Which explains why a fallen, rotting tree is considered a biotic factor and not an abiotic factor? It was once alive. It was never alive. It is part of an ecosystem. It provides shelter for living things.?

All things considered, biotic components are living or once-living things that are in the biological system. So despite the fact that the tree is spoiling and dead, it is as yet biotic since it was once alive.

OR

It was once alive