Question:
When there is low soil moisture, plants close its stomata pores which then decreases photosynthesis.
Response:
Plants open its stomata to avoid losing too much water.
Plant closes its stomata to avoid losing too much water.
Early spring is a tricky time for plants due to the combination of sunny but still quite cold days.
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
soil nutrients.
atmospheric oxygen.
sun light.
soil heat.
Photosynthesis of a tree canopy is driven or influenced by
photosynthetically active solar radiation (PAR).
atmospheric CO2.
air humidity (VPD).
the total leaf area (LAI).
air temperature (T).
soil moisture (REW).
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.
Photoinhibition means the decrease in photosynthesis due to
exposure to excess of CO2.
exposure to excess of light.
exposure to shortage of soil moisture.
exposure to high temperature.
In general, the more carbon dioxide that is available to the plant, the faster the rate of photosynthesis - if other factors are favourable.
As plants respire, they release
carbon dioxide.
oxygen.
Photosynthesis releases oxygen whereas respiration releases CO2.
A complex microbiota lives belowground, releasing carbon dioxide to the soil.
High soil moisture leads to decreased photosynthesis.
In boreal upland forests, low soil moisture decreases the rate of photosynthesis.
Plant respiration captures CO2.
Unlike photosynhesis, plant respiration captures atmospheric oxygen and releases carbon dioxide.
Transpiration decreases as air becomes drier.
The annual cycle of photosynthesis mainly follows
the changes in air temperature.
the changes in light.
the changes in soil temperature.
the changes in CO2 concentration.
