When they aren't providing shade, ridding air and water of toxins, and generally making our world more beautiful, most trees are being chopped down, according to Fast Co. Exist. But after a near-death experience nearly 20 years ago, a man named David Milarch was inspired to help. 

He began archiving "champion trees," a collection that evolved into the Archanglel Ancient Tree Archive, which includes "the 100 most important that are absolutely necessary to sustain the ecosystems that human beings need," he said. 

Along with his two sons, Milarch traveled the world from the Netherlands to Ireland "to identify the six oldest, largest, and strongest specimens of each type, collecting cuttings, then cloning in propagation facilities," wrote Fast Co. Exist. The process wasn't easy and often involved scaling the tree tops—which can be up to 40-feet high—to find the best tissue for cloning. 

Once the needles were propagated in a lab, Milarch planted the trees on college campuses, where they could be studied up-close. Sending "researchers into trees" is too "expensive and hard," he said.  

A book on Milarch called The Man Who Planted Trees is due this year from New York Times' reporter Jim Robbins.

Could cloning extinct animals be next? 

[via Fast Co. Exist]