To transform atmospheric CO2 into organic molecules, plants can use the energy from
What is the source of carbon that is assimilated in photosynthesis?
Early spring is a tricky time for plants due to the combination of sunny but still quite cold days.
In some part of the stems, some photosynthesis may also occur.
The rate of respiration decreases with temperature.
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.
In general, the more carbon dioxide that is available to the plant, the faster the rate of photosynthesis - if other factors are favourable.
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.
Photosynthesis of a tree canopy is driven or influenced by
the total leaf area (LAI).
air humidity (VPD).
photosynthetically active solar radiation (PAR).
soil moisture (REW).
air temperature (T).
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.
When there is low soil moisture, plants close its stomata pores which then decreases photosynthesis.
Plants open its stomata to avoid losing too much water.
Plant closes its stomata to avoid losing too much water.
Plant respiration captures CO2.
Unlike photosynhesis, plant respiration captures atmospheric oxygen and releases carbon dioxide.