De-hardening in spring involves gradual re-hydration of the cells, recovery of photosynthetic capacity and a tight control of water loss.
The annual cycle of photosynthesis mainly follows
the changes in air temperature.
the changes in light.
the changes in CO2 concentration.
the changes in soil temperature.
To transform atmospheric CO2 into organic molecules, plants can use the energy from
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?
Plants open its stomata to avoid losing too much water.
Plant closes its stomata to avoid losing too much water.
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.
Early spring is a tricky time for plants due to the combination of sunny but still quite cold days.
Photosynthesis of a tree canopy is driven or influenced by
soil moisture (REW).
air humidity (VPD).
photosynthetically active solar radiation (PAR).
the total leaf area (LAI).
air temperature (T).
As plants respire, they release
Photosynthesis releases oxygen whereas respiration releases CO2.
In general, the more carbon dioxide that is available to the plant, the faster the rate of photosynthesis - if other factors are favourable.
Transpiration decreases as air becomes drier.
High soil moisture leads to decreased photosynthesis.
In boreal upland forests, low soil moisture decreases the rate of photosynthesis.
Almost half of the total biomass of a tree may be allocated to the roots.
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.