BIOL 3240 Plant and Animal Ecology
Temperature/Heat
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• Macroclimate: Large scale weather variation.
• Microclimate: Small scale weather variation,
usually measured over shorter time period.
– Altitude
•
– Aspect
•
– Vegetation
•
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• Ground Color
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• Boulders / Burrows
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• Specific Heat
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• 1 cal energy to heat 1 cm3 of water 1o C.
– Air - .0003 cal
• Latent Heat of Evaporation
–
• Latent Heat of Fusion
–
• Riparian Areas
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• Riparian vegetation influences stream
temperature by providing shade.
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• Biomolecular Level
–
• Low temperatures cause low reaction rates, while
excessively high temperatures destroy the shape.
– Baldwin and Hochachka studied the influence of temperature
on performance of acetylcholinesterase in rainbow trout
(Oncorhynchus mykiss).
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• Photosynthesis
–
• Different plants have different optimal temperatures.
• Acclimation: Physiological changes in response to
temperature.
Optimal Photosynthetic
Temperatures
Temperature and Microbial Activity
• Morita studied the effect of temperature on
population growth among ________________
marine bacteria around Antarctica.
– Grew fastest at 4o C.
– Some growth recorded in temperatures as cold as 5.5o C.
• Some _____________ microbes have been found
to grow best in temperatures as hot as 110o C.
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Heat Exchange
Pathways
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Balancing Heat Gain Against Heat Loss
• HS = Hm  Hcd  Hcv  Hr - He
– HS =
– Hm =
– Hcd =
– Hcv =
– Hr =
– He =
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Body Temperature Regulation
• Poikilotherms
–
• Ectotherms
–
• Endotherms
–
• Homeotherms
–
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Temperature Regulation by Plants
• Desert Plants: Must reduce heat storage.
– Hs = Hcd  Hcv  Hr
– To avoid heating, plants have (3) options:
• Decrease
• Increase
• Reduce
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Temperature Regulation
by Plants
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• Arctic and Alpine Plants
– Two main options to stay warm:
• Increase …
• Decrease …
• Tropic Alpine Plants
– Rosette plants generally retain dead leaves, which
insulate and protect the stem from freezing.
• _______________________increases leaf temperature.
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Temperature Regulation by Ectothermic Animals
• Eastern Fence Lizard (Sceloporus undulatus)
–
– Preferred temperature closely matches the
temperature at which…
–
• Grasshoppers
– Some species can adjust for ________________
by varying intensity of pigmentation during
development.
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Thermal Neutral Zones
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Temperature Regulation by
Endothermic Animals
• Swimming Muscles of Large Marine Fish
– Lateral swimming muscles of many fish (Mackerel,
Sharks, Tuna) are …
• Keep body temperature above that of surrounding
water.
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Countercurrent Heat
Exchange
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• Warming Insect Flight Muscles
– Bumblebees maintain temperature of thorax
between _______________C regardless of air
temperature.
– Sphinx moths (Manduca sexta) increase thoracic
temperature due to flight activity.
•
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Moth Circulation and
Thermoregulation
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Temperature Regulation by Thermogenic Plants
• Almost all plants are …
– Plants in family Araceae use _______________ to
heat flowers.
– Skunk Cabbage (Symplocarpus foetidus) stores
large quantities of starch in large root, and then
translocate it to the inflorescence where it is
metabolized thus generating heat.
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Eastern Skunk Cabbage
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Surviving Extreme Temperatures
• Inactivity
–
• Reducing Metabolic Rate
–
– Hibernation – Estivation -