Transpiration decreases as air becomes drier.
Plant respiration captures CO2.
Unlike photosynhesis, plant respiration captures atmospheric oxygen and releases carbon dioxide.
Carbon becomes locked as part of the accumulating plant biomass as plants grow.
Almost half of the total biomass of a tree may be allocated to the roots.
The rate of respiration decreases with temperature.
In some part of the stems, some photosynthesis may also occur.
Photosynthesis of a tree canopy is driven or influenced by
soil moisture (REW).
the total leaf area (LAI).
photosynthetically active solar radiation (PAR).
air temperature (T).
air humidity (VPD).
De-hardening in spring involves gradual re-hydration of the cells, recovery of photosynthetic capacity and a tight control of water loss.
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.
At low air humidity, a plant closes its stomata to prevent transpiration. The action also decreases photosynthesis
High soil moisture leads to decreased photosynthesis.
In boreal upland forests, low soil moisture decreases the rate of photosynthesis.
Plants open its stomata to avoid losing too much water.
Plant closes its stomata to avoid losing too much water.
A complex microbiota lives belowground, releasing carbon dioxide to the soil.
As plants respire, they release
What is the source of carbon that is assimilated in photosynthesis?