A new look at old forests

MBL study revises theory on growth and carbon storage in mature trees

2014-06-03

(Press-News.org) WOODS HOLE, Mass.— As forests age, their ability to grow decreases, a new study by Marine Biological Laboratory (MBL) scientists and colleagues has determined. Since most U.S. forests are maturing from regeneration that began about 100 years ago when extensive clear-cutting occurred, the study suggests the future growth of U.S. forests will decline.

"All forests are in succession: They get old, die (due to fire, insects, hurricane, etc.), and regenerate. This paper improves on a fundamental theory in ecosystem development: How a forest evolves over time. It demonstrates that when a forest gets old, its ability to grow decreases because it takes up less carbon dioxide and sunlight and respires less, just like an animal or human being," says lead author Jianwu (Jim) Tang, an assistant scientist in the MBL Ecosystem Center.

The traditional theory had posited that when a forest gets old, it would respire more and use more energy. But Tang and colleagues found both energy production (photosynthesis) and energy consumption (respiration) decrease with age, resulting in an overall decrease in growth rates.

"Forests are also big carbon sinks that offset, in part, human-induced carbon emissions. Our finding also suggests the forest carbon sink may decrease in the U.S. because of the slowdown in forest growth," Tang says. "In some other countries, young forests could grow faster and take up more carbon dioxide. To mitigate human-induced climate change and global warming, we may either plant more forests in non-forested lands, decrease use of fossil fuels, or do both."

INFORMATION: Citation:

Tang J, Luyssaert S, Richardson AD, Kutsch W, Janssens IA (2014) Steeper declines in forest photosynthesis than respiration explain age-driven decreases in forest growth. Proc. Natl. Acad. Sci.: doi/10.1073/pnas.1320761111.

The Marine Biological Laboratory (MBL) is dedicated to scientific discovery and improving the human condition through research and education in biology, biomedicine, and environmental science. Founded in Woods Hole, Massachusetts, in 1888, the MBL is a private, nonprofit institution and an affiliate of the University of Chicago.

[Attachments] See images for this press release:

ELSE PRESS RELEASES FROM THIS DATE:

With developing world's policy support, global renewable energy generation capacity jumps to record

2014-06-03

The number of emerging economy nations with policies in place to support the expansion of renewable energy has surged more than six-fold in just eight years, from 15 developing countries in 2005 to 95 early this year. Those 95 developing nations today make up the vast majority of the 144 countries with renewable energy support policies and targets in place, says REN21's Renewables 2014 Global Status Report. And the rise of developing world support contrasts with declining support and renewables policy uncertainty and even retroactive support reductions in some European ...

Liver cancer vaccine effective in mice

2014-06-03

AUGUSTA, Ga. – Tweaking a protein expressed by most liver cancer cells has enabled scientists to make a vaccine that is exceedingly effective at preventing the disease in mice. Alpha-Fetoprotein, or AFP – normally expressed during development and by liver cancer cells as well – has escaped attack in previous vaccine iterations because the body recognizes it as "self," said Dr. Yukai He, immunologist at the Medical College of Georgia and Georgia Regents University Cancer Center. Liver cancer is among the fastest-growing and deadliest cancers in the United States with ...

Spiders know the meaning of web music

2014-06-03

Spider silk transmits vibrations across a wide range of frequencies so that, when plucked like a guitar string, its sound carries information about prey, mates, and even the structural integrity of a web. The discovery was made by researchers from the Universities of Oxford, Strathclyde, and Sheffield who fired bullets and lasers at spider silk to study how it vibrates. They found that, uniquely, when compared to other materials, spider silk can be tuned to a wide range of harmonics. The findings, to be reported in the journal Advanced Materials, not only reveal more ...

'Liquid biopsy' offers new way to track lung cancer

2014-06-03

Scientists have shown how a lung cancer patient's blood sample could be used to monitor and predict their response to treatment – paving the way for personalised medicine for the disease. The recent study, published in the journal Nature Medicine, also offers a method to test new therapies in the lab and to better understand how tumours become resistant to drugs. Small cell lung cancer (SCLC) is an aggressive disease with poor survival and new treatments are desperately needed. In many cases the tumour is inoperable and biopsies are difficult to obtain, giving scientists ...

