„Populační ekologie živočichů !í
Stano Pekár
evropský
SOC'a,nL 1 MINISTERSTVO ŠKOLSTVÍ,
TOnd V CR     EVROPSKÁ UNIE       MLÁDEŽE A TĚLOVÝCHOVY
TTT,
OP Vzdělávání pro konkurenceschopnost
INVESTICE DO ROZVOJE VZDĚLÁVÁNÍ
Linear model
► model is based on the assumption that development rate is a linear function of temperature
► valid for the region of moderate temperatures (15-25°)
► at low temperatures organisms die due to coldness, and at high temperatures organisms die due to overheating
D .. development time (days) v .. rate of development = 1/D tmin .. lower temperature limit - temperature at which
development rate = 0
0)
H—>
(0 s_
H—>
c
0)
E
Q.
O
0)
>
0) Q
0.045
0.04 0.035
0.03 0.025 ]
0.02 0.015
0.01 0.005 0
0
10
20
30
40
Temperature
mm
ET.. effective temperature .. developmental temperature between tmax and tm-S .. sum of effective temperature .. number of degree-days [°D] required to complete development
.. does not depend on temperature = D*ET
tmin and S can be estimated from the regression line of v = a + bt
t
mm *
a + bt:„ = 0 ^=>
mm
^min ,
b
S:
S = D(t-tmm) = D
t + — b
V
J
► sum of effective temperature (S) [°D] is equal to area under temperature curve restricted to the interval between current temperature if) and tmin
► biofix .. the date when degree-days begin to be accumulated
time, days
i=i
► for temperatures between tmin and t    (upper threshold)
mm
time, days
► several different non-linear models (Briere, Lactin, etc.)
► allow to estimate tmin, tmSiX and topt (optimum temperature)
► easy to interpret for experiments with constant temperature
► instead of using average temperature, use actual temperature because below and above ET model is non-linear
Briere et al. (1999)
v = axtxit-t^ )x^max -t
v .. rate of development (=11 D) t.. experimental temperature tmin.. low temperature threshold tmSiX.. upper temperature threshold a .. constant
Optimum temperature:
► parameters are estimated using non-linear regression
Lactin et al. (1995)
v .. rate of development
t.. experimental temperature
t , A, p, <f>.. constants
tmaY and t- can be estimated from the formula:
iiiaX mm
0 = e pt - e
topt can be estimated from the first derivative:
—y—= nep!--e
dt A