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.
Carbon becomes locked as part of the accumulating plant biomass as plants grow.
Almost half of the total biomass of a tree may be allocated to the roots.
The annual cycle of photosynthesis mainly follows
the changes in air temperature.
the changes in CO2 concentration.
the changes in light.
the changes in soil temperature.
Plants open its stomata to avoid losing too much water.
Plant closes its stomata to avoid losing too much water.
High soil moisture leads to decreased photosynthesis.
In boreal upland forests, low soil moisture decreases the rate of 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.
Photoinhibition means the decrease in photosynthesis due to
exposure to excess of CO2.
exposure to shortage of soil moisture.
exposure to excess of light.
exposure to high temperature.
The rate of respiration decreases with temperature.
Transpiration decreases as air becomes drier.
What is the source of carbon that is assimilated in photosynthesis?
As plants respire, they release
Photosynthesis releases oxygen whereas respiration releases CO2.
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.
In some part of the stems, some photosynthesis may also occur.