2.5 Flashcards
wind speed (terrestial)
anemometer
light (terrestial)
lightmeter
flow velocity (freshwater ecosystems)
flow velocity is the speed at which the water is moving anf it determines which species can live in a certain area, it varies with; time, depth, position
flowmeter
impellers
floats
turbidity (freshwater ecosystems)
secchi disc
turbidity- the cloudiness of a body of fresh water
high turbidity- cloudy water
low turbidity - clear water
pH (freshwater ecosystems)
pH meter
datalogging pH probe
rainfall (terrestial)
rain gauge
check every 24h and record
soil (terrestial)
texture (particle size)
soil moisture
organic content
mineral and oH
quadrat sampling
map out study area and divided into squares
use random number generator to identify which squares to sample
transect
a transect is a sample path along which you record the occurrence and distribution of plants and animals in a particular study area
line transect
belt transect - two parallel line transects
salinity (marine ecosystems)
salinity is the concentration of salts expressed in %
can be determined by measuring the electrical conductivity or the density of the water
dissolved oxygen (marine)
is affected by temperature and water pollution
measured by using an oxygen-selective electrode connected to an electronic meter
wave action (marine)
in coastal zones
high wave activity means high levels of dissolved oxygen, e.g coral reefs
catching small motile animals, terrestial ecosystems
- pitfall traps
- sweep nets
- tree beating
catching small motile animals, aquatic ecosystems
kick sampling
measuring abunance
density
frequency
percentage cover
lincoln index
used to measure the population size of animals which move about or do not appear during the day
Method
capture individuals and mark them, then release and let time pass so they can mix
then take a second sample and count how many of the captured organisms are marked
at least 05 of the marked species should be recaptured for the estimate to be fairly accurate
assumptionsin lincoln index
mixing is complete
marks do not disappear
marks are not harmful or increase predation by making the individual more easily seen
it is equally easy to catch every individual
no immigration, emigration, births or deaths between the times of sampling
trapping the organisms does not affect the chances of being trapped a second time
lincoln index formulae
m2/n2 = n1/N
or
N= (n1 x n2)/ m2
where
n1 -number of animals first marked and released
n2 - number of animals captured in the second sample
m2 - number of marked animals the second sample
N - lincoln index or total population
Simpsons diversity index
D = N(N-1) / Sum of n(n-1)
D- Simpsons diversity index
N - total number of organisms of all species found
n - number of individuals of a particular species
