Testing preconceptions

Connecting concepts and “Big” ideas

Where does most of the mass in this piece of wood come from?

1. Air

2. Soil

3. Water

4. Nutrients dissolved in water

Where does most of the mass in this piece of wood come from?

1. Air

2. Soil

3. Water

4. Nutrients dissolved in water

What is the basic molecule from which this mass is derived?

1. N2

2. O2

3. CO2

4. H2O

What is the basic molecule from which this mass is derived?

1. N2

2. O2

3. CO2

4. H2O

Question 1

0

20

40

60

80

100

Air Soil Water Nutrient inwater

Q1

Question 2

0

20

40

60

80

100

N2 O2 CO2 H2O

Q2

Question 1

0

20

40

60

80

100

Air Soil Water Nutrient inwater

Q1

Question 2

0

20

40

60

80

100

N2 O2 CO2 H2O

Q2

Answer to Q1 provided prior to Q2

Answer to Q1 NOT provided prior to Q2

Photosynthesis – part of a big idea, a spanning idea

THE PERSPECTIVE OF AN ECOLOGIST

PsynthCarbon from Air

Plant physiologyCell biologyChemistryAnatomy

Energy and Ecosystems

Carbon Fixation Net Primary productivityJoining biological and abiological Energy flowNutrient cycles

Human impacts

Limiting factorsFeedbacks

Starch Cellulose

Calvin Cycle – light independent

RuBP 3PG

G3P

CARBOX

REDUCTREGEN

ATP

NADPHATP

NADP+

ADP

Carbon CO2

RUBISCO

ADP

Temperature and Enzyme Activity

Activity for the two is not on the same scale

Psynth & Patterns of Primary Productivity

kgC/m2 -yr

3

2

1

0

54.1

Energy &

Nutrient dynamics

• Primary production

• Secondary production energy flow

Psynth and CO2 fixation

Atmosphere Green plants

Consumers

DetritusDetritivores

microbes

Fossil fuel

Ocean

Sediments

The Carbon Cycle

photosynthesis

resp

iratio

n

Energy/biomass transferFood chain--system level

bog

1.5

11

37

809

0 100 200 300 400 500 600 700 800 900

1

2

3

4

small mammals

small carnivore (e.g, weasel)

top carnivore (e.g., hawk, fox)

Trophic efficiency is the percentage of production (energy) transferred from one trophic level to the next to form new

biomass

Trophic efficiency (%)

14%

29%

4.6%

Florida Bog

6.3-6.5 billion metric tonnes!

1.8-2 billion

Human Alterations to Global Carbon Dynamics