Download Lecture 4 The Distribution of Life

Lecture 4
The Distribution of Life:
Physical and Biological
Lecture 4
The Distribution of Life:
Physical and Biological
I.
The Physical Environment
A. Light
B. Temperature
C. Moisture
D. Environmental Gradients and Species Niches
II. Biological Interactions
A. Predation
B. Competition
C. Symbiosis
D. Physical and Biological Controls at work
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Lecture 4
The Distribution of Life
I.
The Physical Environment
A. Light
Light
6CO2 + 12H2O
Carbon Water
Dioxide
C6H12O6 + 6H2O +6O2
Sugar
Water Oxygen
Lecture 4
The Distribution of Life
I.
The Physical Environment
A. Light
Sciophyte
(Adiantum aleuticum)
Heliophyte
(Salvia leucophylla)
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Lecture 4
The Distribution of Life
I.
The Physical Environment
A. Light
Adaptations for living in high or low light intensities.
1. Physiological
Lecture 4
The Distribution of Life
I.
The Physical Environment
A. Light
Adaptations for living in high or low light intensities.
2. Morphological
(Arctostaphylos patula)
Sciotrophic leaves
(Yucca schidigera)
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Lecture 4
The Distribution of Life
I.
The Physical Environment
A. Light
Adaptations for living in high or low light intensities.
2. Life history and reproductive behavior
Ex. annuals
Lecture 4
The Distribution of Life
Distribution of Earth’s Forests
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Lecture 4
The Distribution of Life
I.
The Physical Environment
B. Temperature
1. Plants (poikilotherms)
Lecture 4
The Distribution of Life
I.
The Physical Environment
B. Temperature
1. Plants (poikilotherms)
Plant adaptations to cold temperatures:
a. Deciduous leaves (maple, beech, birch, and ashes)
b. Supercooling and extracellular water loss (pine, spruce,
and fir trees)
c. Heat re-radiation (saguaro cactus)
a.
b.
Big leaf maple
(Acer macrophyllum)
c.
Spruce tree
(Picea sp.)
(Carnegiea gigantea)
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Lecture 4
The Distribution of Life
I.
The Physical Environment
B. Temperature
1. Plants (poikilotherms)
Plant adaptations to warm temperatures:
a. Dimorphic leaves (sage scrub in southern California)
b. Waxy leaves (any cactus)
c. Water storage capacity (cactus, baobab tree, etc.)
Baobab Tree
(Adansonia
digitata)
Sagebrush
(Artemesia californica)
Lecture 4
The Distribution of Life
I.
The Physical Environment
B. Temperature
2. Animals
Poikilotherms - a.k.a.ectotherms (fish, reptiles, amphibians)
Homeotherms – a.k.a. endotherms (birds and mammals)
Antarctic icefish
(Trematomus borchgrevinki)
San Joaquin Kit Fox
(Vulpes macrotis)
Eurythermic
Vs.
Stenothermic
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Lecture 4
The Distribution of Life
2. Animals
Animal adaptations to warm environments:
a. Differences in metabolic rate
b. Release of sweat or panting
Lecture 4
The Distribution of Life
Animal adaptations to warm environments:
a. Use of microclimate (reptiles and insects)
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Lecture 4
The Distribution of Life
2. Animals
Animal adaptations to warm
environments:
a. Morphological adaptations
Chameleon
(Chamaeleo calyptratus)
African elephant
(Loxodonta africana)
Lecture 4
The Distribution of Life
I.
The Physical Environment
B. Temperature
2. Animals
Animal adaptations to cold environments:
a. Hibernation, torpor,
(Chordeiles
acutipennis )
(Ursus arctos)
(Taxidea taxus)
(Lasiurus spp.)
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Lecture 4
The Distribution of Life
I.
The Physical Environment
B. Temperature
2. Animals
Animal adaptations to cold environments:
a. Hibernation
b. Changes in metabolism with changes in air temperature
Lecture 4
The Distribution of Life
I.
The Physical Environment
B. Temperature
2. Animals
Animal adaptations to
cold environments:
c. Morphology
Polar bear
(Thalarctos maritimus)
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Lecture 4
The Distribution of Life
2. Animals
Allen’s Rule:
Animals that live in cold environments have shorter
extremities (relative to body mass) than related forms
in warm environments.
Jack rabbit
(Lepus californicus)
Arctic hare
(Lepus arcticus)
Lecture 4
The Distribution of Life
I.
The Physical Environment
C. Moisture
1. Xerophyte
2. Hydrophyte
3. Mesophyte
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Lecture 4
The Distribution of Life
I.
The Physical Environment
C. Moisture
Lecture 4
The Distribution of Life
I.
The Physical Environment
C. Moisture
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Lecture 4
The Distribution of Life
I.
The Physical Environment
C. Water
Plant adaptations to dry conditions:
a. Water stress escapees
b. Water stress avoiders
c. Water stress tolerators
Poppies
(Eschscholzia spp.)
Chamise
(Adenostoma fasciulatum)
Baobab tree
(Adensonia digitata)
Lecture 4
The Distribution of Life
I.
The Physical Environment
C. Water
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Lecture 4
The Distribution of Life
I.
The Physical Environment
C. Water
The Impact of moisture on terrestrial animals:
• Most mammals can withstand a loss of about 10% of their
body water
• Frogs can use as much as 40% of their body water
• Water is replenished by drinking from free water such as
lakes, streams, springs, and dew on leaves
• Water can be replenished via food for some species
(Kangaroo rate)
Lecture 4
The Distribution of Life
I.
The Physical Environment
D. Environmental Gradients and Species Niches
• Geographic range
• Density
• Carrying capacity
Fig. 3.12: The range and population density of eastern Bluebird
(Sialia sialis)
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Lecture 4
The Distribution of Life
The Physical Environment
D. Environmental Gradients and Species Niches
•
•
•
•
Soil moisture
I.
Niche
Habitat
Generalist
Specialist
Air temperature
Figure 3.14. The niches of hypothetical plant species as
defined by two gradients.
Lecture 4
The Distribution of Life
I.
Biological Interactions
A. Predation
• Stenophagus
• Euryphagous
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