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.
What is the source of carbon that is assimilated in photosynthesis?
Early spring is a tricky time for plants due to the combination of sunny but still quite cold days.
In some part of the stems, some photosynthesis may also occur.
At low air humidity, a plant closes its stomata to prevent transpiration. The action also decreases photosynthesis
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 light.
the changes in soil temperature.
the changes in air temperature.
the changes in CO2 concentration.
In general, the more carbon dioxide that is available to the plant, the faster the rate of photosynthesis - if other factors are favourable.
To transform atmospheric CO2 into organic molecules, plants can use the energy from
Photoinhibition means the decrease in photosynthesis due to
exposure to excess of light.
exposure to high temperature.
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.
A complex microbiota lives belowground, releasing carbon dioxide to the soil.
The rate of respiration decreases with temperature.
Transpiration decreases as air becomes drier.