Photosynthesis of a tree canopy is driven or influenced by
photosynthetically active solar radiation (PAR).
soil moisture (REW).
the total leaf area (LAI).
air temperature (T).
air humidity (VPD).
At low air humidity, a plant closes its stomata to prevent transpiration. The action also decreases photosynthesis
Almost half of the total biomass of a tree may be allocated to the roots.
As plants respire, they release
Photosynthesis releases oxygen whereas respiration releases CO2.
To transform atmospheric CO2 into organic molecules, plants can use the energy from
In some part of the stems, some photosynthesis may also occur.
In general, the more carbon dioxide that is available to the plant, the faster the rate of photosynthesis - if other factors are favourable.
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.
Early spring is a tricky time for plants due to the combination of sunny but still quite cold days.
Carbon becomes locked as part of the accumulating plant biomass as plants grow.
De-hardening in spring involves gradual re-hydration of the cells, recovery of photosynthetic capacity and a tight control of water loss.
Plant respiration captures CO2.
Unlike photosynhesis, plant respiration captures atmospheric oxygen and releases carbon dioxide.
Plants open its stomata to avoid losing too much water.
Plant closes its stomata to avoid losing too much water.
A complex microbiota lives belowground, releasing carbon dioxide to the soil.