Question:
Transpiration decreases as air becomes drier.
Response:
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.
To transform atmospheric CO2 into organic molecules, plants can use the energy from
soil nutrients.
sun light.
soil heat.
atmospheric oxygen.
Early spring is a tricky time for plants due to the combination of sunny but still quite cold days.
As plants respire, they release
oxygen.
carbon dioxide.
Photosynthesis releases oxygen whereas respiration releases CO2.
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.
What is the source of carbon that is assimilated in photosynthesis?
Soil nutrients
Atmospheric CO2
Soil water
Solar radiation
The annual cycle of photosynthesis mainly follows
the changes in CO2 concentration.
the changes in light.
the changes in air temperature.
the changes in soil temperature.
De-hardening in spring involves gradual re-hydration of the cells, recovery of photosynthetic capacity and a tight control of water loss.
Carbon becomes locked as part of the accumulating plant biomass as plants grow.
In some part of the stems, some photosynthesis may also occur.
Photosynthesis of a tree canopy is driven or influenced by
air humidity (VPD).
the total leaf area (LAI).
atmospheric CO2.
photosynthetically active solar radiation (PAR).
air temperature (T).
soil moisture (REW).
Photoinhibition means the decrease in photosynthesis due to
exposure to high temperature.
exposure to excess of light.
exposure to shortage of soil moisture.
exposure to excess of CO2.
Almost half of the total biomass of a tree may be allocated to the roots.
Carbon capture is performed by the green parts of plants via photosynthesis.
