Oldest trees are growing faster, storing more carbon as they age

Courtesy of Eurekalert.org:

In a finding that overturns the conventional view that large old trees are unproductive, scientists have determined that for most species, the biggest trees increase their growth rates and sequester more carbon as they age.

In a letter published today in the journal Nature, an international research group reports that 97 percent of 403 tropical and temperate species grow more quickly the older they get. The study was led by Nate L. Stephenson of the U.S. Geological Survey Western Ecological Research Center. Three Oregon State University researchers are co-authors: Mark Harmon and Rob Pabst of the College of Forestry and Duncan Thomas of the College of Agricultural Sciences.

The researchers reviewed records from studies on six continents. Their conclusions are based on repeated measurements of 673,046 individual trees, some going back more than 80 years.

This study would not have been possible, Harmon said, without long-term records of individual tree growth. “It was remarkable how we were able to examine this question on a global level, thanks to the sustained efforts of many programs and individuals.” Continue reading

Younger People Have “High Definition” Memories

Courtesy of Parent Herald:

It’s not that younger people are able to remember more than older people. Their memories seem better because they are able to retrieve them in higher definition. So says Philip Ko of Vanderbilt University in the US, in a study that sheds light on how differences in the behavioral and neural activity of younger and older adults influence the different generations’ ability to store and recall memories. The findings appear in the journal Attention, Perception & Psychophysics, published by Springer.

Under the mentorship of Dr. Brandon Ally, Ko led the research team to focus on visual working memory, a person’s ability to briefly retain a limited amount of visual information in the absence of visual stimuli. Their examination of why this function is reduced during the course of healthy aging took the multiple stages of encoding, maintenance, and the retrieval of memorized information into account.

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