Question

Which of the following factors (given .below) determines the vegetation of any area?

(i) pH of soil.

(ii) Mineral composition of the soil.

(iii) Water holding capacity of the soil.

(iv) Precipitation.

A. (i) and (ii)
B. (ii) and (iii)
C. (i), (ii) and (iii)
D. (i), (ii), (iii) and (iv)

Answer 1

Hint: Type of vegetation of any area depends on the type of soil it has. There are different abiotic as well as biotic components that determine the type of vegetation. Soil is one of the important abiotic factors. Soil is also present in different conditions such as water content, salt concentration, etc.

Step-by-step solution:
Major abiotic factors include temperature, water, light and soil. Soil is also of different types, such as sandy soil, clay soil and loam soil. Vegetation on each soil is of different types. Hence the soil properties matter in the process of vegetation.
The pH of the soil determines the vegetation. The optimal pH for the growth of the plants is between 6 to 7.5. On acidic or alkaline soil, most of the plants can not grow.
Minerals are required for the proper growth of plants. Deficiency or absence or excess of some minerals may cause abnormal growth or no growth in a given area if the soil has high salt content, the plants that can tolerate the high amount of salt, such as halophytes, can be grown. Hence, the proper mineral composition of the soil determines the type of vegetation that can occur in a given area.
Soil with high water holding capacity will be seen in forests and the one with low water holding capacity will be seen in deserts. Water holding capacity depends on the particle size of the soil. Hence water holding capacity is a major factor that determines the type of vegetation.
Precipitation can occur as rainfall or snow. The amount of rainfall and periodicity determines the type of forest in the type area, evergreen or deciduous, etc.
Hence the type of vegetation depends on pH, mineral composition, the water-holding capacity of the soil and precipitation.

So, option D is correct.

Note: The abiotic conditions of different habitats vary. Organisms living in such extreme conditions manage to overcome stressful conditions by maintaining their homeostasis.