Early spring is a tricky time for plants due to the combination of sunny but still quite cold days.
High soil moisture leads to decreased photosynthesis.
In boreal upland forests, low soil moisture decreases the rate of photosynthesis.
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 annual cycle of photosynthesis mainly follows
the changes in CO2 concentration.
the changes in air temperature.
the changes in light.
the changes in soil temperature.
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?
In general, the more carbon dioxide that is available to the plant, the faster the rate of photosynthesis - if other factors are favourable.
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.
The rate of respiration decreases with temperature.
To transform atmospheric CO2 into organic molecules, plants can use the energy from
As plants respire, they release
In some part of the stems, some photosynthesis may also occur.
Photosynthesis of a tree canopy is driven or influenced by
the total leaf area (LAI).
photosynthetically active solar radiation (PAR).
air temperature (T).
soil moisture (REW).
air humidity (VPD).
Almost half of the total biomass of a tree may be allocated to the roots.
Carbon capture is performed by the green parts of plants via photosynthesis.