…from the Smithsonian Institution…
“Parker began his tree census work Sept. 8, 1987—his first day on the job at the Smithsonian. He recorded and tracked trees 2 centimeters or more in diameter, identifing them to species and marking each tree’s exact coordinates on a map.
“By knowing its species and diameter, McMahon, who specializes in data-analysis and forest ecology, is able to calculate the biomass of a tree. “Walking in the woods helps, but so does looking at the numbers,” he says.
““We made a list of reasons these forests could be growing faster and then ruled half of them out,” Parker says. The reasons that remained included increased temperature, a longer growing season and increased levels of atmospheric CO2.”