biodiversity Flashcards
(26 cards)
what is random sampling ?
what are advantages of random sampling ?
each individual has an equal chance of being selected
– reduces the impacts of bias
what is non random sampling ?
sample in which individuals are not chosen by chance
give examples of non random sampling ?
opportunistic - organisms are easily available
- stratified - pop divided into subgroups
- systematic - shows how species change throughout habitat
what causes samples to be not representative ?
sampling bias - selsction of individuals to sample biased consciously and unconsiously
chance - may not be representative
what are different types of sampling techniques ?
pooter
sweep nets
pitfall traps
tree beating
kick sampling
capture mark release recapture
which sample techniques is appropriate to sample insects ?
pooter
- suction on mouthpiece - draws insects into chamber
- piece of gauze /filter prevents insects entering the mouth .
what is sweep nets used for ?
to sample insects
- nets is swept through long grass
Control;
size of nets
how often / fast sweep
what sample technique is used for small invertebrates ?
pitfall traps
- dig hole in the ground
-place container in the hole -insects falls into the trap
- cover the top with a roof to prevent flooding
- leave it overnight to smaple nocturnal insects
what is tree beating used for
for invertebrates in trees /bushes
- stretch white cloth underneath
shake the tree bushes /beat with a stick to dislodge invertebrates
what sample technique is used for organisms living in a water ?
- kick sampling
river bed is distrubed by kicking it - place net in downstream so the water and distrubed bed flows through net
what sample technique is used to estimate the size of animals population ?
capture mark release recapture
- capture individuals in an area
- mark organism and release #
- allow animals to disperse
recapture individuals marked and others
- compare the number of marked and unmarked individual
estimate population size
how are plants sampled
- using a quadrant
what is point quadrat ?
frame with a horizontal bar and pins
plants touching pins are recorded
what is a frame quadrat ?
frame that is divided into equal sections
give limitations of using quadrats ?
can only be used for immobile species e.g plants
- hard to be consistency in counting number of species
-
what is biodiversity ?
the variety of living organism present in an area measured by the number of habitats , the number of species and amount of gentic diversity .
how is biodiversity measured ?
habitat bidoversity
species biodiversity
genetic biodiversity
what is habitat biodiveristy ?
the number of different habitat found within an rea e.g grassland , medows
what is species richness?
the number of diffrerent species ;iving in a particular area
species eveness ?
the number of individuals of each species living
what are factors affecting biodiversity ?
deforestation
agriculture
climate change
why is important to maintain biodiversity
Aesthetic
economic
ethical
ecological
what are methods of maintaining biodiversity ?
In situ - conservation inside a natural habitat
ex situ - outside a natural habitat
