United States Tree Cover

Credit: Image by Robert Simmon/USGS/NASA, Posted on: Tuesday, 14 October 2003, 06:00 CDT Download full size image

Trees are the interface between earth and sky. They draw water from the soil and give it back to the atmosphere as water vapor. They draw carbon from the air and give it back to the soil when their leaves, stems and trunks decay. Knowing where and how dense our planet’s forests are makes it easier for scientists to understand nature’s interrelated biological, geological, and chemical cycles. Up-to-date maps of tree cover guide forest and conservation policy, and over time, they can document human exploitation of forested landscapes. Satellite observations are the best way to make routine global maps of Earth’s tree-covered landscapes, as with this MODIS image.

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