Question:
The air is moist if VPD (Vapour Pressure Deficit) is high.
Response:
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.
Photosynthesis shuts down if the temperature of previous night has been lower than
5 celsius.
-5 celsius.
-10 celsius.
0 celsius.
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.
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.
"Stage of acclimation" refers to the seasonality of
the growth activity.
the photosynthetic activity.
the litter fall activity.
the flowering activity.
High soil moisture leads to decreased photosynthesis.
In boreal upland forests, low soil moisture decreases the rate of photosynthesis.
The stage of acclimation at any given day depends on the temperatures experienced by the plant during the previous months.
The stage of acclimation at any given day depends on the temperatures experienced by the plant during the previous days.
REW stands for "Relative Extractable Water"
In trees, approximately half of the carbon bound in photosynthesis is used for construction of new biomass.
Respiration is a cellular process to obtain chemical energy from
the oxidation of water.
the oxidation of plant tissues.
the oxidation soil nutrients.
the oxidation of organic molecules.
When there is low soil moisture, plants close its stomata pores which then decreases photosynthesis.
Photosynthesis of a shoot can be measured by enclosing it within a chamber and following the change of
air temperature in this chamber.
PAR radiation next to the chamber.
water vapour concentration in the air of this chamber.
carbon dioxide concentration in the air of this chamber.
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.
