Showing posts with label Nature (Journal). Show all posts
Showing posts with label Nature (Journal). Show all posts

Friday, January 24, 2014

Report: Trees Grow Faster, Store More Carbon as They Age


Jan 16, 2014 by Sci-News.com

According to an international group of scientists led by Dr Nate Stephenson of the US Geological Survey, most of tropical and temperate tree species grow more quickly and sequester more carbon as they grow older.
Eucalyptus bridgesiana tree.
Eucalyptus bridgesiana tree.
The report, published in the journal Nature, is based on repeated measurements of 673,046 individual trees belonging to 403 species, some going back more than 80 years.
“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. A large tree may put on weight equivalent to an entire small tree in a year,” said co-author Dr Richard Condit from the Smithsonian Tropical Research Institute.
“This report would not have been possible 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,” added co-author Dr Mark Harmon of Oregon State University.
“Extraordinary growth of some species, such as Australian mountain ash – also known as eucalyptus – (Eucalyptus regnans), and the coast redwood (Sequoia sempervirens) is not limited to a few species,” Dr Stephenson said.
“Rather, rapid growth in giant trees is the global norm and can exceed 600 kg per year in the largest individuals. 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.”
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Sunday, November 3, 2013

Water will not be the only resource in short supply, as drylands of the world become even drier

FARM NEWS

Plant production could decline as climate change affects soil nutrients





The cliff face of Cedar Mesa, in southeast Utah, overlooks one of many sites sampled in the world's drylands.

by Staff Writers Flagstaff AZ (SPX) Nov 04, 2013

As drylands of the world become even drier, water will not be the only resource in short supply. Levels of nutrients in the soil will likely be affected, and their imbalance could affect the lives of one-fifth of the world's population.
That includes people living in Arizona, who may be in for a dustier future.
The findings are presented in a study published in Nature that details how soil changes may occur and discusses the implications. Co-author Matthew Bowker, assistant professor of forest soils and ecosystem ecology at Northern Arizona University, was involved with the project since 2009.
Bowker explained that most of the 17 nutrients that plants need to grow to their potential are soil resources, such as nitrogen and phosphorus. The statistical model he helped develop for the study suggests that as the climate becomes more arid, nitrogen will decrease and phosphorus will increase.
"Both are essential for plant growth, and both are typical components of fertilizer, but both need to be around in the right quantities for plant growth to proceed most efficiently," Bowker said.

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