Hi all.
I havn't been in for a good while so maybe you have already seen this and
discussed it, though I can't find any mention.
This was posted on society.culture.scottish. and I wondered if any of you
learned ladies and gentlemen would care to comment.
At first I thought it was just another Phd season paper but the team working
on it seem quite credible.
What do you make of it?

.................................................. ........

JAMES REYNOLDS
Thursday, 13th March 2003
The Scotsman (Scottish quality newspaper based in Edinburgh)


"POLLUTION from pine trees could be as bad for the world's environment
as emissions from factories and motor vehicles, according to new
research.

Scientists found that, in the right conditions, Scots pine trees [Pinus
sylvestris]
release smog-making nitrogen oxides directly into the air. Nitrogen
oxides (NOx) are a group of trace gases that prompt chemical reactions
in the atmosphere. They help to create both smog and acid rain.

A team of scientists, led by Pertti Hari, from the University of
Helsinki, in Finland, discovered that Scots pine shoots emit higher
levels of the gases when exposed to sunlight.

Ultraviolet radiation appears to be the key factor, triggering the
release of nitrogen oxides.

The researchers studied young trees enclosed in special chambers made
of ultraviolet-transparent quartz glass.

Nitrogen oxide concentrations went up when shoots were placed in the
chambers and decreased when they were removed. The scientists, in the
journal Nature, claimed: "Global NOx emissions from boreal coniferous
forests may be comparable to those produced by industrial and traffic
sources."

They said the source of the oxides was still unclear. It could arise
from plant metabolism, or the effect of sunlight hitting pine-needle
surfaces.

According to the campaign group Trees for Life, whose aim is to see
the regeneration of the old Caledonian pine forest that once covered
Scotland, Scots pine has the largest distribution of any conifer tree
in the world.

Dr Mandy Meikel, a spokes-woman for Reforesting Scotland, said: "Trees
have been around for millions of years and, if they have always been
emitting these gasses, then so be it, as that is part of the natural
cycle of the planet.

"The problems of industrial and vehicle emissions are a product of the
industrial revolution and have only occurred in the last 200 years."

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A W-S