Question:
To transform atmospheric CO2 into organic molecules, plants can use the energy from
soil nutrients.
atmospheric oxygen.
soil heat.
sun light.
Response:
The effect of light on photosynthesis has a clear saturating pattern: more light results in more photosynthesis but eventually leaves cannot take full advantage of all the extra light.
The rate of respiration decreases with temperature.
The annual cycle of photosynthesis mainly follows
the changes in light.
the changes in soil temperature.
the changes in air temperature.
the changes in CO2 concentration.
As plants respire, they release
carbon dioxide.
oxygen.
Photosynthesis of a tree canopy is driven or influenced by
photosynthetically active solar radiation (PAR).
the total leaf area (LAI).
atmospheric CO2.
air temperature (T).
air humidity (VPD).
soil moisture (REW).
Plants open its stomata to avoid losing too much water.
Plant closes its stomata to avoid losing too much water.
Leaf area increases with stand age, resulting in a decreasing rate of photosynthesis in the stand.
An increment in leaf area increases also the photosynthesis of a tree stand. However, the relationship is saturating.
Carbon becomes locked as part of the accumulating plant biomass as plants grow.
Almost half of the total biomass of a tree may be allocated to the roots.
In general, the more carbon dioxide that is available to the plant, the faster the rate of photosynthesis - if other factors are favourable.
At low air humidity, a plant closes its stomata to prevent transpiration. The action also decreases photosynthesis
Plant respiration captures CO2.
Unlike photosynhesis, plant respiration captures atmospheric oxygen and releases carbon dioxide.
When there is low soil moisture, plants close its stomata pores which then decreases photosynthesis.
What is the source of carbon that is assimilated in photosynthesis?
Atmospheric CO2
Solar radiation
Soil nutrients
Soil water
