Wire tree sculptures have been around for at least 30 years as far as I can tell. Here is a link to trees designed by the late metal artist Omer Huremovic: YouTube Wire Tree Sculpture or an article on his works.
Here are three of my favorite artist, who have been designing sculptures for over 25 years:
Clive Madison – WireWood – http://www.clivemaddison.com/gallery-page.html
Kevin Iris – Kai Trees – https://www.deviantart.com/kaitrees
Kevin Chrislip – Art of the Tree – https://squareup.com/store/kevin-chrislip/
Learning How To Make Trees
I learned everything I needed to know to get started by another favorite artist:
Andy Elliot – http://andyelliottart.com
Check out Andy’s webpage My Work to see a couple of time-lapse videos on the creation of his tree sculptures.
To learn how to make a wire tree sculpture go to his tutorial page. View some of the available videos and purchase the full set for a very reasonable price. This is how I got started and allowed me to create over 120 trees in my first year.