the question is :
how can i use this tree not changing it and not saving another copy of this nodes in memory and displaying only one part of it to client.
Multiple trees can share the same data model (e.g. session- or application-scoped). Tree component doesn't modify model by itself, only nested input components (if any) bound to tree nodes can do that.
And as you've already switched caching off using attribute, component won't create copies of data model.