Unlike humans, old trees grow faster than young ones, new study shows
97% of species studied grew faster over time
It makes intuitive sense to use that most living things, us included, have a growth spurt when they're young, and then slow down or stop. But in a new paper titled Rate of tree carbon accumulation increases continuously with tree size published in the prestigious scientific journal Nature, scientists explain how they've found that this doesn't apply to trees; in fact, the inverse is true. Older ones grow faster than younger ones. This is an important finding because it goes against a widely held belief that large trees are not as productive as small ones when it comes to taking CO2 out of the atmosphere.
The researchers looked at 403 tropical and temperate species of trees, and found that 97% of them were growing at increasingly faster rates as they aged.
"Large, old trees do not act simply as senescent carbon reservoirs but actively fix large amounts of carbon compared to smaller trees," the authors of the study write. "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."
Even trees that aren't growing taller keep getting wider and thus turn CO2 into wood at increasing rates.
The study was a collaboration between 38 scientists around the globe and was based on 673,046 individual trees using 80+ years of data. Now that's a broad sample!