So strong were Dartmouth’s ties to the trees that it got the nickname “The College of a Thousand Elms.” Then, one by one, the College had to cut them down. By the 1980s, more than 200 had been lost.

He held a photo from Dr. Seuss’ beloved eco-minded book, “The Lorax,” depicting a stump where a Truffula tree had been slashed. Just around the school’s corner, more than a dozen real-life ...