Climate change: Weighing the world’s trees
In a forest just west of Chesapeake Bay, Geoffrey Parker wraps a tape measure around a young tulip tree. He jots the reading down in a field notebook, marks the tree with blue chalk and moves on to the next trunk. Parker spends about 10 seconds on each tree. Wrap, measure, record. Since 1987, he and others have logged more than 300,000 tree measurements at their plots in the Smithsonian Environmental Research Center (SERC) near Edgewater, Maryland.