Photosynthesis of a tree canopy is driven or influenced by
photosynthetically active solar radiation (PAR).
the total leaf area (LAI).
air humidity (VPD).
air temperature (T).
soil moisture (REW).
To transform atmospheric CO2 into organic molecules, plants can use the energy from
Photoinhibition means the decrease in photosynthesis due to
exposure to shortage of soil moisture.
exposure to excess of light.
exposure to excess of CO2.
exposure to high temperature.
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.
De-hardening in spring involves gradual re-hydration of the cells, recovery of photosynthetic capacity and a tight control of water loss.
In some part of the stems, some photosynthesis may also occur.
Early spring is a tricky time for plants due to the combination of sunny but still quite cold days.
The annual cycle of photosynthesis mainly follows
the changes in CO2 concentration.
the changes in soil temperature.
the changes in light.
the changes in air temperature.
At low air humidity, a plant closes its stomata to prevent transpiration. The action also decreases photosynthesis
Almost half of the total biomass of a tree may be allocated to the roots.
A complex microbiota lives belowground, releasing carbon dioxide to the soil.
What is the source of carbon that is assimilated in photosynthesis?
Plant respiration captures CO2.
Unlike photosynhesis, plant respiration captures atmospheric oxygen and releases carbon dioxide.
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.
Transpiration decreases as air becomes drier.