Hi,
Dan sent me your message, which I have included below.

He has been documenting vegetation loss in PA for a long time now.
I shall leave it the details to him.

As far as the reasons for this: it is our belief that human induced
stress is causing death, not only to trees but also to other life.

Ozone is only part of the problem. Earthworms are changing the soil
chemistry under conifer forests so as to render them unviable. You
will find many other examples in the literature.

You are, of course, aware of vegetation zones migrating northward
and upward. The same is happening to animals. We have coyotes in 
Chicago and soon they will be in Canada. Marmots and picas will
be history as they run out of altitude in the mountains.

Animals can try and migrate, but sessile plants and trees cannot. 
They survive by spreading  seeds, but that is stopped by inexorable 
human trespass into their habitats, including ozone and other pollution.

So as the world changes around them, we see more and more death in
our familiar landscapes.

The dying trees are supplanted by invaders from the South, and from 
Eurasia, fast growing primary growth, such as Ailanthus. In time, if 
allowed, they in turn would be replaced by secondary and tertiary growth 
more representative of tropical climes. But we have stressed the land
to the point that humankind consumes 40% of Net Primary Production,
of all the green things that grow. And I do not know what can survive
for our effluents kill a great deal of what remains.

I do recommend replacing dying plants by ones suited better to the 
changing climate. I have planted native American prairie plants
such as coneflowers and grasses, as well as Colorado blue spruce,
maples and birches (in soggy areas) with good results. All we
can do is replace what we can, and teach the young children what
is happening, for after all, they will inherit the Earth.

sidd



> Greetings Daniel et al.
>
> I've been reading the links about ozone on your site and it is positively
> terrifying, especially considering annual crops cannot tolerate it either.
>
> Is ozone a localized effect or more or less even world-wide?  Why is it so
> sudden, that after slow but steady decline for decades in the last year,
> that a mass plunge has taken effect at least here in New Jersey?
>
> Who are you guys and where are you located?  I have been searching and
> writing dozens of academics for info about ozone and trees and never found
> any of the citations you have linked to.
>
> WOW.
>
> Gail<p>
>
>