On Thursday, we signed up for a nature walk tour run jointly by Aspen Ski Company and ACES, the Aspen Center for Environmental Services.Nick was our guide on the nature walk. He was recently graduated from college, where he majored in ecology. Here, he's pointing out the way aspen trees lose their lower branches so that they spend their energy on photosynthesis up high where the Sun is shining. Each of the small knots on the trunk represents a fallen branch. Aspens also use their trunks to perform photosynthesis, accounting for the greenish color of the bark.
