A complex microbiota lives belowground, releasing carbon dioxide to the soil.
Early spring is a tricky time for plants due to the combination of sunny but still quite cold days.
What is the source of carbon that is assimilated in photosynthesis?
Carbon becomes locked as part of the accumulating plant biomass as plants grow.
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.
De-hardening in spring involves gradual re-hydration of the cells, recovery of photosynthetic capacity and a tight control of water loss.
To transform atmospheric CO2 into organic molecules, plants can use the energy from
Transpiration decreases as air becomes drier.
Photoinhibition means the decrease in photosynthesis due to
exposure to shortage of soil moisture.
exposure to excess of light.
exposure to excess of CO2.
exposure to high temperature.
exposure to excess of CO2
exposure to excess of light
exposure to shortage of soil moisture
exposure to high temperature
The rate of respiration decreases with temperature.
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.
Photosynthesis of a tree canopy is driven or influenced by
air temperature (T).
air humidity (VPD).
the total leaf area (LAI).
soil moisture (REW).
photosynthetically active solar radiation (PAR).
As plants respire, they release
When there is low soil moisture, plants close its stomata pores which then decreases photosynthesis.