Temperature
„ Populační ekologie živočichů "
Stano Pekár
E:
*xt of CO
4;
► all conditions affect population growth via controlling metabolic processes in ectotherms
► temperature, humidity, day length, pH, etc.
Universal effect of temperatare
► with respect to body temperature: cold-blooded / warm-blooded
► with respect to temperature change: poikilotherms / homoiotherms
► with respect to production of temperature: endotherms /ectotherms
► temperature affects population growth of ectotherms    Go = 2-5
- rate of metabolism increases approx. by 2.5x for every 10 °C
► physiological time - combination of time and temperature
► rate of metabolism B:      ~ e % (T.. temperature)
- rate increases with body mass (Af): ^ per mass unit ...
1/ P/
- biological time tb:        / — 71/ 4e
ikear model
► model is based on the assumption that developmental rate is a linear function of temperature T
► valid for the region of moderate temperatures (15-25°)
► at low temperatures organisms die due to coldness
D .. development time (days)
v.. rate of development = IAD
Tmin .. lower temperature limit - temperature at which
developmental rate = 0
0.045
0.04 ■
0)
"pg    0.035 -
0)
E
Q.
O
0)
>
0)
Q
0.03 -0.025 -
0.02 -0.015 ■
0.01 -0.005 ■ 0
0
10
15       20       25 30
35
Temperature
ET.. effective temperature .. developmental temperature between 7 and Tmit S.. sum of effective temperature .. number of day-degrees [°D] required to complete development
.. does not depend on temperature = D*ET
can be estimated from the regression line of v = a + bT
a + bT = 0
a
S:     S = D(T-Trrm) = D T +
b)
V
► sum of effective temperature (S) [°D] is equal to area under temperature curve restricted to the interval between current temperature (T) and Tmin
► biofix .. the date when day-degrees begin to be accumulated
mm
time, days
sis
► when development rate is a non-linear function of temperature
► ET.. developmental temperature between Tmin and T
max
► at high temperatures organisms die due to overheating
7max .. upper temperature threshold - temperature at which developmental rate = 0
	0.045 -I
	0.04 -
Q)	
CO	0.035 -
	
nt	0.03 -
	
E	0.025 -
Q.	0.02 -
O	
vel	0.015 -
0	
Q	0.01 -
	0.005 -
	0 -
Temperature
time, days
► several different non-linear models (Briere, Lactin, etc.)
► allow to estimate Tmin, Tmax and T t (optimum temperature)
► easy to interpret for experiments with constant temperature
► instead of using average day temperature, use actual temperature
Briere et al. (1999)
v = ax Tx (T — T    )x ~ T —T
V mm   '       v max
v .. rate of development (=1/D) r.. experimental temperature Tmin.. low temperature threshold Tmax.. upper temperature threshold a .. unknown parameter
Optimum temperature:
0 Tmin
j     Topt Jmax
^opt
AT   +37. +J\6T2  +9T2 -167. T
max min       V        max min min max
10
► parameters are estimated using non-linear regression
Lactin et al. (1995)
v .. rate of development
T.. experimental temperature
Tm, A, p, (f).. unknown parameters
0 7min
Tma„ and 71- can be estimated from the formula:
__,pT
0 = e
T —T CpTm—^-)
A
Topt can be estimated from the first derivative:
dv{T) = pcpT 1 dT A