Functional traits of Giant Sequoia crown leaves respond to environmental threats

Hundreds of feet above the ground, atop a giant sequoia tree, as many as 2 billion leaves vie for resources. Twigs teem with leaves growing long and splayed or short and tight, depending on their placement in the crown. Leaves that establish live for up to 20 years, drawing water up the tree's trunk and sending nutrients down, while the trunk amasses wood and survives for thousands of years. The giant sequoia's size—-it's the most massive non-fungal organism on Earth—-is possible in