Not only do older trees grow faster they also store more carbon than younger ones, per new research appearing in the journal Nature. Contrary to the commonly held belief that trees become unproductive as they grow older, new research tells otherwise.
As part of their research, the study authors reviewed records from studies on six continents, including measurements from over 650,000 trees belonging to 403 tropical and temperate species per redOrbit. They found that 97 percent of the older trees grow more quickly as they advance in age and remove more carbon than expected from the atmosphere.
“Rather than slowing down or ceasing growth and carbon uptake, as we previously assumed, most of the oldest trees in forests around the world actually grow faster, taking up more carbon,” added Smithsonian Tropical Research Institute staff scientist Richard Condit. “A large tree may put on weight equivalent to an entire small tree in a year.”
According to the researcher’s fast growth in giant trees such as the redwood is the rule, but certainly not the exception. The largest types of trees can surpass 1,300 pounds per year. Their paper also includes studies from forests in the Pacific Northwest, measuring growth in trees like the western hemlock and the Douglas fir.
“In human terms, it is as if our growth just keeps accelerating after adolescence, instead of slowing down. By that measure, humans could weigh half a ton by middle age, and well over a ton at retirement,” lead author Nate L. Stephenson, a research ecologist at the US Geological Survey (USGS) Western Ecological Research Center, said in a statement Wednesday.
The authors study authors explain that their findings prove that older trees “do not act simply as senescent carbon reservoirs but actively fix large amounts of carbon compared to smaller trees; at the extreme, a single big tree can add the same amount of carbon to the forest within a year as is contained in an entire mid-sized tree.”