Well, as near as I can interpret this, Sylvari are the Pale Tree’s best approximate ‘copy’ to a humanoid shape which the Asura went over in a explanation about how the bodies’ of Ronan’s family gave the Pale Sapling a basic blueprint for her race. So, the body would be the same but made of different materials as mentioned before e.g. vines for muscles, bark for skin, you get the idea. That means that, in theory, that the ‘equipment’ should be there and it should work the same but the reproductive organs that humans have, Sylvari don’t have a plant equivalent since plant reproduction is different from animal reproduction.