Trees are some of the largest and most widespread organisms on Earth, yet the true number of their species has been an enduring mystery. This lack of knowledge is detrimental to conservation efforts.

Every year, as the leaves turn and a chill enters the air, a familiar debate lights up social media feeds. The question is simple yet divisive: when is the right time to put up the Christmas tree?

Tree planting is one of the most popular fixes for the climate crisis. Trees’ ability to store carbon dioxide and prevent its release into the atmosphere — and they are natural! — but they may not be ...

Chal Landgren is a Christmas tree specialist at Oregon State University’s North Willamette Research and Extension Center in Aurora. Credit: Michelle Klampe, Oregon State University For those who ...

Tropical forests often harbor hundreds of species of trees in a square mile, but scientists often struggle to understand how such a diversity of species can coexist. In a study published in Science, ...

A professor's casual hike in the High Sierra turned into a new elevation record for California's highest tree, the Jeffrey pine, which wasn't formerly known to grow at extreme elevations. UC Davis ...

If a tree's rings are studied in a lab but no one hears them, do they make noise in the climate movement? An associate professor of oboe at the University of Arizona wondered. It led her to team up ...

Trees have special ways to defend themselves against insects, even animals eating their leaves. Learn how trees “talk to each other. Science Trek is available to stream on pbs.org and the free PBS App ...

A Patagonian cypress known as Lañilawal or Alerce Milenario may be the oldest tree on Earth. One researcher estimates it sprouted more than 5,000 years ago, well before the Great Pyramid of Giza was ...