High soil moisture leads to decreased photosynthesis.
In boreal upland forests, low soil moisture decreases the rate of photosynthesis.
The annual cycle of photosynthesis mainly follows
the changes in light.
the changes in CO2 concentration.
the changes in air temperature.
the changes in soil temperature.
Plant respiration captures CO2.
Unlike photosynhesis, plant respiration captures atmospheric oxygen and releases carbon dioxide.
Photosynthesis of a tree canopy is driven or influenced by
the total leaf area (LAI).
soil moisture (REW).
photosynthetically active solar radiation (PAR).
air humidity (VPD).
air temperature (T).
Early spring is a tricky time for plants due to the combination of sunny but still quite cold days.
The rate of respiration decreases with 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?
To transform atmospheric CO2 into organic molecules, plants can use the energy from
Transpiration decreases as air becomes drier.
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.
Carbon becomes locked as part of the accumulating plant biomass as plants grow.
Plants open its stomata to avoid losing too much water.
Plant closes its stomata to avoid losing too much water.
In some part of the stems, some photosynthesis may also occur.
When there is low soil moisture, plants close its stomata pores which then decreases photosynthesis.