The Great Darkness

[Imbefana]

My question I suppose is one of practicality for Melkor and Sauron. Suppose Sauron won the War of the Ring, recovered the One and brought the land into a second darkness. Assuming he had the power to block out all light of the Sun, Moon, and stars, how could his dominion live on? Light is essential at the very least for plant life (necessary for fuel, food, and building materials, not to mention ecosystems and food chains). I think I remember reading somewhere Sauron's hordes in Mordor were fed by distant lands (of men?) to the far east and south.

So, if he had complete dominion, would he give the necessary sunlight to certain lands so all his orcs would not die of starvation, or end up consuming each other?

I know light is a symbol of good, but is it somehow not necessary in Middle Earth for the survival of the forces of evil? Evil must first come from morphing the good.

This is most likely is a rather silly question, but I was just wondering how exactly it would work, seeing how Melkor accomplished an extremely powerful domain during the first Great Darkness.

Or perhaps I should think of it as unanswerable and accept it as part of Tolkien's universe?

Thanks a bunch!