Uses particle system for leaf distribution 3 trees of the same type. Each on it's own group for easy linking.
IMPORTANT
How to use it on other softwares :
I could not convert the particle system, because the file was TOO big. So, you will have to use the rectangles to distribute the leaves using the particle system on your software. Don't forget to set the rectangles (emitters) to not visible and to not render. So it will only render the leaves (particles) After building the first particle system, you can use it to the other trees too.
If it gets too heavy for you or your software, you can try to use the rectangles instead of the leaves. Use a leaf texture with transparent background. This way the three will be lighter, but will not look as good from a closet shot.