Question

what will happen if an ecosystem natural flow of energy is obstructed explain with example

Answer 1

Energy and nutrients are passed around through the food chain, whenone organism eats another organism. ... An example of energy flow in anecosystem would begin with the autotrophs that take energy from the sun. Herbivores then feed on the autotrophs and change the energy from the plant into energy that they can use.

Answer 2

If one trophic level is removed/destroyed, the flow of energy will be disrupted. In such case the preceding and succeeding trophic levels will either face acute shortage of food and perish leading to extinction, etc.

Example-Assuming energy flow is disrupted in plant-->deer-->lion . If deer is removed, plant will not be eaten and thus 10% energy will not transfer to next level.  Also, lions will perish and might face extinction due to lack of food.

(We assume that deers are only food for lions with respect to given food chain)

Thus energy flow is disrupted.

Hope it helps :)