High soil moisture leads to decreased photosynthesis.
In boreal upland forests, low soil moisture decreases the rate of photosynthesis.
De-hardening in spring involves gradual re-hydration of the cells, recovery of photosynthetic capacity and a tight control of water loss.
Almost half of the total biomass of a tree may be allocated to the roots.
Photosynthesis of a tree canopy is driven or influenced by
photosynthetically active solar radiation (PAR).
soil moisture (REW).
air humidity (VPD).
air temperature (T).
the total leaf area (LAI).
In some part of the stems, some photosynthesis may also occur.
Plant respiration captures CO2.
Unlike photosynhesis, plant respiration captures atmospheric oxygen and releases carbon dioxide.
As plants respire, they release
Photosynthesis releases oxygen whereas respiration releases CO2.
In general, the more carbon dioxide that is available to the plant, the faster the rate of photosynthesis - if other factors are favourable.
To transform atmospheric CO2 into organic molecules, plants can use the energy from
Photoinhibition means the decrease in photosynthesis due to
exposure to excess of CO2.
exposure to high temperature.
exposure to shortage of soil moisture.
exposure to excess of light.
The rate of respiration decreases with temperature.
What is the source of carbon that is assimilated in photosynthesis?
When there is low soil moisture, plants close its stomata pores which then decreases photosynthesis.
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