De-hardening in spring involves gradual re-hydration of the cells, recovery of photosynthetic capacity and a tight control of water loss.
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.
Early spring is a tricky time for plants due to the combination of sunny but still quite cold days.
A complex microbiota lives belowground, releasing carbon dioxide to the soil.
What is the source of carbon that is assimilated in photosynthesis?
Carbon capture is performed by the green parts of plants via photosynthesis.
Almost half of the total biomass of a tree may be allocated to the roots.
In general, the more carbon dioxide that is available to the plant, the faster the rate of photosynthesis - if other factors are favourable.
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.
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.
High soil moisture leads to decreased photosynthesis.
In boreal upland forests, low soil moisture decreases the rate of photosynthesis.
Plant respiration captures CO2.
Unlike photosynhesis, plant respiration captures atmospheric oxygen and releases carbon dioxide.
At low air humidity, a plant closes its stomata to prevent transpiration. The action also decreases photosynthesis
The annual cycle of photosynthesis mainly follows
the changes in soil temperature.
the changes in air temperature.
the changes in light.
the changes in CO2 concentration.
As plants respire, they release