Nature World: Giant sequoias, some of the world's oldest and tallest trees, are under pressure from drought, wildfires and climate change, according to scientists with the US Geological Survey.
Although sequoias aren't yet in trouble - even with the ongoing drought in California - scientists worry that them and trees alike, such as ancient redwoods and bristlecone pines, will soon be feeling the heat.
These types of trees aren't built to withstand decades of dry and warming weather. Their seedlings and saplings...