Photoinhibition means the decrease in photosynthesis due to
exposure to high temperature.
exposure to shortage of soil moisture.
exposure to excess of light.
exposure to excess of CO2.
A complex microbiota lives belowground, releasing carbon dioxide to the soil.
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 soil temperature.
the changes in light.
the changes in air temperature.
the changes in CO2 concentration.
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.
At low air humidity, a plant closes its stomata to prevent transpiration. The action also decreases photosynthesis
Photosynthesis of a tree canopy is driven or influenced by
photosynthetically active solar radiation (PAR).
the total leaf area (LAI).
soil moisture (REW).
air temperature (T).
air humidity (VPD).
Transpiration decreases as air becomes drier.
Almost half of the total biomass of a tree may be allocated to the roots.
As plants respire, they release
Photosynthesis releases oxygen whereas respiration releases CO2.
De-hardening in spring involves gradual re-hydration of the cells, recovery of photosynthetic capacity and a tight control of water loss.
What is the source of carbon that is assimilated in photosynthesis?
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.
To transform atmospheric CO2 into organic molecules, plants can use the energy from