sampling Flashcards
What is sampling
a way to count the number of organisms in an area
used for smaller insects and mammals.
what is a quadrat
square frames of wire placed on the ground to look at plants or slow moving animals
what are quadrat’s used for
to record the number of individual species
to record the number of different species
the percentage that is covered by one species
what is random sampling
placing quadrats at random coordinates
what is a transect
used for systematic sampling when you place quatrats at at regular distances down an imaginary line
formula for estimating population
area divided by quadrats multiplied by amount
reliability means…
REPEATS! TEN OR MORE
how to use a transect
tape measure, place quadrats at same distance, along the line. count how much of what youre counting is in each quadrat
what does DICOR mean
dependent variable independent variable control organisms repeats
what is a dependent variable
data (number of what youre counting)
what is an independent variable
the thing you change
what is a controlled variable
what stays the same (weather, time of day)
what do you write about the organisms
same species? same sex? same age?
how many repeats?
10 more more
how to calculate the mean
add values together and divide by the amount of values
how to calculate the median
place numbers in ascending order, the median is the middle number in the list (cross numbers from each end until you get the middle number)
how to calculate the mode
the value that appears most often
what is biomass
living or recently dead tissues
what do pyramids of biomass look like
bars equally spaced around the midpoint
length of each bar is proportional to the amount of biomass
what do the arrows in a food chain show
the transfer of biomass from one organism to another —>
how much biomass is transferred to each trophic level
10% transferred
how is biomass lost
not all matter is digested.
some is excreted by waste, carbon dioxide, water an urine
why are food chains not often longer than 5 levels
biomass is lost so there is not enough energy for another trophic level to survive
what are pyramids of numbers and what shape are they
they show the numbers at any trophic level and can be any shape
