The annual cycle of photosynthesis mainly follows
the changes in CO2 concentration.
the changes in light.
the changes in soil temperature.
the changes in air temperature.
De-hardening in spring involves gradual re-hydration of the cells, recovery of photosynthetic capacity and a tight control of water loss.
Transpiration decreases as air becomes drier.
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.
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.
As plants respire, they release
Photosynthesis releases oxygen whereas respiration releases CO2.
A complex microbiota lives belowground, releasing carbon dioxide to the soil.
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 capture is performed by the green parts of plants via photosynthesis.
Photosynthesis of a tree canopy is driven or influenced by
the total leaf area (LAI).
air temperature (T).
air humidity (VPD).
soil moisture (REW).
photosynthetically active solar radiation (PAR).
What is the source of carbon that is assimilated in photosynthesis?
Carbon becomes locked as part of the accumulating plant biomass as plants grow.
In general, the more carbon dioxide that is available to the plant, the faster the rate of photosynthesis - if other factors are favourable.
In some part of the stems, some photosynthesis may also occur.