Limiting Factors and CO2 Enrichment Experiments

ib bio unit 5 SL year 1

light intensity (brightness), CO2 concentration, temperature

3 limiting factors that impact the rate of photosynthesis

at first an increase of light intensity causes an increase in the rate of photosynthesis, but eventually a maximum rate is reached and the rate of photosynthesis plateaus

how light intensity affects the rate of photosynthesis

initially an increase in CO2 concentration causes an increase in the rate of photosynthesis, but eventually a maximum rate is reached and the rate of photosynthesis plateaus

how CO2 concentration affects the rate of photosynthesis

initially an increase in temperature causes an increase in the rate of photosynthesis because of increased number of collisions. above the optimum temp, the rate declines due to enzyme denaturation

how temperature affects the rate of photosynthesis

CO2 concentrations are rising due to human activity, and scientists want to see how plants will react to these higher levels of CO2

why scientists are conducting CO2 enrichment experiments

greenhouses with manipulated CO2 concentrations, and free air carbon dioxide enrichment experiments (FACE)

the 2 types of CO2 enrichment experimental designs

increased CO2 concentrations in a greenhouse, measure biomass compared to a control

how greenhouses with manipulated CO2 concentrations are used

pro: tighter control, con: “artificial” environment

pros and cons of greenhouses with manipulated CO2 concentrations

pipes surround area and release CO2 into the atmosphere, while sensors monitor CO2 levels

how free air carbon dioxide enrichment experiments (FACE) are used

pros: carried out in a natural ecosystem, cons: expensive and harder to control

pros and cons of free air carbon dioxide enrichment experiments (FACE)