A complex microbiota lives belowground, releasing carbon dioxide to the soil.
As plants respire, they release
In some part of the stems, some photosynthesis may also occur.
The effect of light on photosynthesis has a clear saturating pattern: more light results in more photosynthesis but eventually leaves cannot take full advantage of all the extra light.
The rate of respiration decreases with temperature.
Plants open its stomata to avoid losing too much water.
Plant closes its stomata to avoid losing too much water.
Transpiration decreases as air becomes drier.
Early spring is a tricky time for plants due to the combination of sunny but still quite cold days.
Photosynthesis of a tree canopy is driven or influenced by
air humidity (VPD).
soil moisture (REW).
air temperature (T).
the total leaf area (LAI).
photosynthetically active solar radiation (PAR).
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 high temperature.
exposure to excess of light.
exposure to excess of CO2.
exposure to shortage of soil moisture.
Plant respiration captures CO2.
Unlike photosynhesis, plant respiration captures atmospheric oxygen and releases carbon dioxide.
High soil moisture leads to decreased photosynthesis.
In boreal upland forests, low soil moisture decreases the rate of photosynthesis.
In general, the more carbon dioxide that is available to the plant, the faster the rate of photosynthesis - if other factors are favourable.
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.