Biodiversity

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ellawolfe
Flashcards by ellawolfe, updated more than 1 year ago
ellawolfe
Created by ellawolfe over 10 years ago
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Question Answer
habitat the place where an organism lives including the non living factors aswell as the other species that live there
species a group of organisms whose members are similar to one another and can interbreed to produce fertile offspring
biodiversity the number and range of different species to be found in the world, the genes they carry and the habitats in which they live
habitat diversity the number of different habitats in an area
species diversity the number of different species and the abundance of each species in an area
genetic diversity the variation of different alleles within a species
what is the abundance referring to? the number of species
what is the distribution referring to? where the species are found in a habitat
why must sampling be random to ensure the data collected is representative
why must species be identified using a key? to ensure accuracy
2 reasons why only a small part of the habitat is sampled 1)saves time and energy 2)minimise damage done to habitat by taking measurements
how would you go about measuring the distribution of plants- give one advantage and one disadvantage of this method -line transect -random starting point -pull line across habitat - all species touching line identified and recorded -ad=immediate impression disad- results are qualitative
what are the conditions required for measuring the abundance of a plant species with random sampling uniform abiotic conditions
how would you go about measuring the abundance of a plant species in a habitat -random sampling grid up area assign coordinates generate random coords using a table of random numbers place 0.5m2 quadrat on said co ge cords - at least 15 quadrats placed in 5 different areas must be placed -percentage cover is estimated by the number of squares it appears in -quantitative results
what conditions are necessary for measuring abundance of a plant species using a belt transect changing abiotic conditions
how would a belt transect be used to sample plants a line is stretched across a habitat from a random starting point frame quadrats are placed at regular intervals along the line (every 1m) and percentage cover of plants is measured.
how would you make a belt transect more reliable? several transects should be placed parallel to one another (at least 5)
how may the abundance of flying animals be sampled? sweep netting and pooter animals are counted and released light trap
3 ways to sample the distrution of land bound animals binoculars tullgren funnel pitfall traps
why are tullgren funnels used? can be used to force organisms out of leaf litter without having to touch them so they can be counted more easily
what method could you use to prevent counting the same animal twice and how does it work mark release recapture method mark using harmless uv paint
how would you estimate the population trapped after 2 captures? count from capture 1 x capture 2 -------------------------------- number of marked in second capture
species richness the number of different species present in a habitat
species evenness a measure of the relative abundance of individuals in each species
with regards to species evenness and richness, what type of habitat is the most biodiverse one with a high species richness and a high species evenness
what is simpsons index of biodiversity? a formula used to measure the diversity of a habitat.. it considers both richness and evenness
what does n stand for in simpsons index of diversity the number of individuals of a particular species.. for a plant this is percentage cover
what does N stand for in simpson index of diversity the total number of all individuals of all species
how would you work out simpsons index of diversity n -> n/N -> (n/N)^2 sum of all (n/N)^2 take this from 1
what does a high value of the simpsons index imply? high biodiversity, stable habitat- no species dominates habitat- stable food web- extinction unlikely to occur
what does a low value for simpsons index imply? not biodiverse- one species dominates- food web is unstable- a change in an environmental factor (eg disease) could cause the extinction of a species from an area
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