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[Duurzaamlijst] Planting New Forests Can't Match Saving Old Ones in Cutting Greenhouse

Voor al diegene werkzaam in bossen bescherming en bosbouw,

Dit onderzoek doet hier en daar wat stop opwaaien.
Het onderstaande artikel is gepubliseerd in the New York Times op 22
september jonsgst leden. Onderzoek is te vinden in Science Magazine van 22
september, 2000.

Met vriendelijke groeten,

Anton van Walraven


Planting New Forests Can't Match Saving Old Ones in Cutting Greenhouse
Gases, Study Finds

A new study has cast doubts on an important element of a proposed treaty to
fight global warming: the planting of new forests in an effort to sop up
carbon dioxide, a heat-trapping gas.
The research concludes that old, wild forests are far better than
plantations of young trees at ridding the air of carbon dioxide, which is
released when coal, oil and other fossil fuels are burned.

The United States and other countries with large land masses want to use
forest plantations to meet the goals of the proposed treaty. The study's
authors say that any treaty also needs to protect old forests and that, so
far there is no sign that such protections are being considered.
Without such protections, the scientists conclude, some countries could be
tempted to cut down old forests now and then plant new trees on the
deforested land later, getting credit for reducing carbon dioxide when they
have actually made matters worse.

The analysis, published in the journal Science today(September 22, 2000
(Anton)) was done by Dr. Ernst-Detlef Schulze, the director of the Max
Planck Institute for Biogeochemistry in Jena, Germany, and two other
scientists at the institute.
Several climate and forestry experts familiar with the work said the study
provided an important new argument for protecting old-growth woods. And they
say the study provides a reminder that the main goal should be to reduce
carbon dioxide emissions at the source, smokestacks and tailpipes.
In old forests, huge amounts of carbon taken from the air are locked away
not only in the tree trunks and branches, but also deep in the soil, where
the carbon can stay for many centuries, said Kevin R. Gurney, a research
scientist at Colorado State University. When such a forest is cut, he said,
almost all of that stored carbon is eventually returned to the air in the
form of carbon dioxide.
"It took a huge amount of time to get that carbon sequestered in those
soils," he said, "so if you release it, even if you plant again, it'll take
equally long to get it back."
Negotiators are to meet in November to settle on methods for staving off a
predicted warming that could disrupt ecosystems, harm agriculture and cause
sea levels to rise, eroding coasts.
The negotiations are taking place under the Kyoto Protocol, an agreement
that was signed by more than 100 countries in 1997 but has not yet been
ratified. It sets goals for cutting greenhouse gas emissions starting in
2008 but includes few details on how to achieve them.

The United States, Canada, Russia and other countries have been pressing to
achieve as much as half their greenhouse gas reductions not at the source
but by using "sinks" like forests to remove carbon dioxide.
In the last round of talks, which ended last week in Lyon, France, some
countries were still seeking treaty language that could allow some new
planting to occur on land that was recently cleared of old forest and get
credit for greenhouse-gas reductions, said Mr. Gurney, who attended the
talks as an observer.
David B. Sandalow, an assistant secretary of state who was the chief
American delegate in Lyon, said that the treaty drafts so far could
theoretically allow such a practice but that the United States was seeking
to prevent this.
"We're committed to protecting old growth and finding ways to address this
issue," Mr. Sandalow said.
The German study, together with other similar research, has produced a
picture of mature forests that differs sharply from long-held notions in
forestry, Dr. Schulze said. He said aging forests were long perceived to be
in a state of decay that releases as much carbon dioxide as it captures.

But it turns out that the soils in undisturbed tropical rain forests,
Siberian woods and some German national parks contain enormous amounts of
carbon derived from fallen leaves, twigs and buried roots that can bind to
soil particles and remain for 1,000 years or more. When such forests are
cut, the trees' roots decay and soil is disrupted, releasing the carbon
Centuries would have to pass until newly planted trees built up such a
reservoir underground.
New forests are fine as long as they are planted on land that was previously
vacant, Dr. Schulze said, adding, "but there has to be a focus on preserving
the old growth."

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