Biodiversity Flashcards
Define abiotic factors
Non-living conditions in a habitat
Define belt transect
Two parallel lines are marked along the ground and samples are taken out of the area at specified points
Define biodiversity
The variety of living organisms present in an area
Define species
The smallest and most specific taxonomic group
Define Succession
The progressive replacement of one dominant type of species or community by another in an ecosystem, until a stable climax community is established.
Define intraspecific variation
The differences between organisms of the same species
Define interspecific varation
The difference between organisms of different species
Define monoculture
The cultivation of a single crop in a given area
Define normal distribution curve
The bell-shaped curve that results from plotting continuous variation data on a graph
Define correlation coefficient
Statistical test used to consider the relationship between two sets of data
Define keystone species
Species which are essential for maintaining biodiversity-they have a disproportionately large effect on their environment relative to their abundance
Define stratified sampling strategy
Populations are divided into strata based on a particular characteristic
A random sample is then taken from each of the strata proportional to its size
Define random sampling
Sampling where each individual in the population has an equal likelihood of selection
Define kingdom
The second biggest and broadest taxonomic group
Define autotrophic
Organisms that acquire nutrients by photosynthesis
Define genetic bottleneck
When large numbers of a population die prior to reproducing leading to reduced genetic biodiversity within the population
Define mutation
A change in the genetic material of an organism which may affect the phenotype of an organism
Define community
All populations of living organisms in a particular habitat
What is the founder effect?
When a few individuals of a species colonise a new area, their offspring initially experience a loss in genetic variation and rare alleles become much more common within the population
Define discontinuous variation
A characteristic that can only result in certain discrete values
Give an example of discontinuous variation
Blood type
Define continuous variation
A characteristic that can take any value within a range
Give an example of continuous variation
Height
Weight
Define divergent evolution
Species diverge over time into two different species, resulting in a new species becoming less like the original one
What is ex situ conversation?
Conservation methods out of the natural habitat
What is a seed bank?
A store of genetic material from plants in the form of seeds
Define gene flow
When alleles are transferred from one population to another by interbreeding
Define natural selection
The process by which organisms best suited to their environment survive and reproduce, passing on their characteristics to their offspring via their genes
Define ecosystem
All the interacting living organisms and non-living conditions in an area
Define habitat
The natural environment of an organism
Define population
The number of organisms of the same species living in a particular geographic area
What are the 3 types of biodiversity?
- habitat
- species
- genetic
What is habitat biodiversity?
The number of different habitats
What is species biodiversity?
The number of species and the abundance of each species in a particular location
What is genetic biodiversity?
The total number of genetic characteristics in the genetic make-up of a species
What is sampling?
The process of collecting data in a suitable way
Why is sampling important?
- means data is representative is as it can be
- makes data collection more manageable
What is random sampling?
Each individual in the population has an equal likelihood of selection
What is non-random sampling?
An alternative sampling method where the sample is not chosen at random
How could an area be randomly sampled?
- a grid could be laid out using two tape measures
- a random number generator is used to generate a grid reference
- a quadrat is placed at the grid reference
- a sample is collected
What are the 3 main non-random sampling techniques?
- opportunistic (pragmatic)
- stratified
- systematic
What is opportunistic sampling?
Sampling which uses organisms conveniently avaliable
What is stratified sampling?
- some populations can be divided into distinct groups
- a random sample is then taken from each of these groups proportional to its size
What is systematic sampling?
Samples are taken at regular intervals
What is a frame quadrat?
A frame quadrat consists of a square frame divided into a grid of equal sections
What is a point quadrat?
a point quadrat consists of a frame containing a horizontal bar, pins can be pushed down at set intervals to reach the ground. The plant which the pin touches is what is recorded
What is a line transect?
A line is marked along the ground between two points and samples are taken at specified points
What is a belt transect?
Two parallel lines are marked and samples are taken of the area between the two lines
What is an interrupted belt transect?
A transect is marked out and frame quadrats are placed at regular intervals along the transect
When would systematic sampling be useful?
When studying how biodiversity changes along an area
When would random sampling be useful?
