·
grade 11
paper z
, Population Studies population ecology : Part of ecology focusing on factors
influencing
population growth forms distribution of individuals
. size ,
rate ,
growth and
Logistic (S-shaped) growth form
inside a population factors
limiting transform geometric-logistic
.
·
can
O
population size :
·
↳
popu
lation total number of Individuals
size :
&
in a
population Indirect techniques
population density : number of individuals per part of the
populatiosn tai
-
unit ②
counting only
area ↳
total sample
↳ estimate population size
-
pation
parameters :
↳ Mark and Recapture
D =
MXS
~
total and sample
r W
↳
birth
Natality Populations
number of marked individuals
9) : rate ;
number of live births 1) Area is demarcated in and sample time
↳ increase
per
thousand individuals 2) Number individuals caught counted and marked (I sample)
of ⑧ population acclimatise adapt little environmental
per year , and to ⑳ · to
resistance
no
environment
3) sample I released into the environment ; given time to mix with the population
maturity Natality > mortality
↑
sexual
reaching
·
·
b) Mortality Populations : death rate ;
number of deaths 4) second sample caught and counted ; use formula to estimate size
③ .
increase in enviramental resistance population reaches
decrease thousand individuals conditions : Carrying capacityaration
do
↳
per per year ·
mig
-
closed population with short period between samples limiting effects of dis
clear markings ora
6)
Immigration :
one-way movement of organism into that do not injure organisms or affect movement
↳ increase
an area where they become established surface area of the area
number
average X
↳
Quadrats population ofindividualsa surface
of quadrant
& capitasy
size =
area
unstable population population exceeding carrying Capacity
d) Emigration frame :
known
One-way movement of wooden ·
:
out an area to · metal or
of size Im
?
.
eg
decrease
↳
become established ·
area
organisms must be counted is demarsated and surface area determined decrease an environments carrying capacity
·
process repeated a few times mmun
limiting factors
I
·
migration Seasonal
:
flunctuation
↳litwaDezdopdatfactoar
*
Closed population (eg .
fish in dam) unaffected by G & d) reliability -
exact number of organisms in each
quadrat must be known ompetition
A
·
mining Population
predation diseases
Size
·
. · surface area
of quadrat and demarcated area must be known · decrease living space and shelter
·
be placed (suited to sessive/slow
quadict must
randomly moving organisms) and predation spread of diseases
·
method determined
by mobility
· +
size and
Density Independant factors
Growth Forms mun
Mulation
-
Direct techniques : Initial slow increase · Extreme
natural
temperature
disasters
changes +
Counting total of individuals within population
↳ Census :
&
direct contact Geometric (J-shaped) growth form
counting smaller organisms/humans
-
:
-
direct contact counting from vehicles/helicopter larger organisms :
-
Counting from aerial photographs moving organisms :