Early spring is a tricky time for plants due to the combination of sunny but still quite cold days.
When there is low soil moisture, plants close its stomata pores which then decreases photosynthesis.
In general, the more carbon dioxide that is available to the plant, the faster the rate of photosynthesis - if other factors are favourable.
In some part of the stems, some photosynthesis may also occur.
Carbon becomes locked as part of the accumulating plant biomass as plants grow.
Transpiration decreases as air becomes drier.
De-hardening in spring involves gradual re-hydration of the cells, recovery of photosynthetic capacity and a tight control of water loss.
High soil moisture leads to decreased photosynthesis.
In boreal upland forests, low soil moisture decreases the rate of photosynthesis.
What is the source of carbon that is assimilated in photosynthesis?
The annual cycle of photosynthesis mainly follows
the changes in air temperature.
the changes in CO2 concentration.
the changes in soil temperature.
the changes in light.
Photosynthesis of a tree canopy is driven or influenced by
the total leaf area (LAI).
air temperature (T).
photosynthetically active solar radiation (PAR).
soil moisture (REW).
air humidity (VPD).
At low air humidity, a plant closes its stomata to prevent transpiration. The action also decreases photosynthesis
Photoinhibition means the decrease in photosynthesis due to
exposure to excess of CO2.
exposure to shortage of soil moisture.
exposure to high temperature.
exposure to excess of light.
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.