As VPD increases, photosynthesis decreases due to the closure of the stomata.
REW stands for "Relative Extractable Water"
The air is moist if VPD (Vapour Pressure Deficit) is high.
Photosynthesis shuts down if the temperature of previous night has been lower than
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.
When there is low soil moisture, plants close its stomata pores which then decreases photosynthesis.
"Stage of acclimation" refers to the seasonality of
the photosynthetic activity.
the growth activity.
the flowering activity.
the litter fall activity.
Respiration is a cellular process to obtain chemical energy from
the oxidation of plant tissues.
the oxidation of water.
the oxidation soil nutrients.
the oxidation of organic molecules.
Photosynthesis of a shoot can be measured by enclosing it within a chamber and following the change of
water vapour concentration in the air of this chamber.
air temperature in this chamber.
carbon dioxide concentration in the air of this chamber.
PAR radiation next to the chamber.
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.
In trees, approximately half of the carbon bound in photosynthesis is used for construction of new biomass.
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.
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.
Since stomata are the same pores through which carbon dioxide enters into the leaves, the result of their closure is a reduction in photosynthesis.