Biodiversity Flashcards
Types of biodiversity!
Habitat
Species
Genetic
2 types of species biodiversity
Species richness & evenness
Habitat biodiversity
Number of different habitats in an area
Genetic biodiversity
The variety of genes that make up a species
Species richness vs species evenness
Richness = the number of diff species in an area
Evenness = a comparison of the numbers of individuals of each species in an area
What is community
The populations of living organisms in a particular habitat
What’s sampling
Taking measurements of a limited number of individuals organisms present in a particular area
-> to measure biodiversity in an area
We can use it to
- estimate no. of organisms
- measure particular characteristics of organisms
- then you can make generalisations & assumptiond
What’s random sampling + procedure
Selecting individuals by chance
E.g. @ a grass verge
1. Mark our a grid on the grass using 2 tape measures
2. Use random numbers to determine the x-co-ordinate & the y-co-ordinate in your grid
3. Then take a sample at each of the co-ordinate pairs generated
3 ways to do. Non - random sampling
- Opportunistic
- Stratified
- Systematic
What’s opportunistic sample
Using organisms that are conveniently available. May not be representative of population, therefore weakest form of sampling
What’s stratified sampling
Dividing populations can be putting them into groups based on a particular characteristic e.g. males & females.
A random sample is then taken from each of the strata proportional to its size
What is systematic sampling + the 2 types
Different areas within an overall habitat are identified & then sampled separately. Often done using
-> a belt transect: mark 2 parallel lines & sample the area in between
-> a line transect: mark a line & take samples @ specific points
Why is it important to sample a range
More reliable
-> sample bias reduced & a larger sample size also minimises idea of chance
This also makes the sample more representative
Ways to sample animals
- Pitfall traps
- Sweep nets
- Pooter
How do use pitfall traps
How to use a pooter
Why use a sweep net
Catch insects in areas of long grass
Why do we use quadrats to sample plants
As they’re immobile
Point vs frame quadrant
Most valid & representative sample =
- random sample + quadrats along a belt / line transect
How to measure species richness
Use sampling techniques to make a list of all the species identified
How to measure species evenness
How to measure diversity
Proportion of polymorphic gene loci
Number of polymorphic gene loci / total number of loci
The greater the proportion, the greater the biodiversity within the population
Factors that affect genetic biodiversity
Factors affecting biodiversity
Factors affecting biodiversity
Reasons for maintaining biodiversity
Markscheme answer -> why maintain biodiversity for ecological aesthetic & economic reasons
What are the 2 methods of maintaining biodiversity (both are ways of conservation)
In situ & ex situ
Ex situ vs in situ
What’s ‘in situ’ & examples of it
- inside natural habitat, therefore maintains not only genetic diversity of species, but also the evolutionary adaptions
Keeps the endangered interacting, therefore independent relationships are maintained
- Wild life reserves
- Marine conservation zones
How do wildlife reserves work?
- requires active management & techniques involve:
1. Restricting human access
2. Feeding animals
3. Controlling grazing
4. Reintroduction of species
5. Removing invading species
6. Halting succsssion
How do Marine conservations work
Create areas of refuge where populations can build up & repopulate adjacent areas
How does ex-situ conservation work + examples
- normally used in conjunction with in situ
- involves removal of organisms from their natural habitat
E.g.
Botanic gardens
Seed banks
Captive breeding/Zoos
How do botanic gardens work
Provide the species with the best resources e.g. provision of soil nutrients, sufficient watering, etc
How do seed banks work
Storing the seeds (& their genetical material) so new ones can be planted way later, for reintroduction or breeding
How do zoos/captive breeding work
Producing offspring in a human controlled environment, before careful reintroduction of the species
Pros & cons of zoos & captive breeding
What are the 3 conservation agreements
CSS (COUNTRYSHIP STEWARDSHIP SCHEME)
CBD (RIO CONVENTION ON BIOLOGICAL DIVERSITY)
CITES (CONSERVATION ON INTERNATIONAL TRADE IN ENDANGERED)
What’s the CSS / Countryside stewardship scheme
1991-2014: offered governmental payments to farmers to enhance & conserve the English landscape
Specific aims e.g. sustaining beauty & diversity, improving habitats etc.
-> how replaced by the ESS which operates similarly
How does CBD : the Rio convention on biological diversity work
Requires countries to develop natural strategies on sustainable development, for the maintenance of biodiversity
How does CITES work
-> established by the IUCN
- treaty that regulates the international trade of wild plant & animal specimens & their products
- international regulation of trade over borders to safeguard from over exploitation
Over 35000 species
