When I started learning about the massive inputs of organic matter in the US prior to European colonization in "Edible Forest Gardens Vol1" I was utterly dumbfounded by the sheer amount of waste animals would drop into a forest. Picture if you will a flock of pigeons what is so thick it blots out the sun, then they all roost for an hour or so evacuating their bowels to the forest floor. Audobun found as much as 3" of bird waste dropped in a single sitting by the pigeons.
Think about that a moment... so much life it obscures the vision of the sun, then suddenly 3" of white poop all over a forest floor. That signals to me that organic matter can be handled by a healthy forest in very large amounts. However the area needs to be healthy, and that is pretty rare on Earth now.