If the study is only looking at biodiversity in one area
Give 5 methods of sampling animals
- using pooters
- sweep nets
- pitfall trap
- tree beating
- kick sampling
What kind of animals are sampled using a pooter?
Small insects
What kind of animals are sampled using sweep nets
Insects, particularly those that live in long grassland
What kind of animals are sampled using pitfall traps?
Small crawling invertebrates
What kind of animals are sampled using tree beating?
Invertebrates which live in trees/bushes
What kind of animals are sampled using kick sampling?
Animals which inhabit river beds
Describe how pooters can be used to sample animals
By sucking on a mouthpiece insects are drawn into the holding chamber
Describe how pitfall traps can be used to sample animals
- a hole is dug and insects fall in
- this is left overnight so nocturnal species are also sampled
Why must a pitfall trap have a roof structure?
To prevent the hole filling with rainwater
Describe how tree beating can be used to sample animals
- a large white cloth is stretched out under the tree
- the tree is then shaken/beaten
- animals fall onto the sheet where they can be collected
Describe how kick sampling can be used to sample animals
- the riverbank and bed are kicked to disturb substrate
- a net is held downstream to capture organisms that have been disturbed
Give the 2 ways plants can be sampled
- frame quadrats
- point quadrats
Define biotic factor
The living components of an ecosystem
Give 3 ways frame quadrats can be used to sample plants
Frame quadrats can be used to generate data on:
- density
- % cover
- frequency
What is used to measure wind?
Anemometer
What is used to measure Oxygen content in water
Dissolved O2 probe
Why would a temperature probe linked to a data logger be advantageous over a thermometer?
- rapid changes can be detected
- human error in taking reading reduced
- high degree of precision can be achieved
- data can be stored and tracked on a computer
What are the 2 ways of measuring biodiversity?
- Species richness
- Species evenness
What is species richness?
A measure of the number of different species living in an area
What is species evenness?
How close in number the populations of each species in an environment are
What information is required to determine species evenness?
Number of each species in an area
What information is required to determine species richness?
Total number of species present
How can population size of a plant population be estimated?
Through the use of frame quadrats to find density or frequency
How can the size of an animal population be determined?
Mark-release-recapture
Outline the process of mark-release-recapture
- organisms are captured and marked with a non-toxic marking
- time is allowed for organisms to redistribute
- the organisms are recaptured and the number of marked animals is compared to the number of unmarked animals
What is the relationship between diversity of an ecosystem and stability of the ecosystem?
Greater the species diversity, the greater the stability of an ecosystem (usually)
What is the usual effect of pollution on biodiversity?
Pollution usually reduces biodiversity
Why can low species diversity indicate pollution is present?
Pollution usually results in harsh conditions, so few species tend to dominate, and biodiversity is reduced
What is Simpson’s index of diversity?
A measurement of biodiversity which takes into account both species richness and species evenness
What is the range of values for Simpson’s biodiversity index?
Simpson’s biodiversity index always results in a value between 0 and 1
What does a higher result of Simpson’s diversity index indicate?
A more diverse habitat. The higher the value of Simpson’s diversity index, the more diverse the habitat
What are the features of an area with low biodiversity?
- relatively few successful species
- stressful and/or extreme conditions
- few species live in habitat and those which do have very specific adaptations
- relatively simple food webs
- change to whole ecosystem has major effects
What are the features of an area with high biodiversity?
- a large number of successful species
- relatively benign/not stressful conditions
- many species live in the habitat
- complex food webs
- often relatively small effect on ecosystem if there is a change to ecosystem
What is the effect of greater genetic biodiversity on the survival of a species?
Greater genetic biodiversity increase the change of the long term survival of a species
Why does greater genetic biodiversity increase the chance of long term survival for a species?
- better able to adapt to changes in their environment
- there are likely to be some organisms within the population that carry an advantageous allele
- which enables them to survive in the altered conditions
How can genetic diversity of a population be increased?
- mutations in DNA of an organism
- interbreeding between different populations (gene flow)
How can genetic biodiversity of a population be decreased?
- selective breeding
- captive breeding
- natural selection
- genetic bottleneck
- genetic drift
How does deforestation reduce biodiversity?
