Four years of too little water is killing millions of trees in the Sierra, yet some giant sequoias still thrive. Tree-climbing scientists are exploring sequoias branch by branch to find their secret.
Rawlings baseball bats have a big place in sports history. But now the ash trees used to make those iconic bats are threatened by an invasive beetle that's spreading in forests across the Northeast.
In Hawaii, more than 34,000 acres of forest have died from a mysterious disease. The blight is affecting a tree critical to Hawaii's natural water supply and cultural heritage.
Hardly anyone roasts American chestnuts over an open fire anymore: A blight all but wiped out the trees they grow on. Now the discovery of a soaring survivor could aid efforts to breed a hardier tree.
In Melbourne, Australia, the city assigned trees email addresses so citizens could report problems with them. Instead, people wrote thousands of love letters to their favorite trees.
Urban orchards are dropping everything from apples to avocados on Seattle, Bloomington, Ind., Boston and several other cities. Advocates say orchards can have longer lasting impact than gardens.
Once embraced by cities for its beautiful white flowers, disease resistance and ability to grow just about anywhere, the Callery pear is now considered a nuisance due to its smell and invasive nature.
The master luthier's violins and cellos include spruce from the Fiemme Valley. The forest still thrives, and its trees are still made into fine instruments.
This third-largest wildfire in California's history struck the area near Yosemite National Park. Since then, controversy has broken out over whether to log the trees and replant seedlings.