Where are most of the trees in the U.S.? Concentrations in areas like New York's Adirondack Park or the Cascade Range in the west are predictable, but other areas of dense biomass might surprise you.
A newly released map, shown below, depicts the density of aboveground vegetation across the contiguous United States. Created by NASA Earth Observatory, the map represents years of data compiled by the Woods Hole Research Center (WHRC) in Massachusetts.
WHRC's National Biomass and Carbon Dataset (NBCD) project, released in 2011, measured the density of organic carbon in vegetation across the United States.
The project, which used computer models, space-based radar, satellite sensors and ground-based data, was completed in six years in collaboration with the U.S. Forest Service and U.S. Geological Survey. According to NASA Earth Observatory, "It is possibly the highest resolution and most detailed view of forest structure and carbon storage ever assembled for any country."
According to Gizmodo, the map has a 30 meter resolution. Thus every four pixels represent one acre (10 pixels to a hectare). WHRC's Josef Kellndorfer claims that the entire biomass mapping project measured "about five million trees," reported NASA Earth Observatory.
Despite the biomass concentrations in some areas and the protection of old-growth forests, not all of the U.S. has adequate tree cover. According to the Daily Mail, American cities have lost a quarter of their trees in the past three decades. In fact, 634 million trees would be needed "to provide adequate canopy cover for the largest cities."
Check out the biomass density map below. According to NASA Earth Observatory, the map's darker spots represent "the areas with the densest, tallest, and most robust forest growth." Image courtesy of NASA Earth Observatory and Robert Simmon.