- reduces the number of animal species in an area as it destroys their habitat
- food sources are reduced/removed
- animals are forced to migrate to other areas
Give 3 ways human have reduced biodiversity
- deforestation
- agriculture
- climate change
How does removal of hedgerows reduce biodiversity?
- reduces number of plant species in an area
- destroys habitat for animals
- reduces/removes food sources
Give 3 ways agriculture reduces biodiversity
- removals of hedgerows
- monoculture
- use of pesticides and herbicides
What is monoculture?
The farming technique where only one crop is grown
What is global warming?
A gradual increase in overall temperature of the earth due to pollutants released and the greenhouse effect
What is climate change?
A change in global or regional climate patterns due to increasing levels of CO2 in the atmosphere produced by use of fossil fuels
Give 4 ways climate change will reduce biodiversity
- rising sea levels flood low lying land
- insect life cycles and population would change
- saltwater would flow further up rivers
- in some areas rainfall would lower
What are the 3 categories of reasons for maintaining biodiversity?
- ecological
- aesthetic
- economic
Give an ecological reason why biodiversity should be maintained
-all organisms are interdependent on others for survival, removal of one species may have significant effect on others
Give 2 aesthetic reasons why biodiversity should be maintained
- natural world provides inspiration for people
- studies have shown that patients recover more quickly when supported by the natural environment
Give 4 economic reasons why biodiversity should be maintained
- species with potential economic importance may become extinct before they are discovered
- continuous monoculture depletes soil of nutrients and so makes the ecosystem more fragile
- greater biodiversity means greater potential for the manufacture of different products in the future
- high biodiversity provides protection against abiotic stress factors and disease
Define invasive species
An organism that is not native to an area and has negative effects on the economy, environment, or health
Describe the role of marine conservation zones in maintaining biodiversity
- vital in protecting species rich areas e.g. coral reefs
- doesn’t prevent fisherman in the area
- creates area of refuge within which populations can build and repopulate adjacent areas
What is a downside of marine conservation zones?
Large areas are required
How are seeds stored in a seed bank?
The seeds are dried and stored at -20 degrees
Give 4 examples of active management of wildlife reserves
- controlled grazing
- restricting human access
- controlling poaching
- culling/removal of invasive species
Give 2 examples of in situ conservation
- marine nature reserves
- land nature reserves
Give 3 examples of ex situ conservation
- seed banks
- botanic gardens
- captive breeding programmes
Why are seed banks used?
- seeds stored so new plants may be grown in the future
- stores seeds for reintroduction and research for breeding and genetic engineering in the future
Give a problem with seed banks
Not all seeds are still viable after being frozen
What are captive breeding programmes?
Offspring of endangered species are bred in a human controlled environment
How do captive breeding programmes try to maintain genetic diversity?
- an international catalogue of individuals’ genealogical data is maintained
- mating can be arranged to ensure genetic diversity is maximised
Why might some captively bred organisms not be able to be released into the wild?
- loss of resistance to local diseases
- learned behaviour
- genetic make-up of captive animals can become so different to original population they cannot interbreed
- natural habitat must be restored before populations are introduced
Give an advantage of in situ conservation
It enables a species to adapt continually to changing environmental conditions
Give a disadvantage of ex situ conservation
It is very expensive, more expensive than in situ conservation
What does IUCN stand for?
International union for conservation of nature
What does the IUCN do?
- assist in securing agreements between nations
- publishes the red list showing status of threatened animals
What does CITES stand for?
Convention on international trade in endangered species
What does CITES do?
-regulates international trade of wild plants and animals and their products
What was the Rio convention?
A meeting between 172 nations about how to maintain biodiversity
Give 2 examples of agreements the Rio convention resulted in
- CBD
- UNCCD
What does CBD stand for?
Convention on biological diversity
What does UNCCD stand for?
United nations convention to combat desertification
Give an example of a UK based conservation scheme
Countryside stewardship scheme
Outline the countryside stewardship scheme
- governmental payments offered to farmers to enhance and conserve the English landscape
- restoring neglected land
- local conservation schemes
