3.2 distribution of organims Flashcards
where does energy used by living organisms originally come from
SUN energy is captured by plants carrying out photosynthesis these producers then provide energy for rest of organisms in food web
four examples of abiotic factors
temperature
ph
moisture
light intensity
how to measure abiotic factors
light intensity- measured using light intensity metre with a light sensor
moisture- measures using soil moisture probe which is wiped dry and then inserted into soil to take reading
soil ph- measured by either using ph probe or using universal indication solution
temp measures using a thermometer
errors of sampling abiotic factors
light intensity - eliminated is making sure that there is no accidental shadowing of a light sensor during reading
moisture- making sure that the probe is wiped dry between samples
soil ph- making sure that the probe sampling equipment is cleaned between samples
temp- ensuring that reading is given time to settle before measurement is recorded
effect of abiotic factors on biodiversity and distribution of organims
huge impact on biodiversity and distribution of organisms light intensity will be able to determine wether plants are able to carry out photosynthesis and survive in area
biotic factors
disease
food availability
grazing
predation
what is a quadrat
frame of known area eg 1msquared a quadrat is placed on the ground and used to randomly sample an area to estimate the distribution of a particular plant or slow moving animal species.
errors of using quadrat and how they can be solved
to small a sample taken - increase the number of quadrat samples used to calculate avarage value
sample taken is not representative- ensure that the quadrat sampling is done randomly to eliminate bias and ensure that sample is representative
during sampling errors can occur in terms of consistency when the
organism found under edge of frame a decision should be made to whether to count these as part of sample or not and this decision should be followed consistently for every quadrat sample
pitfall trap
set up by digging a hole place a container into soul with top of container flush with soil level. the container should then be covered over with vegetation from the surrounding area to camouflage top
errors when setting up pitfall trap and how these errors can be minimised
the pitfal trap is set flush with ground level and camouflage with surrounding vegetation to ensure that representative sample is collected
pitfall traps checked regularly- if pitfal trap is left to long before checking only predators will be collected within sample
a large number of pitfall traps are set randomly within sample area to gather representative sample of the organism in sample area
how to ensure samples are representative
RANDOM SAMPLING OF AREA to eliminate BIAS RESULTS
why edaquate replication of sampling is nesscessary
replication ei sampling a large number of times and then calculating average values increases the RELIABILITY FOR THE RESLUTS
transect line is used for
a transect line is a tape or string that is laid along the ground in a straight line between two points this line is then used as a guide for sampling to measure the distribution of organisms along the transect line
affect on biotic factors on biodiversity
huge impact on ecosystem eg disease could reduce the number of distribution of a population potentially wiping out the species and reading biodiversity
indicator species
group of organisms who’s presence and a sense indicates the environmental quality levels of pollution in an area
