What is the source of carbon that is assimilated in photosynthesis?
A complex microbiota lives belowground, releasing carbon dioxide to the soil.
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.
The annual cycle of photosynthesis mainly follows
the changes in air temperature.
the changes in soil temperature.
the changes in CO2 concentration.
the changes in light.
In general, the more carbon dioxide that is available to the plant, the faster the rate of photosynthesis - if other factors are favourable.
As plants respire, they release
To transform atmospheric CO2 into organic molecules, plants can use the energy from
When there is low soil moisture, plants close its stomata pores which then decreases photosynthesis.
Almost half of the total biomass of a tree may be allocated to the roots.
High soil moisture leads to decreased photosynthesis.
In boreal upland forests, low soil moisture decreases the rate of photosynthesis.
Transpiration decreases as air becomes drier.
Photoinhibition means the decrease in photosynthesis due to
exposure to excess of light.
exposure to shortage of soil moisture.
exposure to high temperature.
exposure to excess of CO2.
exposure to excess of CO2
exposure to shortage of soil moisture
exposure to high temperature
exposure to excess of light
Photosynthesis of a tree canopy is driven or influenced by
air temperature (T).
photosynthetically active solar radiation (PAR).
air humidity (VPD).
the total leaf area (LAI).
soil moisture (REW).
De-hardening in spring involves gradual re-hydration of the cells, recovery of photosynthetic capacity and a tight control of water loss.
Early spring is a tricky time for plants due to the combination of sunny but still quite cold days.