The annual cycle of photosynthesis mainly follows
the changes in CO2 concentration.
the changes in air temperature.
the changes in soil temperature.
the changes in light.
Transpiration decreases as air becomes drier.
Almost half of the total biomass of a tree may be allocated to the roots.
As plants respire, they release
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.
In some part of the stems, some photosynthesis may also occur.
Carbon capture is performed by the green parts of plants via photosynthesis.
To transform atmospheric CO2 into organic molecules, plants can use the energy from
At low air humidity, a plant closes its stomata to prevent transpiration. The action also decreases photosynthesis
Plant respiration captures CO2.
Unlike photosynhesis, plant respiration captures atmospheric oxygen and releases carbon dioxide.
A complex microbiota lives belowground, releasing carbon dioxide to the soil.
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.
Photosynthesis of a tree canopy is driven or influenced by
photosynthetically active solar radiation (PAR).
soil moisture (REW).
air temperature (T).
air humidity (VPD).
the total leaf area (LAI).
High soil moisture leads to decreased photosynthesis.
In boreal upland forests, low soil moisture decreases the rate of photosynthesis.