When more that one tree of the same kind is added to the scene, the resulted export size of those trees becomes squared

Example:

One Azalea tree is added to the scene - the export scene file size is 22 Kb (slide 1) and number of vertices for the tree is 414 (slide 2)

Five Azalea tree is added to the scene - the export scene file size is 426 Kb (slide 3) and number of vertices for EACH of 5 trees is 2070 (slide 4)

So having 5 same trees in the scene resulted in having 25 trees in the export
Having 10 same trees would result in 100 trees in the export.