How does temperature impact living things

1
Lecture 06Temperature Relations

• How does temperature impact living things?
• Competitive survival w/i a particular environment
• Geographical range limits
• Ability to (adaptations related to)
• Carry out vital biochemical processes
• Survive extremes of temperature
• Psychrophilic
• thermophilic
• Ability to reproduce

2

• Metabolic theory of Ecology
• Within physiologic range of adaptation rate of
  metabolic processes relate directly to ambient
  temperature (measure as O2 consumption)
• Q10 rate at temp.a
• rate at temp. a10

3
(No Transcript)
4

• Temperature optima
• Mesophiles optimal growth 20-45C
• Thermophilic adapted to high temperature
• Psychrophilic adapted to cold environment
• Acclimation physiologic adaptations
• Physiological change

5

• Plant adaptations
• Photosynthetic rate optimized
• Factors affecting internal leaf temperature
• Leaf shape
• Leaf coloration
• Ability to develop antifreeze compounds
  (glycoproteins)

6
Growth Habit and Color Arctic Plants
7

• Coloration and Architecture Bright, Hot
  Environments
• Grey coloration increases reflection
• Hairs shade, modify environment at leaf surface
  by altering air circulation

8
(No Transcript)
9

• Animals Regulation of Body Temperature
• Body heat heat of metabolic activities /- head
  gained/lost from various sources
• Poikilotherms organisms whose body temp. varies
  with environmental temperatures
• Ectotherms absorb heat from environment
• Homeotherms maintain constant body
  temperature
• Endotherms internal energy/activities regulate

heat gained/lost from various sources
heat of metabolic activities
Body heat
/-
10

• Poikilotherms
• Metabolic activity increases with
  temperature/limited by ambient conditions
• Operative temperature range temps of max.
  activity
• May possess alternate forms of critical enzymes
  with diff. temp. optima
• Behavioral adaptations
• Seek microclimate
• In cold marine environments
• Development of antifreeze compounds
• Counter-current circulatory system maintains
  functional temperature of swim muscles

11
(No Transcript)
12

• Acetylcholinesterase in a Poikilotherm Rainbow
  Trout
• Degrades acetylcholine neurotransmitter
• Two forms
• 2 C - winter form
• 17 C summer form

13

• Counter-current heat exchange Poikilotherm
• Thermo-regulation of swim muscle in Tuna and
  Sharks
• Warm blood leaving muscles warms blood entering

14

• Homeotherms
• Metabolic activity provides heat energy
• Control via hypothalamus/pituitary homeostasis
• Metabolically expensive!
• Strategies to prevent heat loss
• High metabolic rate
• Insulation
• Countercurrent heat exchange
• Survival of food unavailability
• Storage in body fat
• Torpor/hibernation

15

• Bird on Ice thermal regulation via heat exchange
• Blood entering feet warms blood returning
• Other mechanisms
• Cutaneous circulation reduced with cold temps

16

• Torpor esp in small creatures
• Enter torpor if food unavailable
• Torpor ? low metabolic rate, even at high temps

17

• Thermoneutral Zone Temperature range over which
  metabolic rate does not change
• Maintenance of body temperature comes with a
  metabolic cost ability to survive and reproduce
  various environments

18

• Reproduction and Temperature Impact on fitness
• Wedge tailed shearwater nesting success

19

• Seed germination and temperature
• Optimal temp.
• Minimal days to emergence
• http//tomclothier.hort.net/page11.html

20

• Disease and temperature
• Development of Trichostongylus retortaeformis in
  rabbit as a function of temperature
• http//www.ciesin.org/docs/001-364/001-364.html

21

• Climatic changes influence distribution of
  species
• Mass extinctions associated with glaciations
• Documented changes in range of species associated
  with global warming