Free for all to use. Public domain (CC0).
The zip file you download will contain 2 PNG files :
The Preview, which is the file you see on this deviation page. It measures 1300 by 770 pixels at 90 dpi.
All 8 trees on one page, without the background. It measures 2700 by 2500 pixels at 90 dpi.
Done in Inkscape.
More Stuffs you can download in my RESOURCES FOLDER .