dynamic energy budget theory - v
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Dynamic Energy Budget Theory - V. Tânia Sousa with contributions from :Bas Kooijman. The Arrhenius relationship has good empirical support - PowerPoint PPT PresentationTRANSCRIPT
Dynamic Energy Budget Theory - V
Tânia Sousa with contributions from : Bas Kooijman
K 293K; 6400
}exp{)(
1
11
TTTT
TTkTk
A
AA ln ra
te
104 T-1, K-1
Daphnia magna
Metabolic rates: the effect of temperature
The Arrhenius relationship has good empirical support The Arrhenius temperature is given by minus the slope:
the higher the Arrhenius temperature the more sensitive organisms are to changes in temperature
reproductionyoung/d
ingestion106 cells/h
growth, d-1
aging, d-1
Arrhenius relationship:
The Arrhenius relationship is valid in the
temperature tolerance range At temperatures too high the organism usually dies At temperatures too low the rates are usually
lower than predicted by the Arrhenius relationship, e.g., the black bears spend the winter months in a state of hibernation. Their body temperatures drop, theirmetabolic rate is reduced, and they sleep for long periods.
Many extinctions are tought to be related with to changes in temperature late Pleistocene, 40,000 to 10,000 years
ago, North America lost over 50 percent of its large mammal species. These species include mammoths, mastodons, giant ground sloths, among many others.
Metabolic rates: temperature range
All parameters that have units time-1 depend
on temperature
Metabolic rates: the effect of temperature
Exercise: do all metabolic rates depend on temperature on the same way? Yes, because otherwise it would be difficult for organisms
to cope with changes in temperature (evolutionary principle)
�̇�
Xm Xm 11exp A Ap p T T T T
Am Am 11exp A Ap p T T T T
11expT T A Ap p T T T T
11expM M A Ap p T T T T
1 1expJ J A Ak k T T T T
1 1exp A Av v T T T T
What is the effect of temperature on dL/dt?
How does the von Bertallanfy growth rate depends on temperature?
Does ultimate length depends on temperature?
Metabolic rates: the effect of temperature
𝑑𝐿𝑑𝑡 =1
3𝑘𝑚𝐸 �̇� [𝑀𝑉 ]− [ �̇� 𝐸𝑀 ]𝐿− { �̇�𝐸𝑇 }
𝑘𝑚𝐸 [𝑀𝑉 ]+[𝑀𝑉 ] 𝑦𝐸𝑉
�̇� 𝐵=[ �̇� 𝐸𝑀 ]
3 [𝑀𝑉 ]𝑚𝐸+3 [𝑀𝑉 ]𝑦𝐸𝑉
Von Bertalanffy growth: the effect of temperature
The von Bertallanffy growth rate increases with temperature
The ultimate length does not change with temperature
Length, mm
Age, d
Arrhenius
1T
BrlogK6400AT
DEB prediction: ultimate
size does not depend on temperature
Lei de Bergmann: numa espécie que tenha uma distribuição que se extenda ao longo de diferentes latitudes as espécies com maior tamanho e mais pesadas estão junto dos polos
Lei de Bergmann (1847)
How can we explain this rule using DEB theory? At a higher temperature the organism has a higher maximum
ingestion rate which means that to the same absolute amount of food in the environment corresponds a lower f(x)
Ultimate size is proportional to mE (which is equal to f(X)) implying that for the same absolute amounts of food the organism reaches a smaller ultimate length in higher temperatures
Ornitorrinco na Austrália
Two aspects of shape are relevant for
energetics: surface areas (acquisition processes) and volume (maintenance processes)
Shape defines how these measures relate to each other
An individual that does not change in shape during growth is na isomorph, e.g., surface area is proportional to volume2/3
Prove that in an isomorph:
Energetics: the importance of shape
𝐴1
𝐴2=𝐿1
2
𝐿22
𝑉 1
𝑉 2=𝐿1
3
𝐿23
Isomorph: surface area proportional to
volume2
V0-morph: surface area proportional to volume0
the dinoflagelate Ceratium with a rigid cell wall V1-morph: surface area proportional to
volume1
The cyanobacterial colony Merismopedia
Change in body shape
Chorthippus biguttulus Psammechinus miliaris
To judge weather or not an organism is isomorphic,
we need to compare shapes at different sizes. All shapes can grow isomorphically
Are these organisms isomorphic? Sphere with an increasing diameter:
Rectangle with constant width and high and an increasing length:
Energetics: the importance of shape
In the DEB model equation the surfaceV2/3 (the
isomorphic surface area) should be replaced by the real surface area = Where is the shape correction function volume
Prove that for: Isomorph: V0-morph: where vd is the volume at which the
surface area is equal to the surface area of an isomorph
V1-morph:
Shape correction function
𝑀 (𝑉 )=surface area / isomorphic surface area
Physical length
where is the volumetric length and the shape coefficient
What are the shape coefficients of a sphere with a diameter of and a cube with length ?
Physical volume Wet weight
Measurements vs. DEB variables
𝐿=𝑉 1 /3=𝑀 𝐿𝑤
𝑉 𝑤=𝑉 +(𝐸+𝐸𝑅)𝑤𝐸
𝑑𝐸𝐸
𝑊𝑤=𝑑𝑉𝑉+ (𝐸+𝐸𝑅)𝑤𝐸
𝐸
Scales of life: the importance of size
Life span10log a
Volume10log m3
earth
whale
bacterium
water molecule
life on earth
whale
bacteriumATP molecule
30
20
10
0
-10
-20
-30
Scales of life: the importance of
size Specific oxygen consumption decreases with
body weigth in mammals
Life-span increases with weigth in mammals
Differences between species are reduced to differences
between parameters values Scaling relationships: the parameter values tend to co-
vary across species Constant Primary Parameters: There are parameters
that are similar across (related) species because they characterize biochemical processes that are similar across species: Cells of equal size have similar growth, maintenance and
maturation costs, i.e., are similar Energy partioning of energy mobilized from reserves is
done at the level of somatic and reproductive cells, i.e., is similar
Two individuals of different but related species with the same size and reserve density have similar metabolic needs, i.e., is similar
Scaling Relations I
Empirical support: Cells are very similar independent of size of the organism
Differences between species are reduced to differences
between parameters values Scaling relationships: the parameter values tend to co-
vary across species Design Primary Parameters: There are parameters that
are similar across (related) species because they characterize biochemical processes that are similar across species: Cells of equal size have similar specific maturation
thresholds, i.e., and are proportional to Lm3.
How do the following parameters vary across related species?
mEm
Scaling Relations II
- maximum length- maximum reserve density
Interspecies comparisons are done for:
Fully grown organism Abundant food f(X)=1 Null heating length LT=0
The relationship between maximum sizes is the zoom factor:
Differences between intra and terspecies comparisons:
Inter vs. Intra species comparisons
Primary parameters standard DEB model
Kooijman 1986J. Theor. Biol. 121: 269-282