9/8/08 1 Biogeography Prof. J. Hicke 1 Physical environment plantphys.info/Plant_Physiology/photoeco.html Photosynthesis as a function of available PAR saturation point Biogeography Prof. J. Hicke 2 Physical environment www.uga.edu/srel/ESSite/MMLight_acclimation.htm How does canopy cover affect light penetration? PAR = 67 mol/m2/s PAR = 185 mol/m2/s Biogeography Prof. J. Hicke 3 Physical environment Smith and Smith, 2006 Leaf area index = surface area of leaves/ground area Light penetration into canopy
Transcript
9/8/08
1
Biogeography Prof. J. Hicke 1
Physical environment
plantphys.info/Plant_Physiology/photoeco.html
Photosynthesis as a function of available PAR
saturation point
Biogeography Prof. J. Hicke 2
Physical environment
www.uga.edu/srel/ESSite/MMLight_acclimation.htm
How does canopy cover affect light penetration?
PAR = 67 mol/m2/s PAR = 185 mol/m2/s
Biogeography Prof. J. Hicke 3
Physical environment
Smith and Smith, 2006
Leaf area index =
surface area of leaves/ground area
Light penetration into canopy
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2
Biogeography Prof. J. Hicke 4
Physical environment
Barnes et al., 1998
Which has more understory vegetation?
Biogeography Prof. J. Hicke 5
Physical environment
Waring and Major, 1964
Light availability to understory: variability by vegetation type
% of full daylight at 1 m
Biogeography Prof. J. Hicke 6
Physical environment
Canopy: 90% of photosynthesis
Understory: 10% of
photosynthesis on only 1% of
light available at top of the
canopy
library.thinkquest.org/26252/explore/3.htm Images: Steven Holt
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Biogeography Prof. J. Hicke 7
Physical environment
plantphys.info/Plant_Physiology/photoeco.html
Shade-tolerant plants are more efficient at low-light levels
Shade tolerant species reach
light saturation at 5-10% of full sunlight, e.g., red maple (Acer
rubrum), American beech (Fagus grandifolia)
full sun 10% full
sun
Biogeography Prof. J. Hicke 8
Physical environment
Too much light: photoinhibition
plantphys.info/Plant_Physiology/photoeco.html
Biogeography Prof. J. Hicke 9
Physical environment
Adaptations to light
Smith and Smith, 2006
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Biogeography Prof. J. Hicke 10
Physical environment
Rhode et al., 2001
Concentration
higher in water column without
UVB
Concentration
lower in water column with
UVB
UV Radiation Controls on Species Distributions
Escape of zooplankton in water column from UV radiation
NO UV UV
Biogeography Prof. J. Hicke 11
Physical environment
Adaptations to low/no light: Animals
lsb.syr.edu/projects/cyberzoo/greathornedowl.html
Long-Eared Bat Myotis evotis
www.inkart.net/art/wildlife_art/long_eared_bat
/long_eared_bat_art.htm
Great Horned Owl Bubo virginianus
Deep sea anglerfish Melanocetus johnsonii
www.mbayaq.org/efc/living_species
/default.asp?inhab=169
Biogeography Prof. J. Hicke 12
Physical environment
Species variability in temperature optimum
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Biogeography Prof. J. Hicke 13
Physical environment
Smith and Smith, 2006
C4 species better adapted to higher temperatures
C4 species
C3 species
Biogeography Prof. J. Hicke 14
Physical environment
Temperature effects on respiration/metabolism
Slide courtesy C. Still
Biogeography Prof. J. Hicke 15
Physical environment
Temperature and the saguaro
cactus (Carnegiea gigantea)
Lomolino et al., 2006
More than 12 to 24
hours below freezing damages the plant
1961 1966 1979
Frost damage in 1962:
0 deg C for >24 hours
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Biogeography Prof. J. Hicke 16
Physical environment
Slide courtesy of C. Still
Biogeography Prof. J. Hicke 17
Physical environment
Slide courtesy of C. Still
Biogeography Prof. J. Hicke 18
Physical environment
Latitude, elevation, and timberline
Lomolino et al., 2006
What is the driving factor?
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Biogeography Prof. J. Hicke 19
Physical environment
DeFries et al., 2000
Adaptations to cold: Deciduous broadleaf
Broadleaf
Biogeography Prof. J. Hicke 20
Physical environment
But, not all conifers are resistant to cold, and not
all deciduous trees are intolerant to cold
Redwood (Sequoia sempervirens) Big-leafed (bur) oak (Quercus macrocarpa)
Northern, upper elevation limit is
-15 to -25 deg C Can withstand -60 deg C
esp.cr.usgs.gov/data/atlas/little
Biogeography Prof. J. Hicke 21
Physical environment
www.s-weeds.net/familjer/apiaceae/liguscot.html
Ligusticum scoticum - Scots Lovage
Southern range of many arctic plants governed by summer temperatures
Scots lovage:
• southern limit reached at 14.4 deg C • plant adapted to shorter growing season
• higher respiration rates under warmer conditions and longer growing season => depletion of carbohydrate stores
www.habitas.org.uk/flora/map.asp?item=3702
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Biogeography Prof. J. Hicke 22
Physical environment
Slide courtesy C. Still
Biogeography Prof. J. Hicke 23
Physical environment
Body size versus metabolic rate
Lomolino et al., 2006
m = cM0.75
Smith and Smith, 2006
Biogeography Prof. J. Hicke 24
Physical environment
Bull and Vogt, 1979
Temperature affects sex ratio of turtle hatchlings
