Question:
At low air humidity, a plant closes its stomata to prevent transpiration. The action also decreases photosynthesis
Response:
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.
To transform atmospheric CO2 into organic molecules, plants can use the energy from
sun light.
soil nutrients.
atmospheric oxygen.
soil heat.
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.
In some part of the stems, some photosynthesis may also occur.
Plants open its stomata to avoid losing too much water.
Plant closes its stomata to avoid losing too much water.
De-hardening in spring involves gradual re-hydration of the cells, recovery of photosynthetic capacity and a tight control of water loss.
Photosynthesis of a tree canopy is driven or influenced by
air temperature (T).
atmospheric CO2.
air humidity (VPD).
soil moisture (REW).
photosynthetically active solar radiation (PAR).
the total leaf area (LAI).
What is the source of carbon that is assimilated in photosynthesis?
Atmospheric CO2
Solar radiation
Soil nutrients
Soil water
As plants respire, they release
carbon dioxide.
oxygen.
Photosynthesis releases oxygen whereas respiration releases CO2.
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.
Plant respiration captures CO2.
Unlike photosynhesis, plant respiration captures atmospheric oxygen and releases carbon dioxide.
Carbon capture is performed by the green parts of plants via 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.
