Study Finds Oldest Trees Grow Slowest - Even as Youngsters

Feb 05, 2009

(PhysOrg.com) -- A newly published study has found that the oldest trees in the forest also grow the slowest - and they likely aren’t the prettiest.

These ancient trees, whether they are evergreens or hardwoods, often are stunted and may be growing in a harsh micro-climate, such as in poor soil, in the shade of larger neighbors, or on a slope. Slow-growing trees “co-mingle” with faster-growing trees, the study found, and why the trees grow at different rates likely is a combination of genetics and environment.

“It has always been suspected but never proven that within a species, old trees grow slower,” said Bryan Black, an assistant professor of forestry at Oregon State University, who works out of OSU’s Hatfield Marine Science Center in Newport, Ore. “The oldest trees, though, are not necessarily the biggest. Even though they have longer lifespans, the long-lived trees grow so slowly that they rarely get as big as their faster-growing, shorter-lived counterparts.

“That creates implications for management because this slow growth is apparent within the first 50 years,” Black added. “If the goal for a certain forest is timber production, resource managers may want to develop strategies to enhance fast-growing trees. The flip side would be logical if the goal was to produce an old-growth forest.”

Results of the meta-analysis study were published in the recent issue of the journal Ecoscience.

Black, who often works with marine scientists, said the study was inspired by his collaboration with fisheries research, where slow growth among long-lived individuals has long been accepted. A dendrochronologist, he began his research looking at how tree rings might contain clues to climate change and has studied similar age rings in the shells of clams and other bivalves and in the otoliths (ear bones) of long-lived fish.

In his analysis of old trees, Black combed through tree-ring studies looking at Douglas-fir, white oak, ponderosa pine and eastern hemlock and found the same held true regardless of species or location - old trees grow more slowly, and it begins early in their lives.

“Faster growing trees may put all of their energy into growth and burn out before they can achieve really old age,” he said. “Slow-growing trees may invest a lot in producing strong wood and defense mechanisms against insects and disease and never rise above the forest canopy.”

Why these different trees co-mingle is something of a mystery, Black admits. It may be a “tortoise-and-hare” situation.

Rapidly growing trees may occupy space more quickly, reach sexual maturity earlier, and are more prone to frequent, catastrophic disturbances, including flood, fire and windstorms, Black said. They also die at a younger age. Meanwhile, the slower growing trees channel their energy into structural support and defense compounds, don’t burn out from reproducing, and slowly-but-surely outpace their mercurial cousins.

These Methuselah-like trees are, in a word, “rugged,” Black said.

“These long-lived trees grow slowly - but not too slow,” Black said. “It seems to be some kind of balance that the trees grow at just the right pace for their environment and the conditions stop just short of causing them to die. The lesson is that there may be even greater diversity to our forests than we had realized.

“Moreover, this study adds to the growing body of research that links slow growth with longevity,” Black added. “It’s certainly true of animal species and apparently it is a phenomenon also shared by trees.”

Provided by Oregon State University

Explore further: Expedition finds Nemo can travel great distances to connect populations

add to favorites email to friend print save as pdf

Related Stories

The devastating spread of the mountain pine beetle

Aug 27, 2014

When the mountain pine beetle began blazing a path across forests in British Columbia and Alberta, nobody could have imagined the extent of the damage to come. But as the insect devastated pine forests and ...

Brain of world's first known predators discovered

Jul 16, 2014

An international team of paleontologists has identified the exquisitely preserved brain in the fossil of one of the world's first known predators that lived in the Lower Cambrian, about 520 million years ...

Blueprints finalized for digital archive

Jun 23, 2014

One of the oldest and most complete historical archives in the world is a step closer to being developed into an open digital archive. The Lombard Odier Foundation is joining as a funding partner to take ...

Marine reserves havens for large snapper

Apr 01, 2014

The new study led by scientists from Massey University's Coastal-Marine Research Group (CMRG) has estimated the effects of three Hauraki Gulf marine reserves on snapper, by comparing numbers of fish inside ...

Recommended for you

Stem cells use 'first aid kits' to repair damage

32 minutes ago

Stem cells hold great promise as a means of repairing cells in conditions such as multiple sclerosis, stroke or injuries of the spinal cord because they have the ability to develop into almost any cell type. ...

Tropical fish a threat to Mediterranean Sea ecosystems

2 hours ago

The tropical rabbitfish which have devastated algal forests in the eastern Mediterranean Sea pose a major threat to the entire Mediterranean basin if their distribution continues to expand as the climate ...

User comments : 0