Nature | News

Where The Trees Are: MAP


A new map has been released showing where the largest and densest masses of trees are in the United States. NASA's Earth Observatory explains:

Josef Kellndorfer and Wayne Walker of the Woods Hole Research Center (WHRC) recently worked with colleagues at the U.S. Forest Service and U.S. Geological Survey to create such an inventory for the United States. The map above was built from the National Biomass and Carbon Dataset (NBCD), released in 2011. It depicts the concentration of biomass—a measure of the amount of organic carbon—stored in the trunks, limbs, and leaves of trees. The darkest greens reveal the areas with the densest, tallest, and most robust forest growth,

Over six years, researchers assembled the national forest map from space-based radar, satellite sensors, computer models, and a massive amount of ground-based data. It is possibly the highest resolution and most detailed view of forest structure and carbon storage ever assembled for any country.

Forests in the U.S. were mapped down to a scale of 30 meters, or roughly 10 computer display pixels for every hectare of land (4 pixels per acre). They divided the country into 66 mapping zones and ended up mapping 265 million segments of the American land surface. Kellndorfer estimates that their mapping database includes measurements of about five million trees.

Feed This post's comment feed


  1. I find it fascinating that the more urbanized East seems to have denser areas of trees than the Western states.

    Posted by: Derek | Jan 11, 2012 9:44:00 AM

  2. Interesting. The midwest is so bare! At least my hometown of Houston seems to be the starting point for Texas' smidgen of trees.

    Posted by: Christian | Jan 11, 2012 9:47:42 AM

  3. Go New England!

    Posted by: Eddie | Jan 11, 2012 10:00:32 AM

  4. @DEREK what you're missing is that much of the Western states are either high desert or mountains--if you look to the right of the dark green in Oregon and Washington, that's desert.

    Posted by: Rich | Jan 11, 2012 10:03:09 AM

  5. Rich is right, I've been to concerts at the Gorge in central WA and it's amazing to go from the lush forests around Seattle to the barren desert near the concert site. Doesn't make the non-concert parts of the trip much fun, either.

    Nice to see the Sierra Nevada's show up.

    Posted by: Henry Holland | Jan 11, 2012 10:18:31 AM

  6. I would have thought the LA bayou would have had more.

    Posted by: NoSleep4Sam | Jan 11, 2012 10:23:16 AM

  7. The Midwest has always been "bare"--it's called the Great of the world's largest grasslands. In the arid West, there is generally only enough moisture/precipitation for trees to grow at higher elevations, which explains why the green areas in the Far West correspond almost exactly to the map of mountain ranges. As for extreme south Louisiana, it has always been marshland similar to the Everglades in Florida--a grassland, just like the Great Plains, only inundated with water--which makes it impossible for most tree species to survive.


    Rick the Geography Major

    Posted by: Rick | Jan 11, 2012 10:40:22 AM

  8. Remember that California's central valley is mostly agriculture so outside of town areas there's not so many trees.

    Posted by: Vince | Jan 11, 2012 11:39:33 AM

  9. This is always apparent from the air on cross country flights. I always know I'm near home when I see the mass of trees outside the window.

    Posted by: James C | Jan 11, 2012 12:39:59 PM

  10. @Derek the western states are actually denser where there are trees. See how dark the green is?

    Posted by: KM | Jan 11, 2012 1:05:01 PM

  11. West of the 100th parallel, most areas receive less than 20 inches of rain a year and hence have few trees. The exception is the western slopes of the Rocky, Coastal, Sierra Nevada, and Cascade Mountains, where the moisture is effectively scraped out of clouds coming from the Pacific. The eastern slopes of the mountains and the areas to the eastern leeward side are extremely dry (and barren of trees).

    Posted by: DB | Jan 11, 2012 2:06:51 PM

  12. @Rick. A small correction in your midwest assertion. I grew up in NW Ohio. Ohio and Indiana were solid forest until cleared extensively for farmland. The plains thing doens't show up til Illinois and westward.. I realize everybody's recognition of what is 'midwest' is different. But peeps in OH consider themselves midwesterners for sure.


    Posted by: SononaBill | Jan 11, 2012 5:02:44 PM

  13. I'm from the west coast, I've spent most of my life within 30 miles of the Pacific Ocean, usually near either redwood or conifer forests. That dark green mass to the west means "home" to me. I've never understood how people can live without being surrounded by green growing things.

    To me, anything east of the Mississippi is East, and anything between the Mississippi and the Rockies is Midwest. Everything between the Sierras and the Rockies is, um... that space between with lots of rocks and dirt.

    Posted by: Jean | Jan 11, 2012 10:26:18 PM

  14. In the southeast, the Smoky Mountains National Park sticks out pretty well.

    Posted by: Rob | Jan 12, 2012 10:09:41 AM

Post a comment


« «Jon Stewart Rips CNN's Horrible New Morning Show for Making Celebrity Wake-Up Calls: VIDEO« «