Organisms can be
collected using a variety
of methods, including:
Nets, Pooters, Pitfall
traps, Quadrats
capture recapture
The numbers of marked and
unmarked animals caught in the
traps are recorded. The
population size is estimated
using this formula:
Population size = Number in
first sample x number in
second sample / number in
second sample previously
marked
There is no death,
immigration or emigration
The sampling methods used
are identical The marking
has not affected the survival
rate of the animals
Biodiversity Biodiversity is the
variety of different species living
in a habitat. The greater the
number of different species in a
habitat, the greater its
biodiversity.
kite diagrams: The
distribution of
organisms in a
habitat is affected by
the presence of other
living organisms. It is
also affected by
abiotic factors
(physical factors)
such as availability of
light or water
A gradual change
in the distribution
of species across
a habitat is called
zonation