Carbon becomes locked as part of the accumulating plant biomass as plants grow.
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.
Photosynthesis of a tree canopy is driven or influenced by
photosynthetically active solar radiation (PAR).
the total leaf area (LAI).
soil moisture (REW).
air humidity (VPD).
air temperature (T).
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.
Plant respiration captures CO2.
Unlike photosynhesis, plant respiration captures atmospheric oxygen and releases carbon dioxide.
In some part of the stems, some photosynthesis may also occur.
Photoinhibition means the decrease in photosynthesis due to
exposure to high temperature.
exposure to shortage of soil moisture.
exposure to excess of light.
exposure to excess of CO2.
When there is low soil moisture, plants close its stomata pores which then decreases photosynthesis.
Almost half of the total biomass of a tree may be allocated to the roots.
As plants respire, they release
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.
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.
To transform atmospheric CO2 into organic molecules, plants can use the energy from