Board Thread:Theories and Speculation/@comment-26422475-20181104100351/@comment-1512913-20181104105111

Finally an interesting topic. Most of these forum topics are stupid or toxic. People are more interested discussing which character's got the bigger dick than an aspect of the series such as chakra.

Now, what we know:
 * the Earth's God Tree got nurtured by blood of those slain in battle, this comes from 4th Databook.
 * the anime filler stated the God Tree was draining Earth of its nature energy, slowly killing everything in its vicinity.
 * the canon has not provided 100% clear answer about where the God Trees come from, but in the anime filler, we saw something pretty much fall from the sky on Earth, from which the tree then began to grow. But we have strong hints that the Otsutsuki Clan is pretty much responsible for the God Trees, since Momoshiki could even make new ones casually.

So this suggests, that the God Trees are pretty much parasitic organisms made by the Otsutsuki Clan, possibly thrown at planets with life on them, in order for the God Trees to drain the planets and their inhabitants in order to produce chakra fruits, which the Otsutsuki would then later come to harvest.

So pretty much canon says the trees feed on life to grow and produce chakra fruits, with anime stating that they drain natural energy, the latter can still be true, but the filler should not be taken at face value.

But the canon kind of supports this, since we saw 2 barren worlds harvested by Momoshiki. So my theory is, that the blood of living organisms nurtures the God Trees, while in the meantime, the God Trees slowly drain surrounding natural energy to kill all life on the planets, probably so the Otsutsuki can later safely come to collect the fruits, without having to engage in battles with still living civilizations.