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.
De-hardening in spring involves gradual re-hydration of the cells, recovery of photosynthetic capacity and a tight control of water loss.
Photosynthesis of a tree canopy is driven or influenced by
photosynthetically active solar radiation (PAR).
the total leaf area (LAI).
air humidity (VPD).
air temperature (T).
soil moisture (REW).
Transpiration decreases as air becomes drier.
Almost half of the total biomass of a tree may be allocated to the roots.
Plant respiration captures CO2.
Unlike photosynhesis, plant respiration captures atmospheric oxygen and releases carbon dioxide.
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.
Carbon becomes locked as part of the accumulating plant biomass as plants grow.
What is the source of carbon that is assimilated in photosynthesis?
Carbon capture is performed by the green parts of plants via photosynthesis.
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.
Photoinhibition means the decrease in photosynthesis due to
exposure to shortage of soil moisture.
exposure to excess of CO2.
exposure to high temperature.
exposure to excess of light.
Plants open its stomata to avoid losing too much water.
Plant closes its stomata to avoid losing too much water.
When there is low soil moisture, plants close its stomata pores which then decreases photosynthesis.