Running bamboo is notoriously fast spreading and difficult to remove. What keeps its population balanced in the wild, and prevents it from crowding out the competition? I tried googling, but was inundated with gardening advice, horror stories, and assault / offensive gardening (some of the latter two presumably covering the same incident from both sides). My google-fu failed, I couldn’t really find any info about natural population controls of running bamboo in the thicket of tall tales and gardening advice.
Soil composition, access to water, temperature/seasons, mountains, salt water, etc.
It needs nutrients, water and heat, without access to that it just doesn’t grow or spread fast, or at all. So it can’t cross the deserts on its own. It can’t grow above a certain sea level so it can’t cross the mountains(Pandas regularly have to climb down the mountains to get more access to bamboo)., it can’t use salt water, it can’t grow if it gets too cold for long periods of time and so on. It’s just fast growing in ideal enviroments.
The big horror stories in regards to gardning, isn’t that it throws seeds around and just grows everywhere. It’s that once one seed as taken root, it will start growing rhizomes. Which are similar to roots, except it’s a stem that grows horizontally underground. And famously bamboo stems will grow through most things very quickly. So if you don’t put up a proper root barrier, they will grow across the nearby lawns and start sprouting roots and and shoots.