4.2 BIODIVERSITY Flashcards
Define biodiversity
- a measure of variation
State and describe the three types of biodiversity
1) Habitat biodiversity (e.g sand dunes, meadows, streams, woodland)
2) Species biodiversity (species richness and species evenness)
3) Genetic biodiversity (e.g different breeds within a species)
State how biodiversity can be measured
- Sampling
State the two types of sampling
1) Random sampling
2) Non-random sampling
Describe the process of random sampling
- Sample sites inside the habitat are randomly selected
- Can be done by random number generator to determine co-ordinates
- Calculate mean population per sample
- Multiply value to the size of habitat
State two advantages of random sampling
1) Ensures the data is not bias
2) Useful if species are evenly distributed
State two disadvantages of random sampling
1) May not cover equal areas of the habitat
2) Species with a low presence may be missed leading to underestimate of biodiversity
State the three types of non-random sampling
1) Opportunistic
2) Stratified
3) Systematic
Describe the process of stratified non-random sampling
- Dividing a habitat into areas which appear different and sampling each area separately
Describe the process of systematic non-random sampling
- Samples are taken at fixed intervals across the habitat
- Using a line/belt transect
Describe the process of opportunistic non-random sampling
- Deliberately sampling areas that contain a specific species
State an advantage of opportunistic non-random sampling
- Easier/quicker than random sampling
State two disadvantages of opportunistic non-random sampling
- Bias data
- Leads to an overestimate of biodiversity
State an advantage of stratified non-random sampling
- Ensures species are not underrepresented as all different areas of habitat are sampled
State a disadvantage of stratified non-random sampling
- May lead to over-representation if disproportionate number of samples taken in small areas that look different
State an advantage of sytematic non-random sampling
- Shows a clear gradient in the habitat biodiversity based on an environmental factor
State a disadvantage of systematic non-random sampling
- Only species on the line/belt can be sampled so may lead to underestimate of biodiversity
Define sampling
- Measuring small portions of a larger population to make assumptions of the whole population
State the four instruments used to sample animals
1) Sweep nets
2) Pooter
3) Pitfall trap
4) Tullgren funnel
State the two instruments used to sample plants
1) Quadrat
2) Transect line/belt
Define allele/gene variant
- A version of a gene
Define locus
- The position of a gene on a chromosome
Define polymorphic gene locus
- A locus that has more than two alleles
State the formula for proportion of polymorphic gene loci
State what simpsons index measures
- Measures the species biodiversity of a habitat
Define species richness
- A measure of the number of different species found in a habitat
Define species evenness
- A measure of how evenly represented a species is/ relative abundance
State the five factors affecting biodiversity
1) Monoculture
2) Human population growth
3) Climate change
4) Selective breeding
5) Extinction
State three effects of human population growth on biodiversity
1) Alter ecosystems for food (e.g hunting)
2) Destroy/fragment habitats
3) Pollute the atmosphere
Define monoculture
- Agriculture of crops of one strain of one species
Pick out the two factors that affect GENETIC biodiversity
1) Monoculture
2) Selective breeding
Define climate change
- The significant, long-lasting changes in the weather patterns
Compare the postive and negative impacts of agriculture/monoculture on
✔ Agricultural ecosystems are closely monitored by humans
✘ Pesticides/man made fertilisers may exlude certain organisms (reduced species biodiversity)
✘ Farms selectively breed the more productive crops thus reducing the frequency of alleles (reduced genetic biodiveristy)
✘ Farms may only grow one crop - monoculture (reduced gentic biodiversity)
State the three reasons to maintain biodiversity
1) Ecological
2) Economical
3) Aesthetic
Describe the benefits of biodiversity
- Provides food/medicine/shelter/clothing
- Enables **nutrient cycling/soil formation
Describe the ecological benefits of maintaining biodiversity
- Maintains genetic resource (we can use for genetic engineering)
- Protects keystone species (as organisms in a habitat are interdependant)
Define keystone species
- A species that an entire ecosystem in dependant on
- The ecological niche of a keystone species is not replaceable
(e.g, a keystone species may be a predator that limits the population of herbivores so that vegitation is not overgrazed)
Explain whether higher species biodiversity or low species biodiversity is more stable for a habitat
- High species biodiveristy is more stable because if there is a sudden loss in a species then its predator can still survive by eating another species in the food web
Describe the economic benefits of maintaining biodiversity
- Less money spent on fertilisers as reduced soil depletion
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Biodiveristy provides:
1) Regulation of atmosphere/climate
2) Recycling of nutrients
3) Formation of natural fertilisers in soil
4) Growth of food and fuel
5) Used as medicines
Define soil depletion
- The loss of soil fertility caused by removed minerals that are not replaced after continuous monocuture
Describe the aesthetic benefit of maintaining biodiversity
- Pleasing, creates tourism
- Protects the landscapes
- Maintains habitat biodiversity
Define conservation in situ
- Conservation of endangered species in their natural habitat
- Attempts to minimise the human impact on the natural environment
State three ways of conservation in situ
1) Legislation
2) Wildlife reserves
3) Conservation zones
State six feautures wildlife reserves for conservation in situ
1) Protected area (from preditors)
2) Controlled grazing
3) Restricted human access
4) Controlled poaching
5) Removal of invasive species
6) Feeding animals
Describe the purpose of conservation zones
- Creates areas of refuge so that populations can replenish
Describe advantages of conservation in situ
1) Perminently protects biodiveristy
2) It facilitates scientific research
3) Maintains the genetic biodiversity and species biodiversity of a habitat
Describe disadvantages of conservation in situ
1) The conditions that caused endangerment may still be present
2) Fragmentation of habitats may be to small for survival of the endangered species
Define conservation ex situ
- Conservation of endangered species outside their natural habitat
- Attempts to remove and place them in safer areas under human control
State three ways of conservation ex situ
1) Seed banks
2) Botanic gardens
3) Zoo’s (captive breeding)
Describe how seed banks are used for conservation ex situ
- Contain samples of every seed and remain viable (dry/freezing conditions)
Describe how zoo’s (captive breeding) are used for conservation ex situ
- By breeding endangered species or freezing their sperm/egg
- Endangered species live in human controlled environement with food/shelter/no preditors/vets/breeding partners
Describe how botanic gardens are used for conservation ex situ
- Seeds are collected from the wild during their dormant stage then are germinated in protected/optimum surroundings
- They are then re-planted once fully germinated
Describe advantages of conservationex situ
1) Endangered species are protected from preditation/poaching
2) Habitat fragmentation can protect from natural disasters
3) Conservation sites can be used for education/money
4) Botanic gardens can increase plant numbers very quickly
5) Captive breeding/zoo’s can increase biodiversity
Describe disadvantages of conservationex situ
1) Captive population in zoo’s have less genetic biodiversity
2) Expensive/difficult to provide the right conditions
3) Issues with re-introduction of captive species (rejection/unexperienced)
State the aims of CITES
1) No killing of endangered species
2) Illegal to trade products from endangered species
3) Raise awareness of threats to biodiversity
State the aims of CBD
1) Develop stratergies to conserve biodiversity
2) Use plant/animal products in sustainable ways
3) Provide guidance to governments on how to conserve biodiveristy
State the aims of CSS
1) Conserve wildlife and biodiversity
2) Promote land management tehniques to land owners
