The proportion of $PAR$ in the incident solar radiation is ........

In primary succession in water,the pioneer species are

Which of the following is a functional aspect of an ecosystem?

The character of an ecosystem is determined by the environmental factor which is in the shortest supply. This is known as the:

Both hydrarch and xerarch successions lead to ..........

In the North East region of India,during the process of jhum cultivation,forests are cleared by burning and left for regrowth after a year of cultivation. How would you explain the regrowth of forest in ecological terms?