When there is low soil moisture, plants close its stomata pores which then decreases photosynthesis.
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.
Early spring is a tricky time for plants due to the combination of sunny but still quite cold days.
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?
Plant respiration captures CO2.
Unlike photosynhesis, plant respiration captures atmospheric oxygen and releases carbon dioxide.
Transpiration decreases as air becomes drier.
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.
As plants respire, they release
Carbon becomes locked as part of the accumulating plant biomass as plants grow.
At low air humidity, a plant closes its stomata to prevent transpiration. The action also decreases photosynthesis
In some part of the stems, some photosynthesis may also occur.
Almost half of the total biomass of a tree may be allocated to the roots.
In general, the more carbon dioxide that is available to the plant, the faster the rate of photosynthesis - if other factors are favourable.