New insight into drug resistance in metastatic melanoma

2014-06-03

A study by scientists in Manchester has shown how melanoma drugs can cause the cancer to progress once a patient has stopped responding to treatment. Their findings suggest that using a combination of targeted therapies may be a more effective approach in the clinic. Melanoma is a form of cancer that develops from melanocytes – the pigment-producing cells in skin. Advanced metastatic melanoma – where the cancer has spread throughout the body – is associated with poor survival, so new treatments are urgently needed. In about 50% of melanoma cases, the tumour contains ...

Notifying speeding mariners lowers ship speeds in areas with North Atlantic right whales

2014-06-03

There are only around 500 North Atlantic right whales alive today. In an effort to further protect these critically endangered animals, a recent NOAA regulation required large vessels to reduce speed in areas seasonally occupied by the whales. The policy of notifying--but not necessarily citing--speeding vessels in protected areas was effective in lowering their speeds, helping to protect these magnificent creatures from ship collisions, while keeping punitive fines to mariners to a minimum. A NOAA regulation, instituted in December 2008, requires vessels 65 feet or greater ...

Findings show benefit of changing measure of kidney disease progression

2014-06-03

Developing therapies for kidney disease can be made faster by adopting a new, more sensitive definition of kidney disease progression, according to a study published by JAMA. The study is being released early online to coincide with its presentation at the European Renal Association-European Dialysis and Transplant Association Congress. Chronic kidney disease (CKD) is a worldwide public health problem, with increasing prevalence, poor outcomes, and high treatment cost. Yet, despite the avail¬ability of simple laboratory tests to identify people with earlier stages of ...

Columbia Nursing study exposes infection risks in home health

2014-06-03

(NEW YORK, NY, June 3, 2014) – Millions of Americans depend on home health care services to recover from surgeries and hospital stays, as well as to manage daily life with chronic conditions. But all too often, evidence-based practices for preventing infections aren't followed when care is provided at home, leaving patients vulnerable to serious and potentially fatal complications. A study by researchers at Columbia University School of Nursing, published in the American Journal of Infection Control, found that unsterile living conditions and untrained caregivers contribute ...

Proteins 'ring like bells'

2014-06-03

As far back as 1948, Erwin Schrödinger—the inventor of modern quantum mechanics—published the book "What is life?" In it, he suggested that quantum mechanics and coherent ringing might be at the basis of all biochemical reactions. At the time, this idea never found wide acceptance because it was generally assumed that vibrations in protein molecules would be too rapidly damped. Now, scientists at the University of Glasgow have proven he was on the right track after all. Using modern laser spectroscopy, the scientists have been able to measure the vibrational spectrum ...

Molecular 'scaffold' could hold key to new dementia treatments

2014-06-03

Researchers at King's College London have discovered how a molecular 'scaffold' which allows key parts of cells to interact, comes apart in dementia and motor neuron disease, revealing a potential new target for drug discovery. The study, published today in Nature Communications, was funded by the UK Medical Research Council, Wellcome Trust, Alzheimer's Research UK and the Motor Neurone Disease Association. Researchers looked at two components of cells: mitochondria, the cell 'power houses' which produce energy for the cell; and the endoplasmic reticulum (ER) which ...

LAST 30 PRESS RELEASES:

Printed skin to replace animal testing

Precision medicine could be possible in the fight against antibiotic resistance

Researchers at the Lewis Katz School of Medicine at Temple University identify new targeted approach to protect neurons against degeneration

Scientists uncover the first clear evidence of air sacs in the fossilized bones of alvarezsaurian dinosaurs: the "hollow bones" which help modern day birds to fly

[Press-News.org] A new look at old forests
MBL study revises theory on growth and carbon storage in mature trees