I am from <Link removed by moderator> Indonesia and I want to ask a question.
I dug up a wild Populus trichocarpa growing on the outside edge of a very rocky and dry logging road at about 3,000 foot elevation in August. I nursed it into a ceramic pot and it looks like it will make it. I've no idea how old it is. The site it grew on was very severe. See photo attached.

My question is, can this tree be trained like a conventional bonsai? Will its lateral buds respond if/when I nip off a leading bud? Is there a trick in pruning its root system?
I'd like to give it a shot, but don't see many hits when doing a search on cottonwood and bonsai - so could use your advice, please.