems and destroying habitats,
Using up natural resources,
More energy sources and materials needed = pollution,
Over hunting/fishing
How does climate change decrease biodiversity?
Changes to temperatures and rainfall
Some species with low genetic diversity unable to adapt to climate changes
Species could migrate to areas they are more suited to
Diseases will migrate - e.g. diseases confined to warmer climates may spread to Europe
Define reproducibility
The precision of results collected by different people using equivalent equipment in different places over a wider period of time.
Define repeatability
The precision of results collected by one person with the same equipment on the same day.
Define uncertainty
An estimate of the range of values within which the true value is thought to lie. This is normally expressed e.g. 44.0 ± 0.4.
What is a keystone species?
A species that has a disproportionately large effect on its environment relative to its abundance
Define soil depletion
The loss of soil fertility caused by removal of minerals by continuous cropping
Give 2 ecological reasons to maintain biodiversity
Interdependence of organisms
Genetic resource
List 8 economic reasons to maintain biodiversity
It regulates the atmosphere and climate It purifies fresh water It forms and fertilises soil It recycles nutrients It detoxifies and recycles wastes Crop pollination Growth of timber, food and fuel It can bring about the discovery of molecules with potential as medicines
Define extinction
Where no members of a species remain and it ceases to exist
Define critically endangered
Likely to become extinct as the species numbers have become low due to man-made or natural changes in the environment
Define conservation
Maintaining biodiversity between species, genetic diversity within species and a variety of habitats and ecosystems
What are the 2 types of conservation
In situ and ex situ
Define conservation in situ
Conserving a species in its natural habitat and attempting to minimise human impact on the natural environment and protecting the natural environment.
List 8 measures to help preserve species in the wild
Ban hunting
Create protected reserves
Provide breeding sites
Prevent habitat destruction
Monitoring of species e.g. with tagging
Feeding programmes
Educate tourists on not feeding wild animals and not dropping litter etc
Promotion of ecotourism to generate money to help with preservation in case the population falls again, create sperm and egg banks
List 9 advantages of conservation in situ
Conserving species in their natural habitat
Conditions and food etc that they require for survival already present – cheaper than ex situ
Species are already well adapted to living in habitat
No special provisions need to be made
Can create protected reserves
Can ensure sustainable use of environment including land and resources
Allows for scientific research of ecosystem etc
Permanently protects biodiversity in area and whole ecosystems
Creates areas of interest for ecotourists
List 4 disadvantages of conservation in situ
There may be threats to the survival of the species in this area
e.g. predation, hunting
Human activity could threaten species in wild e.g. hunting deforestation
Disease could threaten survival of species
Species could be outcompeted by other species
What are the 3 principles when choosing a wildlife park?
Comprehensiveness - how many species are represented in the area and what are the prevailing environmental conditions?
Adequacy - is the area large enough to provide for the long-term survival of all the species, populations and communities represented?
Representativeness - is there a full range of diversity within each species and each set of environmental conditions?
Define conservation ex situ
Conserving an endangered species by activities that take place outside its normal environment
Give 3 scenarios where conservation ex situ is necessary
Natural habitat destroyed or under threat from climate change human activity e.g. deforestation
If the population in natural habitat is very low
If reproduction in the wild is difficult e.g. if numbers are low
Give 3 ways how conservation ex situ can conserve both plants and animals
Breeding ex situ can maintain genetic diversity
Allows protection from competition / grazers (plants), poachers (animals)
Allows protection from disease
List 5 advantages of conservation ex situ
Health of individuals can be monitored and treated for disease to ensure survival
Young can be hand reared which reduces mortality of young
Provision of mates for breeding can be manipulated
Protection from hunting and predation
Competition reduced between individuals
List 4 disadvantages of conservation ex situ
Expensive
Often animals don’t breed successfully due to:
captive stress, they experience altered breeding cycles, don’t have a compatible mate
Space is limited:
limiting the number of individuals kept which limits the genetic diversity, lack of genetic variation which could lead to inbreeding
Can be difficult to reintroduce species to the wild as:
the animals may become too tame and not be afraid of humans, may be unable to reintegrate into the wild population, may have difficulties finding food for themselves, may face predation, habitats may have been destroyed
List 3 important factors of seed banks
To maintain genetic diversity
To maintain plants for future or currently unknown uses
To counteract extinction or prevent inbreeding
Why is it easier to conserve plant species in seed banks?
They can be stored in huge numbers for a long period of time
List 7 advantages of using seed bank rather than adult plants to conserve endangered plant species
Most plants produce an excess So can be collected from wild without damaging wild population Take up little space Able to store large numbers Easy and cheap to transport Remaining viable for long periods Less susceptible to disease / pests
List 5 disadvantages/problems with seed banks
Collection of wild seeds may disturb environment
Collected samples may not be representative of genetic diversity of species
Seeds from one area may not survive in different area
Seeds stored for a long time may not stay viable
Asexually bred plants will have no genetic variation – reducing biodiversity
How are seeds kept viable in seed banks?
Ensure that seeds are germinated from time to time
Ensure new seeds are produced
Freeze seeds
Dehydrate seeds
How is genetic variation ensured in seed banks?
Ensure you have many seeds
Collect seeds from many areas
Ensure the seeds have a mixture of genotypes
What does CITES stand for?
Convention on International Trade un Endangered Species of wild flora and fauna
What is CITES?
An international agreement by most of the world’s governments.
Its overall aim is to ensure international trade in wildlife does not threaten their survival.
What are CITES’ aims?
Conservation of biodiversity
Regulate, monitor and prevent trade in endangered species
Ensure trade does not endanger wild populations
Prohibit commercial trade in wild plants
Allow some trade in less endangered plants and animals
Allow trade in artificially propagated plants
How does CITES help save endangered species?
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 on Biological Diversity?
An international agreement by 150 governments
Its overall aim is to promote sustainable development
It recognises human needs for food, land, medicine, clean environment as well as need for maintaining biodiversity
What are the aims for Rio Convention on Biological Diversity?
Conservation of biodiversity
Sustainable use of organisms / habitats / ecosystems
Share genetic resources
Share access to scientific knowledge
Promoting ex situ conservation methods (to complement in situ measures)
Raising profile of biodiversity with governments / general public
International cooperation on biodiversity issues
What is the Countryside Stewardship Scheme?
A scheme to encourage farmers and landowners to manage parts of their land in a way that promotes conservation.
It was introduced in 1991 and funds were given to people to help achieve this goal.
What replaced the Countryside Stewardship Scheme?
The Environmental Stewardship Scheme in 2005.
It provides funding to farmers and landowners in England to deliver effective environmental management on their land.