What is the source of carbon that is assimilated in photosynthesis?
To transform atmospheric CO2 into organic molecules, plants can use the energy from
Transpiration decreases as air becomes drier.
A complex microbiota lives belowground, releasing carbon dioxide to the soil.
Almost half of the total biomass of a tree may be allocated to the roots.
The annual cycle of photosynthesis mainly follows
the changes in light.
the changes in CO2 concentration.
the changes in air temperature.
the changes in soil temperature.
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
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 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.
When there is low soil moisture, plants close its stomata pores which then decreases photosynthesis.
Carbon capture is performed by the green parts of plants via photosynthesis.
High soil moisture leads to decreased photosynthesis.
In boreal upland forests, low soil moisture decreases the rate of photosynthesis.