Biodiversity Flashcards
Define biodiversity
The variety of living organisms in an area
Define species
A group of similar organisms able to reproduce to give fertile offspring
Define habitat
The area inhabited by a species. Including physical factors eg soil and temperature or biotic factors eg food availability or predators
Define habitat diversity
The number of different habitats in an area
Define species diversity
The number of different species and the abundance of each in an area
Define species diversity
The number of different species and the abundance of each in an area
Define genetic diversity
The variation of alleles within a species
What is the process of sampling
1) Choose and area to sample
2) Count the number of individuals of each species
3) Repeat the process as many times needed
4) Use the results to estimate the total number of individuals or different species
How to complete random sampling
Use a random number generator to select coordinates along a tape measure
What are the three types of non random sampling
Systematic
Opportunistic
Stratified
What is systematic sampling
Samples are taken at fixed intervals along a line such a quadrats
What is opportunistic sampling
Samples are chosen by the investigator. It is simple but often biased
What is opportunistic sampling
Samples are chosen by the investigator. It is simple but often biased
What is stratified sampling
Different areas in a habitat are identified and sampled separately in proportion to their part of the habitat as a whole.
What is species richness
The number of different species in an area. The higher the number of species the greater the species richness.
How is species richness measured
By taking random samples of a habitat and counting the number of different species
What is species evenness
A measure of the relative abundance of each species in an area. The more similar the population size of each species, the greater the species evenness.
How is species evenness measured
By taking random samples of a habitat, and counting the number of individuals of each species
How is diversity measured
Simpson’s Index of Diversity
How to calculate Simpson’s Index of Diversity
D = 1 - (sum of (n/N) ^2)
Where:
n = total number of individuals of one species
N = Total number of organisms of all species
What is Polymorphism
A locus that has two or more alleles
How can you measure genetic diversity
Calculating the proportion of polymorphic gene loci. This can be done by:
number of polymorphic gene loci / total number of loci
What factors affect global biodiversity
Human population growth, increased use of monoculture in Agriculture, climate change
What factors does human population growth involve
Habitat loss - human development
Over-explotation - greater demand for resources so are used up before being replenished
Urbanization - isolate species due to major developments and lead to inbreeding
Pollution - destroy habitats or kill species
Why is the increased use of monoculture in agriculture damaging to biodiversity
Habitats are lost for land
Local and naturally occuring plants and animals are seen as weeds and pests so are destroyed
Heritage (traditional) varieties of crops are lost because they don’t make enough money and so are not planted any more, reducing species diversity
How does climate change affect biodiversity
Most species need a particular climate to survive
A change means an area that was previously inhabitable becomes uninhabitable and vice versa. Forcing changes in species levels and some species may be forced to migrate. This then changes species distribution and decrease biodiversity.
Why does biodiversity need to be maintained
To protect species including keystone species
To maintain genetic resources
To reduce soil depletion
Aesthetically pleasing
How can protecting species including keystone species help to maintain biodiversity
Stops:
Disruption of food chains
Disruption of nutrient cycles
What are keystone species
Species in an ecosystem depend and without which the ecosystem would change dramatically
Why does genetic resources need to maintained for biodiversity
They provide us with everyday products such as food and drink, clothing, drugs and fuels. And are very important to the global economy.
Allow us to adapt to changes in the environment. This is such as having a drought-resistant crop.
What are genetic resources
Any plant, animal or microorganism containing genes that we find valuable
How does reduction of soil depletion help maintain biodiversity
The economic costs of soil depletion include increased spending on fertilizers and decreased yields
Why should biodiversity be maintained for aesthetic reasons
Provide pleasant and attractive landscapes that people can enjoy
There are more visitors and has economic attractions
What is in situ conservation
Means on site conservation - protecting species in their natural habitat
Methods of in situ conservation
Establishing protected areas such as national parks and wildlife reserves by restricting urban and industrial development and farming
Controlling or preventing the introduction of species that threaten local biodiversity
Protecting habitats so organisms can continue to live
Promoting particular species such as protecting food sources
Giving legal protection to endangered species
What is one advantage of in situ conservation
Both the species and their habitat are conserved. Large populations can be protected and it’s less disruptive than removing organisms from their habitats.
What is the disadvantage of in situ conservation
It can be difficult to control some factors that are threatening a species.
What is ex situ conservation
Off site conservation involving protecting a species by removing part of the population from a threatened habitat and placing it in a new location.
Methods of ex situ conservation
Relocating an organism to a safer area
Breeding organisms in captivity then reintroducing them to the wild
Endangered plant species and those extinct in the wild can be grown in botanic gardens before being reintroduced to habitats.
Seed banks to help store and freeze seeds in need if natural reserves are destroyed
Advantages of ex situ conservation
It can be used to protect individual animals in a controlled environment
Can be used to reintroduce species that have left an area
Disadvantages of ex situ conservation
Only a small number of individuals can be cared for
Can be difficult and expensive for the right environment
Many species cannot breed successfully in captivity
What are international cooperation examples
Rio Convention on Biological Diversity
CITES Agreement
An example of a local conservation agreement
The Country Stewardship Scheme
