Transcript Document

Giussani et al 2001
Stowe and Teeri 1978
Investigation 2 – Causes and consequences of energy and
carbon dynamics in biological systems: Scaling from
molecules to ecosystems
Pigment &
enzyme
chemistry;
Cell/leaf
anatomy
Leaf photosynthesis;
leaf respiration
Species interactions
Community structure
Environmental conditions
Periodic fire
Individual growth rate
Resource allocation
today’s exercise
CERA research
at end of semester
Carbon and
energy dynamics
in ecosystems
Investigation 2 – Causes and consequences of energy and
carbon dynamics in biological systems: Scaling from
molecules to ecosystems
Biochem
allocation
Anatomy
Physiology
Energy, matter, allocation, and growth
in a vascular plant
E
C
H2O
ions
RGR
RGR
What is RGR?
[Mass time time t+1 – Mass time t ]
[Mass time t · time interval]
units? Time –1
meaning – RGR’s like an interest rate
initial account size
100
100
50
interest rate d-1
0.05 = (105-100/100)
0.06
0.06
acct size in 100 d
100(1.05)100 = 13,150
100(1.06)100 = 33,930
50(1.05)100 = 16,965
therefore RGR = good measure of size increase rate
Cast of characters
"We will also fund additional
research in cutting edge
methods in producing
ethanol...not just from corn,
but from wood chips, stalks,
or switchgrass." GW Bush,
2006 SOTU address.
B ro m u s ka lm i (w ild chess)
G rass fam ily (P oaceae)
Elym u s ca na den sis
(C anada w ild rye) (P o aceae )
A nd ro po go n gerardii
(b ig bluestem ) (P oaceae)
Am aran th us retroflexu s
(red roo t p igw eed )
(A m aran th aceae)
Elym u s villo su s
(hairy w ildrye) (P o ac eae )
S orgh astru m n utan s
(In dian grass) (P o ac eae )
P an icu m virg atum
(sw itchg rass) (P o ace ae)
A nd ro po go n scop arius
(= S chyza ch yrium sco pa riu m )
(little b lu estem ) (P oaceae)
E lym us virg in icu s
(V irginia w ildrye) (P o ac eae)
There’s
a nice
stand
of little
bluestem
south of
Kershaw.
Where did the data come from?
A) Biochemical traits
1) C3 v. C4 photosynthesis
phylogeny
of C4 traits
in grass
family
Where did the data come from?
A) Biochemical traits
2) Chlorophyll concentration
Grind the 9 cm2 of leaf tissue in 9 ml of 80% acetone.
Centrifuge at full speed for 5 min.
Dilute supernatant to 10 ml with 80% acetone.
Total chlorophyll mg/ml = 0.0202 A645 + 0.00802 A663
mg chlorophyll per gram fresh weight:=
= [mg. chlor./ml X volume of extract (ml)] ÷ fresh weight (g)
Where did the data come from?
B) Leaf gas exchange
1) Photosynthetic rate
2) Respiration rate
http://web.grinnell.edu/courses/bio/qubitmanual/Information/Respiration/intro.htm
Where did the data come from?
C) Resource allocation
Grow plants individually
Root fraction
Initial harvest at 1 month
• clip shoots
• wash roots
• dry 48 h at 65°C
• weigh
• root wt / total wt
Where did the data come from?
D) Growth rate
Grow plants individually
RGR
2nd harvest 1 wk later
• unearth & wash
• dry 48 h at 65°C
• weigh
RGR =
(Massfinal – Massinitial)
Massinitial wk
Today’s plan
1) Take the variables in Table 1  groups create models depicting:
A) Relationships among variables
B) Controls of variation in RGR
2) Class creates consensus model.
3) Groups evaluate the model statistically, and hand in worksheets.
4) Class reviews findings and their lessons.
C4
C3
C3