Chapter 4
鄭先祐 (Ayo)
靜宜大學 生態學系
Ayo 台南站： http://mail.nutn.edu.tw/~hycheng/
Email add: Japalura@hotmail.com
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Outline
Microclimates ( 微氣候 )
Aquatic Temperatures ( 水域溫度 )
Temperature and Animal Performance
Extreme Temperature and Photosynthesis
Temperature and Microbial Activity
Balancing Heat Gain Against Heat Loss
Body Temperature Regulation ( 體溫調節 )
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Plants
Ectothermic Animals ( 外溫動物 )
Endothermic Animals ( 內溫動物 )
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Microclimates ( 微氣候 )
Macroclimate : Large scale weather variation. ( 大尺度的氣象變化 )
Microclimate : Small scale ( 小尺度 )weather variation, usually measured over shorter time period.
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Altitude ( 高度 )
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Higher altitude - lower temperature.
Aspect ( 面向 )
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Offers contrasting environments.
Vegetation ( 植被 )
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Ecologically important microclimates.
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Microclimates
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Ground Color ( 地表顏色 )
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Darker colors absorb more visible light.
Boulders ( 大圓石 ) / Burrows ( 洞穴 )
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Create shaded, cooler environments.
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Aquatic Temperatures( 水域溫度 )
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Specific Heat
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Absorbs heat without changing temperature.
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1 cal energy to heat 1 cm 3 of water 1 o C.
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Air - .0003 cal
Latent Heat of Evaporation
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1 cal can cool 580 g of water.
Latent Heat of Fusion
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1 g of water gives off 80 cal as it freezes.
Riparian Areas ( 河岸邊地區 )
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Aquatic Temperatures
Riparian vegetation influences stream temperature by providing shade.( 提供陰影 )
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Temperature and Animal
Performance
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Bio-molecular Level ( 生物分子層級 )
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Most enzymes have rigid, predictable shape at low temperatures
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Low temperatures cause low reaction rates, while excessively high temperatures destroy the shape.
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Baldwin and Hochachka studied the influence of temperature on performance of acetylcholinesterase in rainbow trout
( Oncorhynchus mykiss ).
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Extreme Temperatures and
Photosynthesis
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Photosynthesis( 光合作用 )
6CO
2
+ 12H
2
O  C
6
H
12
O
6
+ 6O
2
+ 6H
2
0
Extreme temperatures usually reduce rate of photosynthesis.
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Different plants have different optimal temperatures.
Acclimation ( 適應 ): Physiological changes in response to temperature.
Acclimatization ( 適應 )
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Optimal Photosynthetic
Temperatures
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Temperature and Microbial
Activity
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Morita studied the effect of temperature on population growth among psychrophilic ( 嗜
冷 ) marine bacteria around Antarctica ( 南
極洲 ).
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Grew fastest at 4 o C.
Some growth recorded in temperatures as cold as 5.5
o C.
Some thermophilic ( 嗜熱 ) microbes have been found to grow best in temperatures as hot as 110 o C.
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Optimal Growth Temperatures
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Balancing Heat Gain Against
Heat Loss
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H
S
= H m
+ H cd
+ H cv
+ H r
- H e
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H
S
= Total heat stored in an organism
H m
= Gained via metabolism
H cd
= Gained / lost via conduction
H cv
H r
= Gained / lost via convection
= Gained / lost via electromag. radiation
H e
= Lost via evaporation
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Heat Exchange Pathways
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Body Temperature Regulation
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Poikilotherms ( 變溫 )
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Body temperature varies directly with environmental temperature.
Ectotherms ( 外溫 )
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Rely mainly on external energy sources.
Endotherms ( 內溫 )
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Rely heavily on metabolic energy.
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Homeotherms maintain a relatively constant internal environment.
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Temperature Regulation by
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Plants
Desert Plants: Must reduce heat storage.
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H s
= H cd
+ H cv
+ H r
To avoid heating, plants have (3) options:
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Decrease heating via conduction (H cd
).
Increase conductive cooling (H cv
).
Reduce radiative heating (H r
).
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Temperature Regulation by Plants
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Temperature Regulation by Plants
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Arctic and Alpine Plants
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Two main options to stay warm:
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Increase radiative heating (H r
).
Decrease Convective Cooling (H cv
).
Tropic Alpine Plants
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Rosette plants generally retain dead leaves, which insulate and protect the stem from freezing.
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Thick pubescence increases leaf temperature.
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Temperature Regulation by
Ectothermic Animals
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Liolaemus Lizards
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Thrive in cold environments.
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Burrows
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Dark pigmentation
Sun Basking
Grasshoppers
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Some species can adjust for radiative heating by varying intensity of pigmentation during development.
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Temperature Regulation by
Endothermic Animals
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Thermal neutral zone is the range of environmental temperatures over which the metabolic rate of a homeothermic animal does not change.
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Breadth varies among endothermic species.
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Thermal Neutral Zones
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Temperature Regulation by
Endothermic Animals
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Swimming Muscles of Large Marine Fish
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Lateral swimming muscles of many fish
(Mackerel, Sharks, Tuna) are well supplied with blood vessels that function as countercurrent heat-exchangers .
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Keep body temperature above that of surrounding water.
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Countercurrent Heat Exchange
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Temperature Regulation by
Endothermic Animals
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Warming Insect Flight Muscles
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Bumblebees maintain temperature of thorax between 30 o and 37 o C regardless of air temperature.
Sphinx moths ( Manduca sexta ) increase thoracic temperature due to flight activity.
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Thermoregulates by transferring heat from the thorax to the abdomen
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Moth Circulation and Thermoregulation
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Temperature Regulation by
Thermogenic Plants
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Almost all plants are poikilothermic ectotherms.
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Plants in family Araceae use metabolic energy 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
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Inactivity
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Seek shelter during extreme periods.
Reducing Metabolic Rate
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Hummingbirds enter a state of torpor when food is scarce and night temps are extreme.
Hibernation - Winter
Estivation - Summer
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Review
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Microclimates
Aquatic Temperatures
Temperature and Animal Performance
Extreme Temperature and Photosynthesis
Temperature and Microbial Activity
Balancing Heat Gain Against Heat Loss
Body Temperature Regulation
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Plants
Ectothermic Animals
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Endothermic Animals
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0n the net
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Biological structure and function
Temperature regulation
Thermal relations
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