Dynamic Energy Budget Theory - I Tânia Sousa with contributions from :Bas Kooijman

Metabolic rates: the effect of temperature Why do metabolic rates depend on temperature?

Metabolic rates: the effect of temperature Low metabolism (body temperature between 27ºC – 33ºC)

ln rate 10 4 T -1, K -1 Daphnia magna reproduction young/d ingestion 10 6 cells/h growth, d -1 aging, d -1 Metabolic rates: the effect of temperature How do metabolic rates ln k ( T ) depend on temperature?

ln rate 10 4 T -1, K -1 Daphnia magna reproduction young/d ingestion 10 6 cells/h growth, d -1 aging, d -1 Metabolic rates: the effect of temperature How do metabolic rates depend on temperature?

ln rate 10 4 T -1, K -1 Daphnia magna reproduction young/d ingestion 10 6 cells/h growth, d -1 aging, d -1 Metabolic rates: the effect of temperature How do metabolic rates depend on temperature? What is the meaning of the slope cte= T A ? Write the constant as a function of T 1 Write na expression for k(T)

ln rate 10 4 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 reproduction young/d ingestion 10 6 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., at cold temperatures the sloths become letargic 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

How do feeding power depends on temperature? Metabolic rates: the effect of temperature

Metabolic rates: the effect of temperature

All parameters that have units time -1 depend on temperature Metabolic rates: the effect of temperature

All parameters that have units time -1 depend on temperature Metabolic rates: the effect of temperature

What is the effect of temperature on dL/dt? Metabolic rates: the effect of temperature

What is the effect of temperature on dL/dt? How do the von Bertallanfy growth rate and ultimate length depend on temperature? Metabolic rates: the effect of temperature

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? Ornitorrinco na Austrália

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 lower temperatures they have a higher ultimate size because they have more food (higher reserve density) Closer to the poles you have stronger seasons. The bleak season thins populations, so reduces intra-specific competition, so more food per individual. More food means higher m_E. Ornitorrinco na Austrália

What is the effect of temperature on dL/dt? How do the von Bertallanfy growth rate and ultimate length depend on temperature? How do growth and catabolic powers depend on temperature? Metabolic rates: the effect of temperature

What is the effect of temperature on dL/dt? How do the von Bertallanfy growth rate and ultimate length depend on temperature? How do growth and catabolic powers depend on temperature? Metabolic rates: the effect of temperature

Metabolic rates: the effect of temperature All metabolic rates depend on temperature on the same way because otherwise it would be difficult for organisms to cope with changes in temperature (evolutionary principle)

Endotherms: mantain their body temperature Most mammals mantain their body mperature at 36ºC - 40ºC Most birds mantain their body temperature at 40-43ºC How? Ectotherms: have a variable temperature mostly dictated by environmental conditions Any regulation? Expected differences in metabolism? Metabolic rates: the effect of temperature

Obtain an expression for the dynamics of the reserve density m E Set dm E /dt=0 (weak homeostasis). What is the maximum value of m E ? Can you understand the meaning? What is the value for m E in weak homeostasis? Exercises

Exercises

Exercises

Exercises

Metabolic rates: the effect of temperature

Metabolic rates: the effect of temperature