Question

The carbon dioxide fertilization effect is
(A) Warming effect of carbon dioxide
(B) Photosynthetic enhancement of elevated carbon dioxide level
(C) Both summer and winter rainfall at higher latitudes
(D) Poleward shifting of temperate zero

Answer 1

Hint: Carbon dioxide fertilization effect, also known as carbon fertilization effect is the increased rate of photosynthesis due to the increased amount of carbon dioxide in the atmosphere. This effect depends on many other factors like temperature, plant species, water, and soil mineral nutrients.

Complete answer: Carbon dioxide fertilization effect or carbon fertilization effect is the increased rate of photosynthesis in producers due to elevated carbon dioxide levels in the atmosphere. It leads to increased biomass. This effect varies depending on factors like temperature, climatic conditions, plant species, water availability, and soil mineral nutrition. However, due to increased photosynthetic activity, the temperature increases leading to a decrease in photosynthesis. An increased level of carbon dioxide results in lowering the concentration of minerals in plant tissues. It is observed that there is an initial increase in net primary productivity which is not sustained.

Understanding the options one by one,
Option (A)-Warming effect of carbon dioxide: The carbon fertilization effect leads to the warming of Earth and the atmosphere, but this is not the ideal definition. Hence, this is not the correct answer.
Option (B)-Photosynthetic enhancement of elevated carbon dioxide level: The carbon dioxide fertilization effect is defined as the increased photosynthetic activity due to elevated carbon dioxide levels. Therefore, this is the correct answer.
Option (C)-Both summer and winter rainfall at higher latitudes: The carbon fertilization effect is not concerned with rainfalls and hence this is not the correct answer.
Option (D)-Poleward shifting of temperate zero: Carbon dioxide is the reason for global warming leads to a poleward shift.
Therefore, Option (B) is correct.

Note: The carbon fertilization effect, even though it increases photosynthetic activity, is not sustainable. It actually causes more hazards than benefits. It leads to an increase in temperature, decrease in mineral nutrition in plant tissues. Therefore, knowing the exact definition and effects of this phenomenon is essential.