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

Individual growth rate

Resource allocation

Carbon and energy dynamics in ecosystems

Species interactionsCommunity structureEnvironmental conditionsPeriodic fire

today’s exercise

CERA researchat end of semester

Investigation 2 – Causes and consequences of energy and carbon dynamics in biological systems: Scaling from

molecules to ecosystems

allocation

Biochem

Anatomy

Physiology

Energy, matter, allocation, and growthin 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

interest rate d-1

acct size in 100 d

100

0.05 = (105-100/100)

100(1.05)100 = 13,150

100

0.06

100(1.06)100 = 33,930

50

0.06

50(1.05)100 = 16,965

therefore RGR = good measure of size increase rate

Cast of characters

B ro m u s ka lm i (w ild chess )

G rass fam ily (P oaceae)

E lym u s ca na den sis

(C anada w ild rye) (P o aceae)

A nd ro po go n gerard ii

(b ig b lues tem ) (P oaceae)

A m aran th us re tro flexu s

(red roo t p igw eed ) (A m aran th aceae)

E lym u s villo su s

(ha iry w ildrye) (P o ac eae )

S orgh as tru m n utan s

(In d ian grass ) (P o ac eae )

P an icu m v irg atum

(sw itchg rass ) (P o ace ae)

A nd ro po go n scop ar ius

(= S chyza ch yrium sco pa riu m ) (lit tle b lu estem ) (P oaceae)

E lym us v irg in icu s

(V irg in ia w ildrye) (P o ac eae)

"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.

There’sa nicestandof littlebluestemsouth ofKershaw.

Where did the data come from?

A) Biochemical traits

1) C3 v. C4 photosynthesis

phylogenyof C4 traitsin grassfamily

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

Root fraction

Grow plants individually

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

RGR

Grow plants individually

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 variablesB) 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