ok tnx.
So, i suppose there isn't a way to tell maya to render tree only when it's close enough to camera?

Also, if i make instance objects, i suppose that could reduce memory useage. I was makeing test and watching memory usage and i saw that while regular 3 trees used 274 mb memory, while instanced only took 264mb. which is 10 mbs less and that's for only 3 trees. But is there any way to cut down memory usage even more? Even if it takes a bit longer to render?