Tropical rainforest once extended east from the Congo Basin into what is now western Kenya. That’s almost all gone now, ...

FLAGSTAFF — As the morning light spread across the San Francisco Peaks, a group of about 50 volunteers from across Arizona ...

A pine tree (front) is dubbed ″President's Tree″ in a forest fostered by Korean hygiene product manufacturer Yuhan Kimberly and a forestry service in Selenge in Mongolia on April 17.

An invasive fungus called white pine blister rust is spreading rapidly through Montana's limber pine forests. Brought to ...

Native Monterey pine trees in Cambria, California, are struggling to survive drought and diseases. Cal Fire wants to manage the forest and reduce fire danger.

California’s drought and bark-beetle infestation killed more than 129 million trees between 2012 and 2016 in the Sierra Nevada. But amid the devastation stood some survivors.

Downed trees on Don Hardin’s Black Forest property show the blue stain from the mountain pine beetle on July 3. Hardin is waiting to remove the timber before taking down more of the infested trees.

Environmentalists and local leaders oppose a federal plan to thin trees from a scenic spot deep inside Los Padres National Forest.

Bristlecone Pine Forest manager John Louth said signs of climate change are clear: Warmer temperatures cause more trees to sprout above 10,000 feet.