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.
Early spring is a tricky time for plants due to the combination of sunny but still quite cold days.
At low air humidity, a plant closes its stomata to prevent transpiration. The action also decreases photosynthesis
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.
Plant respiration captures CO2.
Unlike photosynhesis, plant respiration captures atmospheric oxygen and releases carbon dioxide.
Almost half of the total biomass of a tree may be allocated to the roots.
In some part of the stems, some photosynthesis may also occur.
What is the source of carbon that is assimilated in photosynthesis?
As plants respire, they release
Photosynthesis releases oxygen whereas respiration releases CO2.
Photoinhibition means the decrease in photosynthesis due to
exposure to excess of CO2.
exposure to excess of light.
exposure to high temperature.
exposure to shortage of soil moisture.
A complex microbiota lives belowground, releasing carbon dioxide to the soil.
High soil moisture leads to decreased photosynthesis.
In boreal upland forests, low soil moisture decreases the rate of photosynthesis.
The annual cycle of photosynthesis mainly follows
the changes in air temperature.
the changes in light.
the changes in CO2 concentration.
the changes in soil temperature.